Myocardial infarction in the young. Angiographic features and risk factor analysis of patients with myocardial infarction at or before the age of 35 years.

We reviewed the records of 2,400 consecutive patients undergoing cardiac catheterization at USAF Medical Center Keesler between 1978 and 1984 and found 35 patients (1.5 percent of all cardiac catheterizations) aged 35 years or less (mean age, 32 years) who underwent cardiac catheterization after myocardial infarction. These 35 patients (group 1) were compared to a randomly selected group of 100 patients (group 2) aged 55 years or greater who underwent cardiac catheterization for evaluation of coronary artery disease during the same period. The two groups were compared in terms of angiographic features and risk factors for coronary artery disease. The patients in group 1 had a higher proportion of normal coronary arteries (14 percent [5 patients] vs 0; p less than 0.01) and single-vessel disease compared to group 2, while the incidence of three-vessel disease was much less (14 percent [5] vs 47 percent; p less than 0.001). Involvement of the left main coronary artery was uncommon in group 1 (3 percent [1] vs 15 percent in group 2; p less than 0.01). Risk factor analysis revealed smoking to be the most common risk factor in both groups (89 percent [31] in group 1 and 91 percent in group 2). Hypertension (28 percent [10] vs 48 percent; p less than 0.05) and diabetes (3 percent [1] vs 23 percent; p less than 0.01) were more common in group 2. Importantly, of 19 patients in group 1 who underwent cardiac catheterization for prognosis despite being asymptomatic and able to reach at least stage 4 on a Bruce protocol exercise test, none was found to have residual surgically correctable disease.