ORIGINAL ARTICLE
Adherence to the 2010 American College of Cardiology Foundation Appropriate Use Criteria for Cardiac Computed Tomography: Quality Analysis at a Tertiary Referral Center Manavjot S. Sidhu, MD, Heidi Lumish, BS, Shanmugam Uthamalingam, MD, Leif-Christopher Engel, MD, Suhny Abbara, MD, Thomas J. Brady, MD, Udo Hoffmann, MD, MPH, and Brian B. Ghoshhajra, MD, MBA
Background: In November 2010, the American College of Cardiology Foundation published revised appropriateness criteria (AC) for cardiac computed tomography (CT). We evaluated adherence to these criteria by providers of different subspecialties at a tertiary referral center. Methods: Reports of 383 consecutive patients who underwent clinically indicated cardiac CT from December 1, 2010, to July 31, 2011, were reviewed by physicians with appropriate training in cardiac CT. Scans were classified as appropriate, inappropriate, or uncertain based on the revised 2010 AC. Studies that did not fall under any of the specified indications were labeled as unclassified. Adherence to the AC was also analyzed as a function of provider type. Research scans were excluded from this analysis. Results: Three hundred eight exams (80%) were classified as appropriate; 26 (7%), as inappropriate; 30 (8%), as uncertain; and 19 (5%), as unclassified. Of the 19 (5%) unclassified cardiac CT exams, the most common indication was for evaluation of suspected aortic dissection. Three hundred five exams (80%) were referred by cardiologists; 73 (19%), by internists; and 5 (1%), by neurologists. Of the 305 cardiology-referred studies, 221 (73%) were ordered by general cardiologists; 28 (9%), by interventional cardiologists; and 56 (19%), by electrophysiologists. There was no significant difference in adherence to the criteria between provider specialties or between cardiology subspecialties (P > 0.05). Conclusions: Adherence to the 2010 AC at our center was uniformly high across provider specialties. Key Words: cardiac computed tomography, quality improvement, appropriate use criteria (J Patient Saf 2016;12: 40–43)
BACKGROUND Cardiovascular imaging has emerged as an important noninvasive tool for the evaluation of myocardial perfusion, cardiac function, as well as coronary and cardiac anatomy.1,2 It has gained popularity because of its potential for defining the risks of major clinical events using a noninvasive strategy.3 However, cardiovascular imaging has also been controversial and has come under particular scrutiny because of claims of overuse and high consequent costs.4 Between 2000 and 2006, there was a documented rise in imaging use.5 Although use of all imaging modalities increased during
From the Department of Cardiovascular Imaging, Cardiac MR PET CT Program, Department of Radiology and Division of Cardiology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts. Correspondence: Manavjot S. Sidhu, MD, Department of Cardiovascular Imaging, Cardiac MR PET CT Program, Department of Radiology and Division of Cardiology, Massachusetts General Hospital and Harvard Medical School, 165 Cambridge St, Suite 400, Boston, MA 02114 (e‐mail: [email protected]). The authors disclose no conflict of interest. Ms Lumish and Dr Sidhu have contributed equally in the preparation of the manuscript. Copyright © 2014 by Wolters Kluwer Health, Inc. All rights reserved.
