Continuing Anticoagulation During TAVR in A-fib Patients May Be Safe, Study Suggests

How to manage A-fib in patients requiring TAVR is a hot topic in anticoagulation research. Now new, retrospective data suggest it may be safe to continue oral anticoagulation with either a vitamin K antagonist (VKA) or direct oral anticoagulant (DOAC) during the procedure.

In the study, the rate of safety events within 30 days of transfemoral TAVR was lowest in patients who continued a DOAC (13.2%), with no difference between those who continued a VKA (19.7%) or interrupted VKA therapy (23.1%), lead authors Norman Mangner, MD (Heart Center Dresden, Germany), and Lisa Crusius, MD (Heart Center Leipzig-University Hospital, Germany), report.

Moreover, the study— published online January 7, 2019, ahead of print in the American Journal of Cardiology—showed that DOAC-treated patients had a lower risk of 1-year mortality compared with those who interrupted VKA therapy (8.8% vs 20.1%; HR 0.56; 95% CI 0.32-0.99). The rate in the group with continued VKA therapy was 13.7%, which was not significantly different from the figure in the interrupted VKA group.

“It is safe to perform transfemoral TAVI under continued oral anticoagulation in our center, and we [have done] so for more than 5 years now,” Mangner told TCTMD in an email. “Moreover, this regime has the potential to save hospital capacity since stopping and reinitiation, in particular with VKA, can be time-consuming. [Whether] this is transferrable to other operators and patient cohorts needs to be evaluated in each specific center and, hopefully, in an RCT.”

Mangner said that many physicians still fear continuing oral anticoagulation during cardiac interventions, despite the existence of data showing that it is safe in various settings, particularly catheter ablation for A-fib. Patients undergoing TAVR, however, are older and sicker and the procedure requires large-bore sheaths, he pointed out. “Therefore, it is uncertain if those positive results coming from the field of ablation therapy are also true for TAVI.”

To explore that question, the investigators looked at data on 598 patients with A-fib who were on oral anticoagulation at the time of TAVR for severe aortic stenosis or bioprosthetic aortic valve failure. The procedures, performed between 2011 and 2016, were all done transfemorally.

In 2011 and 2012, it was generally recommended at these centers that VKA therapy should be interrupted, with heparin bridging during the procedure. Starting in 2013, the decision was made to continue patients’ prescribed anticoagulation during TAVR. Overall, half of patients had interrupted VKA therapy, 30% had continued DOAC therapy, and 20% had continued VKA therapy. On top of anticoagulation, all patients received clopidogrel for 6 months after TAVR.

The primary outcome was Valve Academic Research Consortium (VARC)-2 early safety at 30 days, a composite of all-cause mortality, stroke, life-threatening bleeding, stage 2 or 3 acute kidney injury, coronary obstruction requiring intervention, major vascular complication, or valve-related dysfunction requiring a repeat procedure. Patients continuing on DOAC therapy carried the lowest risk, with no increased risk seen with continued versus interrupted VKA therapy.

Stroke and bleeding rates did not differ across the three groups, although there were numerically lower rates in the continued DOAC group. Renal failure was lowest in the DOAC group (7.7%), followed by continued VKA therapy (9.5%) and interrupted VKA therapy (15.8%; P = 0.02).

All-cause mortality was nonsignificantly lower in the DOAC group versus in the VKA groups at 30 days, with the difference compared with the interrupted group reaching significance at 1 year.

Findings ‘Thought-Provoking’ but Limited

Commenting for TCTMD, Santiago Garcia, MD (Minneapolis Heart Institute at Abbott Northwestern Hospital, Minneapolis, MN), said the handling of oral anticoagulation around TAVR is a question with which physicians struggle and said the findings of this study are “thought-provoking.”

He added, however, that limitations of the analysis hamper the ability to make strong conclusions. For one, the study lacked a true interrupted VKA group because those patients were still receiving anticoagulation during the procedure in the form of heparin bridging.

The second major limitation, Garcia said, is that the patients in the three groups were enrolled during different time periods; the interrupted VKA group was enrolled earliest and the continued DOAC group was enrolled latest. That’s reflected by the generally lower risk profile of the DOAC-treated patients, which could have influenced the findings, he said.

“There are so many biases in this study that I am afraid it’s hard to make any strong recommendations based on the data,” Garcia said.

He said important questions about how to manage oral anticoagulation in patients undergoing TAVR remain. In the United States, he said, most patients with A-fib have their anticoagulation stopped before the procedure, with no heparin bridging. Though it’s probably safe to do TAVR with warfarin on board, Garcia added, it’s interrupted for most patients in case complications that require surgical intervention arise.

A separate question is what antithrombotic regimen to use after TAVR. “I do think there is a role for anticoagulation,” Garcia said. “The data for dual antiplatelet therapy is quite weak.”

There was a lot of enthusiasm for trying to replace warfarin with a DOAC in patients who had undergone TAVR, but GALILEO “put, I think, a stop to that,” Garcia said. The GALILEO trial looked at rivaroxaban (Xarelto; Bayer/Janssen) in patients without A-fib undergoing TAVR and was halted in October due to the potential for harm.

So, until there are more data, “I think the default option for patients that need an anticoagulant agent after the procedure is warfarin,” he said, noting that if patients come in for TAVR on a DOAC, his practice has been to switch them to warfarin after the procedure.

More data are needed on choice of anticoagulant after TAVR and duration of therapy in patients without A-fib, Garcia said.

“Many physicians are reluctant to keep these patients on warfarin indefinitely—and I’m not sure that’s needed—but I think a brief period of anticoagulation after TAVR, whether it’s 6 weeks or 3 months, and then aspirin after that makes a lot of sense. [Still], it certainly needs to be studied,” he said.

As for the role of DOACs after TAVR, Mangner said, “We really have to wait for the results of GALILEO and ATLANTIS to make any recommendations.”