Antithrombotic therapy after mitral valve repair: VKA or aspirin?

Sake J Van Der Wall,Alexander B A Vonk,Anton Tomsic,Samuel Heuts,Evert K Jansen,Jules R Olsthoorn,Peyman Sardari Nia,Menno V Huisman,Frederikus A Klok,Robert J M Klautz

doi:10.1007/s11239-018-1724-0

Abstract

The optimal antithrombotic therapy following mitral valve repair (MVr) is still a matter of debate. Therefore, we evaluated the rate of thromboembolic and bleeding complications of two antithrombotic prevention strategies: vitamin K antagonists (VKA) versus aspirin. Consecutive patients who underwent MVr between 2004 and 2016 at three Dutch hospitals were evaluated for thromboembolic and bleeding complications during three postoperative months. The primary endpoint was the combined incidence of thromboembolic and bleeding complications to determine the net clinical benefit of VKA strategy as compared with aspirin. Secondary objectives were to evaluate both thromboembolic and bleeding rates separately and to identify predictors for both complications. A total of 469 patients were analyzed, of whom 325 patients (69%) in the VKA group and 144 patients (31%) in the aspirin group. Three months postoperatively, the cumulative incidence of the combined end point of the study was 9.2% (95%CI 6.1–12) in the VKA group and 11% (95%CI 6.0–17) in the aspirin group [adjusted hazard ratio (HR) 1.6, 95%CI 0.83–3.1]. Moreover, no significant differences were observed in thromboembolic rates (adjusted HR 0.82, 95%CI 0.16–4.2) as well as in major bleeding rates (adjusted HR 1.89, 95%CI 0.90–3.9). VKA and aspirin therapy showed a similar event rate of 10% during 3 months after MVr in patients without prior history of AF. In both treatment groups thromboembolic event rate was low and major bleeding rates were comparable. Future prospective, randomized trials are warranted to corroborate our findings.

Highlights

Mitral valve repair (MVr) is recognized as the gold standard for degenerative mitral regurgitation
Based on recent literature and anecdotal reports, we hypothesized that vitamin K antagonist (VKA) treatment is associated with an increased risk of major bleeding events and no reduction in thromboembolic events [18]
Data were collected from the databases of the departments of cardiothoracic surgery of the Leiden University Medical Centre (LUMC), VU University medical centre (VUmc) and Maastricht University Medical Centre (MUMC)

Summary

Introduction

Mitral valve repair (MVr) is recognized as the gold standard for degenerative mitral regurgitation. Compared to mitral valve replacement, repair results in improved survival, better preservation of postoperative left ventricular function and avoidance of the need for long-term anticoagulation treatment [1, 2]. The risk of thromboembolic events following MVr varies from 0.4 to 1.6% per year, and reaches 2.5% during the first postoperative month, even with routine anticoagulation therapy [3, 4]. The risk of thromboembolism secondary to a high incidence of new onset atrial fibrillation (AF) postoperatively and the thrombogenic tendency of the nonendothelialized repair components could motivate surgeons and cardiologists to prescribe VKA therapy for the first months after MVr [14]. Based on recent literature and anecdotal reports, we hypothesized that VKA treatment is associated with an increased risk of major bleeding events and no reduction in thromboembolic events [18]

Methods

Results

Conclusion