Abstract WP71: Endovascular Thrombectomy With Or Without Bridging Thrombolysis In Patients With Acute Ischemic Stroke: A Cost-utility Analysis

Introduction: There is clinical equipoise behind bridging intravenous thrombolysis (BT) with endovascular thrombectomy (EVT). We performed a cost-effectiveness analysis comparing BT versus EVT alone. Methods: We conducted a model-based cost-utility analysis comparing the cost-effectiveness of BT vs EVT only for patients with acute ischemic stroke. We used a decision tree to examine the short-term costs and outcomes at 90 days after the index stroke, and developed a Markov state transition model to assess the costs and outcomes over 1-year, 5-year, and 20-year time horizons. Clinical outcome inputs were derived from our systematic review. We considered the impact of disability and recurrent stroke on mortality risk, health-related quality of life, and costs. We estimated total and incremental cost, quality-adjusted life years (QALYs), and incremental cost-effectiveness ratio (ICER). Probabilistic analysis was used to calculate the reference case estimates. Results: The average costs per patient were estimated to be $55,503, $57,814, $68,183, and $84,946 for EVT only strategy, and $47,311, $49,556, $59,625, and $75,898 for BT over 90-day, 1-year, 5-year, and 20-year, respectively. The cost saving of EVT only strategy was driven by the avoided medication costs of IVT (ranging from $8,193 to $9,048). The additional thrombolytics led to slight decrease in QALY estimate during the 90-day time horizon (loss of 0.0016 QALY), but a small gain over 1-year, 5-year, and 20-year time horizons (0.0108, 0.0638, and 0.1481 QALY). With similar outcomes and less cost, the EVT only strategy was cost-effective compared with BT. Analyses with longer time horizon show lower probabilities of EVT only strategy being cost-effective. At a fixed willingness to pay threshold of $50,000, the probabilities of EVT only to be cost-effective were 100%, 100%, 99.0%, and 65.9% over 90-day, 1-year, 5-year, and 20-year time horizons. At the willingness to pay thresholds of $100,000 per QALY, the probabilities of EVT only strategy being cost-effective was 22.8% over the 20-year time horizon. Conclusions: Our cost-effectiveness model suggested that bridging with thrombolytics may not be cost-effective for patients with acute ischemic stroke secondary to large vessel occlusion.