Characteristics and Outcomes of Early Recurrent Myocardial Infarction After Acute Myocardial Infarction

BACKGROUND: We aimed to understand the characteristics and outcomes of patients readmitted with a recurrent myocardial infarction (RMI) within 90 days of discharge after an acute myocardial infarction (early RMI). METHODS AND RESULTS: We analyzed the timing of reinfarction, etiology, and outcome for all patients admitted with an early RMI within 90 days of discharge after an acute myocardial infarction between January 1, 2010 and January 1, 2017. We identified 6626 admissions for acute myocardial infarction (index myocardial infarction) which led to 168 cases of RMI within 90 days of discharge. The mean patient age was 65.1±13.1 years, and 37% were women. The 90‐day probability of readmission with an early RMI was 2.5%. Black race, medical management, higher troponin T, and shorter length of stay were independent predictors of early RMI. Medically managed group had a higher risk for early RMI compared with percutaneous coronary intervention (P=0.04) or coronary artery bypass grafting (P=0.2). Predominant mechanisms for reinfarction were stent thrombosis (17%), disease progression (12%), and unchanged coronary artery disease (11%). At 5 years, the all‐cause mortality rate for patients with an early RMI was 49% (95% CI, 40%–57%) compared with 22% (95% CI, 21%–23%) for patients without an early RMI (P<0.0001). CONCLUSIONS: Early RMI is a life‐threatening condition with nearly 50% mortality within 5 years. Stent‐related events and progression in coronary artery disease account for most early RMI. Medication compliance, aggressive risk factor management, and care transitions should be the cornerstone in preventing early RMI.