MANAGEMENT AND PREVENTION OF THROMBOEMBOLIC EVENTS IN PATIENTS WITH CANCER-RELATED HYPERCOAGULABLE STATES - A RISKY BUSINESS

Objective: To determine the optimal strategy for managing and preventing thromboembolic events in malignancy-associated hypercoagulable states. Design: A Markov-based decision and cost - effectiveness analysis was performed. The authors explicitly considered consequences of embolic and bleeding events, filter complications, and cancer-related excess mortality. Data were drawn from the current literature. The main outcome measure for each strategy was the quality-adjusted life expectancy and the total average variable costs. Subjects: Patients with advanced malignancies prone to develop thromboembolic events, patients with acute proximal deep venous thrombosis (DVT), and patients who have survived a first episode of pulmonary embolism (PE). Interventions: The authors considered three different interventions: 1) OBSERVATION, in which neither anticoagulant therapy nor filter placement is pursued, 2) ANTICOAGULATION, in which long-term anticoagulant therapy is started immediately, and 3) VENA CAVAL FILTER. Main results: Vena caval filter was the preferred strategy for every malignancy studied, yielding an 11% gain in quality-adjusted life expectancy, compared with observation, for patients with acute DVT, and an 18% gain for patients having survived a PE. Anticoagulant therapy yielded gains of 9% and 16%, respectively. Compared with anticoagulant therapy, filter was less costly due to the avoidance of additional expenses incurred by bleeding events. Prophylactic therapy was the least effective of the three strategies examined. Conclusions: Vena caval filter placement and long-term anticoagulation therapy yield similar outcomes in the setting of cancer-related hypercoagulable states. However, filter insertion is less expensive than anticoagulation. Given the short life expectancy and morbidity of patients with end-stage malignancy, patient preferences for health states must be considered in the decision-making process. If active treatment is pursued, vena caval filter should be used as a primary therapy. Prophylactic therapy is not warranted in any circumstance.