40
www.journalpatientsafety.com
this time, the steepest rise in use was seen in the most expensive modalities, namely, computed tomography (CT), magnetic resonance imaging, and nuclear medicine. Use of imaging services in physician offices, as compared with hospital settings, also increased between 2000 and 2006. Of the costs accrued from in-office imaging, it was estimated that studies ordered by cardiologists represented one-third of total imaging costs.4 More physicians have purchased imaging equipment to be used in their offices, leading to self-referrals.6 Experts have also cited practices in defensive medicine as a source of high use.7 Cardiovascular CT (CCT) is a relatively new modality and has been targeted to have potential for overuse,8 prompting the American College of Cardiology Foundation to develop appropriateness criteria (AC) for CCT in 2006. The AC are based on common applications, anticipated uses, and current practice guidelines of CCT, and in November 2010, the American College of Cardiology Foundation published revised AC for CCT.8 The 2006 AC evaluated each of 60 indications as appropriate, inappropriate, or uncertain. In the 2010 AC, a total of 93 clinical scenarios were assigned an appropriateness score between 1 and 9 by a technical panel. A score of 7 or higher was considered appropriate, a score between 4 and 6 was uncertain, and a score between 1 and 3 was considered inappropriate. An appropriate imaging study was described as one in which “the expected incremental information, combined with clinical judgment, exceeds the expected negative consequences by a sufficiently wide margin for a specific indication that the procedure is generally considered acceptable care and a reasonable approach for the indication.” The members of the technical panel, composed of both specialists and general practitioners, reviewed and rated the clinical scenarios first independently and subsequently as part of a collaborative, inperson meeting.8 The 2010 AC updated the existing 2006 criteria to reflect differences in test use and to expand the number of clinical scenarios. The criteria were modified to reflect new clinical guidelines, including recommendations for symptomatic patients without known heart disease, patients with heart failure, as well as the use of CCT for evaluation of cardiac structure and function.8 Adherence to the AC has implications not only for preventing resource overuse but also for increasing patient safety. Cardiovascular CT, although noninvasive, involves premedication with β-blockers and nitroglycerine, which can potentially induce bradycardia, respiratory side effects, and hemodynamic instability. In addition, CCT scans involve administration of both ionizing radiation (with attendant future malignancy risks)9,10 and iodinated contrast media, which can, in rare cases, cause anaphylactoid reactions (including death) or potentiate renal insufficiency.11 We elected to analyze adherence to the revised 2010 AC at our tertiary referral center as a quality improvement initiative by identifying provider subspecialties that were not yet compliant with the new AC and to identify CCT indications that were still not classifiable by the newly revised criteria. By analyzing adherence J Patient Saf • Volume 12, Number 1, March 2016
Copyright © 2016 Wolters Kluwer Health, Inc. All rights reserved.
to the AC on the basis of provider specialty and exam indication, we also sought to identify areas in which adherence to the criteria might be improved.
138 0 1
n = 139 (36%)
Appropriate Use Criteria for Cardiac CT
METHODS The study was approved by the human research committee of the institutional review board, and compliance with the Health Insurance Portability and Accountability Act guidelines was maintained. The requirement for informed consent was waived for this retrospective study. All authors have no relevant financial disclosures and had unrestricted control of the data at all stages of the study. No outside funding was used.
8 1 4
n = 13 (3%)
Financial Disclosure
N = 383 (100%)
0 0 0
15 0 10
119 21 8
1 4 6
Reports and medical records for all consecutive patients who underwent physician-supervised and tailored CCT from December 1, 2010, to July 31, 2011, were reviewed by 2 cardiologistsin-training with 2 years of advanced cardiac imaging training and Core Cardiology Training Symposium (COCATS) level 3 equivalent training in CCT. Patients who had incomplete medical records or CCT performed for research purposes were excluded from the analysis.
Classification of Scans CABG indicates coronary artery bypass grafting; CTA, CT angiography; PCI, percutaneous coronary intervention.
n = 28 (7%)
Total No. Studies
27 0 1
1. CAD Detection in Symptomatic Patients Without Known CAD
n = 0 (0%)
n = 25 (7%)
n = 148 (39%)
n = 11 (3%)
Study Population
Appropriate 308 (80%) Inappropriate 26 (7%) Uncertain 30 (8%) Unclassified 19 (5%)
TABLE 1.
2. CAD Detection in Asymptomatic Patients Without Known CAD
3. CAD Detection in Other Clinical Scenarios
4. Use of CTA in 5. Preoperative Evaluation the Setting of for Noncardiac Surgery Prior Test Without Active Cardiac Results Conditions
6. Risk Assessment After Revascularization (PCI or CABG)
7. Evaluation of Cardiac Structure and Function
J Patient Saf • Volume 12, Number 1, March 2016
© 2014 Wolters Kluwer Health, Inc. All rights reserved.
