Risk factors in schoolchildren associated with a family history of unheralded myocardial infarction or uncomplicated stable angina in male relatives.

Objectives: The aim of this study was to compare risk factors for coronary atherosclerosis in children with a family history of unheralded myocardial infarction or uncomplicated stable angina.

Background: In patients with unheralded myocardial infarction, coronary atherosclerosis might have a greater tendency to cause acute coronary occlusion than in patients with uncomplicated stable angina, suggesting the possibility of different risk factors in these two groups of patients.

Methods: Serum lipid levels were compared in children with a family history of unheralded myocardial infarction (236 children) or uncomplicated stable angina (48 children) or no family history of ischemic heart disease (613 children).

Results: Mean (+/- 1 SD) total serum cholesterol was higher in children with a family history of myocardial infarction than in control subjects (161 +/- 28 vs. 154 +/- 25 mg%, p < 0.01). In children with a family history of stable angina, mean total serum cholesterol (159 +/- 25 mg%) was similar to that in children with family history of myocardial infarction. High density lipoprotein cholesterol and apolipoprotein A-I were higher in children with family history of stable angina than in children with family history of myocardial infarction and control subjects (69 +/- 18 vs. 61 +/- 13 and 60 +/- 13 mg%, p < 0.01; 143 +/- 23 vs. 130 +/- 18 and 129 +/- 18 mg%, p < 0.01, respectively). In children with a family history of myocardial infarction, the low density/high density lipoprotein cholesterol ratio was significantly higher than in control subjects (1.53 +/- 0.64 vs. 1.44 +/- 0.56, p < 0.05). Conversely, in children with a family history of stable angina, this ratio (1.24 +/- 0.51) was significantly lower (p < 0.05) than in control subjects.

Conclusions: Risk factors for coronary athersclerosis in children with a family history of unheralded myocardial infarction are different from those in children with a family history of uncomplicated stable angina. Higher levels of apolipoprotein A-I early in life might reduce the risk of acute coronary syndromes.