Incidence of symptomatic venous thromboembolism in 2372 knee and hip replacement patients after discharge: data from a thromboprophylaxis registry in Montreal, Canada

Andréa Senay,1,2 Milanne Trottier,3 Josée Delisle,2,4 Andreea Banica,2,4 Benoit Benoit,2,4 G Yves Laflamme,2,4 Michel Malo,2,4 Hai Nguyen,4 Pierre Ranger,2,4 Julio C Fernandes2–4 1Faculty of Pharmacy, Université de Montréal, Montréal, QC, Canada; 2Department of Orthopaedic Surgery, Hôpital du Sacré-Coeur de Montréal, Montréal, QC, Canada; 3Faculty of Medicine, Université de Montréal, Montréal, QC, Canada; 4Department of Orthopaedic Surgery, Hôpital Jean-Talon, Montréal, QC, Canada Background: Low-molecular-weight heparin (LMWH) is a recommended anticoagulant for thromboprophylaxis after major orthopedic surgery. Dabigatran etexilate is an oral anticoagulant recognized as noninferior to LMWH. We aimed to assess the incidence of symptomatic venous thromboembolic events (VTEs) after discharge in patients who underwent joint replacement, using a hospital registry. Patients and methods: Patients who underwent total knee and hip arthroplasty between September 2011 and March 2015 were selected. Subcutaneous enoxaparin (30 mg twice daily) was given during hospitalization. At discharge, patients received either enoxaparin 30 mg twice daily/40 mg once daily or dabigatran 220 mg/150 mg once daily. Patients were seen or called at 2, 6, and 12 weeks after surgery. Outcomes were the number of VTEs, including deep venous thrombosis, pulmonary embolism, and the number of major/minor bleeding events after discharge. Results: After discharge, 1468 patients were prescribed enoxaparin and 904 dabigatran (1396 total knee arthroplasty and 976 total hip arthroplasty patients). Mean age was 66±10 years, and 60% were female. The cumulative incidence of VTEs during the 12-week follow-up was 0.7%. One patient sustained a VTE during the switch window. Seven patients sustained a pulmonary embolism (0.3%). There was no statistical difference between the total knee arthroplasty and total hip arthroplasty groups. The incidence of major and minor bleeding events during follow-up was 0.3% and 30.3%, respectively. These events had a higher incidence in the dabigatran group compared to the enoxaparin group after discharge (p