Patients at low surgical risk with bicuspid aortic valves appear to have similar outcomes to low-risk patients with tricuspid valves at 1 year after transcatheter aortic valve replacement (TAVR) with a self-expanding, supra-annular transcatheter heart valve, according to late-breaking trial results presented Tuesday at Transcatheter Valve Therapies (TVT) 2021.
Bicuspid patients were excluded from the major randomized TAVR trials, including those studying low-risk patients, yet up to 50% of low-risk patients referred for aortic valve replacement have bicuspid valves, John K. Forrest, MD, of the Yale University School of Medicine, said in presenting the results at TVT in Miami Beach, Florida.
The Low-Risk Bicuspid Study showed that TAVR with a self-expanding valve (Evolut R or PRO, Medtronic) had favorable outcomes, including a 1.3% composite rate of all-cause mortality or disabling stroke at 30 days. The analysis presented Tuesday reported 1-year outcomes and compared results between low-risk patients with bicuspid and tricuspid valves.
The study enrolled 150 patients at 25 U.S. sites that also participated in the Evolut Low-Risk Trial. For the analysis presented Tuesday, Low-Risk Bicuspid Study patients were propensity-matched to TAVR patients in the Evolut Low-Risk Trial, resulting in 145 matched pairs. An independent clinical events committee adjudicated all serious adverse events, and an independent core laboratory assessed all echocardiograms.
After matching, the only significant differences between the Low-Risk Bicuspid Study patients and tricuspid patients in the Evolut trial were pre-implant balloon valvuloplasty (bicuspid 133 patients [91.7%] vs. tricuspid 43 [29.7%], p<0.001), the use of embolic protection (bicuspid 43 [29.7%] vs. tricuspid 2 [1.4%], p<0.001) and performance of resheathing or recapture (bicuspid 47 [32.4%] vs. tricuspid 65 [44.8%], p=0.03).
At 1 year, clinical outcomes in matched patients were similar, including the composite of death or disabling stroke (bicuspid 2 patients [1.4%] vs. tricuspid 4 patients [2.8%], p=0.413).
The valve hemodynamics improvements were nearly identical in both sets of patients. Mean gradient improved from 47.7±15.9 mmHg at baseline to 8.7±3.9 mmHg at 1 year in bicuspid patients and from 45.1±11.5 mmHg at baseline to 8.5±3.1 mmHg at 1 year in tricuspid patients (p=0.754 at 1 year). Effective orifice area improved from 0.8±0.2 cm2 at baseline to 2.2±0.7 cm2 at 1 year in bicuspid patients and from 0.9±0.2 cm2 at baseline to 2.3±0.6 cm2 at 1 year in tricuspid patients (p=0.677 at 1 year).
Also, fewer bicuspid patients had mild or greater paravalvular regurgitation at 1 year as compared to tricuspid patients (bicuspid 21.3% vs. tricuspid 42.6%, p<0.001).
“We can conclude from this that the presence of a bicuspid valve does not appear to impact procedural or early outcomes at 1 year in low-risk patients undergoing TAVR using a self-expanding, supra-annular valve,” Forrest said.
Referencing a 2020 study of bicuspid patients in an international TAVR registry, Forrest added, “It is likely that the impact of calcium distribution, regardless of whether it’s a bicuspid or a tricuspid patient, is going to impact outcomes more than just purely the number of leaflets that are there on the valve.”
Finally, he said, “vigilant case planning” and a focus by the Heart Team on computed tomography angiography are “critical for success.”
The Low-Risk Bicuspid Study and Evolut Low-Risk Trial were sponsored by Medtronic, the manufacturer of the Evolut transcatheter heart valves.