Prevention of thromboembolism after a fracture: is aspirin enough?

Venous thromboembolism (VTE) is a serious complication that can arise during and after hospitalization, particularly following surgery under general anaesthesia. Particularly at risk are major orthopaedic surgical procedures such as elective knee or hip replacement and the treatment of hip fractures. In these patients, current guidelines recommend (low or low-moderate level of evidence) aspirin as a possible alternative to anticoagulant therapy for the prophylaxis of long-term venous thromboembolism after an initial period with anticoagulant drugs. Several randomized trials and meta-analyses demonstrate no significant differences in the risk of VTE when comparing aspirin with anticoagulants. However, it must be considered that most recommendations are based on elective orthopaedic surgery and that trials after fractures have excluded patients at high thrombotic risk. Consequently, the overall incidence of major clinical events (death and pulmonary embolism) was ∼1% with wide confidence margins in even large non-inferiority studies. The incidence of asymptomatic VTE, especially distal, appears to be higher with aspirin. Patient preference and lower costs could play an important role in the choice in favour of aspirin.