[Acute myocardial infarction in patients under 40 years of age]. / Infarto agudo do miocárdio em pacientes com idade inferior a 40 anos.

ABSTRACT

PURPOSE: To evaluate the short and long-term prognosis of a group of patients aged 40 and under, who developed an acute myocardial infarction. PATIENTS AND METHODS: In the last 15 years we studied a group of 73 patients aged 40 and under with a confirmed diagnosis of first acute myocardial infarction. Patients with infarctions caused by coronary embolisms or to revascularization procedures were excluded. RESULTS: Ninety percent were male and mean the age was 35. The most frequent risk factors observed were cigarette smoking in 64 (88%), hypertension in 16 (22%), hypercholesterolemia in 12 (16%) and diabetes in 3 (4%). Seven (9%) patients had no risk factors. The myocardial infarction was anterior em 50 (68%) cases and inferior in the remaining 23 (32%). Severe heart failure (Killip III and IV) was present in 3 (4%). Angiographic studies were performed in 63 (86%). Cineangiography showed critical coronary lesions (obstruction greater than 70%) in one vessel in 38 (60%) patients, multivessel disease in 18 (28%) and 7 (12%) had normal coronary vessels. In-hospital mortality was 5% (3 patients died due to severe heart failure and 1 due to cerebro-vascular accident). The 56 survivors were followed-up to 15 years, with overall survival of 74%. Fourty-nine (71%) were asymptomatic and 7 (10%) had recurrent chest pain. There were 7 (10%) late deaths and follow-up was lost in 6 (9%). Reinfarctions were observed in 5 cases (7%). Revascularization procedures were performed in 12 (17%) patients (bypass-graft surgery in 9 and coronary angioplasty in 3). CONCLUSION: Young patients with acute myocardial infarction have a low mortality rate in the early phase and a favorable outcome after the discharge of the hospital.