NATIONAL HARBOR, MD – Data presented at the 2020 CRT meeting, sponsored by MedStar Heart & Vascular Institute, show that transcatheter aortic valve replacement (TAVR) is safe and effective, at least in the short term, for low-risk patients with bicuspid aortic stenosis, which addresses a data gap.
In an investigator-driven prospective study, called LRT, there was no mortality, no myocardial infarctions (MI), and no disabling strokes 30 days after the procedure, according to Ronald Waksman, MD, associate director of cardiology at Medstar Heart Institute in Washington.
TAVR was approved in 2019 for low-risk patients with symptomatic severe aortic stenosis regardless of aortic valve morphology, but the pivotal industry-led trials only enrolled patients with tricuspid valves, excluding the bicuspid population, according to Dr. Waksman.
However, bicuspid patients were enrolled in the investigator-led LRT study. The 1-year results with tricuspid values have been published previously (JACC Cardiovasc Interv. 2019;12:901-7), but new data from this same study provides the first prospective evaluation in low-risk bicuspid patients.
The LRT enrollment criteria were the same for the bicuspid patients as they were for those enrolled with tricuspid valves. These included a low surgical risk, defined as a Society of Thoracic Surgeons (STS) score of 3 or less; no high-risk criteria independent of STS score; and eligibility for a transfemoral percutaneous procedure. Patients were permitted to undergo TAVR with any commercially available device.
The 61 patients enrolled from August 2016 to September 2019 were compared at 30 days of follow-up with 211 low-risk bicuspid patients undergoing surgical aortic valve replacement (SAVR). Propensity matched, the two groups had generally similar baseline characteristics with some exceptions. Relative to the SAVR group, the TAVR group had an older median age (68.6 vs. 63.4 years) and a lower proportion of males (42.6% vs. 65.7%) and a lower proportion with New York Heart Association heart failure of class III or higher (15.8% vs. 24.6%).
For the primary outcome of all-cause mortality at 30 days, there were no deaths in the TAVR group versus one death in the SAVR group. TAVR was associated with a shorter length of stay (2.0 vs. 5.8 days) and a lower risk of new-onset atrial fibrillation (1.6% vs. 42.6%). However, pacemaker implantations were more common in the TAVR group (11.5% vs. 5.6%). There was one stroke in the TAVR group, but it was not disabling.
Following TAVR, there was one case of paravalvular leak, but it was of moderate severity, according to Dr. Waksman. Leaflet thrombosis in the form of hypoattenuated leaflet thickening (HALT), which occurred in 10.2% of patients; reduced leaflet motion (RELM), which occurred in 6.9%; and hypoattenuation affecting motion (HAM), which also occurred in 6.9%, was observed at 30 days following TAVR, but these have not so far been associated with any clinical consequences.
At baseline, only 4.9% of the bicuspid patients met criteria for NYHA class I function and 23% were in NYHA class III or higher. By 30 days, the proportion in NYHA class I had risen to 78.3%, and no patient was in NYHA class III or higher. Dr. Waksman characterized the improvement in hemodynamics – measured by mean aortic valve gradient and aortic valve area – as “excellent” at 30 days.
Further follow-up of bicuspid patients in the LRT study is needed to confirm long-term safety and efficacy, but Dr. Waksman indicated that the 30-day results are encouraging, in part because they show no greater risk of periprocedural complications than that observed in the tricuspid population.