CLINICAL RESEARCH
Europace (2014) 16, 1580–1586 doi:10.1093/europace/eut416
Sudden death and ICDs
Awareness of indications for device therapy among a broad range of physicians: a survey study Clara Hu¨binette 1,2, Lars H. Lund 1,2, Fredrik Gadler 1,2, and Marcus Sta˚hlberg 1,2* 1
Department of Medicine, Karolinska Institutet, 171 77 Stockholm, Sweden; and 2Department of Cardiology, Karolinska University Hospital, 171 76 Stockholm, Sweden
Received 12 October 2013; accepted after revision 3 December 2013; online publish-ahead-of-print 22 January 2014
Aims
----------------------------------------------------------------------------------------------------------------------------------------------------------Keywords
Heart failure † Device therapy † Cardiac resynchronization therapy † Implantable cardioverter-defibrillator † Referring physicians
Introduction Several randomized, controlled trials have documented that cardiac resynchronization therapy (CRT) and primary prophylactic implantable cardioverter-defibrillators (ICDs) reduce morbidity and mortality in selected patients with heart failure (HF) and reduced ejection fraction.1 – 7 Accordingly, the European Society of Cardiology has recommended the use of these device therapies in management guidelines since 2007.8 In Europe, the implantation rates of CRT and ICD have increased during several years since 2004,9 but there is accumulating evidence of remaining underutilization of these effective and guideline-recommended therapies.10 Several studies from the USA have documented that only 35 –50% of eligible patients actually received a CRT and/or ICD.11 – 14 Similarly, underutilization
of primary prophylactic ICDs in post-acute myocardial infarction patients with depressed ejection fraction has recently been reported in a Swedish cohort study.15 One important factor for the underutilization of device therapy in HF may be low referral rates to advanced centres. Indeed, in one study, it was documented that non-referral was the most common cause for not being implanted with an ICD in spite of having an indication.14 In turn, low referral rates may, at least in part, originate from low awareness of indication for device therapies among physicians responsible for follow-up of patients with HF. On this note, previous survey studies, predominantly from the USA and New Zealand, have shown that awareness of indications for ICDs in HF is poor.16 – 19 The awareness of the current indication for CRT therapy remains largely unknown, and a European perspective is absent regarding
* Corresponding author. Tel: +46 8 5177 1729; fax: +46 8 311044, E-mail: [email protected] Published on behalf of the European Society of Cardiology. All rights reserved. & The Author 2014. For permissions please email: [email protected].
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Cardiac resynchronization therapy (CRT) and primary prophylactic implantable cardioverter-defibrillators (ICDs) are underutilized in heart failure (HF). This may originate from an unawareness of device benefits and indications among physicians responsible for HF care and referral. We aimed to describe the awareness of indications for device therapy in a generalized sample of Swedish physicians. ..................................................................................................................................................................................... Methods A randomly selected sample of Swedish physicians specializing in cardiology, internal medicine, and family medicine and and results interns (5% of eligible physicians, n ¼ 519) was invited to fill in a 23-item survey, testing their awareness of indications for device therapy and, as comparison, pharmacological therapy. Acceptable awareness (AA) of CRT indication was predefined as recognizing that a left bundle branch block on ECG warrants further evaluation for CRT. Acceptable awareness of ICD indication was predefined as recognizing that ejection fraction ≤35% alone, without a history of ventricular tachycardia, is sufficient to warrant a primary prophylactic ICD. The response rate was 37% (n ¼ 168). Overall, 32% met AA of CRT indication, and significantly less (15%) met AA of ICD indication. Specialist certification in cardiology was the only significant predictor for AA [odds ratio (95% confidence interval): 37 (10 –138)]. However, even among cardiologists, awareness of ICD indications was low (61% with AA). Guideline-recommended indications for pharmacological therapy were conceived significantly better (P ¼ 0.02) than device therapy [median (interquartile range) of correct answers: 50% (33–50) compared with 36% (14 –57)]. ..................................................................................................................................................................................... Conclusions The study identified an important and substantial awareness gap in the medical community that may explain some of the previously reported low referral rates and utilization of device therapy in HF.
Survey study of device awareness
What’s new? † Awareness of current indications for cardiac resynchronization therapy and implantable cardioverter-defibrillator (ICD) in patients with heart failure (HF) was low in a representative sample of Swedish physicians. † Awareness of indications for primary prophylactic ICD treatment was particularly low, even among cardiologists. † This study identified a substantial knowledge gap in the medical community that may explain some of the previously reported under-referral and underutilization of device therapy in HF patients.
Methods Selection of the study group The questionnaire-based survey aimed at studying Swedish physicians presumed to be responsible for follow-up and, therefore, monitoring appropriate referral of HF patients. Therefore, specialists in cardiology, internal medicine, and family medicine as well as interns were included. Interns were included in the study sample not only since they are likely to treat patients with HF, but also because they graduated more recently from medical school and therefore were considered more likely to have been exposed to the novel information about the use of devices in HF. Information on study subjects was acquired from Ha¨lso-och sjukvårdens adressregister (HSAR), a national registry of medical professionals that comprehends all licensed physicians in Sweden from registration at medical school until death, at present with a total of 48 572 physicians. Ha¨lso-och sjukva˚rdens adressregister obtains the information from The National Board of Health and Welfare (Socialstyrelsen), the government agency responsible for licensing physicians in Sweden. Ha¨lso-och sjukva˚rdens adressregister is owned and administered by a private company, Cegedim. The registry contains information of workplace of 877 cardiologists, 1559 specialists in internal medicine, and 6712 specialists in family medicine, as well as 877 interns in Sweden. A representative sample (5% each, n ¼ 519) of the physicians from the four chosen groups (n ¼ 10 025) with a workplace registered in HSAR was randomly selected (Figure 1). Cegedim performed the selection using a randomizing algorithm, based on a physician-unique ID number together with inclusion criteria: known address and one of the four selected specialties. The 5% sample size was chosen to achieve a manageable yet generalizable sample size.
Survey design and conduction of the study Subjects were asked to fill in a 23-item survey (see Supplementary material online, Appendix) developed by the study team. The predicted time to
answer the questionnaire was 5 – 10 min. The survey comprised five parts: Part 1 included questions used to describe the demographics and clinical experience of the responder, while Part 2 covered questions regarding the responders’ management of HF patients, including history of referrals for device therapy. In Parts 3 and 4, subjects’ awareness of indications for CRT and ICD therapy, respectively, was tested using multiple-choice questions. The last part included multiple-choice questions testing subjects’ awareness of indications for pharmacological therapy in HF. The clarity and consistency of the survey were asserted by testing and revising the questionnaire internally with 15 independent cardiologist subjects at the investigators’ institution. The survey included two predefined key questions each regarding awareness of indications for CRT and ICD, respectively. For the correct answer to the first CRT key question [question (Q) 13 in the Supplementary material online, Appendix], responders had to correctly identify that an ECG had to be controlled for evaluation of indication for CRT in a clinical scenario where all other items indicating indication for CRT were known [ejection fraction (EF) ,35%, NYHA Class III, optimal medications]. For the correct answer to the second CRT key question (Q16 in the Supplementary material online, Appendix), survey responders had to acknowledge left bundle branch block (LBBB) as the ECG feature prompting further evaluation for CRT. In principle, the two ICD key questions were designed to evaluate whether responders were aware of the guideline recommendations regarding the use of ICD as a primary prophylactic therapy in HF. For the correct answer to the first ICD key question (Q 17 in the Supplementary material online, Appendix), subjects had to acknowledge that all information needed for assessment of ICD indication (EF , 35%, NYHA Class III, optimal medical therapy for .3 months) was present in a described clinical scenario. For the correct answer to the second ICD key question (Q 18 in the Supplementary material online, Appendix), responders had to state that an ICD could be indicated in the absence of documented ventricular tachycardia/fibrillation (VT/VF) or aborted sudden cardiac death. In this study, AA of CRT indication was defined as (i) correct answers to both CRT key questions, suggesting that responders knew that LBBB on an ECG constitutes an indication for CRT, or (ii) having referred one or more patient for CRT and providing the correct answer to one of the two key questions. Acceptable awareness of ICD indication was defined as providing correct answers on both ICD key questions. Furthermore, AA of indication for device therapy in general was defined as AA of indications for both CRT and ICD. The survey was sent to the selected study subjects by mail. An addressed and stamped return envelope was included, but recipients could opt to respond by e-mail, fax, or telephone. If the subjects did not respond within 2 – 3 weeks, a reminder mail with the questionnaire was sent. If study subjects failed to respond to the second mail, they were contacted by phone. Data were collected from March to May 2013. Responses were made anonymously.
