Factor V Leiden mutation in postthrombotic and non-postthrombotic venous ulcers

Objective: To determine the prevalence of the factor V Leiden mutation in p atients with postthrombotic and nonpostthrombotic venous ulcers. Design: Case-control study. Setting: Department of Dermatology, University Hospital of Zurich, Zurich, Switzerland. Participants: Seventy-three consecutive outpatients and inpatients with ven ous ulcers and 45 age- and sex-matched control subjects (matched to the 42 patients with postthrombotic syndrome). Main Outcome Measures: Frequency of postthrombotic and non-postthrombotic f indings in patients with venous ulcers. Prevalence of the factor V Leiden m utation in these different subgroups. Results: Postthrombotic syndrome was identified as the cause of 42 (58%; 95 % confidence interval [CI], 45%- 69%) of 71 venous ulcers, and the remainde r were caused by primary valvular insufficiency. In postthrombotic ulcers, the prevalence of the factor V Leiden mutation was 38% (95% CI, 24%-54%) (1 6/42),which corresponds to an odds ratio of 13.2 (95% CI, 2.8-62.3; P < .00 1). In nonpostthrombotic venous ulcers, the prevalence was 16% (95% CI, 5%- 34%) (5/31), which corresponds to an odds ratio of 3.2 (95% CI, 1.0-10.0; P =.07). Conclusions: The factor V Leiden mutation is highly prevalent in patients w ith postthrombotic venous ulcers. Even patients with non-postthrombotic Ven ous ulcers show a moderately elevated prevalence of the factor V Leiden mut ation. Some of the latter might be misclassified because of near-to-perfect revascularization after asymptomatic deep venous thrombosis. However, as l ong as the therapeutic consequences of the factor V Leiden mutation are not established, systematic screening cannot be recommended in patients with v enous ulcers.