Comparative effectiveness of direct oral anticoagulants and warfarin in patients with cancer and atrial fibrillation.

• Type of Material: Article
• Authors: Surbhi Shah, University of Minnesota; Faye L. Norby, University of Minnesota; Yvonne H. Datta, University of Minnesota; Pamela L. Lutsey, University of Minnesota; Richard F. MacLehose, University of Minnesota; Lin Y. Chen, University of Minnesota; Alvaro Alonso, Emory University
• Language: English
• Date: 2018-02-13
• Publisher: American Society of Hematology
• Publication Version: Final Published Version
• Copyright Statement: © 2018 by The American Society of Hematology
• Final Published Version (URL): http://dx.doi.org/10.1182/bloodadvances.2017010694
• Title of Journal or Parent Work: Blood Advances
• ISSN: 2473-9529
• Volume: 2
• Issue: 3
• Start Page: 200
• End Page: 209
• Grant/Funding Information: The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.; This work was supported by National Institutes of Health, National Heart, Lung, and Blood Institute grants R01-HL122200 and R01-HL131579 and American Heart Association grant 16EIA26410001 (A.A.).
• Research Categories: Health Sciences, Public Health; Health Sciences, Epidemiology

Abstract

Randomized clinical trials comparing direct oral anticoagulants (DOACs) to warfarin in cancer patients have not been performed. We evaluated the effectiveness and associated risk of DOACs vs warfarin, as well as comparisons of DOACs, in a large population of cancer patients with nonvalvular atrial fibrillation (AF). Using the MarketScan databases, we identified 16 096 AF patients (mean age, 74 years) initiating oral anticoagulant and being actively treated for cancer between 2010 and 2014. Anticoagulant users were matched by age, sex, enrollment date, and drug initiation date. Study end points were identified with diagnostic codes and included ischemic stroke, severe bleeding, other bleeding, and venous thromboembolism (VTE). Cox regression was used to estimate associations of anticoagulants with study end points. Compared with warfarin, rates of bleeding (hazard ratio [95% confidence interval]) were similar in rivaroxaban (1.09 [0.79, 1.39]) and dabigatran (0.96 [0.72, 1.27]) users, whereas apixaban users experienced lower rates (0.37 [0.17, 0.79]). Rates of ischemic stroke did not differ among anticoagulant users. Compared with warfarin, rate of VTE (hazard ratio [95% confidence interval]) was lower among rivaroxaban (0.51 [0.41, 0.63]), dabigatran (0.28 [0.21, 0.38]), and apixaban (0.14 [0.07, 0.32]) users. In head-to-head comparisons among DOACs, dabigatran users had lower rates of VTE than rivaroxaban users; apixaban users had lower rates of VTE and severe bleeding than rivaroxaban users. In this population of patients with AF and cancer, DOAC users experienced lower or similar rates of bleeding and stroke compared with warfarin users, and a lower rate of incident VTE.