Reclassifications and definition of response rate Survey responders with multiple specialties (n ¼ 15) were reclassified according to the following hierarchy: (i) cardiology, (ii) internal medicine, and (iii) family medicine. Residents (n ¼ 11) were reclassified into their training specialty. Deputizing doctors before internship were reclassified as interns (n ¼ 5). The response rate (RR) was defined as the number of responses divided by the number of subjects invited (×100). Subjects with incorrect contact information regarding workplace (n ¼ 59) who did not receive the survey were not counted as part of the denominator when calculating
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awareness of indication for ICD therapy among a broader range of physicians responsible for follow-up, care, and referral of patients with HF. Therefore, the aim of this study was to describe the awareness of indications for both CRT and ICD therapy in a randomly selected sample of physicians presumably responsible for HF follow-up. In addition, it aimed at identifying predictors for acceptable awareness (AA) of indication for device therapy. Moreover, we related device awareness to awareness of pharmacological therapy in HF and described referral patterns for device therapy.
1581
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Cardiology Registered physicians in Sweden (n =)
Internal medicine
Family medicine
Interns
1260
5007
8783
3387
Physicians with specified work place (n =)
877
1559
6712
877
Selected participants (5% from above) (n =)
48
83
343
45
519
Selected participants (n =)
Duplicates (n =)
7
Incorrect working place (n =)
Final study population (n =)
59
453 36
Non responders
Responders (n = and RR ¶ in %)
Responders grouped by specialty (and RR in %)
23 (48%)*
249
168 (37%)
31 (40%)
91 (31%)
23 (62%)*
Figure 1 Flow chart of subject selection and RRs, grouped by specialty. }Response rate was defined as number of responses divided by number of subjects in the final study population. *P , 0.001 vs. RR of specialists in family medicine.
the RR. Incorrect contact information regarding workplace was defined as (i) returned survey due to address unknown, (ii) information by telephone that the doctor had changed working place, or (iii) failure to respond to both mails and having an incorrect telephone number in the registry. The final study protocol was reviewed and approved by the local ethical review board. Individual participant informed consent was not required nor collected.
medicine, if the subject was involved in HF follow-up, and score on the pharmacological part of the survey) for AA of device therapy and if subjects had previously referred a patient for device therapy were analysed in a logistic regression model. The overall accuracy of the final logistic regression model was described using Cox and Snell as well as Nagelkerke R 2. A P value of ,0.05 was considered statistically significant. All statistical analysis was performed using IBM SPSS (version 19, IBM corp.).
Statistical analysis
Results
Data are expressed as percentage or as median and interquartile range (IQR). Data were evaluated for normality using the Shapiro– Wilk test and normal probability plots and parametric and non-parametric statistics were subsequently used as appropriate. x 2 Statistics (categorical outcome variables) and the Mann– Whitney U test (continuous outcome variables) were used to test for significant differences between each specialty in terms of knowledge about HF therapy. Five predefined predictors (specialty, age, years after license to practice
Study group—response rates and characteristics Figure 1 shows an overview of the selection process and the RR. In the selected group (n ¼ 519), there were 7 duplicates and 59 subjects with incorrect working addresses, which reduced the final eligible group to 453. Among them, 36 declined participation and 249 did
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Declined participation
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Survey study of device awareness
Table 1 Demographics of the study group Variable
Overall n 5 168
Cardiology n 5 23
Internal medicine n 5 31
Family medicine n 5 91
Internship n 5 23
............................................................................................................................................................................... Demographics Age, years median (IQR)
45 (33–58)
Male sex, n (%) Years after LTPM median (IQR)
102 (61) 13 (5– 28)
Years after SL median (IQR) Drs performing HF FU, n ¼ (%) n ¼ (%) No. of patients/Dr median (IQR)
47 (43–56)
41 (37– 58)
53 (38–61)
29 (27–33)
18 (78) 17 (13–24)
20 (65) 13 (9 –31)
50 (55) 17 (6– 30)
15 (65) 0 (0 –0)
6 (0– 22)
10 (5– 18)
6 (1 –25)
9 (0– 25)
0 (0 –0)
106 (63) 5 (0– 20)
15 (65) 20 (0– 45)
21 (68) 5 (0 –25)
65 (71) 10 (0– 25)
4 (17) 0 (0 –0)
Cardiology Internal medicine Family medicine Interns
30
20
10
0 0 1 2 3 4 5 6
7
8 9 10 11 12 13
Score
Figure 2 Histogram showing the frequency of overall survey scores of the study subjects, grouped by specialty.
not respond, resulting in a total of 168 responders (the study group) and an overall RR of 37%. The characteristics of the study group are shown in Table 1. In short, the median age was 45 (33 –58) years, 39% were females, and the median time after license to practice medicine (LTPM) was 13 (5–28) years. Figure 2 shows the frequency of overall survey scores in the study group, grouped by specialty.
Awareness of indications for device therapy In the overall study group, awareness of indications for device therapy in HF was poor. Only 32% of survey responders met the criteria for AA of CRT indication. The proportion of subjects with AA of ICD indication was even less (15%, P , 0.05 vs. AA of CRT indication). Of note, 63 responders (37%) stated explicitly that an ICD is never indicated without preceding documented VT/VF or were unaware of the implications of ventricular arrhythmias when evaluating indication for an ICD in a an HF patient. Combined AA of both CRT and ICD indications was as low as 12%, suggesting that the vast majority of physicians, in a representative sample, are unaware of current indications for CRT or an ICD (Table 2).
The proportion of subjects with AA of CRT and ICD indication varied substantially between specialties. Among cardiologists, 96% displayed an AA of CRT indication, but only 65% provided correct answers on the ICD key questions (P , 0.05 vs. correct answers on CRT key questions). The proportion of physicians with AA of CRT and ICD indications was significantly less among other specialties. The proportion of correct answers on the device part of the survey [median (IQR): 36% (14 –57)] was significantly lower compared with on the part evaluating awareness of indications for pharmacological therapy in HF [median (IQR): 50% (33– 50), P ¼ 0.02].
