Race/Ethnicity and Cardiovascular Events Among Patients With Systemic Lupus Erythematosus

Objective. Systemic lupus erythematosus (SLE) is more prevalent and results in more severe outcomes among blacks, Asians, and Hispanics than among whites. Cardiovascular disease (CVD) is the leading cause of death among SLE patients. We undertook this study to examine racial/ethnic variations in risk of CVD events among SLE patients. Methods. Within the Medicaid Analytic eXtract from 2000 to 2010, we identified patients ages 18-65 years with SLE (>= 3 International Classification of Diseases, Ninth Revision 710.0 codes, >= 30 days apart) and with >= 12 months of continuous enrollment. Subjects were followed up from the index date to the first CVD event (myocardial infarction [MI] or stroke), death, disenrollment, loss to follow-up, or end of follow-up period. Race/ethnicity-specific annual CVD event rates were calculated. Cox regression models estimated hazard ratios (HRs) with 95% confidence intervals (95% CIs), accounting for competing risk of death and adjusting for baseline demographics and comorbidities. Results. Of 65,788 SLE patients, 93.1% were women and similar to 42% were black, 38% were white, 16% were Hispanic, 3% were Asian, and 1% were American Indian/Alaska Native. Mean +/- SD follow-up was 3.8 +/- 3.1 years. CVD event rates were highest among blacks (incidence rate [IR] 10.57 [95% CI 9.96-11.22]) and lowest among Asians (IR 6.63 [95% CI 4.97-8.85]). After multivariable adjustment, risk of CVD events was increased among blacks (HR 1.14 [95% CI 1.03-1.26]) compared to whites. Hispanics and Asians had a lower risk of MI (HR 0.61 [95% CI 0.48-0.77] and HR 0.57 [95% CI 0.34-0.96], respectively), while blacks and Hispanics had a higher risk of stroke (HR 1.31 [95% CI 1.15-1.49] and HR 1.22 [95% CI 1.03-1.44], respectively). Conclusion. Among SLE patients enrolled in Medicaid, the risk of MI was lower among Hispanics and Asians compared to whites, while the risk of stroke was elevated among blacks and Hispanics compared to whites.