Myocardial infarction in the young.

Coronary angiography was done in 88 patients of myocardial infarction (MI) less than 40 years of age (Group I) and the results were compared with an equal number of patients with MI over 40 years (Group II). Severity of coronary stenosis was evaluated by a coronary index (CI) which determined the extent of myocardium at jeopardy. The severity of coronary artery disease increased with age (CI in Group I = 6.2; Group II = 8.4). Normal coronaries (16% vs 5.7%) and single vessel disease (41% vs 23%) were common in Group I. Smoking was the commonest risk factor in both groups, its prevalence being higher in Group I (66% vs 42%) while the prevalence of diabetes was lower (4.5% vs 21.5%).