Risk Factors and Outcomes of Very Young Adults Who Experience Myocardial Infarction: The Partners YOUNG-MI Registry

Background: Despite significant progress in primary prevention, the rate of myocardial infarction has not decreased in young adults. We sought to compare the risk factor profiles and outcomes between individuals who experienced a first myocardial infarction at a very young (≤40 years) and a young (age 41-50 years) age. Methods: We evaluated all patients ≤50 years of age admitted with a Type 1 myocardial infarction to 2 large academic hospitals from 2000 to 2016. Risk factors were determined by review of electronic medical records. The primary outcomes of interest were all-cause and cardiovascular mortality. Results: Among 2097 consecutive young patients with myocardial infarction, 431 (20.5%) were ≤40 years of age. When compared with their older counterparts, very young patients had similar risk profiles, with the exception of greater substance abuse (17.9% vs 9.3%, P < .001) and less hypertension (37.9% vs 50.9%, P < .001). Spontaneous coronary artery dissection was more prevalent in very young patients (3.1% vs 1.1%, P = .003). Over a median follow-up of 11.2 years, very young myocardial infarction patients had a similar risk of all-cause and cardiovascular mortality. Conclusions: Despite being, on average, 10 years younger and having a lower prevalence of hypertension, very young myocardial infarction patients had similar 1-year and long-term outcomes when compared with those aged 41 to 50 years at the time of their index infarction. Our findings suggest the need for aggressive secondary prevention measures in very young patients who experience a myocardial infarction.