Predictors of acceptable awareness of device therapy When testing the predictive power of the five predefined possible predictors, only specializing in cardiology significantly increased the odds of having AA of device therapy [odds ratio (OR) and 95% confidence interval (CI) 37 (10–138)] (Table 3). Likewise, specializing in cardiology was the only significant predictor of having referred one or more HF patient for device therapy [OR, 95% CI: 19 (5–73)].
Referral patterns for device therapy Overall, 31% (n ¼ 52) of survey responders had referred one or more HF patient for device therapy (Figure 3), and previous experience with device referrals varied substantially between specialties. Among subjects who had never referred a patient for device therapy (n ¼ 116), the most common cause (49%) was selfperceived unawareness of the indication (Figure 4). The selfperceived unawareness was particularly high in specialists in family medicine (62%).
Discussion In this study, we tested the awareness of indications for CRT and ICDs in a randomly selected and representative sample of Swedish physicians. There were three main findings. First, AA of indications for device therapy for HF is low and varies substantially between specialties. Secondly, AA of ICD indication was particularly low, even among cardiologists. Thirdly, awareness of guideline-recommended
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Number of responders
LTPM, license to practice medicine; SL, specialist license; HF, heart failure; FU, follow-up; IQR, interquartile range; Drs, doctors.
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Table 2 Awareness of indications for HF therapies grouped by specialty Variable
Overall n 5 168
Cardiology n 5 23
Internal medicine n 5 31
Family medicine n 5 91
Internship n 5 23
............................................................................................................................................................................... Device therapy Correct on CRT key questions, n ¼ (%)
53 (32)
Correct on ICD key questions, n ¼ (%) Correct on device key questions, n ¼ (%)
19 (62)†
22 (96)
26 (15)* 20 (12)
†
15 (65)* 14 (61)
5 (16)* 4 (13)†
9 (10)†
3 (13)†
5 (5)† 2 (2)†
1 (4)† 0 (0)†
% correct answers on CRT part, median (IQR)
50 (25–75)
100 (75– 100)
50 (50–75)
25 (25–50)
25 (25–50)
% correct answers on ICD part, median (IQR) % correct answers on device part, median (IQR)
33 (0– 33) 36 (14–57)
67 (33– 67) 71 (71– 86)
33 (0 –33) 43 (29–57)
33 (0– 33) 29 (14–43)
33 (0– 33) 29 (14–43)
50 (33–50)‡
50 (33– 67)
50 (33–50)
33 (17–50)
50 (33–50)
Pharmacological therapy % correct on drug therapy part, median (IQR)
Data expressed in numbers of responders and percentage of responders with correctly answered questions in categories device therapy and pharmacological therapy. CRT, cardiac resynchronization therapy; ICD, implantable cardioverter-defibrillator; IQR, interquartile range. † P , 0.05 vs. proportion of correct answers among cardiologists. *P , 0.05 vs. proportion of correct answers on CRT key Qs. ‡ P ¼ 0.02 vs. ratio of correct answers on the device part of the survey.
OR
95% CI for P OR
60
0
Included Constant Cardiology
23.4 (2.2)a 3.62 (0.66)
Age
20.02 (0.06)
0.98 0.88– 1.11
0.78
Years LTPM Performing HF-FU
20.01 (0.07) 0.60 (0.68)
1.00 0.88– 1.13 1.82 0.48– 6.94
0.93 0.38
0.02 (0.01)
1.02 0.99– 1.04
0.29
37
10– 138
,0.001
Figure 3 Percentage of survey responders having referred at least one HF patient for device therapy. *P , 0.05 vs. all others.
Unaware of indications
Predictors of having referred ≥1 patient for device therapy
No HF patients
80
b
21.35 (1.42) 2.95 (0.68)
19
5– 73
20.36 (0.40) 0.41 (0.40)
0.96 0.89– 1.04 1.04 0.96– 1.12
0.36 0.31
Performing HF FU
0.72 (0.45)
2.07 0.86– 4.97
0.11
% Correct on pharma
0.15 (0.01)
1.02 0.99– 1.04
0.12
Age Years LTPM
B, standardized beta; SE, standard error; OR, odds ratio; CI, confidence interval. a Model summary: R 2 ¼ 0.24 (Cox and Snell), 0.46 (Nagelkerke). Model X 2 (1) ¼ 46.12, P , 0.001. b Model summary: R 2 ¼ 0.22 (Cox and Snell), 0.32 (Nagelkerke). Model X 2 (1) ¼ 42.48, P , 0.001.
No suitable patients Other
,0.001
60 %
Cardiology
*
20
Predictors of correct answer on device key questions
Included Constant
Overall Cardiology Internal medicine Family medicine Interns
40
................................................................................
% Correct on pharma
*
80 %
B (SE)
100
40 20 0 Overalll Cardiology Internal (n = 116) (n = 3) medicine (n = 13)
Family medicine (n = 79)
Interns (n = 21)
Figure 4 Reasons for not having referred any HF patient for device therapy. indications for pharmacological therapy is better than for device therapy. Furthermore, we could describe a low history of referrals for CRT and ICD therapy, which was mainly attributed to selfperceived unawareness of indications for device therapy.
The first main finding is supported by three similar survey studies carried out in the USA16,17 and New Zealand.19 In the largest study, Castellanos et al.16 found that approximately one-third of a sample of
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Table 3 Predictors of correct answers on device key questions and having referred ≥1 patient for device therapy
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Survey study of device awareness
document that a majority had never referred a single HF patient for consideration of device therapy. Emphasizing the association between low awareness of indications and low referral rate, we could demonstrate that a high number (49% in the overall group, 62% among specialists in family medicine) specified that the main reason for not referring was self-perceived lack of knowledge about the indication criteria. We believe that in the present study, we have identified an important and large knowledge gap, across different specialist categories, regarding both CRT and ICD therapy in HF and that this may, at least in part, explain the under-referral and underutilization previously documented by others. There is also evidence of underutilization of pharmacological therapies in HF. In a study of Swedish HF patients treated in the primary care, a reasonable number of patients were treated with angiotensinconverting enzyme inhibitor (ACE-I)/angiotensin II receptor antagonists (75%) or b-blockers (68%) but only 20% was on combined treatment, as recommended by guidelines.23 More recently, another study showed that even after correcting for the presence of contraindications, the proportion of patients receiving every guideline-recommended drug was only 70%.24 In the same study, it was documented that utilization of ACE-I (95%) and b-blockers (98%) was considerably higher compared with both ICD (82%) and CRT (59%) therapy. In the present study, we found that the overall awareness of indications for pharmacological therapy was less than previously reported.25 One reason may be that we included questions not only about indications for conventional pharmacological therapy for HF, such as b-blockers and ACE-I inhibitors, but also questions regarding a new HF drug (ivabradine) and about the latest updated guideline recommendations for mineralocorticoid receptor antagonists in HF.26 These questions were added to make the awareness of pharmacological therapy more comparable to that of device therapy, since the guidelines regarding the latter are fairly recent. Despite the relatively poor knowledge of pharmacological therapy, we found that physicians scored significantly better on the pharmacological part compared with the device part of the questionnaire. This suggests that the knowledge gap of guideline recommendations for HF therapies is wider regarding device therapies compared with pharmacological therapies.
