Higher Mortality Among TAVR Patients With Atrial Fibrillation Treated With Triple Therapy

WASHINGTON, DC—Patients with atrial fibrillation undergoing transcatheter aortic valve replacement who were treated with a potent cocktail of triple therapy—oral anticoagulation, plus aspirin, plus a P2Y12 inhibitor—experienced higher rates of death at 30 days and 1 year than those treated with less potent antithrombotic regimens, a new single-center series showed.

TAVR patients with atrial fibrillation treated with dual antiplatelet therapy alone—typically a combination of aspirin and clopidogrel—had the lowest rate of death and bleeding at 30 days, report investigators.

Speaking with TCTMD, lead investigator M. Chadi Alraies, MD (MedStar Washington Hospital, Center, DC) said it is unknown if the patients died from major bleeding or stroke, which makes interpretation of their data difficult. The bottom line, however, is that physicians should avoid prescribing triple therapy after TAVR in patients with atrial fibrillation.

“If you are really concerned about the patients—if they have a history of stroke or a high CHA2DS2-VASc score, an indication of their risk of stroke—then I would say the second safest thing to do is prescribe warfarin and aspirin,” said Alraies. As for patients with a history of bleeding or those with a previous transfusion, the warfarin/aspirin combination still “provides protection without placing the patients at harm,” he added.  

The analysis, presented Sunday at CRT 2017 in Washington, DC, suggests a need for prospective studies to define the ideal antithrombotic therapy following TAVR in patients with the arrhythmia, a scenario that is frequently encountered in clinical practice. 

Single-Center Retrospective Study

The single-center retrospective registry included 305 consecutive patients with atrial fibrillation and severe symptomatic aortic stenosis who underwent TAVR between 2007 and 2016. At discharge, 33% of patients were treated with dual antiplatelet therapy, 54% with oral anticoagulation and a single antiplatelet agent, and 13% with triple therapy (oral anticoagulation with warfarin and DAPT).

Overall, the admission and discharge hemoglobin levels were similar in all three groups and there was no difference in major and life-threatening bleeding. At 1 year, the rate of ischemic stroke was not significantly different between those treated with DAPT, oral anticoagulation and a single antiplatelet agent, or triple therapy.

“Although the number of strokes was small, the rate of ischemic stroke was not different between three groups, which tells us that dual antiplatelet therapy would be enough for this cohort rather than putting them on triple therapy,” said Alraies.

Mortality rates were very low at 30 days, with no deaths observed among patients treated with dual antiplatelet therapy. Next, patients treated with oral anticoagulation and a single antiplatelet agent had the second-lowest mortality rate while those treated with triple therapy had the highest rate of death (approximately 0.1%). At 1 year, the results were similar, with patients treated with triple therapy having the highest risk of death.

To TCTMD, Alraies said there is limited data on the ideal antithrombotic strategy and outcomes in the US, and as a result, oral anticoagulation prescribing patterns for atrial fibrillation patients vary following TAVR.

George Michael Deeb, MD (University of Michigan, Ann Arbor), who chaired the session, told TCTMD that replacing oral anticoagulation with dual antiplatelet therapy in these high-risk patients puts them at risk for stroke. As a surgeon, Deeb said oral anticoagulation is mandated after surgical valve replacement for stroke prevention, with some physicians recently adding low-dose aspirin. “The real question is whether you can get the same effect with these tissue valves, and protect the patient from developing stroke,” he said. 

Like Alraies, Deeb said the appropriate antithrombotic regimen is unknown for atrial fibrillation patients undergoing TAVR. “I don’t think anybody has the answer right now but I don’t think putting them on triple therapy is the right thing.”     

Howard Herrmann, MD (University of Pennsylvania Perelman School of Medicine, Philadelphia) also highlighted the lack of clinical evidence to address antithrombotic therapy in atrial fibrillation patients treated with TAVR. In most instances, he will continue with warfarin after the valve replacement and add low-dose aspirin. Occasionally, a patient might require triple therapy, such as those who recently received a drug-eluting stent and have undergoing valve replacement.

“In those instances, you would not want to stop their dual antiplatelet therapy,” said Herrmann. “In that case, you have to either choose a warfarin/clopidogrel regimen or choose short-term triple therapy and then [eventually] drop one of the antiplatelet agents.” The other option would be to have the patient go without oral anticoagulation for a month or so, which can be done. “It really depends on the risk profile of the patient for bleeding and their need for dual antiplatelet therapy,” he said.