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 veno us thromboembolism. Design: Secondary analysis of a prospective, rando mized, assessor-blind, multicenter clinical trial. Setting: One univer sity and 2 regional teaching hospitals. Patients: 188 patients treated with heparin or danaparoid for acute venous thromboembolism. Measurem ents: The presenting clinical features, the doses of the drugs, and th e anticoagulant responses were analyzed using univariate and multivari ate logistic regression analysis in order to evaluate prognostic facto rs for bleeding. In addition, the recently developed Utrecht bleeding risk score and Landefeld bleeding risk index were evaluated prospectiv ely. Results: Major bleeding occurred in 4 patients (2.1%) and minor b leeding in 101 patients (53.7%). For all (major and minor combined) br eeding, body surface area less than or equal to 2 m(2) (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 in creased treatment-related risk of bleeding was observed in patients tr eated with high doses of heparin, independent of the concomitant activ ated partial thromboplastin time ratios. Both bleeding risk scores had low diagnostic value for bleeding in this sample of mainly minor blee ders. Conclusions: A small body surface area and malignancy were assoc iated with a higher frequency of bleeding. The bleeding risk scores me rely offer the clinician a general estimation of the risk of bleeding. In patients with a small body surface area or in patients with malign ancy, it may be of interest to study whether limited dose reduction of the anticoagulant drug may cause less bleeding without affecting effi cacy.