Self-Expanding Transcatheter Aortic Heart Valve May Be Safe

Implantation of the self-expanding Biovalve transcatheter heart valve for the treatment of severe aortic stenosis was deemed to be safe, with clinical outcomes similar to those of other first-generation devices designed for the same indication, according to study results published in JACC: Cardiovascular Interventions.

For patients with severe aortic stenosis — particularly high-risk patients for whom surgery is contraindicated — transcatheter aortic valve implantation (TAVI) has been established as an effective alternative to surgical replacement, with newer devices designed to supplement those already available. Investigators sought to evaluate the performance and safety of the Biovalve device, a supra-annular valve that is inserted transfemorally, using objective measures as well as comparisons to similar products.

A total of 68 participants aged 65 years or older (mean, 82.4 years; 61.8% women) with severe symptomatic calcific aortic stenosis and considered to be high surgical risks were enrolled between September 2014 and February 2018 in 2 studies: BIOVALVE I (n=13), a single-center prospective feasibility trial, and BIOVALVE II (n=55), a multicenter pilot trial. The implantation protocol was similar for all study participants. The primary outcome was 30-day “early safety,” as defined in the Valvular Academic Research Consortium-2 (VARC-2) criteria. Follow-up visits occurred at 1, 3, 6, and 12 months and then annually until 5 years postprocedure. An intention-to-treat analysis was conducted and Kaplan-Meier estimates were reported. A post-hoc analysis was conducted to compare the first and second halves (by recruitment order) of the patient cohort.

At baseline, comorbidities in this cohort included concomitant coronary artery disease (57.4%), diabetes mellitus (32.4%), chronic obstructive pulmonary disease (19.1%), renal insufficiency of stage 3 or greater (50.0%), current anemia (29.4%), prior cerebrovascular events (17.6%), and frailty (19.1%). The mean annular diameter was 24.0 mm.

Early safety was established in 13 patients (Kaplan-Meier estimate, 19.1%; 95% CI, 11.6-30.6), with 20.6% and 17.6% reaching this benchmark in the first vs second half of the cohort, respectively. Device success was documented in 45 of 60 patients (75.0%), with 21 of 31 (67.7%) and 24 of 29 patients (82.8%) achieving success in the first and second halves, respectively. At 30 days, 1 (1.5%) non-cardiac death occurred, and 4 (7.8%) additional fatalities were reported at 180 days, 2 (3.3%) of which were from cardiac causes. 

Moderate-to-severe paravalvular leakage was seen in 2 (3.8%) and 4 (9.1%) participants at 1 and 6 months, respectively. Effective orifice areas at these same time points were 2.0 ± 0.4 cm² at 1 month and 1.9 ± 0.5 cm² at 6 months, and the mean gradient was 6.4 mm Hg at both points. These values represented substantial increases and decreases, respectively, from baseline.

Overall, following implantation, 9 (13.4%) participants had new atrioventricular blocks, new-onset atrial fibrillation developed in 3 (4.5%) patients, and 24 (35.8%) and 1 (1.5%) participants had new left and right bundle branch blocks, respectively. Nine (13.4%) patients had new permanent pacemakers implanted within the first 30 days. Disabling strokes occurred in 1 (1.5%) participant at 1 month and in 2 (3.2%) patients at 6 months.

Study limitations include a small sample size, inadequate comparisons with other studies, and a lack of systematic assessment of the degree of calcification.

“This self-expanding supra-annular transcatheter heart valve demonstrated low complication rates despite several procedural problems, which is in line for a first-in-men study with a first generation device and the associated learning curve,” noted the authors. They recommended that future research involve larger trials to confirm their findings.

Disclosure: This clinical trial was supported by Biotronik AG, Buelach, Switzerland. Please see the original reference for a full list of authors’ disclosures.

Reference

Schäfer U, Kempfert J, Verheye S, et al. Safety and performance outcomes of a self-expanding transcatheter aortic heart valve [published online October 16, 2019]. JACC Cardiovas Interv. doi:10.1016/j.jcin.2019.07.058