[Acute myocardial infarction in patients under 45 years].

Introduction And Objective: To evaluate the differential features of acute myocardial infarction in patients younger than 45 years old compared to older patients.

Patients And Methods: From 1995 to 1999, delays in the assistance, evaluation, and therapeutic strategies as well as complications in patients hospitalized with a diagnosis of acute myocardial infarction, have been registered in the intensive care units of the 17 hospitals participating in the PRIMVAC Register.

Results: During the study, 10,213 patients were registered, 6.8% younger than 45 years old (691 patients). Young patients show a greater prevalence of cigarette smoking (80.9 vs 34.1%; p < 0.0001) and hypercholesterolemia (39.9 vs 28.6%; p < 0.0001), whereas arterial hypertension, diabetes, and history of coronary disease were significantly more frequent in the older group. This subgroup reached the healthcare system at an earlier stage (120 vs 160 min; p < 0.0001). Thrombolysis was performed in 59.9% of patients younger than 45 years and in 45.9% of patients older than 45 years. Young patients were more frequently given aspirin (94.5%), heparin (70.6%), and beta-blocker drugs (38.4%), whereas patients older than 45 years were given a higher percentage of ACEI, digoxin, and inotropic drugs. Younger patients had a better prognosis and a lower mortality rate (3.5 vs 14%; p < 0.00001).

Conclusions: Acute myocardial infarction in patients younger than 45 years had different clinical features and responded to different therapeutic and diagnostic approaches than acute myocardial infarction in patients over 45 years, as well as a better short-term prognosis.