Is Post-TAVR Triple Therapy Safe in Patients with Atrial Fibrillation?

As transcatheter aortic valve replacement (TAVR) moves toward center stage for management of high-risk aortic stenosis patients, more physicians are seeing an increasing number of patients on “triple therapy” (dual antiplatelet therapy plus warfarin or a novel oral anticoagulant [NOAC]). The current practice recommends dual antiplatelet therapy following TAVR (aspirin indefinitely and clopidogrel for 1 to 6 months afterwards) and is somewhat empirically determined, without significant supporting data. Increased use of antiplatelet and antithrombotic regimens does lead to an increased risk of bleeding and access site complications and therefore, these practices need to be re-visited. Much exploration has been done on triple therapy in the setting of TAVR for aortic stenosis, however, the use of antiplatelet agents plus warfarin in TAVR patients with concomitant atrial fibrillation (AF) remains poorly studied. It is estimated that up to 30% of TAVR patients have an indication for vitamin K antagonists (VKA), with the majority of these for treatment of AF.

A study presented at the European Society of Cardiology Scientific Sessions in Rome, Italy and simultaneously published in JACC: Interventions investigated whether post-TAVR antiplatelet therapy reduced the risk of stroke in patients with AF who were already on VKA.  In this non-randomized, observational study, 621 patients with AF who underwent TAVR were followed for a median of 13 months with two groups: monotherapy with VKA (n=101) vs multiple antithrombotic therapy (ie, VKA plus 1 or 2 antiplatelet agents, n=520). Indeed, there was no difference in thrombotic complications, including stroke (5% vs 5.2%), MACE (13.9% vs. 16.3%, adjusted HR 1.33, 95% CI 0.75-2.36) or death (22.8% vs. 19.2%). There was, not surprisingly, a higher risk of major or life-threatening bleeding (14.9% vs. 29.9%, p=0.04); these results were consistent whether patients received only one or two antiplatelet agents.

Important points to consider when interpreting the result of this study:

 â–º The sample size for the VKA monotherapy arm and overall study is small and therefore, confidence intervals are wide.

 â–º NOACs were not studied (so this only applicable to patients on VKAs).

 â–º This study is non-randomized and observational so it is subject to confounding; further randomized trials are needed.

Regardless of its limitations, this study does suggest that triple antithrombotic therapy may not be necessary in patients with AF who are on VKA and undergoing TAVR to reduce thrombotic complications and increases the risk of bleeding complications.

Source: Abdul-Jawad Altisent O, Durand E, Muñoz-García AJ, et al. Warfarin and antiplatelet therapy versus warfarin alone for treating patients with atrial fibrillation undergoing transcatheter aortic valve replacement.J Am Coll Cardiol Intv. 2016;9:1706-1717. doi:10.1016/j.jcin.2016.06.025.