In our study, admission and discharge notes, clinic visit notes, dates and results of previous invasive and noninvasive diagnostic tests, as well as documented indications for CCT were used to classify the 383 scans according to the 7 broad indications described in the 2010 revised AC. The indications included (1) the detection of coronary artery disease (CAD) in symptomatic patients without known heart disease, (2) the detection of CAD in asymptomatic patients without known CAD, (3) the detection of CAD in other clinical scenarios, (4) the use of CT angiography in the setting of prior test results, (5) risk assessment before noncardiac surgery without active cardiac conditions, (6) risk assessment after revascularization, including percutaneous coronary intervention and coronary artery bypass grafting, and (7) evaluation of cardiac structure and function. Cardiovascular CT scans were classified as appropriate, inappropriate, or uncertain based on the guidelines by cardiologists-in-training with level 3 training in CCT, under the supervision of a board-certified cardiac radiologist with 8 years of experience. Studies that did not fall under any of the specified indications were labeled as unclassified. Adherence to the criteria was examined as a function of scan indication. Cardiovascular CT scans were further grouped according to the specialty of the provider who ordered the exam, including cardiologists, internists, and neurologists, on the basis of information available in the documented CCT results. Adherence to the criteria was analyzed as a function of this referring provider specialty. Scans ordered by cardiologists were further stratified by subspecialty within cardiovascular medicine, including general cardiologists, interventional cardiologists, and electrophysiologists, and adherence was compared across subspecialties.
Statistical Analysis Categorical variables were expressed as frequencies or percentages and were compared using the χ2 test. A P value of less than 0.05 was considered significant for all statistical tests. Statistical calculations were performed using SAS (Statistical Analysis Software; SAS Institute, Inc, Cary NC) version 9.2. www.journalpatientsafety.com
Copyright © 2016 Wolters Kluwer Health, Inc. All rights reserved.
41
J Patient Saf • Volume 12, Number 1, March 2016
Lumish et al
RESULTS Overall Adherence to the Revised AC Most of the scans (80%) ordered at our tertiary referral center were deemed appropriate according to the revised 2010 AC. The most common indications were the use of CCT in the setting of prior tests results and for evaluation of cardiac structure and function (Table 1).
Inappropriate, Uncertain, and Unclassified CCT Scans The most common inappropriate indication for CCT at our institution was the use of CCT in the setting of prior test results, specifically for periodic repeated testing in the setting of prior stress imaging or coronary angiography for asymptomatic or
stable patients. Of the 30 uncertain scans, 33% were ordered as a preoperative coronary evaluation for noncoronary cardiac surgery, an indication considered uncertain in patients at low risk for coronary disease. Other common uncertain indications included use of CCT after a stress imaging procedure showing mild ischemia and the use of CCT for patients with a functional capacity of less than 4 metabolic equivalents (METS) with 1 or more clinical risk predictors but no active cardiac conditions, as part of a preoperative evaluation of noncardiac surgery. Of the 19 unclassified CCT studies, the most common indication was for evaluation of suspected aortic dissection (Table 1).
Adherence by Provider Subspecialty Most, 305 (80%), of the CCT scans were ordered by cardiologists, followed by 73 (19%) by internists and 5 (1%) by
FIGURE 1. A, Adherence to CCT AC by provider specialty. B, Adherence to CCT AC by cardiology subspecialty.
42
www.journalpatientsafety.com
© 2014 Wolters Kluwer Health, Inc. All rights reserved.
Copyright © 2016 Wolters Kluwer Health, Inc. All rights reserved.
J Patient Saf • Volume 12, Number 1, March 2016
neurologists. Of the 305 cardiology-referred studies, 221 (73%) were ordered by general cardiologists; 28 (9%), by interventional cardiologists; and 56 (18%), by electrophysiologists. Adherence was uniformly high across provider specialties, with no significant differences in adherence to the criteria between provider specialties or between cardiology subspecialties (P > 0.05, Fig. 1).
Appropriate Use Criteria for Cardiac CT
CONCLUSIONS Most of the CCT studies performed at our tertiary referral center were ordered for appropriate indications. Although most studies were ordered by cardiologists, adherence to the 2010 AC at our center was uniformly high across all provider specialties. Our analysis of gaps in adherence will allow for targeted areas for improvement and will increase the rates of appropriate use of CCT.
