[Mechanism of clinical onset and outcome of coronary disease before 40 years of age. 148 cases].

This study reviewed the clinical histories of 148 coronary patients aged 34 +/- 5 years (20-40 years) documented in the same cardiology unit. Myocardial infarction was the presenting condition in 114 patients (77%): inaugural 65%, with prodrome 7%, asymptomatic 4%. The presentation was angina pectoris in 32 patients (22%): effort angina 15%, unstable angina 7%. Two patients had other symptoms (1%). The coronary lesions were significant (greater than 50%) in 112 patients (77%) which included 41% single vessel diseases and 36% multiple vessel diseases. The coronary lesions were insignificant in 10 patients (7%) and absent in 21 (15%) (33% under and 11% over 30 years of age). After an average follow-up of 48 months (range 1 to 10 years), 20 of the 32 patients presenting with angina developed myocardial infarction and 6 had episodes of unstable angina (65% in the first year following diagnosis). Six patients had no serious coronary events, but thereafter, 3 died. Fifteen patients (47%) are asymptomatic (including 8 after coronary bypass surgery). Ten patients are symptomatic. Of the 114 patients with inaugural myocardial infarction, 3 have died, 67 (58%) are symptomatic; the average number of risk factors per patient was related to age and to the degree of coronary artery disease. The left ventricular ejection fraction was significantly higher in asymptomatic patients than in those who had presented a coronary event after myocardial infarction.(ABSTRACT TRUNCATED AT 250 WORDS)