Limitations The present study has some important limitations. First, the overall RR was 37%, which is below average among published mail survey studies.27 Although there is no agreed-upon absolute cut-off value for what is an acceptable RR in survey studies, the subjects responding to the survey may have been biased, compromising the generalizability of the results. However, it is reasonable to believe that subjects actually choosing to respond to the survey, if anything, were biased towards a greater interest in HF and also possibly better awareness of HF therapies compared with those who did not respond. Therefore, we argue that the fairly low RR is unlikely to influence the main findings in this study or the generalizability of the results. Secondly, the overall study population was small, which reduced the statistical power of the study. Thirdly, the analysis of predictors of AA should be interpreted with caution since the background information regarding the study subjects was limited, and we therefore may have
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physicians provided answers discordant to the current guidelines regarding primary prophylactic ICD therapy. Similar but smaller studies also documented that a majority of physicians had limited awareness of indications for ICD therapy.17,19 Our study not only confirms these previous data on low awareness of indication for ICD therapy, but also expands this notion in three ways. First, we documented a low AA of not only ICD, but also CRT indication in our study sample. Secondly, we could document a widespread unawareness of device therapy also among Swedish physicians, which may be more easily translatable to a European setting. Thirdly, we compared the awareness of indications for device therapy with that of pharmacological therapy and found that it was significantly lower. Similar to previous studies, we found that awareness of indication for device therapy varied between specialties.16,17 There was a particularly low rate of AA, as defined in this study, regarding both CRT and ICD indications among specialists in family medicine. It is unreasonable to expect specialists in family medicine to be updated regarding all new therapies and guidelines. However, basic awareness of device indications and thereby appreciation of important triggers for referral for advanced HF therapies is likely to be important also in the primary care setting, since 50% of HF patients in Sweden are primarily followed up in the setting of primary care outpatient clinics.20 Furthermore, compared with previously, when CRT was indicated only in moderately to severely symptomatic patients, today’s guideline recommendations21 also include NYHA Class II patients who, to an even greater extent, may be managed mostly in the primary care. Also, since CRT can slow disease progression,22 it is seemingly important that patients receive treatment early after symptom onset and diagnostic evaluation. Therefore, we argue that awareness of the importance of severely reduced EF and LBBB in patients with HF also needs to improve among specialists in family medicine. Castellanos et al.16 documented that specializing in cardiology and having a history of previous referrals were significant predictors of providing answers concordant with guidelines, while significant predictors for answers disconcordant with guidelines were specializing in family medicine and practicing in the western USA. In our study, the only significant predictor of having AA of indication was specializing in cardiology, which supports the previous findings from Castellanos. Considering this finding, it was expected that cardiologists were more aware of current guidelines and indications for device therapy than other specialties, but somewhat surprisingly, only 65% of cardiologists displayed an AA, as defined in this study, of indication for an ICD. Likewise, Castellanos et al.16 showed that 4% of the cardiologists never thought it was indicated with an ICD without documented VT/VF, and 25% reported an incorrect EF limit. Seemingly, the awareness of primary prophylactic ICD treatment in HF also needs to improve among cardiologists, considering the proven mortality-reducing effect of this therapy. Bradfield et al. 14 demonstrated that 32% of eligible patients were never referred for implantation of a primary prophylactic ICD despite no presence of contraindications for the therapy, and that non-referral was the most common cause of not receiving therapy. Not surprisingly, considering the low awareness of indications for device therapy among physicians in our study sample, we could
1586 missed important confounders. For example, differences in the area of subspecialization in cardiology, hospital setting (i.e. university hospital compared with non-academic hospital), and geographical location of the care facility may influence awareness of device therapy, but was not included in the analysis of predictors due to lack of information and/or low statistical power.
Conclusions Taken together, our findings highlight widespread unawareness of indications for device therapy in a broad range of Swedish physicians, which may explain some of the previously reported under-referral and underutilization of device therapy in heart failure. Bridging this gap in awareness is seemingly important to improve the prerequisites for widespread use of evidence-based medicine in heart failure. Since both underutilization and unawareness are larger regarding device therapy compared with pharmacological therapy, we argue that although general educational efforts to increase awareness of evidence-based treatment for HF is welcomed, such efforts should be focused primarily on raising awareness of CRT and ICD treatment.
Supplementary material Acknowledgements The authors express their sincere gratitude to Raquel Binisi for expert help with the logistics in this study. Conflict of interest: M.S. and L.H.L. have received research funding and consulting and speaker’s honoraria from manufacturers of CRT/ ICDs (Boston Scientific, Medtronic, St Jude Medical).
Funding This study was supported by grants from the Stockholm County Council and the following pacemaker and ICD manufacturers: St Jude Medical; Boston Scientific; Biotronik and Medtronic, Inc., through Swedish Medtech (the Association for Medical Technology in Sweden). The study sponsors had no part in the development of the study protocol, data collection, interpretation of the results, or preparation of the manuscript.
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Implementation of device therapy (cardiac resynchronization therapy and implantable cardioverter defibrillator) for patients with heart failure in Europe: changes from 2004 to 2008. Eur J Heart Fail 2009;11:1143 – 51. 10. Camm AJ, Nisam S. European utilization of the implantable defibrillator: has 10 years changed the ‘enigma?’ Europace 2010;12:1063 – 9. 11. Curtis AB, Yancy CW, Albert NM, Stough WG, Gheorghiade M, Heywood JT et al. Cardiac resynchronization therapy utilization for heart failure: findings from IMPROVE HF. Am Heart J 2009;158:956 –64. 12. Mehra MR, Yancy CW, Albert NM, Curtis AB, Stough WG, Gheorghiade M et al. Evidence of clinical practice heterogeneity in the use of implantable cardioverterdefibrillators in heart failure and post-myocardial infarction left ventricular dysfunction: findings from IMPROVE HF. Heart Rhythm 2009;6:1727 – 34. 13. Hernandez AF, Fonarow GC, Liang L, Al-Khatib SM, Curtis LH, LaBresh KA et al. Sex and racial differences in the use of implantable cardioverter-defibrillators among patients hospitalized with heart failure. JAMA 2007;298:1525 –32. 14. Bradfield J, Warner A, Bersohn MM. Low referral rate for prophylactic implantation of cardioverter-defibrillators in a tertiary care medical center. Pacing Clin Electrophysiol 2009;32:S194 –7. 15. Sjoblom J, Ljung L, Frick M, Rosenqvist M, Frykman V. Primary prevention of defibrillator implantation after myocardial infarction: clinical practice and compliance to guidelines. Europace 2012;14:490 –5. 16. Castellanos JM, Smith LM, Varosy PD, Dehlendorf C, Marcus GM. Referring physicians’ discordance with the primary prevention implantable cardioverterdefibrillator guidelines: a national survey. Heart Rhythm 2012;9:874 –81. 