DISCUSSION
REFERENCES
We evaluated adherence to the new 2010 AC for CCT during an 8-month period beginning in December 2011, allowing for a 1-month adjustment after the release of the new AC. The adherence to the new 2010 AC observed in our study was relatively high compared with prior studies looking at adherence to AC for imaging studies. We observed 80% adherence to the new 2010 AC, which is high relative to the 45% adherence rate observed for the 2006 CCT AC in a prior prospective study12 and the 49% adherence rate observed for the 2010 CCT AC in a prior retrospective study.13 Exams classified as inappropriate and uncertain (7% and 8%, respectively) were low compared with exams classified as inappropriate and uncertain in the 2006 AC (15% and 13%, respectively) in the same prospective study.12 Similar studies on adherence to the AC for echocardiography yielded variable results. One such study of 368 outpatient transthoracic echocardiograms suggested an adherence rate of 56%,14 whereas a retrospective study of transthoracic and transesophageal echocardiography suggested an adherence rate as high as 89%.15 Most of the CCT studies performed at our tertiary referral center were ordered by cardiologists. However, adherence to the 2010 AC at our center was uniformly high across provider specialties. The uniformly high adherence across specialties in our study might be explained by the exam scheduling and ordering systems as well as the insurance preauthorization processes in place at our institution that discourage inappropriate scans. Although this might limit the ability of our study to evaluate physician awareness and knowledge of the new AC, evaluation of appropriateness in this study was achieved using a thorough review of patient records and medical histories and is therefore powered to capture inappropriate scans that may have escaped systematic screening for inappropriate orders. This high adherence might also be explained by the improved classification of CCT examinations with the new criteria as compared with older criteria.12 Overall, these results are reflective of the improvement in patient care observed with the 2010 criteria. We were unable to capture scenarios in which CCT was appropriate but was not ordered by the provider, although this is a potential area for future research that might improve the use of CCT and consequently patient care. Our study identified the use of CCT in the setting of prior test results as the most common area of inconsistent adherence. Given the frequent use of CCT after a normal stress test result, future studies might investigate the value of CCT in this setting, to prevent the overuse of CCT imaging and to ensure the use of CCT in settings in which it is indicated. An analysis of downstream resource use after CCT as compared with stress testing would help to elucidate the value of CCT. Moreover, given that most inappropriate scans were ordered for the same indication, there is the potential for targeted physician education to improve adherence. Given that CCT is a rapidly changing technology, there is the potential for increased usefulness of CCT with improved technology,16 facilitated by improved specificity and lower radiation doses. It will be important to continue to revise the criteria to adapt to these changes and to optimize the patient populations that could benefit from CCT.
1. Di Carli MF, Hachamovitch R. New technology for noninvasive evaluation of coronary artery disease. Circulation. 2007;115:1464–1480.
© 2014 Wolters Kluwer Health, Inc. All rights reserved.
2. Lucas FL, DeLorenzo MA, Siewers AE, et al. Temporal trends in the utilization of diagnostic testing and treatments for cardiovascular disease in the United States, 1993–2001. Circulation. 2006;113:374–379. 3. Wennberg DE, Kellett MA, Dickens JD, et al. The association between local diagnostic testing intensity and invasive cardiac procedures. JAMA. 1996;275:1161–1164. 4. Steinwald A. Medicare Part B imaging services: rapid spending growth and shift to physician offices indicate need for CMS to consider additional management practices. United States Government Accountability Office report to Congressional Requesters. June 2008. 5. Steinwald A. Medicare: trends in fees, utilization, and expenditures for imaging services before and after implementation of the Deficit Reduction Act of 2005. United States Government Accountability Office report to Congressional Requesters. June 2008. 6. Iglehart JK. Health insurers and medical-imaging policy—a work in progress. N Engl J Med. 2009;360:1030–1037. 7. Iglehart JK. The new era of medical imaging—progress and pitfalls. N Engl J Med. 2006;354:2822–2828. 8. Taylor AJ, Cerqueira M, Hodgson JM, et al. ACCF/SCCT/ACR/AHA/ ASE/ASNC/NASCI/SCAI/SCMR 2010 appropriate use criteria for cardiac computed tomography. A report of the American College of Cardiology Foundation Appropriate Use Criteria Task Force, the Society of Cardiovascular Computed Tomography, the American College of Radiology, the American Heart Association, the American Society of Echocardiography, the American Society of Nuclear Cardiology, the North American Society for Cardiovascular Imaging, the Society for Cardiovascular Angiography and Interventions, and the Society for Cardiovascular Magnetic Resonance. J Am Coll Cardiol. 