Patients at low surgical risk with favorable bicuspid valve anatomy had similar clinical outcomes to low-risk tricuspid patients at 1 year after transcatheter aortic valve replacement (TAVR) with a balloon-expandable bioprosthetic THV, according to late-breaking trial results presented Tuesday at Transcatheter Valve Therapies (TVT) 2021.
Bicuspid aortic valves are a relatively common congenital abnormality, affecting about 1% of Americans, and aortic stenosis is a frequent complication, said Mathew R. Williams, MD, of NYU Langone Health, during his presentation at TVT in Miami Beach, Florida.
Bicuspid patients have historically been excluded from TAVR studies, but recent reports suggest that the SAPIEN 3 transcatheter heart valve (THV; Edwards Lifesciences) is safe and effective in patients with high surgical risk. Data in low-risk bicuspid patients are limited, Williams said.
The purpose of the analysis presented Tuesday was to study the 1-year safety and efficacy of the SAPIEN 3 THV in low-risk bicuspid patients and compare clinical results to a similar cohort of tricuspid patients from the PARTNER 3 randomized trial.
Bicuspid patients were enrolled into a registry as part of the PARTNER 3 trial, and follow-up was part of the study. Once that study’s enrollment closed, bicuspid patients were enrolled into a continued-access protocol (CAP), and follow-up was part of the Society of Thoracic Surgeons/American College of Cardiology Transcatheter Valve Therapy Registry.
A multidisciplinary Heart Team and case review board reviewed each patient, including imaging studies. Patients underwent baseline and 30-day neurological assessment, serial examinations by neurologists, and neurological imaging for suspected neurological events.
All patients also underwent three-dimensional cardiac imaging by computed tomography (CT) or transesophageal echocardiography, and the CT core lab determined whether a patient had bicuspid anatomy. Echocardiogram results from the PARTNER 3 bicuspid registry patients were from the core lab, whereas the bicuspid CAP patients’ echo results were site-reported.
The primary endpoint of the main PARTNER 3 trial was a composite of all-cause death, stroke or cardiovascular rehospitalization at 1-year post-TAVR. All major endpoint events were adjudicated, using Valve Academic Research Consortium 2 definitions when applicable, by a clinical events committee. Outcomes in the CAP registry were all-cause death, stroke, valve-related hospitalization and new permanent pacemaker implantation at 30 days and 1 year; these were assessed by an independent medical reviewer.
Patients from the two bicuspid registries were pooled to form one group of 169 patients. They were propensity-matched to the tricuspid arm of the PARTNER 3 randomized trial. After propensity matching, there were 148 matched pairs.
The overwhelming majority of bicuspid patients had a Sievers Type 1 classification (one raphe; 84.5% in the PARTNER 3 registry, 86.7% in the CAP). The remainder had Type 0 (no raphe), except that one patient in the study registry had Type 2 (two raphae).
Procedural outcomes were similar between the bicuspid and tricuspid groups except for length of procedure (bicuspid 64 minutes [95% confidence interval (CI) 46.0, 89.5] vs. tricuspid 50.0 minutes [95% CI 36.0, 65.0], p<0.01) and fluoroscopy (bicuspid 13.3 minutes [95% CI 10.0, 19.8] vs. tricuspid 12.0 minutes [95% CI 9.0, 16.0], p<0.01). Also, more valves were oversized in the tricuspid arm (bicuspid 5.7±8.37% vs. tricuspid 8.0±8.82%, p=0.02), but Williams said that was “probably not very clinically significant.”
Procedural success was high. Only one patient, in the tricuspid group, had to be converted to surgery from TAVR.
At 1 year post-TAVR, the rate of the primary PARTNER 3 endpoint was similar between the matched bicuspid and tricuspid patients (bicuspid 10.9% vs. tricuspid 10.2%, log-rank p = 0.8). Williams also noted that the rate of new pacemaker was low in both groups at 30 days (bicuspid 6.1% vs. tricuspid 6.8%, p=0.81) and 1 year (bicuspid 6.8% vs. tricuspid 7.4%, p=0.82).
Similarly good results were seen at 30 days and 1 year in terms of hemodynamics, paravalvular regurgitation and New York Heart Association heart failure classification. The only significant difference was in Kansas City Cardiomyopathy Questionnaire (KCCQ) score at 30 days, with bicuspid patients having a statistically, but not clinically, significantly higher score (bicuspid 91.4 vs. tricuspid 88.4, p=0.02), Williams said. However, by 1 year, the KCCQ scores were similar (bicuspid 92.3 vs. tricuspid 91.6, p=0.50).
Williams noted that these results reflect outcomes only up to 1 year and that longer-term data for the bicuspid CAP patients will not be available. He added that conclusions from the limited sample size of this analysis “might not be generalizable to all bicuspid morphologies.”
“Patients with severe, symptomatic aortic stenosis who are low surgical risk with favorable bicuspid anatomy who underwent TAVR with a SAPIEN 3 valve demonstrated hemodynamic outcomes and adverse events that were comparable to a similar group of patients with tricuspid anatomy,” he concluded. “They had a significant quality of life and symptomatic improvement.”
The PARTNER 3 trial was sponsored by Edwards Lifesciences, the manufacturer of the SAPIEN 3 THV.