Background/Purpose: SLE patients have elevated rates of acute myocardial infarctions (MI), but the sociodemographic groups that are most affected have not been well studied. We examined acute MI rates among SLE patients in different sociodemographic groups enrolled in Medicaid, the program providing medical insurance to low income individuals in the U.S., from 2000 to 2006.

Methods: From Medicaid Analytic eXtract (MAX) data, containing all billing claims from 2000-2006 for Medicaid patients from 47 U.S. states and Washington, D.C., we identified patients aged 18-65 with prevalent SLE (>3 SLE International Classification of Disease, 9^threvision, [ICD-9 codes] of 710.0, >30 days apart). Demographic data included age, sex, race/ethnicity, U.S. region of residence (Northeast, Midwest, South or West) and calendar year. Within MAX inpatient claims files, ICD-9 code were used to identify all inpatient diagnoses for acute MI (ICD-9 codes 410.XX). CVD event incidence rates per 1,000 person-years with 95% CIs for patients with SLE in each sociodemographic group were calculated. We also performed Cox regression models stratified by sex and race/ethnicity, and adjusting for age, calendar year and U.S. region, to calculate hazards ratios for acute MIs in this population.

Results: We identified 43,351 patients with prevalent SLE. 40,417 (93%) were female. Racial and ethnic breakdown was: African American (35%), White (35%), Hispanic (14%), Asian (3%), and Native American (1%). The incidence rate for acute MI was 6.26 (95%CI 5.86, 6.69) per 1,000 person-years for the entire SLE population. Incidence rates were higher among males than females for all race/ethnicities (except for Native Americans for whom there were no events among males). (Table) Among women with SLE, Asians and Hispanics had the lowest incidence rates for acute MIs. Among males, incidence rates were also highest among White and African American patients, and lower in Asian and Hispanic SLE patients. Adjusted hazard ratios for acute MIs were significantly lower among Hispanic women compared to White women; however, they were not statistically lower among Asian women compared to White women. Although not statistically significant, lower hazard ratios for acute MIs were found in all non-White groups of men with SLE as well.

Conclusion: We found marked sex and race/ethnicity-specific variation in acute MI incidence rates and adjusted hazards ratios among Medicaid patients with SLE. The rates were higher among Whites and African American individuals. Further research is necessary to understand whether there is variation in acute MI prevention, cardiac risk factors, presentation, diagnosis and management among SLE patients in different sociodemographic groups. 

 

Table. Incidence Rates and Adjusted Hazards Ratios for Hospitalizations for Acute Myocardial Infarctions among Medicaid patients with SLE in the U.S. by Race and Ethnicity, 2000-2006
SLE Patients in Medicaid*	Total Individuals	N events	IR**	95% CI	Person-years	HR***	95% CI
Females
White	14,010	296	6.34	5.66 – 7.11	46,672	1.0 (ref.)	–
African American	14,195	277	5.93	5.27 – 6.67	46,702	1.05	0.89 – 1.24
Asian	1,095	****	2.81	1.51 – 5.22	3,558	0.68	0.36 – 1.28
Hispanic	5,887	63	3.14	2.45 – 4.02	20,045	0.66	0.50 – 0.87
Native American	519	11	6.65	3.68 – 12.01	1,654	1.21	0.66 – 2.22
Other/ Multiple	2,667	72	7.71	6.12 – 9.71	9,344	1.23	0.95 – 1.60
Males
White	1,007	44	15.89	11.82 – 21.35	2,769	1.0 (ref.)	–
African American	877	22	8.68	5.72 – 13.18	2,535	0.63	0.38 – 1.07
Asian	102	****	3.28	0.46 – 23.29	305	0.36	0.05 – 2.66
Hispanic	373	****	3.78	1.42 – 10.07	1,057	0.40	0.14 – 1.15
Native American	41	0	****	****	88	****	****
Other/ Multiple	176	****	11.12	5 – 24.75	540	0.81	0.34 – 1.93
*Race/ethnicity missing for 2043 females and 359 males **IR: incidence rate, events per 1,000 patient-years ***HR: hazard ratio, adjusted for age, calendar year and region of the U.S. ****Cell size <11 suppressed per Centers for Medicare and Medicaid Services policies Bold: confidence intervals are significant compared to White patients as reference group

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ACR Meeting Abstracts - https://acrabstracts.org/abstract/acute-myocardial-infarction-variation-among-u-s-medicaid-recipients-with-systemic-lupus-erythematosus-by-race-and-ethnicity-2000-2006/