2010;56:1864–1894. 9. Brenner DJ, Hall EJ. Computed tomography—an increasing source of radiation exposure. N Engl J Med. 2007;357:2277–2284. 10. Raff GL. Radiation dose from coronary CT angiography: five years of progress. J Cardiovasc Comput Tomogr. 2010;4:365–374. 11. Namasivayam S, Kalra MK, Torres WE, et al. Adverse reactions to intravenous iodinated contrast media: an update. Current problems in diagnostic radiology. 2006;35:164–169. 12. Wasfy MM, Brady TJ, Abbara S, et al. Comparison of cardiac computed tomography examination appropriateness under the 2010 revised versus the 2006 original Appropriate Use Criteria. J Cardiovasc Comput Tomogr. 2012;6:99–107. 13. Mazimba S, Grant N, Parikh A, et al. Comparison of the 2006 and 2010 cardiac CT appropriateness criteria in a real-world setting. J Am Coll Radiol. 2012;9:630–634. 14. Kirkpatrick JN, Ky B, Rahmouni HW, et al. Application of appropriateness criteria in outpatient transthoracic echocardiography. J Am Soc Echocardiogr. 2009;22:53–59. 15. Aggarwal NR, Wuthiwaropas P, Karon BL, et al. Application of the appropriateness criteria for echocardiography in an academic medical center. J Am Soc Echocardiogr. 2010;23:267–274. 16. Ghoshhajra BB, Engel LC, Major GP, et al. Evolution of coronary computed tomography radiation dose reduction at a tertiary referral center. Am J Med. 2012;125:764–772.
www.journalpatientsafety.com
Copyright © 2016 Wolters Kluwer Health, Inc. All rights reserved.
43
Adherence to the 2010 American College of Cardiology Foundation Appropriate Use Criteria for Cardiac Computed Tomography: Quality Analysis at a Tertiary Referral Center Manavjot S. Sidhu, MD, Heidi Lumish, BS, Shanmugam Uthamalingam, MD, Leif-Christopher Engel, MD, Suhny Abbara, MD, Thomas J. Brady, MD, Udo Hoffmann, MD, MPH, and Brian B. Ghoshhajra, MD, MBA
Background: In November 2010, the American College of Cardiology Foundation published revised appropriateness criteria (AC) for cardiac computed tomography (CT). We evaluated adherence to these criteria by providers of different subspecialties at a tertiary referral center. Methods: Reports of 383 consecutive patients who underwent clinically indicated cardiac CT from December 1, 2010, to July 31, 2011, were reviewed by physicians with appropriate training in cardiac CT. Scans were classified as appropriate, inappropriate, or uncertain based on the revised 2010 AC. Studies that did not fall under any of the specified indications were labeled as unclassified. Adherence to the AC was also analyzed as a function of provider type. Research scans were excluded from this analysis. Results: Three hundred eight exams (80%) were classified as appropriate; 26 (7%), as inappropriate; 30 (8%), as uncertain; and 19 (5%), as unclassified. Of the 19 (5%) unclassified cardiac CT exams, the most common indication was for evaluation of suspected aortic dissection. Three hundred five exams (80%) were referred by cardiologists; 73 (19%), by internists; and 5 (1%), by neurologists. Of the 305 cardiology-referred studies, 221 (73%) were ordered by general cardiologists; 28 (9%), by interventional cardiologists; and 56 (19%), by electrophysiologists. There was no significant difference in adherence to the criteria between provider specialties or between cardiology subspecialties (P > 0.05). Conclusions: Adherence to the 2010 AC at our center was uniformly high across provider specialties. Key Words: cardiac computed tomography, quality improvement, appropriate use criteria (J Patient Saf 2016;12: 40–43)
BACKGROUND Cardiovascular imaging has emerged as an important noninvasive tool for the evaluation of myocardial perfusion, cardiac function, as well as coronary and cardiac anatomy.1,2 It has gained popularity because of its potential for defining the risks of major clinical events using a noninvasive strategy.3 However, cardiovascular imaging has also been controversial and has come under particular scrutiny because of claims of overuse and high consequent costs.4 Between 2000 and 2006, there was a documented rise in imaging use.5 Although use of all imaging modalities increased during
From the Department of Cardiovascular Imaging, Cardiac MR PET CT Program, Department of Radiology and Division of Cardiology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts. Correspondence: Manavjot S. Sidhu, MD, Department of Cardiovascular Imaging, Cardiac MR PET CT Program, Department of Radiology and Division of Cardiology, Massachusetts General Hospital and Harvard Medical School, 165 Cambridge St, Suite 400, Boston, MA 02114 (e‐mail: [email protected]). The authors disclose no conflict of interest. Ms Lumish and Dr Sidhu have contributed equally in the preparation of the manuscript. Copyright © 2014 by Wolters Kluwer Health, Inc. All rights reserved.
