Oral anticoagulation with apixaban after TAVR not superior to the standard of care: Study

France: In a new study conducted by Jean-Philippe Collet and the team, it was shown that Apixaban was not superior to the standard of care after transcatheter aortic valve implantation (TAVI), regardless of the rationale for oral anticoagulation. The findings of this study were published in European Heart Journal.

The roles of oral anticoagulation and antiplatelet treatment after transcatheter aortic valve implantation (TAVI) are still being disputed. ATLANTIS is a randomized, open-label, worldwide study that compares apixaban to the standard of treatment.

Following successful TAVI, 1500 patients were randomly assigned (1:1) to receive apixaban 5 mg twice a day (n = 749) or standard of care (n = 751). The necessity for persistent anticoagulant treatment was used to stratify the randomization. Patients on standard-of-care got a vitamin K antagonist (VKA) (Stratum 1) or antiplatelet treatment (Stratum 2) depending on whether anticoagulation was indicated or not. Over a one-year period of follow-up, the primary endpoint was a composite of death, stroke or transient ischaemic attack, deep vein thrombosis or pulmonary embolism, myocardial infarction, systemic embolism, intracardiac, or bioprosthesis thrombosis, and life-threatening, disabling, or major bleeding. Major, debilitating, or life-threatening bleeding was the key safety objective.

The key findings of this study were as follows:

1. The main outcome occurred in 138 (18.4%) and 151 (20.1%) patients taking apixaban, respectively, and there was no indication of interaction between treatment and stratum.

2. In both groups, the major safety objective was comparable.

3. An exploratory analysis in Stratum 1 (n = 451) revealed no difference between apixaban and VKA for all outcomes.

4. In Stratum 2 (n = 1049), the primary outcome and primary safety endpoint did not vary, although apixaban decreased obstructive valve thrombosis compared to antiplatelet treatment, there was a signal of greater non-cardiovascular mortality with apixaban.

In conclusion, oral anticoagulation with apixaban following TAVI was not better to standard-of-care antithrombotic medication in terms of net clinical benefit over a year, regardless of a concomitant need for oral anticoagulation. However, non-inferiority was proven. In the entire cohort and in each individual strata, bleeding event rates with apixaban were comparable to those with the current standard of treatment.

Reference:

Collet, J.-P., Van Belle, E., Thiele, H., Berti, S., Lhermusier, T., Manigold, T., Neumann, F.-J., Gilard, M., Attias, D., Beygui, F., Cequier, A., Alfonso, F., Aubry, P., … Lefèvre, T. (2022). Apixaban vs. standard of care after transcatheter aortic valve implantation: the ATLANTIS trial. In European Heart Journal. Oxford University Press (OUP). https://doi.org/10.1093/eurheartj/ehac242