Association of Race and Ethnicity With Obstructive Coronary Artery Disease

Background Appropriate selection of patients with stable coronary artery disease (CAD) for coronary angiography is dependent on the pretest probability of obstructive CAD; however, little is known about the potential differences in CAD by race and ethnic groups. Objectives The purpose of this study was to evaluate the association of race and ethnicity with coronary obstruction in stable CAD. Methods We evaluated first coronary angiography for CAD evaluation between 2012 and 2019 in Ontario, Canada. Race and ethnicity were identified by physicians. The main outcome was the rate of obstructive CAD (left main stenosis ≥50% or major epicardial vessel stenosis ≥70%). Multivariable logistic regression analyses evaluated the independent association of race and ethnicity with CAD. Results Among 71,199 CAD patients, 14.0% were South Asian (SA), 4.4% were East Asian (EA), and 58,131 were White patients. SA patients were the youngest at 60.9 years vs 62.4 years for EA patients and 65.1 years for White patients but were most likely to have obstructive CAD (46.9%) (EA 43.0% and White patients 37.9%). SA patients had the highest prevalence of 3-vessel CAD at 13.4% (vs 12.5% in EA and 7.7% in White patients). The adjusted odds ratio was 67% higher (1.67; 95% CI: 1.59 to 1.75) for having obstructive CAD in SA patients than that in White patients. EA patients also had significantly increased adjusted odds of obstructive CAD compared with White patients (1.40; 95% CI: 1.29-1.52). Conclusions SA patients were younger at presentation but had the highest adjusted odds of obstructive CAD. Incorporation of race and ethnicity information may improve risk-prediction tools for detection of coronary obstruction.

2][3][4][5] In 2019, it was estimated that 5.6 million South Asian residents and 15.5 million East Asian residents reside in the United States. 1 It is further estimated that the Asian population will more than double to w46 million in the United States by 2060. 2 Even a higher proportion of South Asian and East Asian individuals reside in Canada.It is estimated that 1.9 million South Asian residents and 2.95 million East Asian residents reside in Canada, where they represent 5.5% and 8.6% of the population, respectively. 36][7][8][9] In contrast, studies that evaluated East Asian patients have shown a lower prevalence of cardiovascular risk factors and a lower incidence of acute myocardial infarction than that in the general population. 10,11However, there remain many gaps of knowledge.[14] Other limitations in the literature included assembling cohorts only with private health insurance coverage, which could introduce selection bias.
It is estimated that 18.2 million Americans and 2.5 million Canadians are currently living with stable coronary artery disease (CAD). 15Selecting appropriate patients for coronary angiography is dependent on understanding the pretest probability of obstructive CAD.The original Diamond and Forrester model predicts obstructive CAD based on age, sex, and symptoms. 16Newer predictive risk scores include cardiac risk factors such as diabetes, hypertension, dyslipidemia, and smoking status and have found improved discrimination ability. 17 well as the number of vessels with obstructive disease, using definitions consistent with prior research.
Coronary anatomy from this database has been previously validated.Many studies have focused primarily on the race and ethnicity difference in the development of acute cardiac conditions such as acute myocardial infarction. 5,11,21,22For example, in a cohort of 824,662 immigrants to Canada, Tu et al 11 found South Asian immigrants had the highest rates of acute myocardial infarction compared with other race and ethnic groups.4][25] We were able to extend these findings by examining a cohort of stable CAD cases undergoing cardiac catheterization and adjusted for cardiac risk factors and cholesterol levels and found persistent difference in the rate of obstructive CAD.
We also observed a higher use of cardiac and antihyperglycemic medications among older South Asian patients to manage these risk factors.However, we were unable to evaluate whether South Asian and East Asian patients received optimal care in primary prevention given the lack of information on factors including diet, physical activity, and social determinants of health.
In addition to these factors, other reasons that could contribute to the discordant rates of obstructive CAD among race and ethnic groups include health behaviors such as dietary habits and exercise,  STUDY LIMITATIONS.Our findings should be interpreted in the context of several potential limitations.
First, even though we had access to data on all coronary angiography procedures in the province of Ontario, it is possible that more obstructive CAD cases in 1 race and ethnic group was due to referral for evaluation later in the course of disease.While we could not exclude this possibility, we observed South Asian patients had the highest rate of obstructive CAD but also had the youngest age of presentation.Second, information on race and ethnicity in our study was based on data obtained by physicians during the referral for cardiac catheterization, and thus, it was not standardized.It has been advocated that raceethnicity determination based on patient selfidentification is optimal because it would allow for a more accurate determination and allows a patient to identify multiple race and ethnicity categories.Third, our study focused on the prevalence of obstructive   CAD because we believe that would allow for an objective primary endpoint in our study in evaluating patients with stable CAD.Nevertheless, our finding may not be generalizable to those with stable angina not having an invasive evaluation.Fourth, we were unable to evaluate potential differences within the South Asian and East Asian patients because our data did not capture country of origin of each patient.