17. Sherazi S, Zareba W, Daubert JP, McNitt S, Shah AH, Aktas MK et al. Physicians’ knowledge and attitudes regarding implantable cardioverter-defibrillators. Cardiol J 2010;17:267 –73. 18. Sadarmin PP, Wong KC, Rajappan K, Bashir Y, Betts TR. Questionnaire survey of cardiologists’ knowledge, attitudes, and guideline application of implantable cardioverter defibrillator therapy. Pacing Clin Electrophysiol 2012;35:672 –80. 19. McHale B, Harding SA, Lever NA, Larsen PD. A national survey of clinician’s knowledge of and attitudes towards implantable cardioverter defibrillators. Europace 2009; 11:1313 –6. 20. Mejhert M, Persson H, Edner M, Kahan T. Epidemiology of heart failure in Sweden—a national survey. Eur J Heart Fail 2001;3:97 –103. 21. Brignole M, Auricchio A, Baron-Esquivias G, Bordachar P, Boriani G, Breithardt OA et al. 2013 ESC guidelines on cardiac pacing and cardiac resynchronization therapy: the task force on cardiac pacing and resynchronization therapy of the European Society of Cardiology (ESC). Developed in collaboration with the European Heart Rhythm Association (EHRA). Europace 2013;15:1070 –118. 22. Linde C, Abraham WT, Gold MR, St John Sutton M, Ghio S, Daubert C et al. Randomized trial of cardiac resynchronization in mildly symptomatic heart failure patients and in asymptomatic patients with left ventricular dysfunction and previous heart failure symptoms. J Am Coll Cardiol 2008;52:1834 –43. 23. Dahlstrom U, Hakansson J, Swedberg K, Waldenstrom A. Adequacy of diagnosis and treatment of chronic heart failure in primary health care in Sweden. Eur J Heart Fail 2009;11:92– 8. 24. Atwater BD, Dai D, Allen-Lapointe NM, Al-Khatib SM, Zimmer LO, Sanders GD et al. Is heart failure guideline adherence being underestimated? The impact of therapeutic contraindications. Am Heart J 2012;164:750 –5 e1. 25. Remme WJ, McMurray JJ, Hobbs FD, Cohen-Solal A, Lopez-Sendon J, Boccanelli A et al. Awareness and perception of heart failure among European cardiologists, internists, geriatricians, and primary care physicians. Eur Heart J 2008;29:1739 –52. 26. McMurray JJ, Adamopoulos S, Anker SD, Auricchio A, Bohm M, Dickstein K et al. ESC Guidelines for the diagnosis and treatment of acute and chronic heart failure 2012: The Task Force for the Diagnosis and Treatment of Acute and Chronic Heart Failure 2012 of the European Society of Cardiology. Developed in collaboration with the Heart Failure Association (HFA) of the ESC. Eur Heart J 2012;33:1787 –847. 27. Asch DA, Jedrziewski MK, Christakis NA. Response rates to mail surveys published in medical journals. J Clin Epidemiol 1997;50:1129 – 36.
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Supplementary material is available at Europace online.
C. Hu¨binette et al.
Europace (2014) 16, 1580–1586 doi:10.1093/europace/eut416
Sudden death and ICDs
Awareness of indications for device therapy among a broad range of physicians: a survey study Clara Hu¨binette 1,2, Lars H. Lund 1,2, Fredrik Gadler 1,2, and Marcus Sta˚hlberg 1,2* 1
Department of Medicine, Karolinska Institutet, 171 77 Stockholm, Sweden; and 2Department of Cardiology, Karolinska University Hospital, 171 76 Stockholm, Sweden
Received 12 October 2013; accepted after revision 3 December 2013; online publish-ahead-of-print 22 January 2014
Aims
----------------------------------------------------------------------------------------------------------------------------------------------------------Keywords
Heart failure † Device therapy † Cardiac resynchronization therapy † Implantable cardioverter-defibrillator † Referring physicians
Introduction Several randomized, controlled trials have documented that cardiac resynchronization therapy (CRT) and primary prophylactic implantable cardioverter-defibrillators (ICDs) reduce morbidity and mortality in selected patients with heart failure (HF) and reduced ejection fraction.1 – 7 Accordingly, the European Society of Cardiology has recommended the use of these device therapies in management guidelines since 2007.8 In Europe, the implantation rates of CRT and ICD have increased during several years since 2004,9 but there is accumulating evidence of remaining underutilization of these effective and guideline-recommended therapies.10 Several studies from the USA have documented that only 35 –50% of eligible patients actually received a CRT and/or ICD.11 – 14 Similarly, underutilization
of primary prophylactic ICDs in post-acute myocardial infarction patients with depressed ejection fraction has recently been reported in a Swedish cohort study.15 One important factor for the underutilization of device therapy in HF may be low referral rates to advanced centres. Indeed, in one study, it was documented that non-referral was the most common cause for not being implanted with an ICD in spite of having an indication.14 In turn, low referral rates may, at least in part, originate from low awareness of indication for device therapies among physicians responsible for follow-up of patients with HF. On this note, previous survey studies, predominantly from the USA and New Zealand, have shown that awareness of indications for ICDs in HF is poor.16 – 19 The awareness of the current indication for CRT therapy remains largely unknown, and a European perspective is absent regarding
* Corresponding author. Tel: +46 8 5177 1729; fax: +46 8 311044, E-mail: [email protected] Published on behalf of the European Society of Cardiology. All rights reserved. & The Author 2014. For permissions please email: [email protected].
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Cardiac resynchronization therapy (CRT) and primary prophylactic implantable cardioverter-defibrillators (ICDs) are underutilized in heart failure (HF). This may originate from an unawareness of device benefits and indications among physicians responsible for HF care and referral. We aimed to describe the awareness of indications for device therapy in a generalized sample of Swedish physicians. ..................................................................................................................................................................................... Methods A randomly selected sample of Swedish physicians specializing in cardiology, internal medicine, and family medicine and and results interns (5% of eligible physicians, n ¼ 519) was invited to fill in a 23-item survey, testing their awareness of indications for device therapy and, as comparison, pharmacological therapy. Acceptable awareness (AA) of CRT indication was predefined as recognizing that a left bundle branch block on ECG warrants further evaluation for CRT. Acceptable awareness of ICD indication was predefined as recognizing that ejection fraction ≤35% alone, without a history of ventricular tachycardia, is sufficient to warrant a primary prophylactic ICD. The response rate was 37% (n ¼ 168). Overall, 32% met AA of CRT indication, and significantly less (15%) met AA of ICD indication. Specialist certification in cardiology was the only significant predictor for AA [odds ratio (95% confidence interval): 37 (10 –138)]. However, even among cardiologists, awareness of ICD indications was low (61% with AA). Guideline-recommended indications for pharmacological therapy were conceived significantly better (P ¼ 0.02) than device therapy [median (interquartile range) of correct answers: 50% (33–50) compared with 36% (14 –57)]. ..................................................................................................................................................................................... Conclusions The study identified an important and substantial awareness gap in the medical community that may explain some of the previously reported low referral rates and utilization of device therapy in HF.
Survey study of device awareness
What’s new? † Awareness of current indications for cardiac resynchronization therapy and implantable cardioverter-defibrillator (ICD) in patients with heart failure (HF) was low in a representative sample of Swedish physicians. † Awareness of indications for primary prophylactic ICD treatment was particularly low, even among cardiologists. † This study identified a substantial knowledge gap in the medical community that may explain some of the previously reported under-referral and underutilization of device therapy in HF patients.
