Further evidence in support of the association between venous thrombosis and atherosclerosis: A case-control study.

INTRODUCTION: Whether there is an association between venous thromboembolism (VTE) and atherosclerosis is still controversial. AIMS: In a case-control study conducted on subjects older than 50, we assessed the prevalence of symptomatic or subclinical atherosclerosis in a group of unselected patients with unprovoked VTE, and compared it with that of patients with secondary VTE and of matched control individuals free from VTE disorders. METHODS: Cases and controls were enquired about the presence of previous symptomatic manifestations of atherosclerosis. Those with a negative history underwent the ultrasound assessment of carotid arteries following a standardized procedure. An intima-media thickness higher than 0.9mm or the detection of at least one carotid plaque was regarded as a subclinical manifestation of atherosclerosis. After adjusting for age, gender and risk factors for atherosclerosis, we calculated the odds ratio (OR) for symptomatic or subclinical atherosclerosis in patients with unprovoked VTE as compared to those with secondary VTE and controls. RESULTS: We recruited 100 patients with unprovoked VTE, 100 with secondary VTE and 100 control individuals. In patients with unprovoked VTE, the adjusted OR for symptomatic or subclinical atherosclerosis was 5.1 (95% CI, 2.0 to 13.1) in comparison to patients with secondary VTE, and 14.5 (95% CI, 5.8 to 36.3) in comparison to controls. The prevalence of atherosclerosis was higher in patients with secondary VTE than in controls (OR, 3.1; 95% CI, 1.6 to 6.1). CONCLUSION: The results of this study confirm the presence of a strong association between venous thrombosis and atherosclerosis.