1. Low-Dose vs Standard Warfarin After Mechanical Mitral Valve Replacement: A Randomized Trial
- Author
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Michael W.A. Chu, Marc Ruel, Allen Graeve, Marc W. Gerdisch, Ralph J. Damiano, Robert L. Smith, William Brent Keeling, Michael A. Wait, Robert C. Hagberg, Reed D. Quinn, Gulshan K. Sethi, Rosario Floridia, Christopher J. Barreiro, Andrew L. Pruitt, Kevin D. Accola, Francois Dagenais, Alan H. Markowitz, Jian Ye, Michael E. Sekela, Ryan Y. Tsuda, David A. Duncan, Daniel G. Swistel, Lacy E. Harville, Joseph J. DeRose, Eric J. Lehr, John H. Alexander, John D. Puskas, Chun 'Dan' Choi, Gosta Pettersson, Marc Gerdisch, O. Howard Frazier, Jeffrey Askew, Ralph Damiano, Andrew Pruitt, David Duncan, Romualdo Segurola, M. Fawaz Shoukfeh, Igor Gregoric, Steven Meyer, Michael Chu, Danny Chu, Robert Hagberg, Ryan Tsuda, Eric Kirker, Daniel Swistel, Lance Landvater, Christopher Barreiro, Brian Castlemain, Peter Tutuska, Reed Quinn, Thomas Beaver, Kevin Accola, Gulshan Sethi, Alan Graeve, David Liu, Michael Wait, Bryan Whitson, Lacy Harville, Joseph DeRose, Eric Lehr, Alan Markowitz, Michael Sekela, Robert Smith, Christian Shults, Prem Shekar, and Vinay Badhwar
- Subjects
Pulmonary and Respiratory Medicine ,Surgery ,Cardiology and Cardiovascular Medicine - Abstract
Current guidelines recommend a target international normalized ratio (INR) range of 2.5 to 3.5 in patients with a mechanical mitral prosthesis. The Prospective Randomized On-X Anticoagulation Clinical Trial (PROACT) Mitral randomized controlled noninferiority trial assessed safety and efficacy of warfarin at doses lower than currently recommended, in patients with an On-X mechanical mitral valve.After On-X mechanical mitral valve replacement followed by at least 3 months of standard anticoagulation, 401 patients at 44 North American centers were randomized to low-dose warfarin (target INR 2.0 to 2.5) or standard-dose warfarin (target INR 2.5 to 3.5). All patients were prescribed aspirin 81 mg daily and encouraged to use home INR testing. The primary endpoint was the sum of the linearized rates of thromboembolism, valve thrombosis, and bleeding events. The design was based on an expected 7.3% event rate and 1.5% noninferiority margin.Mean patient follow-up was 4.1 years. Mean INR was 2.47 and 2.92 (P.001) in the low-dose and standard-dose warfarin groups, respectively. Primary endpoint rates were 11.9%/patient-year in the low-dose group and 12.0%/patient-year in the standard-dose group (difference -0.07, 95% confidence intervals: -3.40, 3.26). The confidence interval exceeded 1.5%, thus noninferiority was not achieved. Rates (%/patient-year) of the individual components of the primary endpoint were 2.3% vs 2.5% for thromboembolism, 0.5% vs 0.5% for valve thrombosis, and 9.13% vs 9.04% for bleeding.Compared to standard-dose warfarin, low-dose warfarin did not achieve noninferiority for the composite primary endpoint. (PROACT Clinicaltrials.gov number, NCT00291525).
- Published
- 2023
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