40
www.journalpatientsafety.com
this time, the steepest rise in use was seen in the most expensive modalities, namely, computed tomography (CT), magnetic resonance imaging, and nuclear medicine. Use of imaging services in physician offices, as compared with hospital settings, also increased between 2000 and 2006. Of the costs accrued from in-office imaging, it was estimated that studies ordered by cardiologists represented one-third of total imaging costs.4 More physicians have purchased imaging equipment to be used in their offices, leading to self-referrals.6 Experts have also cited practices in defensive medicine as a source of high use.7 Cardiovascular CT (CCT) is a relatively new modality and has been targeted to have potential for overuse,8 prompting the American College of Cardiology Foundation to develop appropriateness criteria (AC) for CCT in 2006. The AC are based on common applications, anticipated uses, and current practice guidelines of CCT, and in November 2010, the American College of Cardiology Foundation published revised AC for CCT.8 The 2006 AC evaluated each of 60 indications as appropriate, inappropriate, or uncertain. In the 2010 AC, a total of 93 clinical scenarios were assigned an appropriateness score between 1 and 9 by a technical panel. A score of 7 or higher was considered appropriate, a score between 4 and 6 was uncertain, and a score between 1 and 3 was considered inappropriate. An appropriate imaging study was described as one in which “the expected incremental information, combined with clinical judgment, exceeds the expected negative consequences by a sufficiently wide margin for a specific indication that the procedure is generally considered acceptable care and a reasonable approach for the indication.” The members of the technical panel, composed of both specialists and general practitioners, reviewed and rated the clinical scenarios first independently and subsequently as part of a collaborative, inperson meeting.8 The 2010 AC updated the existing 2006 criteria to reflect differences in test use and to expand the number of clinical scenarios. The criteria were modified to reflect new clinical guidelines, including recommendations for symptomatic patients without known heart disease, patients with heart failure, as well as the use of CCT for evaluation of cardiac structure and function.8 Adherence to the AC has implications not only for preventing resource overuse but also for increasing patient safety. Cardiovascular CT, although noninvasive, involves premedication with β-blockers and nitroglycerine, which can potentially induce bradycardia, respiratory side effects, and hemodynamic instability. In addition, CCT scans involve administration of both ionizing radiation (with attendant future malignancy risks)9,10 and iodinated contrast media, which can, in rare cases, cause anaphylactoid reactions (including death) or potentiate renal insufficiency.11 We elected to analyze adherence to the revised 2010 AC at our tertiary referral center as a quality improvement initiative by identifying provider subspecialties that were not yet compliant with the new AC and to identify CCT indications that were still not classifiable by the newly revised criteria. By analyzing adherence J Patient Saf • Volume 12, Number 1, March 2016
Copyright © 2016 Wolters Kluwer Health, Inc. All rights reserved.
to the AC on the basis of provider specialty and exam indication, we also sought to identify areas in which adherence to the criteria might be improved.
138 0 1
n = 139 (36%)
Appropriate Use Criteria for Cardiac CT
METHODS The study was approved by the human research committee of the institutional review board, and compliance with the Health Insurance Portability and Accountability Act guidelines was maintained. The requirement for informed consent was waived for this retrospective study. All authors have no relevant financial disclosures and had unrestricted control of the data at all stages of the study. No outside funding was used.
8 1 4
n = 13 (3%)
Financial Disclosure
N = 383 (100%)
0 0 0
15 0 10
119 21 8
1 4 6
Reports and medical records for all consecutive patients who underwent physician-supervised and tailored CCT from December 1, 2010, to July 31, 2011, were reviewed by 2 cardiologistsin-training with 2 years of advanced cardiac imaging training and Core Cardiology Training Symposium (COCATS) level 3 equivalent training in CCT. Patients who had incomplete medical records or CCT performed for research purposes were excluded from the analysis.
