Normal angiogram after myocardial infarction in young patients: a prospective clinical-angiographic and long-term follow-up study.

This is an observational study in which we compared the clinical characteristics and the long-term course of young patients having acute myocardial infarction and angiographically normal coronary arteries and young patients showing significant coronary artery disease. In 87 patients aged < or = 40 years who suffered an acute myocardial infarction, enrolled in a prospective study over a period of 6.5 years, coronary anatomy was determined by angiography within a month of admission. The risk factors, clinical data, ventricular function and the long-term outcome were compared between patients with normal angiograms (Group 1, n = 12) and patients with coronary artery disease (Group 2, n = 75). Patients in Group 1 had a lower number of risk factors associated with them (17% vs. 64% with > 1 risk factor, P < 0.005), were younger (32 +/- 5 vs. 36 +/- 4, P < 0.01), lighter smokers (25% vs. 55% for > or = 2 packs per day, P < 0.05), had less frequent hypertension (0 vs. 25%, P < 0.05), hypercholesterolemia (17% vs. 52%, P = 0.02) and had a lower mean total cholesterol level (201 +/- 42 vs. 245 +/- 60 mg/100 ml, P < 0.05) than patients in Group 2. They also had a more common onset of their infarction during heavy physical exertion (67% vs. 17%, P < 0.001). A history of previous myocardial infarction, infarct location, global left ventricular function and regional wall motion were similar in both groups. After a mean follow-up period of 41 +/- 23 months, no patient died or had a second myocardial infarction in Group 1, and 4 patients had died in Group 2. The appearance of angina, less frequent in Group 1 than Group 2, tended to correlate with the extension of the coronary artery disease. We concluded that young patients with myocardial infarction have good prognosis irrespective of the coronary anatomy, although patients with normal coronary angiograms had less risk factors and less frequent new ischaemic events.