Original Manuscript

Do Cardiovascular Risk Factors and Coronary SYNTAX Score Predict Contrast Volume Use During Cardiac Catheterization?

Angiology 1-8 ª The Author(s) 2015 Reprints and permission: sagepub.com/journalsPermissions.nav DOI: 10.1177/0003319715573909 ang.sagepub.com

Hemal Bhatt, MD1, Atika Turkistani, MD1, Dharmesh Sanghani, MD1, Kell Julliard, MA1, and George Fernaine MD2

Abstract The association of cardiovascular risk factors and complexity and severity of coronary artery disease with contrast volume (CV) remains unknown. We assessed the predictive factors of CV use during elective and emergent cardiac catheterization (CC). Electronic medical records from 2010 to 2013 were retrospectively reviewed. A total of 708 patients were eligible. On multivariable regression analysis, the presence of obstructed coronary arteries was associated with CV (P ¼ .01, b ¼ 14.17), with greater CV used in patients with single or double vessel disease compared to those with triple vessel disease. The presence of lesions with >70% stenosis in major epicardial arteries (P ¼ .019, b ¼ 24.39) and STsegment elevation myocardial infarction (P ¼ .001, b ¼ 36.14) was associated with increased CV use. Elevated B-type natriuretic peptide (P ¼ .036, b ¼ 17.23) and increase in Synergy between Percutaneous Coronary Intervention with Taxus and Cardiac Surgery score (P ¼ .024, b ¼ 29.06) were associated with decreased CV use. These aforementioned associations were attenuated after adjusting for percutaneous coronary intervention. Our findings may help predict patient populations who could be exposed to increased CV during CC, thereby possibly increasing their risk of contrast-induced nephropathy. Keywords SYNTAX score, contrast volume, cardiovascular risk factors, coronary artery disease, coronary lesions

Background The contrast volume (CV) used during cardiac catheterization (CC) has been associated with acute kidney injury after CC.1-6 The nephrotoxic effect of contrast media during CC leads to short- and long-term morbidity and mortality.1,7 Contrast media-induced acute kidney injury, also referred to as contrast-induced nephropathy (CIN), is believed to be mediated by contrast-induced renal tubular cell injury, hypoxia, formation of free radicals, and vasoconstriction in the renal vasculature caused by elevated endothelin levels.8-10 Contrast volume has been incorporated in the risk model used for prediction of CIN.11 Although CV has been associated with CIN, there is a lack of data on the association of CV and cardiovascular risk factors in patients undergoing CC. Increased use of CV has been associated with lesions in the left coronary arteries compared to the right coronary arteries,1 but the data are conflicting.12 The association of CV and severity and complexity of coronary artery disease (CAD) remains unknown. Synergy between Percutaneous Coronary Intervention with Taxus and Cardiac Surgery (SYNTAX) is an angiographic tool for grading CAD complexity and severity.13 The SYNTAX score grades coronary vessel anatomy based on characteristics such as

the number of lesions, coronary segments involved, lesion location, presence of calcification and thrombus, lesion length, and coronary dominance.14,15 This scoring system is used to determine optimal revascularization approaches, such as coronary bypass surgery or percutaneous coronary intervention (PCI).14,15 Given that more complex interventions (eg, in multivessel disease) require increased CV compared to single vessel intervention,16 we predicted an association between SYNTAX score and CV use.1 Given that CV is a modifiable risk factor for CIN, it was thought that determining the factors contributing to CV use would help create effective measures to prevent or decrease the risk of CIN. We therefore assessed the association of cardiovascular comorbidities and coronary lesion characteristics with CV in patients undergoing CC. 1

Department of Internal Medicine, Lutheran Medical Center, Brooklyn, NY, USA 2 Department of Cardiology, Lutheran Medical Center, Brooklyn, NY, USA Corresponding Author: Hemal Bhatt, Department of Internal Medicine, Lutheran Medical Center, 150 55th Street, Brooklyn, NY 11220, USA. Email: [email protected]

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Methods

Table 1. Summary of Patient Characteristics.

