Treatment, Outcomes, and Adherence to Medication Regimens Among Dual Medicare-Medicaid-Eligible Adults With Myocardial Infarction

IMPORTANCE Patients with dual Medicare-Medicaid eligibility have a higher burden of chronic disease conditions and increased health care utilization compared with patients with Medicare coverage alone, but the treatment patterns and outcomes of dual-eligible patients with myocardial infarction (MI) are unknown. OBJECTIVE To examine the association of dual-eligible status with clinical outcomes and adherence to medication regimens (hereinafter "medication adherence") among older adults after MI. DESIGN, SETTING, AND PARTICIPANTS In this retrospective study conducted from February 2015 to April 2016, we linked patients 65 years or older enrolled in a national myocardial infarction registry (the Acute Coronary Treatment Intervention Outcomes Network Registry-Get With the Guidelines [ACTION Registry-GWTG]) from July 1, 2007, to December 31, 2009, to Medicare claims data to obtain 1-year follow-up and medication adherence data. The ACTION Registry-GWTG is the largest quality-improvement registry of patients with MI in the United States. Included patients were all 65 years or older; had Medicare Parts A, B, and D; presented with MI; and survived to hospital discharge. EXPOSURES Dual Medicare and Medicaid eligibility. MAIN OUTCOMES AND MEASURES Death, readmission, major adverse cardiovascular events (death, recurrent M 1, stroke), and medication adherence at 1 year. RESULTS Of 17 419 Medicare patients discharged alive after MI, 4674 (27%) were dual eligible. Dual-eligible patients were more likely to be female (64% vs 49%) and nonwhite (29% vs 6%). with a higher prevalence of comorbid conditions and more frequent presentation with non-ST elevation MI (non-STEMI) (75% vs 69%). Dual-eligible patients were less likely to receive primary percutaneous coronary intervention for STEMI (77% vs 81%), revascularization for non-STEMI (58% vs 65%), and prescription of secondary prevention medications at discharge. After multivariable adjustment, dual eligibility status was associated with a higher risk of readmission at 30 days (hazard ratio [HR], 1.16; 95% Cl, 1.06-1.26), death at 1 year (HR, 1.24; 95% Cl, 1.14-1.36), and major adverse cardiac events at 1 year (HR, 1.21; 95% Cl, 1.12-1.31). Dual-eligible patients had higher 1-year adherence to medications prescribed at discharge (HR, 1.55; 95% Cl, 1.39-1.74) than Medicare-only patients. CONCLUSIONS AND RELEVANCE Compared with Medicare-only patients, older adults with dual Medicare-Medicaid eligibility presenting with MI have superior rates of medication adherence but higher rates of postdischarge readmission and adverse cardiovascular outcomes.