Apixaban versus enoxaparin in the prevention of venous thromboembolism following total knee arthroplasty: a single-centre, single-surgeon, retrospective analysis.

BACKGROUND: There is a high risk of developing venous thromboembolism (VTE) following total knee arthroplasty (TKA). Conventional thromboprophylactic agents have limitations, such as route of administration, the need for monitoring, narrow therapeutic windows and interactions. Apixaban is a new oral anticoagulant with the potential to overcome these limitations. AIMS: To report the efficacy and safety of apixaban and low-molecular-weight heparin, enoxaparin, in VTE prophylaxis following TKA. METHODS: This single-centre, single-surgeon, retrospective analysis included 506 consecutive patients who underwent TKA between 2009 and 2015 and received enoxaparin or apixaban as thromboprophylaxis. Baseline characteristics of patients, in-hospital rates of VTE, total DVT, proximal or distal DVT, pulmonary embolism, bleeding outcomes and mortality were compared between the two groups. RESULTS: In-hospital VTE occurred in 22 (8.9%) patients in the enoxaparin group and 11 (4.5%) patients in the apixaban group (P = 0.049). Nine (3.6%) patients in the enoxaparin group and one (0.4%) in the apixaban group experienced a postoperative drop in haemoglobin ≥20 g/L that either necessitated transfusion of ≥2 units blood, caused haemodynamic instability or both (P = 0.020). Thirty-five patients experienced other bleeding events, with 25 (9.9%) in the enoxaparin group and 10 (4.0%) in the apixaban group (P = 0.009). There were no statistically significant differences in rates of total DVT, proximal or distal DVT, pulmonary embolism or mortality between the groups. CONCLUSIONS: Compared with enoxaparin, thromboprophylaxis with apixaban resulted in a lower VTE incidence and fewer haemorrhagic complications.

Thromboprophylaxis in patients undergoing total hip and knee arthroplasty: a review of current practices in an Australian teaching hospital.

BACKGROUND: Venous thromboembolism (VTE) remains a cause of significant morbidity and mortality following total hip arthroplasty (THA) and total knee arthroplasty (TKA). Prophylaxis significantly reduces the rate of VTE following these procedures. Previous studies report suboptimal uptake of guideline recommended thromboprophylaxis. AIMS: To describe VTE prophylaxis prescribing practices in a major hospital for joint replacement surgery. To determine the proportion of patients receiving guideline recommended thromboprophylaxis. To define the incidence of in-hospital VTE following THA and TKA. METHODS: A retrospective chart review of 402 consecutive patients undergoing THA or TKA from June to October 2013. Patient characteristics, operative and anaesthetic factors, details of thromboprophylaxis and the incidence of in-hospital VTE are reported. Comparison is made with recent guidelines. RESULTS: Four hundred and two patients underwent THA (n = 202) or TKA (n = 200). Ninety-nine per cent of patients received mechanical prophylaxis. One hundred percent of patients received chemoprophylaxis in hospital. Enoxaparin was most commonly prescribed followed by aspirin. Patients undergoing TKA were more likely to receive an anticoagulant (89.9% vs 47.8% for THA, P < 0.05). 74.5% received chemoprophylaxis on discharge (mean duration 22.1 days). The incidence of in-hospital VTE was 4.7%. CONCLUSIONS: The proportion of study patients receiving thromboprophylaxis compares favourably with prior research. The overall incidence of VTE is higher than that demonstrated in major orthopaedic trials. Inadequate duration of chemoprophylaxis remains a potential area of improvement. Extended prophylaxis should be prescribed as per current guidelines. Comparison between efficacy and safety of various agents is the subject of future research.