Methods Selection of the study group The questionnaire-based survey aimed at studying Swedish physicians presumed to be responsible for follow-up and, therefore, monitoring appropriate referral of HF patients. Therefore, specialists in cardiology, internal medicine, and family medicine as well as interns were included. Interns were included in the study sample not only since they are likely to treat patients with HF, but also because they graduated more recently from medical school and therefore were considered more likely to have been exposed to the novel information about the use of devices in HF. Information on study subjects was acquired from Ha¨lso-och sjukvårdens adressregister (HSAR), a national registry of medical professionals that comprehends all licensed physicians in Sweden from registration at medical school until death, at present with a total of 48 572 physicians. Ha¨lso-och sjukva˚rdens adressregister obtains the information from The National Board of Health and Welfare (Socialstyrelsen), the government agency responsible for licensing physicians in Sweden. Ha¨lso-och sjukva˚rdens adressregister is owned and administered by a private company, Cegedim. The registry contains information of workplace of 877 cardiologists, 1559 specialists in internal medicine, and 6712 specialists in family medicine, as well as 877 interns in Sweden. A representative sample (5% each, n ¼ 519) of the physicians from the four chosen groups (n ¼ 10 025) with a workplace registered in HSAR was randomly selected (Figure 1). Cegedim performed the selection using a randomizing algorithm, based on a physician-unique ID number together with inclusion criteria: known address and one of the four selected specialties. The 5% sample size was chosen to achieve a manageable yet generalizable sample size.
Survey design and conduction of the study Subjects were asked to fill in a 23-item survey (see Supplementary material online, Appendix) developed by the study team. The predicted time to
answer the questionnaire was 5 – 10 min. The survey comprised five parts: Part 1 included questions used to describe the demographics and clinical experience of the responder, while Part 2 covered questions regarding the responders’ management of HF patients, including history of referrals for device therapy. In Parts 3 and 4, subjects’ awareness of indications for CRT and ICD therapy, respectively, was tested using multiple-choice questions. The last part included multiple-choice questions testing subjects’ awareness of indications for pharmacological therapy in HF. The clarity and consistency of the survey were asserted by testing and revising the questionnaire internally with 15 independent cardiologist subjects at the investigators’ institution. The survey included two predefined key questions each regarding awareness of indications for CRT and ICD, respectively. For the correct answer to the first CRT key question [question (Q) 13 in the Supplementary material online, Appendix], responders had to correctly identify that an ECG had to be controlled for evaluation of indication for CRT in a clinical scenario where all other items indicating indication for CRT were known [ejection fraction (EF) ,35%, NYHA Class III, optimal medications]. For the correct answer to the second CRT key question (Q16 in the Supplementary material online, Appendix), survey responders had to acknowledge left bundle branch block (LBBB) as the ECG feature prompting further evaluation for CRT. In principle, the two ICD key questions were designed to evaluate whether responders were aware of the guideline recommendations regarding the use of ICD as a primary prophylactic therapy in HF. For the correct answer to the first ICD key question (Q 17 in the Supplementary material online, Appendix), subjects had to acknowledge that all information needed for assessment of ICD indication (EF , 35%, NYHA Class III, optimal medical therapy for .3 months) was present in a described clinical scenario. For the correct answer to the second ICD key question (Q 18 in the Supplementary material online, Appendix), responders had to state that an ICD could be indicated in the absence of documented ventricular tachycardia/fibrillation (VT/VF) or aborted sudden cardiac death. In this study, AA of CRT indication was defined as (i) correct answers to both CRT key questions, suggesting that responders knew that LBBB on an ECG constitutes an indication for CRT, or (ii) having referred one or more patient for CRT and providing the correct answer to one of the two key questions. Acceptable awareness of ICD indication was defined as providing correct answers on both ICD key questions. Furthermore, AA of indication for device therapy in general was defined as AA of indications for both CRT and ICD. The survey was sent to the selected study subjects by mail. An addressed and stamped return envelope was included, but recipients could opt to respond by e-mail, fax, or telephone. If the subjects did not respond within 2 – 3 weeks, a reminder mail with the questionnaire was sent. If study subjects failed to respond to the second mail, they were contacted by phone. Data were collected from March to May 2013. Responses were made anonymously.
Reclassifications and definition of response rate Survey responders with multiple specialties (n ¼ 15) were reclassified according to the following hierarchy: (i) cardiology, (ii) internal medicine, and (iii) family medicine. Residents (n ¼ 11) were reclassified into their training specialty. Deputizing doctors before internship were reclassified as interns (n ¼ 5). The response rate (RR) was defined as the number of responses divided by the number of subjects invited (×100). Subjects with incorrect contact information regarding workplace (n ¼ 59) who did not receive the survey were not counted as part of the denominator when calculating
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awareness of indication for ICD therapy among a broader range of physicians responsible for follow-up, care, and referral of patients with HF. Therefore, the aim of this study was to describe the awareness of indications for both CRT and ICD therapy in a randomly selected sample of physicians presumably responsible for HF follow-up. In addition, it aimed at identifying predictors for acceptable awareness (AA) of indication for device therapy. Moreover, we related device awareness to awareness of pharmacological therapy in HF and described referral patterns for device therapy.
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Cardiology Registered physicians in Sweden (n =)
Internal medicine
Family medicine
Interns
1260
5007
8783
3387
Physicians with specified work place (n =)
877
1559
6712
877
Selected participants (5% from above) (n =)
48
83
343
45
519
Selected participants (n =)
Duplicates (n =)
7
Incorrect working place (n =)
Final study population (n =)
59
453 36
Non responders
Responders (n = and RR ¶ in %)
Responders grouped by specialty (and RR in %)
23 (48%)*
249
168 (37%)
31 (40%)
91 (31%)
23 (62%)*
Figure 1 Flow chart of subject selection and RRs, grouped by specialty. }Response rate was defined as number of responses divided by number of subjects in the final study population. *P , 0.001 vs. RR of specialists in family medicine.
the RR. Incorrect contact information regarding workplace was defined as (i) returned survey due to address unknown, (ii) information by telephone that the doctor had changed working place, or (iii) failure to respond to both mails and having an incorrect telephone number in the registry. The final study protocol was reviewed and approved by the local ethical review board. Individual participant informed consent was not required nor collected.
medicine, if the subject was involved in HF follow-up, and score on the pharmacological part of the survey) for AA of device therapy and if subjects had previously referred a patient for device therapy were analysed in a logistic regression model. The overall accuracy of the final logistic regression model was described using Cox and Snell as well as Nagelkerke R 2. A P value of ,0.05 was considered statistically significant. All statistical analysis was performed using IBM SPSS (version 19, IBM corp.).
