94. Factor VIII activity predicts cardiovascular disease. the Rotterdam Study

Objective: To study the association of factor VIII activity to incident myocardial infarction and stroke. Methods: The present study is a prospective cohort study among 7983 subjects aged 55 years and over, living in the suburb of Ommoord in Rotterdam, The Netherlands. The analysis is based on events that occurred from baseline (1990-1993) to December 31, 1994. Hospital discharge records were used to classify incident myocardial infarctions and strokes. Non-hospitalized strokes were classified by a neurologist using a general practitioner's report of signs and symptoms. Factor VIII activity was determined in platelet poor plasma with a chromogenic assay. Factor VIII activity was available of a random sample of 3858 subjects, not currently using anticoagulant drugs. The analyses (logistic regression) were based on the first 106 consecutive events, and are adjusted for age and gender. Results: Relative to subjects in the lowest quartile of factor VUIc (<0.82 U/l), the risk of cardiovascular disease was 1.2 [95% CI 0.6-2.2] in the second quartile (0.82-1.12 U/l), 1.1 [95% 0.6-2.1] in the third quartile (1.13-1.47 U/l), and 2.0 [95% CI 1.1-3.5] in the upper quartile (>1.48 U/l). Additional adjustments for serum lipids, blood pressure, body mass index, smoking and previous cardiovascular history, did not materially alter the findings. Findings were similar for myocardial infarction and stroke. Conclusion: In the present study no graded association was found between factor VIII activity and cardiovascular disease. The risk was confined to subjects with levels in upper quartile of distribution.