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Anticoagulation Goes Head-to-Head With DAPT After Valve Surgery

— Edoxaban not significantly better for thrombosis protection in "underpowered" ADAPT-TAVR trial

MedpageToday

WASHINGTON -- In an open-label, randomized study, treatment with the direct oral anticoagulant edoxaban was not significantly more efficient in preventing complications of leaflet thrombosis following transcatheter aortic-valve replacement (TAVR) when compared with dual antiplatelet therapy (DAPT), a researcher reported here.

In a study that used four-dimensional CT to identify lesions on the valves, there was a 9.8% incidence of leaflet thrombosis at 6 months among patients treated with edoxaban compared with 18.4% among those treated with aspirin and clopidogrel (Plavix), a difference that failed to achieve statistical significance in the intention-to-treat population (P=0.076), reported Duk-Woo Park, MD, of Asan Medical Center and the University of Ulsan in Korea.

In his oral presentation at the American College of Cardiology (ACC) meeting, Park said that in a per-protocol analysis of the primary endpoint, leaflet thrombosis occurred among 9.1% of the patients on edoxaban and 19.1% of those on DAPT (P=0.047).

Incidence of new cerebral lesions on brain MRI was numerically greater among patients in the edoxaban group compared with those on DAPT (25.0% vs 20.6%, P=0.40). The results of the study were published simultaneously in .

The effects on new cerebral thromboembolism and neurological or neurocognitive function were also not different between the two groups, Park said, adding that because the study was underpowered, the results should be considered hypothesis generating only -- "highlighting the need for further research."

"Interestingly, the incidence of clinically significant neurological complications was very small," Fry said, referring to the findings of worsening scores on the modified Rankin Scale seen in 2% of the patients on edoxaban and in 0.9% of those on DAPT.

The multicenter open-label randomized ADAPT-TAVR trial enrolled patients who had undergone successful TAVR and did not have an indication for anticoagulation. The research team from five centers in Korea, Hong Kong, and Taiwan recruited 229 individuals for the study; 111 were randomized to receive edoxaban and 118 were assigned to receive DAPT. The average age of the participants was about 80, about 55% were women, and about one-fourth were diagnosed with New York Heart Association Class III or IV heart failure. In addition, 31% were diagnosed with diabetes, 29% had been diagnosed with documented coronary artery disease, and about 25% had chronic lung disease.

Overall, there were few differences between the two groups in the final intention-to-treat population, Park noted.

"The incidence of any or major bleeding events were not different between two groups," he said at an ACC press conference. "We found no significant association of the presence or extent of leaflet thrombosis with new cerebral lesions and a change of neurological or neurocognitive function."

ACC president Edward Fry, MD, of Ascension Indiana St. Vincent Heart Center in Indianapolis, told ֱ that because the study was small, it is not likely to affect clinical practice in any major way. Still, "if you were thinking about treating with an antiplatelet therapy, ADAPT-TAVR would indicate you are not giving anything up, one way or the other. These results would be reassuring when making those decisions."

He said that while on a large scale, either edoxaban or DAPT would be acceptable, physicians still have to decide on treatment on the basis of the individual patient in front of them.

Fry noted that the study does not answer definitively what treatment should be offered if there are imaging findings of clots on replacement valve leaflets. For example, he asked, do you go full anticoagulation mode or should these lesions be considered part of the healing process?

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    Ed Susman is a freelance medical writer based in Fort Pierce, Florida, USA.

Disclosures

The study was funded by the CardioVascular Research Foundation (Korea) and Daiichi Sankyo Korea.

Park disclosed relationships with Daiichi-Sankyo, Chong Kun Dang, Daewoong Pharmaceuticals, Edwards, Abbott Vascular, and Medtronic.

Fry disclosed no relevant relationships with industry.

Primary Source

Circulation

Park D-W, et al "Edoxaban versus dual antiplatelet therapy for valve thrombosis and cerebral thromboembolism after transcatheter aortic-valve replacement: a randomized ADAPT-TAVR trial" Circulation; DOI: 10.1161/CIRCULATIONAHA.122.059512.