Classification of Scans CABG indicates coronary artery bypass grafting; CTA, CT angiography; PCI, percutaneous coronary intervention.
n = 28 (7%)
Total No. Studies
27 0 1
1. CAD Detection in Symptomatic Patients Without Known CAD
n = 0 (0%)
n = 25 (7%)
n = 148 (39%)
n = 11 (3%)
Study Population
Appropriate 308 (80%) Inappropriate 26 (7%) Uncertain 30 (8%) Unclassified 19 (5%)
TABLE 1.
2. CAD Detection in Asymptomatic Patients Without Known CAD
3. CAD Detection in Other Clinical Scenarios
4. Use of CTA in 5. Preoperative Evaluation the Setting of for Noncardiac Surgery Prior Test Without Active Cardiac Results Conditions
6. Risk Assessment After Revascularization (PCI or CABG)
7. Evaluation of Cardiac Structure and Function
J Patient Saf • Volume 12, Number 1, March 2016
© 2014 Wolters Kluwer Health, Inc. All rights reserved.
In our study, admission and discharge notes, clinic visit notes, dates and results of previous invasive and noninvasive diagnostic tests, as well as documented indications for CCT were used to classify the 383 scans according to the 7 broad indications described in the 2010 revised AC. The indications included (1) the detection of coronary artery disease (CAD) in symptomatic patients without known heart disease, (2) the detection of CAD in asymptomatic patients without known CAD, (3) the detection of CAD in other clinical scenarios, (4) the use of CT angiography in the setting of prior test results, (5) risk assessment before noncardiac surgery without active cardiac conditions, (6) risk assessment after revascularization, including percutaneous coronary intervention and coronary artery bypass grafting, and (7) evaluation of cardiac structure and function. Cardiovascular CT scans were classified as appropriate, inappropriate, or uncertain based on the guidelines by cardiologists-in-training with level 3 training in CCT, under the supervision of a board-certified cardiac radiologist with 8 years of experience. Studies that did not fall under any of the specified indications were labeled as unclassified. Adherence to the criteria was examined as a function of scan indication. Cardiovascular CT scans were further grouped according to the specialty of the provider who ordered the exam, including cardiologists, internists, and neurologists, on the basis of information available in the documented CCT results. Adherence to the criteria was analyzed as a function of this referring provider specialty. Scans ordered by cardiologists were further stratified by subspecialty within cardiovascular medicine, including general cardiologists, interventional cardiologists, and electrophysiologists, and adherence was compared across subspecialties.
Statistical Analysis Categorical variables were expressed as frequencies or percentages and were compared using the χ2 test. A P value of less than 0.05 was considered significant for all statistical tests. Statistical calculations were performed using SAS (Statistical Analysis Software; SAS Institute, Inc, Cary NC) version 9.2. www.journalpatientsafety.com
Copyright © 2016 Wolters Kluwer Health, Inc. All rights reserved.
41
J Patient Saf • Volume 12, Number 1, March 2016
Lumish et al
RESULTS Overall Adherence to the Revised AC Most of the scans (80%) ordered at our tertiary referral center were deemed appropriate according to the revised 2010 AC. The most common indications were the use of CCT in the setting of prior tests results and for evaluation of cardiac structure and function (Table 1).
Inappropriate, Uncertain, and Unclassified CCT Scans The most common inappropriate indication for CCT at our institution was the use of CCT in the setting of prior test results, specifically for periodic repeated testing in the setting of prior stress imaging or coronary angiography for asymptomatic or
stable patients. Of the 30 uncertain scans, 33% were ordered as a preoperative coronary evaluation for noncoronary cardiac surgery, an indication considered uncertain in patients at low risk for coronary disease. Other common uncertain indications included use of CCT after a stress imaging procedure showing mild ischemia and the use of CCT for patients with a functional capacity of less than 4 metabolic equivalents (METS) with 1 or more clinical risk predictors but no active cardiac conditions, as part of a preoperative evaluation of noncardiac surgery. Of the 19 unclassified CCT studies, the most common indication was for evaluation of suspected aortic dissection (Table 1).
