Statin Use Following Hospitalization Among Medicare Beneficiaries With a Secondary Discharge Diagnosis of Acute Myocardial Infarction

BACKGROUND Patients with coronary heart disease are recommended to use statins following hospital discharge. Acute myocardial infarction (AMI) is a common complication of hospitalization, but the use of statins following discharge among patients who were not initially hospitalized for AMI has not been assessed adequately. METHODS AND RESULTS Using the Medicare 5% national random sample, we determined statin use among beneficiaries who were hospitalized and who had a secondary discharge diagnosis of AMI and among beneficiaries who had a primary discharge diagnosis of AMI, coronary artery bypass grafting, or percutaneous coronary intervention in 2007-2009. Statin use was defined by a pharmacy (Medicare Part D) claim within 90 days following discharge. Of 8175 Medicare beneficiaries who did not take statins prior to hospitalization, 31.2% with AMI as a secondary discharge diagnosis, 60.5% with AMI as the primary discharge diagnosis, 67.6% with coronary artery bypass grafting, and 63.9% with a percutaneous coronary intervention initiated statins. After multivariable adjustment, the risk ratio for statin initiation comparing beneficiaries with a secondary versus primary discharge diagnosis of AMI was 0.59 (95% CI 0.54 to 0.65). Among 5468 Medicare beneficiaries taking statins prior to hospitalization, statin use following discharge was lower for those with AMI as a secondary discharge diagnosis (71.8%) compared with their counterparts with AMI, coronary artery bypass grafting, and percutaneous coronary intervention (84.1%, 83.8%, and 87.3%, respectively) as the primary discharge diagnosis. CONCLUSION Medicare beneficiaries with a secondary hospital discharge diagnosis of AMI were less likely to fill statins compared with those with other coronary heart disease events.