Quantitative measurement of carotid atherosclerosis in relation to levels of von Willebrand factor and fibrinolytic variables in plasma--a 2-year follow-up study.

Background: It has been proposed that the mechanism of action of the new risk factors for myocardial infarction and stroke, von Willebrand factor (vWF), tissue plasminogen activator (tPA) and tissue plasminogen activator inhibitor-1 (PAI-1) could possibly be mediated via a primary effect on atherogenesis but there is little data to substantiate this.

Design: A prospective single-centre cohort study of progression of atherosclerosis.

Methods: Carotid plaque area was quantitated by two-dimensional (2D) ultrasound in 258 subjects at entry and after 1 and 2 years. Plasma and serum samples were drawn at baseline and serum lipids and plasma levels of haemostatic factors were measured.

Results: The traditional risk factors, smoking, total cholesterol, hypertension and male gender explained 51% of the variance in plaque area at baseline and 48% at 1-year follow-up. There were small positive associations of plaque area with vWF, tPA and tPA/PAI-1 complex and a tendency to negative associations with PAI-1 levels, independent from the traditional risk factors. The additional explanatory power of the haemostatic factors did not exceed 3%.

Conclusion: The data accord with a marginal role in atherogenesis of vWF and tPA, and underline the major impact of smoking, hypertension and cholesterol on carotid plaque area progression.