Adherence by Provider Subspecialty Most, 305 (80%), of the CCT scans were ordered by cardiologists, followed by 73 (19%) by internists and 5 (1%) by
FIGURE 1. A, Adherence to CCT AC by provider specialty. B, Adherence to CCT AC by cardiology subspecialty.
42
www.journalpatientsafety.com
© 2014 Wolters Kluwer Health, Inc. All rights reserved.
Copyright © 2016 Wolters Kluwer Health, Inc. All rights reserved.
J Patient Saf • Volume 12, Number 1, March 2016
neurologists. Of the 305 cardiology-referred studies, 221 (73%) were ordered by general cardiologists; 28 (9%), by interventional cardiologists; and 56 (18%), by electrophysiologists. Adherence was uniformly high across provider specialties, with no significant differences in adherence to the criteria between provider specialties or between cardiology subspecialties (P > 0.05, Fig. 1).
Appropriate Use Criteria for Cardiac CT
CONCLUSIONS Most of the CCT studies performed at our tertiary referral center were ordered for appropriate indications. Although most studies were ordered by cardiologists, adherence to the 2010 AC at our center was uniformly high across all provider specialties. Our analysis of gaps in adherence will allow for targeted areas for improvement and will increase the rates of appropriate use of CCT.
DISCUSSION
REFERENCES
We evaluated adherence to the new 2010 AC for CCT during an 8-month period beginning in December 2011, allowing for a 1-month adjustment after the release of the new AC. The adherence to the new 2010 AC observed in our study was relatively high compared with prior studies looking at adherence to AC for imaging studies. We observed 80% adherence to the new 2010 AC, which is high relative to the 45% adherence rate observed for the 2006 CCT AC in a prior prospective study12 and the 49% adherence rate observed for the 2010 CCT AC in a prior retrospective study.13 Exams classified as inappropriate and uncertain (7% and 8%, respectively) were low compared with exams classified as inappropriate and uncertain in the 2006 AC (15% and 13%, respectively) in the same prospective study.12 Similar studies on adherence to the AC for echocardiography yielded variable results. One such study of 368 outpatient transthoracic echocardiograms suggested an adherence rate of 56%,14 whereas a retrospective study of transthoracic and transesophageal echocardiography suggested an adherence rate as high as 89%.15 Most of the CCT studies performed at our tertiary referral center were ordered by cardiologists. However, adherence to the 2010 AC at our center was uniformly high across provider specialties. The uniformly high adherence across specialties in our study might be explained by the exam scheduling and ordering systems as well as the insurance preauthorization processes in place at our institution that discourage inappropriate scans. Although this might limit the ability of our study to evaluate physician awareness and knowledge of the new AC, evaluation of appropriateness in this study was achieved using a thorough review of patient records and medical histories and is therefore powered to capture inappropriate scans that may have escaped systematic screening for inappropriate orders. This high adherence might also be explained by the improved classification of CCT examinations with the new criteria as compared with older criteria.12 Overall, these results are reflective of the improvement in patient care observed with the 2010 criteria. We were unable to capture scenarios in which CCT was appropriate but was not ordered by the provider, although this is a potential area for future research that might improve the use of CCT and consequently patient care. Our study identified the use of CCT in the setting of prior test results as the most common area of inconsistent adherence. Given the frequent use of CCT after a normal stress test result, future studies might investigate the value of CCT in this setting, to prevent the overuse of CCT imaging and to ensure the use of CCT in settings in which it is indicated. An analysis of downstream resource use after CCT as compared with stress testing would help to elucidate the value of CCT. Moreover, given that most inappropriate scans were ordered for the same indication, there is the potential for targeted physician education to improve adherence. Given that CCT is a rapidly changing technology, there is the potential for increased usefulness of CCT with improved technology,16 facilitated by improved specificity and lower radiation doses. It will be important to continue to revise the criteria to adapt to these changes and to optimize the patient populations that could benefit from CCT.
1. Di Carli MF, Hachamovitch R. New technology for noninvasive evaluation of coronary artery disease. Circulation. 2007;115:1464–1480.
© 2014 Wolters Kluwer Health, Inc. All rights reserved.
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