Chicago, IL—Atrial fibrillation (AF) is associated with a 5-fold increased risk for ischemic stroke, and its prevalence is rapidly increasing, representing a substantial burden for patients and healthcare consumption. Recent trials of new oral anticoagulants have shown them to be an effective alternative to warfarin (Coumadin) for stroke prevention in patients with nonvalvular AF.
Steven Deitelzweig, MD, Associate Professor, Tulane School of Medicine, Vice President of Medical Affairs, Chairman of Department of Medicine, Ochsner Clinic Foundation, New Orleans, LA, presented the results of research on the impact of these emerging agents on medical costs for patients with AF, at the 2012 American College of Cardiology meeting.
Dr Deitelzweig and colleagues found that compared with warfarin, the use of dabigatran (Pradaxa), rivaroxaban (Xarelto), and the investigational apixaban (which is approved in Europe but not in the United States) was associated with a reduction in the medical costs related to the management of clinical events in patients with AF. This finding is based on the results related to clinical events reported with dabigatran in the Randomized Evaluation of Long-Term Anticoagulant Therapy (RE-LY) trial, rivaroxaban in the ROCKET-AF trial, and apixaban in the Apixaban for the Prevention of Stroke in Subjects with Atrial Fibrillation (ARISTOTLE) trial.
The total annual medical cost for clinical events with warfarin was $2084 per patient. This was reduced to $1599 with apixaban, $1905 with dabigatran, and $1995 with rivaroxaban. The investigators determined the 1-year incremental costs for each category of clinical event in patients with AF using published data and expert reports. Their analysis showed that a hemorrhagic stroke was the costliest event at $51,659 compared with $39,511 for an ischemic stroke, $37,446 for a myocardial infarction (MI), and $34,617 for major bleeding. All costs were inflation-adjusted to 2010 costs using the Consumer Price Index for Medical Care.
The clinical events included in this analysis were ischemic or uncertain type of stroke, hemorrhagic stroke, systemic embolism, MI, pulmonary embolism, deep-vein thrombosis, and major bleeding, excluding hemorrhagic stroke, clinically relevant nonmajor bleeding, and other minor bleeding events. The clinical event rate with each of the new oral anticoagulants was derived from weighting of the reported relative risk using the warfarin clinical event rate that was estimated as the averages weighted by the sample size of each of the trials.
The new anticoagulants reduced the total medical costs based on their estimated lower absolute risk for a clinical event. The total medical cost for ischemic and hemorrhagic strokes, the primary efficacy end points, was lowest with dabigatran (150 mg). For ischemic stroke, the costs were $373 with dabigatran compared with $461 with rivaroxaban, $451 with apixaban, and $490 with warfarin. For hemorrhagic stroke, the costs were $59, $133, $115, and $225, respectively.
For the secondary end point of MI, the costs were $292 with warfarin, $371 with dabigatran, $237 with rivaroxaban, and $257 with apixaban. The costs for major bleeding, a safety end point, were $998 with warfarin, $1030 with dabigatran, $1106 with rivaroxaban, and $715 with apixaban.
The study results were consistent even when other scenarios were evaluated, such as using the median rather than the mean, using incremental medical costs for patients with AF, or when the clinical events in each trial were considered separately rather than the weighted average. These scenarios and the sensitivity analyses were performed to reflect the variety of the real-world settings. The study main limitation is that the results cannot be applied in the real-world setting, because the economic analysis did not include factors such as drug costs, local healthcare costs, drug adherence, and variance in population risk, among others.