Summary
The contribution of coagulation factors and fibrinolytic variables to the development
of ischaemic arterial disease is still not clearly established. The PRIME study is
a prospective cohort study of myocardial infarction in men aged 50-59 years and recruited
from three MONICA field centers in France (Lille, Strasbourg and Toulouse) and the
center in Northern Ireland (Belfast). Baseline examination included measurement of
plasma fibrinogen, factor VII, and PAI-1 activity in over 10,500 participants. We
investigated the associations of these haemo-static variables with cardiovascular
risk factors, prevalent atherosclerotic disease and geographical area. Fibrinogen
level increased with age, smoking, waist-to-hip ratio, LDL-cholesterol, and it decreased
with educational level, leisure physical activity, alcohol intake and HDL-cholesterol.
Factor VII activity increased with body mass index, waist-to-hip ratio, triglycerides,
HDL- and LDL-cholesterol. PAI-1 activity increased with body mass index, waist-to-hip
ratio, triglycerides, alcohol intake, smoking, and decreased with leisure physical
activity. PAI-1 level was higher in diabetic subjects than in subjects without diabetes.
Cardiovascular risk factors explained 8%, 9%, and 26% of the total variance in fibrinogen,
factor VII, and PAI-1, respectively. Compared with participants without prevalent
cardiovascular disease, those with previous myocardial infarction (n = 280), angina
pectoris (n = 230), or peripheral vascular disease (n = 19) had significantly higher
levels of fibrinogen, but those with stroke (n = 67) had not. PAI-1 activity showed
a similar pattern of association. The odds ratio for cardiovascular disease associated
with a rise of a one standard deviation in fibrinogen and PAI-1 was 1.31 (95% confidence
interval: 1.20 to 1.42, p <0.001) and 1.38 (95% confidence interval: 1.27 to 1.49,
p <0.001), respectively. After adjustment for cardiovascular risk factors, these associations
were attenuated but remained highly significant. There was no significant association
between factor VII activity and prevalent cardiovascular disease. Fibrinogen level
and, to a lesser extent, factor VII and PAI-1 activity were higher in Northern Ireland
than France after adjustment for the main cardiovascular risk factors. These geographical
variations are consistent with the 2 to 3-fold higher incidence of myocardial infarction
in Northern Ireland than France. Our results provide further epidemiological evidence
for a possible role of fibrinogen and PAI-1 in the pathogenesis of coronary heart
disease.