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

OBJECTIVE
To determine the prevalence of the factor V Leiden mutation in patients with postthrombotic and non-postthrombotic venous ulcers.


DESIGN
Case-control study.


SETTING
Department of Dermatology, University Hospital of Zurich, Zurich, Switzerland.


PARTICIPANTS
Seventy-three consecutive outpatients and inpatients with venous 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 findings in patients with venous ulcers. Prevalence of the factor V Leiden mutation in these different subgroups.


RESULTS
Postthrombotic syndrome was identified as the cause of 42 (58%; 95% confidence interval [CI], 45%-69%) of 73 venous ulcers, and the remainder were caused by primary valvular insufficiency. In postthrombotic ulcers, the prevalence of the factor V Leiden mutation was 38% (95% CI, 24%-54%) (16/42), which corresponds to an odds ratio of 13.2 (95% CI, 2.8-62.3; P<.001). In non-postthrombotic 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 with postthrombotic venous ulcers. Even patients with non-postthrombotic venous ulcers show a moderately elevated prevalence of the factor V Leiden mutation. Some of the latter might be misclassified because of near-to-perfect revascularization after asymptomatic deep venous thrombosis. However, as long as the therapeutic consequences of the factor V Leiden mutation are not established, systematic screening cannot be recommended in patients with venous ulcers.