A meta-analysis by a team from McMaster University in Canada found men without major risk factors had a 2.2-fold higher risk of developing a second VTE than women. The researchers said the findings had implications for clinical decisions about long-term anticoagulant treatment.
Previous work has found men and women are at a similar risk of a first VTE. Other research has suggested there might be an increased risk of recurrence among men, but this issue has yet to be explored in a community setting.
A team led by Professor James Douketis tracked the progress of 2,554 patients with a first VTE for just over two years after anticoagulant treatment was stopped. After one year, 5.3% of women experienced a recurrence, compared with 9.5% of men.
Even after adjusting for risk in women with previous hormone-associated VTE, the extra risk to men was 1.8-fold higher than to women. Risk of recurrence remained the same between the sexes in patients with first 'provoked' VTE, defined as occurrence in the presence of clinical risk factors, such as surgery or trauma.
The researchers concluded: 'Our findings suggest that in patients with a first unprovoked VTE, sex may be an important consideration in a deciding the need for long-term anticoagulant treatment.'