Antithrombotic therapy after TAVR: Comparing warfarin to DAPT, SAPT
Warfarin use after transcatheter aortic valve replacement (TAVR) is not associated with significantly different medium-term patient outcomes than dual antiplatelet therapy (DAPT) or single antiplatelet therapy (SAPT), according to new research published in the American Journal of Cardiology.[1] The retrospective study focused on patients with no other need for anticoagulation.
“The choice regarding antithrombotic regimen after TAVR in patients with no long-term need for anticoagulation has been controversial, and the most recent United States and European guidelines differ,” wrote first author Jwan A. Naser, MBBS, a resident with the department of internal medicine at Mayo Clinic in Rochester, Minnesota, and colleagues. “The U.S. guidelines recommend aspirin as a class I indication, with 3 to 6 months of DAPT, or 3-month warfarin therapy to be considered in patients at a low risk of bleeding (class IIb indications). Conversely, the European guidelines recommend SAPT and consider oral anticoagulants to be harmful in this patient population (class III indication).”
Hoping to gain a better understanding of how different treatment options can impact patient care, Nasser et al. examined data from more than 1,500 patients who underwent TAVR at a single U.S. institution from 2012 to 2019. Patients with atrial fibrillation were excluded, leaving a final cohort of 844 patients with a mean age of 80. Forty-three percent of patients were women, and the median time to follow-up was 2.5 years.
While 75% of patients received three months of warfarin therapy after TAVR, 19.4% received DAPT with clopidogrel and aspirin before transitioning to SAPT, and 5.6% received SAPT only. Patients who had undergone percutaneous coronary intervention (PCI) within one year of TAVR stayed on DAPT for six to 12 months after PCI, or three to six months after TAVR, whichever was longer. No patients were treated with direct oral anticoagulants (DOACs). To ensure complications related to the actual TAVR procedure were not counted, the researchers did not begin counting incidents until the patient had been discharged from the hospital.
Overall in the group noted, there was no difference in patient outcomes between the different antithrombotic regimens when it came to ischemic strokes, mortality, additional valve interventions or structural valve degeneration. Annualized changes in aortic valve area were “marginally lower” among warfarin patients compared to those treated with DAPT or SAPT, but annualized changes in mean gradients remained the same.
“To the best of our knowledge, this is the first study to evaluate the medium-term outcomes in relation to warfarin after TAVR in patients with no other need for anticoagulation,” the authors wrote. “Our major finding is that an antithrombotic regimen involving 3 months of warfarin after TAVR was associated with a smaller decrease in prosthetic valve area.”
The team did note that their research had certain limitations. This was a retrospective study, for example, and “there are likely hidden confounders that only a randomized clinical trial can address.” Also, because no patients in this study received DOAC therapy, the authors were unable to make any direct comparisons focused on the safety or effectiveness of DOACs.
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Michael has more than 18 years of experience as a professional writer and editor. He has written at length about cardiology, radiology, artificial intelligence and other key healthcare topics.