Continuing Anticoagulation During TAVR: New Data Offer a Glimpse of What Works

New European data are offering reassurance that patients already taking an anticoagulant can continue taking their meds when they undergo TAVR, without needing to stop and bridge or increasing their risk of stroke.

The numbers, drawn from 1,370 consecutive patients undergoing TAVR at three hospitals in Switzerland and Finland, are retrospective but offer insights into a scenario not likely to be studied in a randomized trial, senior investigator Stefan Toggweiler, MD (Heart Center Lucerne, Switzerland), told TCTMD.

“Our data look extremely promising, and we were very happy to see that this approach [of continuing anticoagulation] works,” Toggweiler said. “Clearly, it would result in a simplification of the protocol, it would be easier for patients, and it would be easier for the physician.”

The results were published online April 15, 2019, as a research letter in the Journal of the American College of Cardiology.

One-third of patients undergoing TAVR for severe aortic stenosis have an indication for long-term oral anticoagulation and, according to Toggweiler, standard practice in most valve centers is to stop the patient’s warfarin or direct oral anticoagulant 4 days before the procedure, bridge with low molecular weight heparin during the TAVR, then restart the anticoagulant postprocedure.

But with the burgeoning number of patients eligible for TAVR today—a figure expected to grow exponentially when indications are expanded to include low-risk patients—tens of thousands of patients taking an anticoagulant will need appropriate management of their thromboembolic risk during the procedure. A safe, simplified strategy would be welcome.

Continue or Stop

For their study, Toggweiler, with first author Miriam Brinkert, MD (Heart Center Lucerne), and colleagues, compared outcomes of 186 TAVR patients whose anticoagulation regimen was continued throughout their TAVR procedures with those of 185 patients whose anticoagulation was halted. A full 95% of patients were taking anticoagulation for atrial fibrillation, and the majority were taking a vitamin K antagonist. A direct oral anticoagulant was used in 30% of the patients in the continuation group and in 46% of the patients in whom anticoagulation was stopped.

At 30 days, the rate of periprocedural major or life-threatening bleeding was nearly identical in the continuation versus interruption groups: 10.2% versus 10.8%, respectively, a nonsignificant difference. Major vascular complications, likewise, were 8.6% in the continuation versus 10.3% in the interruption groups, again a nonsignificant difference. Of note, the stroke rate was numerically higher among patients whose anticoagulation was stopped six patients versus one (P = 0.06). That difference, he noted, might be the play of chance but is at least “interesting,” Toggweiler said.

“It does make sense because clearly when interrupting anticoagulation,” he explained, “there is always a question of when do you start the low molecular weight heparin, when do you stop, and when do you restart the anticoagulation? So, you always have some uncertainty.”

To TCTMD, Toggweiler acknowledged that the confidence intervals for all of the study comparisons were wide, speaking to the low patient numbers, but still, in his opinion, reassuring. Given that the effects on the coagulation cascade of stopping and starting different antithrombotics are not fully understood, “it does make some sense to continue the anticoagulation,” he said.

Corroborating Data

Of note, this latest analysis is very similar to a study released earlier this year, and reported by TCTMD, that found very similar outcomes as Toggweiler and colleagues. Citing this paper, by Manger et al, Toggweiler said that the German study had been happening “in parallel,” with neither study group aware of the other’s efforts. He has already been in touch with the other study authors in the hopes that pooling their data sets might allow for a clearer picture, particularly related to the potential impact of continuing anticoagulation on stroke and bleeding.

Toggweiler was careful to stress that these retrospective data, with low patient numbers, are not enough to justify a blanket change of practice, but rather should offer assurances to physicians who believe a patient would be better protected if their anticoagulation was continuous. If subsequent data back up this small study, a simplified protocol that allowed continuation of anticoagulation would likely be gladly received.

“I would not call this the definitive answer yet, but based on our results, this strategy looks very promising,” Toggweiler said.

Commenting on the study for TCTMD, George Dangas, MD (Icahn School of Medicine at Mount Sinai, New York, NY), agreed, also calling the results “reassuring.” Like Toggweiler, he does not see these data supporting a change to current protocols; instead, they offer some peace of mind for rare situations in which a physician would feel more comfortable continuing the patient’s anticoagulation regimen.

“If I have a patient who is on anticoagulation and needs urgent TAVR, without this study I would have the question: can I even do it, or do I need to wait?” Dangas said. “Overall, based on this study, I’m not going to proactively continue anticoagulation in my patients. But if for some reason, a patient arrives [in whom] I think anticoagulation should be continued, I can say that at least these data show that if I’m careful, then this might be feasible.” 

Dangas also pointed to a forthcoming trial that will also offer further insights. The 1,000-patient POPular-TAVI is looking at two cohorts of patients, those with and without an indication for oral anticoagulation prior to TAVR, randomizing them to aspirin plus clopidogrel after TAVR, or to aspirin only.

But a prespecified analysis of this trial will also look at outcomes among patients who stopped or continued their warfarin, Dangas noted. “That’s a nonrandomized comparison, but at least the sample size will give us some answers.”