Premium
Dabigatran versus warfarin in patients with mechanical heart valves: reply
Author(s) -
Eikelboom J. W.,
Brueckmann M.,
Werf F.
Publication year - 2014
Publication title -
journal of thrombosis and haemostasis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.947
H-Index - 178
eISSN - 1538-7836
pISSN - 1538-7933
DOI - 10.1111/jth.12500
Subject(s) - warfarin , aspirin , medicine , vitamin k antagonist , randomized controlled trial , concomitant , dabigatran , intensive care medicine , cardiology , atrial fibrillation
Christensen and Larsen suggest that patients randomized to receive warfarin in the recently published RE-ALIGN randomized trial [1] were suboptimally managed, citing lack of use of aspirin and poor control of anticoagulation. The RE-ALIGN trial was conducted in a real-world setting and left responsibility for the use of aspirin and the control of warfarin anticoagulation to the local investigators. Most of the evidence for using aspirin in combination with a vitamin K antagonist for patients with mechanical heart valves comes from small studies of low quality. In these studies, the addition of aspirin to warfarin appeared to reduce thromboembolic events, but the benefit was largely confined to patients with known atherosclerosis and came at the cost of increased bleeding. The 2012 American College of Chest Physicians Guidelines suggest adding an antiplatelet drug to warfarin in patients with a mechanical who are at low risk of bleeding [2]. The 2012 European Society of Cardiology Guidelines recommend that aspirin be added to vitamin K antagonist therapy only in specific situations according to assessment of the expected benefits and increased risk of major bleeding and, specifically, should be considered in patients with concomitant atherosclerotic vascular disease or in those who had a thrombotic event despite a therapeutic international normalized ratio [3]. The use of aspirin in 30% of patients enrolled in the RE-ALIGN trial is consistent with the guidelines, was well balanced between treatment groups, and cannot account for the trial results. Christensen and Larsen highlight the importance of good anticoagulation control to optimize outcomes. International normalized ratio control during the first 3 months after cardiac surgery is challenging because of postoperative fluid shifts, the high frequency of concomitant amiodarone use, and changing dietary intake of vitamin K. Self-testing, self-management, and management at specialized clinics are not option for many patients worldwide, and the 50% mean time in therapeutic range achieved during the first 3 months after surgery in the RE-ALIGN trial is consistent with published data and reflects real-word experience [4]. The mean time in therapeutic range during the extension phase was 58% in patients randomized after surgery and 70% in those randomized at least 3 months after surgery, and the rates of both thrombotic and bleeding events in warfarin-treated patients were low.