Statistical analysis
Results
Data are expressed as percentage or as median and interquartile range (IQR). Data were evaluated for normality using the Shapiro– Wilk test and normal probability plots and parametric and non-parametric statistics were subsequently used as appropriate. x 2 Statistics (categorical outcome variables) and the Mann– Whitney U test (continuous outcome variables) were used to test for significant differences between each specialty in terms of knowledge about HF therapy. Five predefined predictors (specialty, age, years after license to practice
Study group—response rates and characteristics Figure 1 shows an overview of the selection process and the RR. In the selected group (n ¼ 519), there were 7 duplicates and 59 subjects with incorrect working addresses, which reduced the final eligible group to 453. Among them, 36 declined participation and 249 did
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Declined participation
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Survey study of device awareness
Table 1 Demographics of the study group Variable
Overall n 5 168
Cardiology n 5 23
Internal medicine n 5 31
Family medicine n 5 91
Internship n 5 23
............................................................................................................................................................................... Demographics Age, years median (IQR)
45 (33–58)
Male sex, n (%) Years after LTPM median (IQR)
102 (61) 13 (5– 28)
Years after SL median (IQR) Drs performing HF FU, n ¼ (%) n ¼ (%) No. of patients/Dr median (IQR)
47 (43–56)
41 (37– 58)
53 (38–61)
29 (27–33)
18 (78) 17 (13–24)
20 (65) 13 (9 –31)
50 (55) 17 (6– 30)
15 (65) 0 (0 –0)
6 (0– 22)
10 (5– 18)
6 (1 –25)
9 (0– 25)
0 (0 –0)
106 (63) 5 (0– 20)
15 (65) 20 (0– 45)
21 (68) 5 (0 –25)
65 (71) 10 (0– 25)
4 (17) 0 (0 –0)
Cardiology Internal medicine Family medicine Interns
30
20
10
0 0 1 2 3 4 5 6
7
8 9 10 11 12 13
Score
Figure 2 Histogram showing the frequency of overall survey scores of the study subjects, grouped by specialty.
not respond, resulting in a total of 168 responders (the study group) and an overall RR of 37%. The characteristics of the study group are shown in Table 1. In short, the median age was 45 (33 –58) years, 39% were females, and the median time after license to practice medicine (LTPM) was 13 (5–28) years. Figure 2 shows the frequency of overall survey scores in the study group, grouped by specialty.
Awareness of indications for device therapy In the overall study group, awareness of indications for device therapy in HF was poor. Only 32% of survey responders met the criteria for AA of CRT indication. The proportion of subjects with AA of ICD indication was even less (15%, P , 0.05 vs. AA of CRT indication). Of note, 63 responders (37%) stated explicitly that an ICD is never indicated without preceding documented VT/VF or were unaware of the implications of ventricular arrhythmias when evaluating indication for an ICD in a an HF patient. Combined AA of both CRT and ICD indications was as low as 12%, suggesting that the vast majority of physicians, in a representative sample, are unaware of current indications for CRT or an ICD (Table 2).
The proportion of subjects with AA of CRT and ICD indication varied substantially between specialties. Among cardiologists, 96% displayed an AA of CRT indication, but only 65% provided correct answers on the ICD key questions (P , 0.05 vs. correct answers on CRT key questions). The proportion of physicians with AA of CRT and ICD indications was significantly less among other specialties. The proportion of correct answers on the device part of the survey [median (IQR): 36% (14 –57)] was significantly lower compared with on the part evaluating awareness of indications for pharmacological therapy in HF [median (IQR): 50% (33– 50), P ¼ 0.02].
Predictors of acceptable awareness of device therapy When testing the predictive power of the five predefined possible predictors, only specializing in cardiology significantly increased the odds of having AA of device therapy [odds ratio (OR) and 95% confidence interval (CI) 37 (10–138)] (Table 3). Likewise, specializing in cardiology was the only significant predictor of having referred one or more HF patient for device therapy [OR, 95% CI: 19 (5–73)].
Referral patterns for device therapy Overall, 31% (n ¼ 52) of survey responders had referred one or more HF patient for device therapy (Figure 3), and previous experience with device referrals varied substantially between specialties. Among subjects who had never referred a patient for device therapy (n ¼ 116), the most common cause (49%) was selfperceived unawareness of the indication (Figure 4). The selfperceived unawareness was particularly high in specialists in family medicine (62%).
Discussion In this study, we tested the awareness of indications for CRT and ICDs in a randomly selected and representative sample of Swedish physicians. There were three main findings. First, AA of indications for device therapy for HF is low and varies substantially between specialties. Secondly, AA of ICD indication was particularly low, even among cardiologists. Thirdly, awareness of guideline-recommended
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Number of responders
LTPM, license to practice medicine; SL, specialist license; HF, heart failure; FU, follow-up; IQR, interquartile range; Drs, doctors.
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Table 2 Awareness of indications for HF therapies grouped by specialty Variable
Overall n 5 168
Cardiology n 5 23
Internal medicine n 5 31
Family medicine n 5 91
Internship n 5 23
............................................................................................................................................................................... Device therapy Correct on CRT key questions, n ¼ (%)
53 (32)
Correct on ICD key questions, n ¼ (%) Correct on device key questions, n ¼ (%)
19 (62)†
22 (96)
26 (15)* 20 (12)
†
15 (65)* 14 (61)
5 (16)* 4 (13)†
9 (10)†
3 (13)†
5 (5)† 2 (2)†
1 (4)† 0 (0)†
% correct answers on CRT part, median (IQR)
50 (25–75)
100 (75– 100)
50 (50–75)
25 (25–50)
25 (25–50)
% correct answers on ICD part, median (IQR) % correct answers on device part, median (IQR)
33 (0– 33) 36 (14–57)
67 (33– 67) 71 (71– 86)
33 (0 –33) 43 (29–57)
33 (0– 33) 29 (14–43)
33 (0– 33) 29 (14–43)
50 (33–50)‡
50 (33– 67)
50 (33–50)
33 (17–50)
50 (33–50)
Pharmacological therapy % correct on drug therapy part, median (IQR)
Data expressed in numbers of responders and percentage of responders with correctly answered questions in categories device therapy and pharmacological therapy. CRT, cardiac resynchronization therapy; ICD, implantable cardioverter-defibrillator; IQR, interquartile range. † P , 0.05 vs. proportion of correct answers among cardiologists. *P , 0.05 vs. proportion of correct answers on CRT key Qs. ‡ P ¼ 0.02 vs. ratio of correct answers on the device part of the survey.
OR
95% CI for P OR
60
0
Included Constant Cardiology
23.4 (2.2)a 3.62 (0.66)
Age
20.02 (0.06)
0.98 0.88– 1.11
0.78
Years LTPM Performing HF-FU
20.01 (0.07) 0.60 (0.68)
1.00 0.88– 1.13 1.82 0.48– 6.94
0.93 0.38
0.02 (0.01)
1.02 0.99– 1.04
0.29
37
10– 138
,0.001
Figure 3 Percentage of survey responders having referred at least one HF patient for device therapy. *P , 0.05 vs. all others.
Unaware of indications
Predictors of having referred ≥1 patient for device therapy
No HF patients
80
b
21.35 (1.42) 2.95 (0.68)
19
5– 73
20.36 (0.40) 0.41 (0.40)
0.96 0.89– 1.04 1.04 0.96– 1.12
0.36 0.31
Performing HF FU
0.72 (0.45)
2.07 0.86– 4.97
0.11
% Correct on pharma
0.15 (0.01)
1.02 0.99– 1.04
0.12
Age Years LTPM
B, standardized beta; SE, standard error; OR, odds ratio; CI, confidence interval. a Model summary: R 2 ¼ 0.24 (Cox and Snell), 0.46 (Nagelkerke). Model X 2 (1) ¼ 46.12, P , 0.001. b Model summary: R 2 ¼ 0.22 (Cox and Snell), 0.32 (Nagelkerke). Model X 2 (1) ¼ 42.48, P , 0.001.
No suitable patients Other
,0.001
60 %
Cardiology
*
20
Predictors of correct answer on device key questions
Included Constant
Overall Cardiology Internal medicine Family medicine Interns
40
................................................................................
