Apixaban no better than standard care after TAVR

Following a successful TAVR* procedure, taking apixaban was not superior to standard antithrombotic therapy for the composite primary outcome, regardless of whether patients originally have an indication for oral anticoagulant (OAC), according to the ATLANTIS** trial.

“Post-procedural thrombotic and bleeding events are frequent and negatively affect short-term survival,” said lead investigator Professor Jean-Philippe Collet from Pitié-Salpêtrière Hospital in Paris, France, when explaining the prognosis of TAVR patients during the recent ACC.21 Scientific Session. 

“SAPT*** alone if no need for OAC and [in the] absence of recent stent implantation is the safest option,” he continued. “In patients requiring OAC … VKA^# alone is safer than when combined with antiplatelet therapy.”

“[Thusfar,] there is no evidence that NOAC could replace antiplatelet therapy or VKA after TAVR,” Collet added.

The large multicentre ATLANTIS trial randomized 1,510 patients to receive apixaban 5 mg BID or standard of care (SOC) after a successful TAVR procedure. SOC comprised a VKA for the subgroup of patients who had an indication for OAC and DAPT/SAPT for the subgroup without an indication for OAC.  

At 1 year, there was no significant difference between the apixaban and the SOC arms with regard to the composite primary endpoint of all-cause death, stroke, myocardial infarction (MI), valve thrombosis, deep vein thrombosis, pulmonary or systemic embolism, or major bleeding (18.4 percent vs 20.1 percent; hazard ratio [HR], 0.92, 95 percent confidence interval [CI], 0.73–1.16) — thus not meeting the prespecified superiority criteria for the analysis.  

When the analysis was stratified by whether the patients had an indication for OAC, there was also no interaction based on the need for OAC. 

The rate of subclinical valve thrombosis was lower with apixaban than SOC, in particular among patients without an indication for OAC, although the difference was not statistically different between groups.

However, secondary outcomes including death, stroke, MI, or systemic embolism were numerically higher in the apixaban group compared with the SOC group.

“This difference, although not significant, was unexpected and driven only by the cohort of patients who did not have an indication for OAC and only by the rate of noncardiovascular death,” observed Collet, who pointed out that was a finding deserving further exploration.

Most of the noncardiovascular deaths were associated with sepsis or acute renal failure, and not bleeding events, according to Collet.

“The safety [particularly in terms of bleeding] of apixaban is similar to that of current SOC, globally and in each stratum [with or without OAC indication],” he reported.

The signal on noncardiovascular death in the subset of patients without OAC indication is consistent with results from the GALILEO trial, he noted.

“Our results do not suggest we can routinely use apixaban as the default antithrombotic treatment after successful TAVR,” said Collet.

“Although the safety of apixaban is the same as standard care and it better prevents valve thrombosis, we observed an unexplained signal on noncardiovascular mortality among patients who do not need OAC,” he stated. “In patients with an indication for OAC, apixaban compares favourably with VKA on all endpoints and remains easier to use,” he added.

*TAVR: Transcatheter aortic valve replacement

**ATLANTIS: Anti-Thrombotic Strategy to Lower All cardiovascular and Neurologic Ischemic and Hemorrhagic Events after Trans-aortic valve Implantation for aortic Stenosis  

***SAPT: single antiplatelet therapy

^#VKA: vitamin k antagonist