Nadroparin for the prevention of venous thromboembolism in nonsurgical patients: a systematic review and meta-analysis

Anticoagulant thromboprophylaxis with low molecular weight heparin is widely used in nonsurgical settings. To obtain best estimates of the effects of nadroparin for the prevention of venous thromboembolism (VTE) in nonsurgical patients, we conducted a systematic review and meta-analysis. Data sources were Medline, Embase, and Cochrane Library supplemented with conference abstracts, without language restrictions. Selection criteria were randomized controlled trials with nadroparin at prophylactic dose in adult nonsurgical patients. Main efficacy outcomes were major VTE (the composite of symptomatic deep vein thrombosis, symptomatic pulmonary embolism, asymptomatic proximal deep vein thrombosis and VTE-related death) and symptomatic VTE. The main safety outcome was major bleeding. We expressed treatment effects as risk ratios. Ten studies (4 vs. placebo or no treatment, 4 vs. UFH, 1 vs. fondaparinux and 1 vs. warfarin) enrolling a total of 7658 patients were included. In comparison with placebo, nadroparin reduced major VTE by about one-half (RR 0.48, 95% CI 0.24-0.97) with a consistent effect on symptomatic VTE (RR 0.69, 95% CI 0.46-1.05) and no increase in major bleeding (RR 1.51, 95% CI 0.40-5.79). In comparison with other pharmacological prophylaxis, nadroparin was similarly efficacious for prevention of major VTE (RR 1.14, 95% CI 0.63-2.10) and symptomatic VTE (RR 1.10, 95% CI 0.51-2.35) and produced similar effects on major bleeding (RR 0.60, 95% CI 0.25-1.50). Five studies were open label, and for three of these the adjudication method was not described or not blinded. In nonsurgical populations at risk of VTE, nadroparin reduced VTE by about one half compared with placebo or no treatment and appeared similarly effective and safe as other prophylactic anticoagulants.