A retrospective cross-sectional study was conducted at an urban community teaching hospital in Brooklyn, New York. The study protocol was approved by the hospital’s institutional review board, and a waiver of patient informed consent was granted. Electronic medical records, CC reports, and laboratory data were retrospectively reviewed for the period of January 2010 to December 2013. Cardiac catheterizations were performed by a cardiologist certified in interventional cardiology. The amount of CV used during CC was noted for each patient. In our institution, the documentation of CV use during CC is standard in CC reports. In addition to age and gender, patients were grouped based on the presence or absence of CV risk factors such as hypertension, smoking, and hypercholesterolemia. Patients were further stratified based on their comorbidities such as congestive heart failure (CHF), diabetes mellitus (DM), prior CAD, peripheral arterial disease (PAD), cerebrovascular accident (CVA), and transient ischemic attack (TIA) at baseline. The presence of CAD was determined based on the history of previously documented myocardial infarction or coronary artery stent placement. Patients with a history of coronary artery bypass graft (CABG) surgery were excluded given that the evaluation of bypass grafts would confound the CV used during CC. Patients were also stratified based on renal function and body mass index (BMI). Renal function was determined by calculating estimated glomerular filtration rate (eGFR, mL/ min/1.73 m2) using the Cockcroft-Gault equation, with grades 1 to 5 assigned to creatinine clearances 90, 60 to 89, 30 to 59, 16 to 29, and 15 mL/min/1.73 m2, respectively. Body mass index was determined by kg/m2, and patients were divided into 4 groups: 35 kg/m2. The laboratory data such as B-type natriuretic peptide (BNP) and peak troponin levels during hospitalization were obtained for each patient. The troponin levels were obtained every 8 hours from the presentation of ACS until the peak was reached, including post-CC. The CV use in patients who underwent aortogram or left ventriculogram was compared with those who did not undergo such procedures. The CV in patients who underwent stent placement or angioplasty was also noted. The number of vessels with obstructive lesions (50% stenosis), presence of lesions with 70% stenosis in the major epicardial (ie, left main, left circumflex, left anterior descending, right main, and right posterior descending) and minor epicardial arteries (ie, obtuse marginal, diagonal, and ramus) were noted for each patient from the CC reports. In our institution, the calculation of SYNTAX score is carried out using an algorithm15 and its documentation is standard in these reports. The mean CV used during CC was compared in patients with presence or absence of the aforementioned variables. Statistical analysis was done using IBM SPSS Statistics 20. Univariate analysis was carried out using the chi-square test for categorical variables, and analysis of variance or t test for continuous variables. Pearson correlations were done between

Demographics, Cardiovascular Risk Factors, and Medication Use Hypertension Smoking Hypercholesterolemia eGFR, mL/min/1.73 m2 90 60-89 30-59 16-29 15 BMI, kg/m2 35 Diabetes mellitus Gender Male Female Age, years 50 51-70 71 Prior coronary artery disease Peripheral arterial disease CVA/TIA STEMI NSTEMI Unstable angina Aspirin Statin b-Blocker ACE inhibitor Calcium channel blocker

Number, n (%) 708 Patients 556 (79) 342 (48) 430 (61) 323 208 124 23 30

(46) (29) (18) (3) (4)

11 167 232 163 134 286

(1) (24) (33) (23) (19) (40)

448 (63) 260 (37) 115 363 230 252 48 47 59 110 87 401 359 377 299 149

(16) (51) (33) (35) (7) (7) (8) (16) (12) (57) (51) (53) (42) (21)

Abbreviations: eGFR, estimated glomerular filtration rate; BMI, body mass index; CVA/TIA, cerebrovascular event/transient ischemic attack; NSTEMI, non-ST-segment elevation myocardial infarction; STEMI, ST-segment elevation myocardial infarction; ACE, angiotensin converting enzyme.

statistically significant continuous variables and CV. All risk factors with 2-sided P < .05 on univariate analysis were entered into a multivariable linear regression model to assess combined effects, which then calculated b coefficients.

Results A total of 708 patients were included in the study. Patient demographics, baseline cardiovascular risk factors, and medication use are summarized in Table 1. Coronary lesion characteristics, CC interventions, and cardiac markers are summarized in Table 2. Table 3 shows the univariate analysis of the amount of CV use in patients with major cardiovascular risk factors and medications. Table 4 shows the univariate analysis of the amount of CV use and coronary lesion characteristics, CC interventions,

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Table 2. Summary of Patient Characteristics. Coronary Lesion Characteristics, CC Interventions, and Cardiac Markers Number of obstructed vessels 0 1 2 3 Lesions with >70% stenosis in major epicardial arteries Lesions with >70% stenosis in minor epicardial arteries Lesions with 50%-70% stenosis in major epicardial arteries Lesions with 50%-70% stenosis in minor epicardial arteries Lesions with less than 50% stenosis in epicardial arteries Arteries with diffuse disease Calcified lesions Bifurcation lesions Left ventriculogram Aortogram Stent or angioplasty BNP, pg/mL 70% stenosis in the major epicardial arteries compared to those without it. The association between CV and obstructive lesions was significant (P ¼ .019) on multivariate analysis without adjusting for the type of coronary intervention. However, there was no association between obstructive lesions in minor epicardial arteries and

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Table 3. Univariate Analysis of Contrast Volume Use. Demographics, Cardiovascular Risk Factors, and Medication Use Hypertension Present (n ¼ 556) Absent (n ¼ 152) Smoking Present (n ¼ 342) Absent (n ¼ 366) Hypercholesterolemia Present (n¼ 430) Absent (n¼ 278) Group Body mass index (BMI, n ¼ 482) , kg/m2 1 35 (n ¼ 134) Grade eGFR (n ¼ 708), mL/min/1.73 m2 1 90 (n ¼ 323) 2 60-89 (n ¼ 208) 3 30-59 (n ¼ 124) 4 16-29 (n ¼ 23) 5 15 (n ¼ 30) Diabetes mellitus Present (n ¼ 286) Absent (n ¼ 422) Gender Male (n ¼ 448) Female (n ¼ 260) Age in years 50 (n ¼ 115) 51-70 (n ¼ 363) 71 (n ¼ 230) Prior coronary artery disease Present (n ¼ 252) Absent (n ¼ 456) Peripheral arterial disease Present (n ¼ 48) Absent (n ¼ 660) CVA/TIA Present (n ¼ 47) Absent (n ¼ 661) STEMI Present (n ¼ 59) Absent (n ¼ 649) NSTEMI Present (n ¼ 110) Absent (n ¼ 598) Unstable angina Present (n ¼ 87) Absent (n ¼ 621) Aspirin Present (n ¼ 401) Absent (n ¼ 307) Statin Present (n ¼ 359) Absent (n ¼ 349) b-Blocker Present (n ¼ 377) Absent (n ¼ 321)