CONCLUSIONS
Our findings show substantial race and ethnic differences in cardiac risk factors and presence of obstructive CAD (Central Illustration).In addition, we found that race and ethnicity are independently associated with the presence of obstructive CAD and are more influential than traditional risk factors.This Yet, no study to our knowledge thus far have fully evaluated the potential influence of race and ethnicity in detecting obstructive coronary stenosis in a stable CAD cohort.Accordingly, the main objective of our study was to evaluate the association of race and ethnicity with the detection of obstructive CAD by comparing the incidence of obstructive CAD among South Asians, East Asians, and White patients undergoing initial diagnostic coronary angiography.these databases can be found in prior work. 18,19STUDY POPULATION.Our study cohort included adult patients undergoing their first coronary angiography for a diagnosis of stable CAD between April 1, 2012, and March 31, 2019.The diagnosis of CAD was based on the clinicians' assessment and noninvasive ischemia testing as coronary computed tomography angiographies are performed infrequently in Ontario.We excluded patients with a prior cardiovascular disease (history of myocardial infarction or unstable angina, cerebrovascular disease, peripheral vascular disease) and those with prior coronary revascularization (a percutaneous coronary intervention or a coronary artery bypass graft surgery).For patients who had multiple cardiac catheterizations during the study period, only the first procedure was considered.IDENTIFICATION OF SOUTH ASIAN AND EAST ASIAN PATIENTS.Race and ethnicity information was obtained by the CorHealth registry, which captured data recorded by referring physicians at the time of coronary angiography referral.The CorHealth definition of South Asian patients was individuals of Indian, Pakistani, Sri Lankan, or Bangladeshi descent or culture, while East Asian patients were defined as those of Chinese, Japanese, Vietnamese, Korean, or Taiwanese descent or culture.OUTCOME VARIABLES.The primary outcome of the study was the presence of obstructive CAD, defined as a stenosis of $50% in the left main coronary artery or stenosis of $70% in a major epicardial coronary artery (left anterior descending coronary artery, left circumflex coronary artery, and right coronary artery). 18,19Fractional flow reserve results were not A B B R E V I A T I O N S A N D A C R O N Y M S aOR = adjusted odds ratio CAD = coronary artery disease HDL = high-density lipoprotein required in the diagnosis of obstructive CAD.We also examined diseases in individual artery segments, as

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A C C : A D V A N C E S , V O L . 2 , N O . 1 , 2 0 2 3 socioeconomic status, and the acculturation impact on immigrants.We were unable to account for health-seeking behaviors, and it is possible preventive treatment for primary cardiac prevention may have differed between groups.More than 4 decades ago, Diamond and Forrester 16 found prediction of CAD was possible based on the patients' age, sex, and symptoms of chest pain.Their model is widely recommended and has been adopted into clinical practice guidelines. 24,25Newer models have been developed, but none has considered race and ethnicity of the patients.Given the independent association of race and ethnicity with CAD, our finding suggests that future models that incorporate race and ethnicity could improve the discrimination (ie, the ability of a model to differentiate between patients with and without disease) in predicting obstructive CAD.Concordant with our findings, the latest guidelines on chest pain suggest potential differences in presentation based on patient's race and ethnicity and recommend cultural competency training to help achieve the best outcomes in the evaluation of patients with chest pain. 26

Table 3 .
Table 1 shows the baseline characteristics of the study cohort.South Patients of South Asian decent had an adjusted RESULTSSTUDY SAMPLE.The construction of the study cohort is shown inFigure 1.There were 459,730 cardiac catheterizations performed for the indication of CAD over the period April 1, 2012, to March 31, 2019.We excluded 61,662 patients because of prior coronary revascularization, 54,024 patients for prior cardiovascular conditions, 74,933 repeat coronary angiograms in the study period, and 129,028 patients because the procedure was performed for an acute coronary syndrome.After excluding those without race and ethnicity data, our final study cohort consisted of 71,199 adult patients of which 9,938 (14.0%) were categorized as South Asian, 3,130 (4.4%) as East Asian, and 58,131 (81.6%) as White patients.BASELINE CHARACTERISTICS.White patients).In contrast, South Asian patientswere less likely than the other ethnic groups to smoke (7.1% vs 9.0% East Asians vs 14.0% Whites).They were also more likely to have angina (74.5%) with Canadian Cardiovascular Society Class 1 or more symptoms than East Asian (63.6%) and White (60.3%)patients.Supplemental Tables1 and 2show baseline characteristics by gender, race, and ethnicity.The overall trend was similar in the sex-specific analysis.For example, age of presentation to cardiac catheterization in men and women was youngest among South Asians patients.Cholesterol values were available for 90% of the study cohort within 3 years of cardiac catheterization.South Asian and East Asian patients had similar low-density lipoprotein cholesterol levels (2.39 AE 0.97 mmol/L vs 2.40 AE 0.98 mmol/L), which were slightly lower than 2.51 AE 1.01 mmol/L in Whites.Among patients with diabetes, South Asians had the highest HbA1c (6.69 AE 1.34 mmol/L), followed by East Asian (6.45 AE 1.26 mmol/L) and White patients (6.16 AE 1.14 mmol/L).For patients older than 65 years (where medication information was available), South Asian patients were most likely to be on angiotensin receptor blockers, beta blockers, statins, and antihyperglycemic medications (oral antihyperglycemic agents and insulin).Asians vs 4.0% Whites), whereas the three-vessel disease was more prevalent among South Asian patients (13.4% South Asians vs 12.5% East Asians vs 7.7% Whites).ASSOCIATION OF RACE AND ETHNICITY WITH OBSTRUCTIVE CAD.The association of race and ethnicity with obstructive CAD adjusting for of obstructive CAD (aOR 1.40, 95% CI: 1.29-1.52)than White patients.Traditional cardiac risk factors, such as diabetes (aOR 1.52, 95% CI: 1.46-1.58),current smoking status (aOR 1.46, 95% CI: 1.38-1.54),and non-HDL cholesterol levels (aOR 1.33, 95% CI: 1.31-1.35)were also found to be independently associated with

