Coronary artery disease (CAD) is the major cause of death in Canadian adults. Regional differences in the prevalence of CAD in Canada are due, in part, to differences in cardiovascular risk factor distribution. Two hundred and forty-nine patients of predominantly French Canadian descent (greater than 90%), aged less than 60 years (202 men and 47 women) with angiographically documented CAD were examined in a cardiology secondary prevention clinic and their cardiovascular risk factors and lipoprotein cholesterol levels were determined.
To determine the prevalence of cardiovascular risk factors in a group of French Canadian subjects compared with subjects screened for the Quebec Heart Health Survey and to determine the impact of the National Cholesterol Education Program II (NCEP II) on screening and treatment of these patients.
Observation study of free-living subjects with CAD, compared with a reference group.
Mean ages were 48.6 +/- 6.8 and 50.6 +/- 6.4 years for men and women, respectively. On average, the patients were on a diet containing approximately 31% of calories as fat, with 9.7% as saturated fats at the time of blood sampling. The mean number of risk factors was the same in men and women (3.5 +/- 1.2 for men versus 3.2 +/- 1.3 for women; P not significant) but their prevalence differed between sexes. Family history of CAD was seen in 78.5% of men versus 77.3% of women (P not significant), smoking (defined as more than 10 cigarettes per day in the year preceding the clinical evaluation) in 45.7% of men versus 41.9% of women (P not significant), a history of smoking in 75.5% of men versus 69.8% of women (P not significant) and diabetes in 14.7% of men and 25% of women (P not significant). There was less hypertension in men (31.4% versus 52.3%, P = 0.015) and fewer men had a low density lipoprotein cholesterol of 3.4 mmol/L or greater (66.8% in men versus 83% in women, P < 0.05). Men, however, had a higher prevalence of reduced high density lipoprotein cholesterol (less than 0.9 mmol/L, 57.4% in men versus 31.9% in women, P < 0.01). Only approximately 5% of premature CAD patients had familial hypercholesterolemia. Compared with a reference group from the Quebec Heart Health Survey, men and women with CAD had a higher prevalence of cardiovascular risk factors. With a cut-off point for total cholesterol of 5.2 mmol/L, 26.2% of men and 17% of women had 'normal' cholesterol levels; of these, 67.9% of men and 25% of women had high density lipoprotein less than 0.9 mmol/L.
French Canadian men and women with CAD have a high prevalence of all cardiovascular risk factors. The patients are representative of the Montreal urban area and findings of the present study may not apply to the Quebec population with respect to the prevalence of risk factors. Under the treatment recommendations of NCEP II, 66.8% of men and 83% of women are candidates for drug therapy of dyslipoproteinemia aimed at reducing low density lipoprotein cholesterol levels. According to these data, cardiovascular risk stratification must be based on a complete lipoprotein profile or misclassification, especially in men, may occur.