RESUMO
OBJECTIVE: ST-segment elevation acute myocardial infarction (STEMI) in very young adults is uncommon. Many studies have focused on the cutoff of 45-50 years old to define young patients with STEMI leaving limited data on the group of very young patients aged less than 35 years old. We investigated the incidence of STEMI in different subgroups of young patients and focused on the characteristics, possible pathogenesis and outcomes in very young patients aged less than 35 years old. METHODS: We retrospectively studied 792 STEMI patients aged less than 55 years who underwent successful primary PCI. We categorized patients as very young if they were or less 35 years old and as young if they were between 36 and 55 years old. Baseline characteristics, angiographic findings, as well as short- and long-term outcomes were compared between the two groups. RESULTS: There were 46 (6%) very young patients (age ≤ 35 years) and 748 (94%) young patients (36 < age ≤ 55 years). Very young patients had fewer atherosclerotic risk factors than young patients, but there was no difference in short- or long-term outcomes. Overt hypercoagulable state was evident serologically (antiphospholipid antibodies) in 2/7 (29%) of screened patients and clinically (left ventricular thrombus or acute coronary thrombosis without an atherosclerotic plaque) in 6/46 patients (13%). CONCLUSION: Very young patients with STEMI constitute a distinct subset of young patients with fewer atherosclerotic risk factors yet comparable outcomes. More efforts should be made screening for serologic and clinical evidence of hypercoagulability in this group of patients.