Risk factors for bleeding during treatment of acute venous thromboembolism.

OBJECTIVE

Identification of risk factors for bleeding and prospective evaluation of two bleeding risk scores in the treatment of acute venous thromboembolism.

DESIGN

Secondary analysis of a prospective, randomized, assessorblind, multicenter clinical trial.

SETTING

One university and 2 regional teaching hospitals.

PATIENTS

188 patients treated with heparin or danaparoid for acute venous thromboembolism.

MEASUREMENTS

The presenting clinical features, the doses of the drugs, and the anticoagulant responses were analyzed using univariate and multivariate logistic regression analysis in order to evaluate prognostic factors for bleeding. In addition, the recently developed Utrecht bleeding risk score and Landefeld bleeding risk index were evaluated prospectively.

RESULTS

Major bleeding occurred in 4 patients (2.1%) and minor bleeding in 101 patients (53.7%). For all (major and minor combined) bleeding, body surface area < or = 2 m2 (odds ratio 2.3, 95% CI 1.2-4.4; p = 0.01), and malignancy (odds ratio 2.4, 95% CI 1.1-4.9; p = 0.02) were confirmed to be independent risk factors. An increased treatment-related risk of bleeding was observed in patients treated with high doses of heparin, independent of the concomitant activated partial thromboplastin time ratios. Both bleeding risk scores had low diagnostic value for bleeding in this sample of mainly minor bleeders.

CONCLUSIONS

A small body surface area and malignancy were associated with a higher frequency of bleeding. The bleeding risk scores merely offer the clinician a general estimation of the risk of bleeding. In patients with a small body surface area or in patients with malignancy, it may be of interest to study whether limited dose reduction of the anticoagulant drug may cause less bleeding without affecting efficacy.