A Systematic Review and Meta-Analysis of Proportions of Thrombosis and Bleeding in Patients Receiving Venous Thromboembolism (VTE) Prophylaxis After Orthopedic Surgery (OS). An Update.

Abstract 3125

Poster Board III-62

VTE is the most frequent complication of OS and it can be prevented through anticoagulant prophylaxis. Numerous studies have evaluated different agents for this purpose and there are new agents currently under development or recently approved for this indication. We conducted a systematic review of randomized controlled trials (RCT) evaluating administration of anticoagulants for VTE prophylaxis in OS and performed a MA of proportions to estimate the overall incidence of major VTE (proximal VTE, pulmonary embolism (PE), or death from PE), total VTE (proximal and distal VTE, PE or death from PE), symptomatic VTE and major bleeding episodes (as defined by the International Society on Thrombosis and Hemostasis). We included RCT comparing currently approved anticoagulants (head-to-head or placebo-controlled) for VTE prophylaxis in OS (hip and knee arthroplasty and hip fracture surgery) using systematic evaluation of VTE (ultrasound or venography, pulmonary angiography, CT pulmonary angiography, or ventilation perfusion scan). Heterogeneity of proportions was evaluated using a chi² test and pooled estimates of proportions were obtained using either a fixed or a random effects model in which the weights were estimated as proposed by Laird and Mosteller. We retrieved 74 studies including180 research arms and enrolling 71,012 patients. The total number of events and evaluable patients, percentage of events and 95% CI, and number of study arms included are shown in the table. We found differences in the percentage of VTE and bleeding events associated with the use of different anticoagulants for VTE prophylaxis after OS. Due to the nature of the analysis no effect measure can be estimated. These estimates might help to design future studies.