Head-to-head: post-TAVR edoxaban not better than DAPT

Results from the underpowered ADAPT-TAVR study showed that patients who had received a successful transcatheter aortic valve replacement (TAVR) did not have a significantly reduced incidence of leaflet thrombosis with edoxaban than with dual antiplatelet therapy (DAPT), despite a numerical trend. Effects on cerebral thromboembolism, neurological function, and bleeding were also similar between the arms.

The findings of ADAPT-TAVR (NCT03284827) were presented by Prof. Duk-Woo Park (Asan Medical Center, Korea) and simultaneously published in Circulation [1,2]. ADAPT-TAVR randomised patients who had just received a TAVR (n=229; average age 80 years; 58% women) to either receive 6 months of edoxaban or 6 months of DAPT in this head-to-head study. The primary endpoint was the incidence of subclinical leaflet thrombosis (SLT) in the 6 months after the valve replacement. Secondary endpoints were causative associations of SLT with cerebral thromboembolism in this period, as well as bleeding, and neurological or cognitive decline.

Although the results showed a trend towards a lower incidence of SLT in the edoxaban arm when compared with the DAPT arm, the numbers did not reach the predetermined significance (9.8% vs 18.4%; P=0.076; see Figure). Likewise, the secondary endpoints were also not met; upon brain MRI, the percentage of patients with new cerebral lesions on brain MRI did not significantly differ between the 2 groups (25.0% vs 20.2%, respectively). Furthermore, no differences between neurological or cognitive function were measured between the 2 arms. There were also no differences in bleeding outcomes; in a panel discussion following his presentation, Prof. Park pointed out that prior studies have shown that despite mitigated subclinical leaflet thrombosis after TAVI has been seen in patients treated with DOACs, subsequent protection from cerebral or ischaemic events has not been consistently observed and has been associated with more major bleeding [1].

Figure: ADAPT-TAVR results showed a trend toward a lower incidence of SLT in the edoxaban arm when compared with the DAPT arm in ITT population [1]



DAPT, dual antiplatelet therapy; ITT, intention-to-treat; PP, per-protocol.

 

Prof. Park placed the findings into context: “The key messages from this study are that SLT has not been proven to affect clinical outcomes for patients undergoing valve replacement and that its presence in patients in whom SLT causes no symptoms or complications should not dictate the type of antithrombotic therapy that patients receive following the implantation of an artificial heart valve. Additionally, these findings do not support the routine use of computed tomography (CT) scans to detect SLT.”

However, Prof. Park noted that the study may have been too small to conclusively answer this question; the number of events was too small to reach significant associations with imaging scans. In addition, the 6-month follow-up period was likely too short. These considerations will be taken forward into further studies.

1. 
   
   1. Park DW, et al. Edoxaban Versus Dual Antiplatelet Therapy For Valve Thrombosis And Cerebral Thromboembolism After Transcatheter Aortic-valve Replacement: A Randomized ADAPT-TAVR Trial. Abstract 409–16, ACC 2022, 2–4 April, Washington DC, USA.
   2. Park DW, et al. Circulation. 2022; Apr 4. DOI:10.1161/CIRCULATIONAHA.122.059512.

 

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Posted on 15 June, 202227 March, 2024