Epidemiologic variables and outcome of 1972 young patients with acute myocardial infarction. Data from the GISSI-2 database. Investigators of the Gruppo Italiano per lo Studio della Sopravvivenza nell'Infarto Miocardico (GISSI-2).

Background: Acute myocardial infarction in younger patients is uncommon, occurring mainly in men. The recent introduction of thrombolysis improved survival, left ventricular function, and infarct size.
Objective: To evaluate characteristics and clinical outcome of the patients younger than 50 years randomized in the Gruppo Italiano per lo Studio della Sopravvivenza nell'Infarto Miocardico study. All patients received a thrombolytic treatment.
Methods: The 11483 patients were divided into 3 age subgroups: younger than 50 years (17.2%), between 50 and 70 years (60.2%), and older than 70 years (22.6%). All relations between variables were first determined by an unadjusted analysis. An adjusted analysis was performed by multiple logistic regression models for in-hospital and 6-month mortality.
Results: While older patients had a significantly higher rate of a history of hypercholesterolemia, diabetes, and hypertension, smoking and a positive family history were significantly more frequent in younger patients. Total in-hospital and 6-month mortality were significantly lower in patients younger than 50 years (2.7% and 1.2%, respectively) than in patients between 50 and 70 years old (6.9% and 2.7%) and those older than 70 years (21.1% and 8.4%). After multivariate analysis, the predictive value of age was confirmed.
Conclusions: Our findings, based on a large group of patients who received thrombolytic treatment, suggest that younger age is a significant independent indicator of a favorable prognosis after acute myocardial infarction.