When More Means Less: The Prognosis of Recurrent Acute Myocardial Infarctions.

Recurrent acute myocardial infarctions (AMI) are common and associated with dismal outcomes. We evaluated the clinical characteristics and the prognosis of AMI survivors according to the number of recurrent AMIs (ReAMI) and the time interval of events (TI). A retrospective analysis of patients who survived following hospitalization with an AMI throughout 2002-2017 was conducted. The number of ReAMIs for each patient during the study period was recorded and classified based on following: 0 (no ReAMIs), 1, 2, ≥3. Primary outcome: all-cause mortality up to 10 years post-discharge from the last AMI. A total of 12,297 patients (15,697 AMI admissions) were analyzed (age: 66.1 ± 14.1 years, 68% males). The mean number of AMIs per patient was 1.28 ± 0.7; the rates of 0, 1, 2, ≥3 ReAMIs were 81%, 13.4%, 3.6% and 1.9%, respectively. The risk of mortality increased in patients with greater number of AMIs, HR = 1.666 (95% CI: 1.603-1.720, p < 0.001) for each additional event (study group), attenuated following adjustment for potential confounders, AdjHR = 1.135 (95% CI: 1.091-1.181, p < 0.001). Increased risk of mortality was found with short TI (<6-months), AdjHR = 2.205 (95% CI: 1.418-3.429, p < 0.001). The risk of mortality following AMI increased as the number of ReAMIs increased, and the TI between the events shortened. These findings should guide improved surveillance and management of this high-risk group of patients (i.e., ReAMI).