Table 4
Construction of the Study CohortA total of 459,730 cardiac catheterizations were performed for the indication of coronary artery disease over the period April 1, 2012, to March 31, 2019.After inclusion and exclusion criteria were applied, our final study cohort consisted of 71,199 adult patients shows rates of obstructive CAD and the aOR of the association of race and ethnic groups with obstructive CAD.In prespecified subgroups by age, sex, income, and angina categories, similar patterns were observed for higher incidence of CAD among South Asian and East Asian patients than among White patients.FIGURE 1tion with traditional risk factors, such as diabetes or smoking.Our findings suggest that it is important to consider race and ethnicity information in selecting patients for cardiac catheterization.

TABLE 1
Values are mean AE SD or n (%). a Cholesterol information available on 63,874 patients (89.7% of cohort).b HbA1C information available on 58,314 patients (81.9% of cohort).c Fasting glucose information available on 47,892 (67.3% of cohort).d Medication information based on 3,590 South Asians patients, 1,276 East Asian patients, and 29,232 White patients older than 65 years.HDL ¼ high-density lipoprotein; LDL ¼ low-density lipoprotein.

TABLE 2
Obstructive Coronary Artery Disease for Patients Undergoing First Cardiac Catheterization by Race and Ethnic Group a Values are n (%). a Obstructive coronary artery disease was defined as a stenosis of $50% in the left main coronary artery or stenosis of $70% in a major epicardial coronary artery (left anterior descending coronary artery, left circumflex coronary artery, and right coronary artery).

TABLE 3
Multivariable Model of the Association of Race and Ethnicity and Obstructive Coronary Artery Disease HDL ¼ high-density lipoprotein.

TABLE 4
Crude Proportion and Adjusted Odds Ratio of Obstructive CAD in Major Epicardial Vessels by Race and Ethnicity and Subgroup Parts of this material are based on data and information compiled and provided by the Ontario Ministry of Health and Canadian Institute for Health Information.The analyses, conclusions, opinions, and statements expressed herein are solely those of the authors and do not reflect those of the funding or data sources; no endorsement is intended or should be inferred.The authors thank IQVIA Solutions Canada Inc for access to their Drug Information File.24.Fihn SD, Gardin JM, Abrams J, et al. 2012 ACCF/AHA/ACP/AATS/PCNA/SCAI/STS guideline for the diagnosis and management of patients with stable ischemic heart disease: a report of the American College of Cardiology Foundation/ American Heart Association task force on practice guidelines, and the American College of Physicians, American Association for Thoracic Surgery, Preventive Cardiovascular Nurses Association, Society for Cardiovascular Angiography and Interventions, and Society of Thoracic Surgeons.J Am Coll Cardiol.2012;60(24):e44-e164. 25.Task Force M, Montalescot G, Sechtem U, et al. 2013 ESC guidelines on the management of stable coronary artery disease: the task force on the management of stable coronary artery disease of the European Society of Cardiology.Eur Heart J. 2013;34:2949-3003.26.Writing Committee M, Gulati M, Levy PD, et al. 2021 AHA/ACC/ASE/CHEST/SAEM/SCCT/SCMR guideline for the evaluation and diagnosis of chest pain: a report of the American College of Cardiology/American Heart Asso-ciation Joint Committee on clinical practice guidelines.J Am Coll Cardiol.2021;78:e187-e285.KEY WORDS coronary angiography, coronary artery disease, ethnicity, race APPENDIX For supplemental tables, please see the online version of this paper. ACKNOWLEDGMENTS