Ethnic Differences in the Risk Factors and Severity of Coronary Artery Disease: a Patient-Based Study in Iran.

BACKGROUND Diverse ethnic groups may differ regarding the risk factors and severity of coronary artery disease (CAD). This study sought to assess the association between ethnicity and CAD risk and severity in six major Iranian ethnic groups. METHODS In this study, 20,165 documented coronary artery disease patients who underwent coronary angiography at a tertiary referral heart center were recruited. The demographic, laboratory, clinical, and risk factor data of all the patients were retrieved. The Gensini score (an indicator of CAD severity) was calculated for all, and the risk factors and severity of CAD were compared between the ethnical groups, using adjusted standardized residuals, Kruskal-Wallis test, and multivariable regression analysis. RESULTS The mean age of the participants (14,131 [70.1%] men and 6034 [29.9%] women) was 60.7 ± 10.8 years. The Fars (8.7%) and Gilak (8.6%) ethnic groups had the highest prevalence of ≥4 simultaneous risk factors. The mean Gensini score was the highest for the Gilaks (77.1 ± 55.9) and the lowest among the Lors (67.5 ± 52.8). The multivariable regression analysis showed that the Gilaks had the worst severity (β 0.056, 95% CI 0.009 to 0.102; P = 0.018), followed by the Torks (β 0.032, 95% CI 0.005 to 0.059; P = 0.020). Meanwhile, the Lors showed the lowest severity (β -0.087, 95% CI -0.146 to -0.027; P = 0.004). CONCLUSIONS This study found that there was heterogeneity in CAD severity and a diverse distribution in its well-known traditional risk factors among major Iranian ethnic groups.