Natural history of venous thromboembolism in patients from the Mediterranean region. A systematic review.

BACKGROUND:

Patients with cardiovascular diseases living in the Mediterranean area have a better outcome than those in other parts of the world, but it is not known whether these differences also occur with venous thromboembolism (VTE).

METHODS:

We searched the Medline and EMBASE databases to identify clinical trials and cohort studies of patients with VTE who had been treated with anticoagulant therapy for 3 months. Two reviewers independently extracted the data in a standardized manner. A total of 24 studies that included 7,225 patients (2,414 from the Mediterranean region and 4,811 from other regions) were analyzed.

RESULTS:

The patients from the Mediterranean area were predominately women and older, and the idiopathic VTE was less frequent than in other regions. Compared with patients from other regions, patients from the Mediterranean region had an increased rate of recurrent deep vein thrombosis (4.35% vs. 2.68%; odds ratio [OR], 1.65; 95% confidence interval [95% CI] 1.27-2.15), fatal recurrent VTE (0.75% vs. 0.35%; OR, 2.11; 95% CI 1.09-4.12) and fatal bleeding (0.25% vs. 0.06%; odds ratio: 3.99; 95% CI 1.00-16.0). The case-fatality rate (CFR) for recurrent VTE was 12.8% (95% CI 7.99-19.1) in the Mediterranean region and 8.41% (5.15-12.9) in other areas. The CFR for major bleeding was 11.3% (95% CI 4.72-22.1) and 3.22% (95% CI 0.83-8.53), respectively.

CONCLUSIONS:

Compared to other regions, patients with VTE from the Mediterranean region have greater mortality during the first 3 months of treatment due to a greater incidence of recurrent VTE and severe hemorrhaging.