DOACs safer than warfarin analogues for TAVR patients, JACC study.

The choice of optimal drug for anticoagulation after transcatheter aortic valve replacement (TAVR) remains debated. Recommendations on antithrombotic treatment after TAVR are based on a limited amount of high-quality data, and in patients who have indications for oral anticoagulant (OAC), vitamin K antagonists (VKAs) have been preferentially recommended.

Didlier et al have shown in a recent study published in JACC Cardiovascular Interventions that the long-term mortality and major bleeding were lower with DOACs than VKAs at discharge. The present study supports preferential use of Direct oral anticoagulants (DOACs) rather than VKAs in patients requiring oral anticoagulation therapy after TAVR.

Despite technical improvements in devices and operator experience in recent years, thromboembolic and bleeding events after TAVR remain prevalent, negatively affecting morbidity and mortality. Concomitant diseases in this elderly and frail population also explain the high prevalence of ischemic events. Moreover, atrial fibrillation (AF), a common arrhythmia found in nearly 30% of this population, is a well-known complication of the procedure, impacting long-term mortality.

In this setting, the choice between vitamin K antagonists (VKAs) and direct oral anticoagulants (DOACs) is still a matter of debate. Didlier et al investigated the long-term risk of mortality in patients receiving OAC according to the OAC type DOAC vs VKA in a large nationwide French cohort of patients treated by TAVR.

Propensity score matching was used to reduce treatment-selection bias. Two primary endpoints were death from any cause (efficacy) and major bleeding (safety).

This study is the first long-term report, in a large real life TAVR population, showing significant improvement in survival associated with reduced major bleeding rates with DOACs as compared with VKAs.

VKA use was associated with significantly higher mortality than DOAC use. This difference persisted in propensity-matched populations, which suggests that it was not caused by differences in risk profile.

After propensity matching, at 3 years, mortality and major bleeding including hemorrhagic stroke were 37% and 64% higher with VKAs in comparison to DOACs. The rates of ischemic stroke and acute coronary syndrome did not differ among groups.

In an accompanying editorial Giacoppo notes "The total advantage associated with DOACs observed in the study by Didier et al supports the favorable profile of DOACs after TAVR in terms of both efficacy and safety."

However the editorial adds a word of caution in implementing these results," results beyond 2-year follow-up are based on less than one-third of the original sample size." "superiority of DOACs over VKAs after TAVR was not observed in the recent ATLANTIS (Anti-Thrombotic Strategy After Trans-Aortic Valve Implantation for Aortic Stenosis) trial. In the cohort of patients requiring OAC included in that trial, there was no significant difference between treatments with respect to the primary net composite endpoint. Similarly, no significant differences between treatments across secondary composite and individual endpoints were detected".

The editorial concludes by stating that although heterogeneity in accumulated evidence should continue to promote high-quality research, answers related to OAC alone or associated with single-antiplatelet therapy or DAPT after TAVR are growing. According to available data, OAC alone seems to be the safest therapeutic approach in patients undergoing TAVR, especially in relation to the frequently relevant inherent bleeding risk, while the role of OAC after TAVR in absence of clinical conditions requiring thromboembolic prevention or treatment is limited.

Source: 1. JACC Cardiovascular Interventions: 2021-08-09, Volume 14, Issue 15, Pages 1704-1713

2. J Am Coll Cardiol Intv. 2021 Aug, 14 (15) 1714–1716