Contrast Volume Mean + SD, mL

SEM

Difference of Mean

95% CI of Mean or Difference of Mean

105.37 + 69.93 98.89 + 61.19

2.97 4.96

6.48

17.86 to 4.90

.264

107.23 + 64.40 100.94 + 71.45

3.48 3.73

6.28

16.31 to 3.74

.219

108.44 + 65.91 96.99 + 71.18

3.17 4.27

11.45

21.74 to 1.16

.029a

71.18 95.21 109.49 110.16 100.36

+ 38.39 + 59.76 + 74.64 + 68.08 + 67.13

11.57 4.62 4.9 5.33 5.79

86.08-104.34 99.84-119.15 99.63-120.69 88.89-111.83 98.94-109.0

.124

104.58 106.18 101.90 87.43 102.77

+ 62.90 + 75.28 + 64.27 + 66.0 + 88.92

3.5 5.22 5.77 13.76 16.23

97.7-111.5 95.9-116.5 90.5-113.3 58.9-115.9 98.9-109.0

.875

106.37 + 75.82 102.43 + 62.61

4.48 3.05

3.94

14.59 to 6.72

.468

109.81 + 66.91 93.93 + 69.25

3.16 4.29

15.88

26.36 to 5.41

.003a

106.35 + 53.46 104.82 + 65.74 102.74 + 110.81

11.07 4.88 23.69

115.51 + 67.32 97.60 + 67.82

4.24 3.17

17.91

28.32 to 7.50

.001a

108.44 + 81.22 103.65 + 67.17

11.73 2.61

4.79

28.89 to 19.32

.692

89.11 + 60.04 105.03 + 68.62

8.76 2.67

15.92

2.42 to 34.27

.088

154.85 + 60.92 99.35 + 66.93

7.93 2.62

55.5

73.24 to 37.75

.001a

115.45 + 53.67 102.32 + 60.67

6.54 4.31

13.13

1.79-24.46

107.17 + 59.05 103.53 + 69.37

6.33 2.78

3.65

18.97 to 11.68

.64

107.27 + 70.72 100.57 + 64.21

3.53 3.68

6.7

16.85 to-3.45

.195

105.62 + 64.83 103.09 + 71.26

3.42 3.83

2.53

12.59 to 7.54

.622

108.35 + 73.65 98.72 + 61.16

3.79 3.35

9.63

19.69 to 0.43

.061

63.6-111.97 95.34-114.63 71.68-167.57

P Value

.35

.025a

(continued)

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Table 3. (continued) Demographics, Cardiovascular Risk Factors, and Medication Use ACE inhibitor Present (n ¼ 299) Absent (n ¼ 409) Calcium channel blocker Present (n ¼ 149) Absent (n ¼ 559)

Contrast Volume Mean + SD, mL

SEM

Difference of Mean

95% CI of Mean or Difference of Mean

106.19 + 66.69 103.07 + 69.03

3.87 3.41

3.12

13.32 to 7.07

.548

105.03 + 65.47 104.21 + 68.73

5.42 2.91

0.82

13.25 to 11.59

.896

P Value

Abbreviations: SD, standard deviation; SEM, standard error of mean; eGFR, estimated glomerular filtration rate; CVA/TIA, cerebrovascular event/transient ischemic attack; NSTEMI, non-ST-segment elevation myocardial infarction; STEMI, ST-segment elevation myocardial infarction; ACE, angiotensin converting enzyme; CI, confidence interval. a P < .05.

Table 4. Univariate Analysis of Contrast Volume Use. Coronary Lesion Characteristics, CC Interventions, and Cardiac Markers

Contrast Volume, Mean + SD, mL

Number of obstructed vessels 0 vessel (n ¼ 249) 68.57 1 vessel (n ¼ 163) 126.68 2 vessels (n ¼ 160) 132.71 3 vessels (n ¼ 136) 107.76 Lesions with >70% stenosis in the major epicardial arteries Present (n ¼ 341) 129.21 Absent (n ¼ 367) 82.09 Lesions with >70% stenosis in the major epicardial arteries Present (n ¼ 209) 129.53 Absent (n ¼ 499) 94.81 Lesions with 50%-70% stenosis in the major epicardial arteries Present (n ¼ 201) 119.81 Absent (n ¼ 507) 99.05 Lesions with 50%-70% stenosis in the major epicardial arteries Present (n ¼ 109) 119.31 Absent (n ¼ 599) 102.33 Lesions with