% Correct on pharma
*
80 %
B (SE)
100
40 20 0 Overalll Cardiology Internal (n = 116) (n = 3) medicine (n = 13)
Family medicine (n = 79)
Interns (n = 21)
Figure 4 Reasons for not having referred any HF patient for device therapy. indications for pharmacological therapy is better than for device therapy. Furthermore, we could describe a low history of referrals for CRT and ICD therapy, which was mainly attributed to selfperceived unawareness of indications for device therapy.
The first main finding is supported by three similar survey studies carried out in the USA16,17 and New Zealand.19 In the largest study, Castellanos et al.16 found that approximately one-third of a sample of
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Table 3 Predictors of correct answers on device key questions and having referred ≥1 patient for device therapy
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Survey study of device awareness
document that a majority had never referred a single HF patient for consideration of device therapy. Emphasizing the association between low awareness of indications and low referral rate, we could demonstrate that a high number (49% in the overall group, 62% among specialists in family medicine) specified that the main reason for not referring was self-perceived lack of knowledge about the indication criteria. We believe that in the present study, we have identified an important and large knowledge gap, across different specialist categories, regarding both CRT and ICD therapy in HF and that this may, at least in part, explain the under-referral and underutilization previously documented by others. There is also evidence of underutilization of pharmacological therapies in HF. In a study of Swedish HF patients treated in the primary care, a reasonable number of patients were treated with angiotensinconverting enzyme inhibitor (ACE-I)/angiotensin II receptor antagonists (75%) or b-blockers (68%) but only 20% was on combined treatment, as recommended by guidelines.23 More recently, another study showed that even after correcting for the presence of contraindications, the proportion of patients receiving every guideline-recommended drug was only 70%.24 In the same study, it was documented that utilization of ACE-I (95%) and b-blockers (98%) was considerably higher compared with both ICD (82%) and CRT (59%) therapy. In the present study, we found that the overall awareness of indications for pharmacological therapy was less than previously reported.25 One reason may be that we included questions not only about indications for conventional pharmacological therapy for HF, such as b-blockers and ACE-I inhibitors, but also questions regarding a new HF drug (ivabradine) and about the latest updated guideline recommendations for mineralocorticoid receptor antagonists in HF.26 These questions were added to make the awareness of pharmacological therapy more comparable to that of device therapy, since the guidelines regarding the latter are fairly recent. Despite the relatively poor knowledge of pharmacological therapy, we found that physicians scored significantly better on the pharmacological part compared with the device part of the questionnaire. This suggests that the knowledge gap of guideline recommendations for HF therapies is wider regarding device therapies compared with pharmacological therapies.
Limitations The present study has some important limitations. First, the overall RR was 37%, which is below average among published mail survey studies.27 Although there is no agreed-upon absolute cut-off value for what is an acceptable RR in survey studies, the subjects responding to the survey may have been biased, compromising the generalizability of the results. However, it is reasonable to believe that subjects actually choosing to respond to the survey, if anything, were biased towards a greater interest in HF and also possibly better awareness of HF therapies compared with those who did not respond. Therefore, we argue that the fairly low RR is unlikely to influence the main findings in this study or the generalizability of the results. Secondly, the overall study population was small, which reduced the statistical power of the study. Thirdly, the analysis of predictors of AA should be interpreted with caution since the background information regarding the study subjects was limited, and we therefore may have
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physicians provided answers discordant to the current guidelines regarding primary prophylactic ICD therapy. Similar but smaller studies also documented that a majority of physicians had limited awareness of indications for ICD therapy.17,19 Our study not only confirms these previous data on low awareness of indication for ICD therapy, but also expands this notion in three ways. First, we documented a low AA of not only ICD, but also CRT indication in our study sample. Secondly, we could document a widespread unawareness of device therapy also among Swedish physicians, which may be more easily translatable to a European setting. Thirdly, we compared the awareness of indications for device therapy with that of pharmacological therapy and found that it was significantly lower. Similar to previous studies, we found that awareness of indication for device therapy varied between specialties.16,17 There was a particularly low rate of AA, as defined in this study, regarding both CRT and ICD indications among specialists in family medicine. It is unreasonable to expect specialists in family medicine to be updated regarding all new therapies and guidelines. However, basic awareness of device indications and thereby appreciation of important triggers for referral for advanced HF therapies is likely to be important also in the primary care setting, since 50% of HF patients in Sweden are primarily followed up in the setting of primary care outpatient clinics.20 Furthermore, compared with previously, when CRT was indicated only in moderately to severely symptomatic patients, today’s guideline recommendations21 also include NYHA Class II patients who, to an even greater extent, may be managed mostly in the primary care. Also, since CRT can slow disease progression,22 it is seemingly important that patients receive treatment early after symptom onset and diagnostic evaluation. Therefore, we argue that awareness of the importance of severely reduced EF and LBBB in patients with HF also needs to improve among specialists in family medicine. Castellanos et al.16 documented that specializing in cardiology and having a history of previous referrals were significant predictors of providing answers concordant with guidelines, while significant predictors for answers disconcordant with guidelines were specializing in family medicine and practicing in the western USA. In our study, the only significant predictor of having AA of indication was specializing in cardiology, which supports the previous findings from Castellanos. Considering this finding, it was expected that cardiologists were more aware of current guidelines and indications for device therapy than other specialties, but somewhat surprisingly, only 65% of cardiologists displayed an AA, as defined in this study, of indication for an ICD. Likewise, Castellanos et al.16 showed that 4% of the cardiologists never thought it was indicated with an ICD without documented VT/VF, and 25% reported an incorrect EF limit. Seemingly, the awareness of primary prophylactic ICD treatment in HF also needs to improve among cardiologists, considering the proven mortality-reducing effect of this therapy. Bradfield et al. 14 demonstrated that 32% of eligible patients were never referred for implantation of a primary prophylactic ICD despite no presence of contraindications for the therapy, and that non-referral was the most common cause of not receiving therapy. Not surprisingly, considering the low awareness of indications for device therapy among physicians in our study sample, we could
1586 missed important confounders. For example, differences in the area of subspecialization in cardiology, hospital setting (i.e. university hospital compared with non-academic hospital), and geographical location of the care facility may influence awareness of device therapy, but was not included in the analysis of predictors due to lack of information and/or low statistical power.
Conclusions Taken together, our findings highlight widespread unawareness of indications for device therapy in a broad range of Swedish physicians, which may explain some of the previously reported under-referral and underutilization of device therapy in heart failure. Bridging this gap in awareness is seemingly important to improve the prerequisites for widespread use of evidence-based medicine in heart failure. Since both underutilization and unawareness are larger regarding device therapy compared with pharmacological therapy, we argue that although general educational efforts to increase awareness of evidence-based treatment for HF is welcomed, such efforts should be focused primarily on raising awareness of CRT and ICD treatment.
Supplementary material Acknowledgements The authors express their sincere gratitude to Raquel Binisi for expert help with the logistics in this study. Conflict of interest: M.S. and L.H.L. have received research funding and consulting and speaker’s honoraria from manufacturers of CRT/ ICDs (Boston Scientific, Medtronic, St Jude Medical).
Funding This study was supported by grants from the Stockholm County Council and the following pacemaker and ICD manufacturers: St Jude Medical; Boston Scientific; Biotronik and Medtronic, Inc., through Swedish Medtech (the Association for Medical Technology in Sweden). The study sponsors had no part in the development of the study protocol, data collection, interpretation of the results, or preparation of the manuscript.
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