Transcatheter aortic valve replacement (TAVR) with the novel repositionable, self-expanding Hydra transcatheter heart valve (THV) device has “favorable” outcomes in terms of efficacy and complication rates at 1 year, trial data suggest. Findings from the pre-market, prospective, multicenter, single-arm Hydra CE study, which assessed the safety and performance of the Hydra THV (Sahajanand Medical Technology Pvt. Ltd., Mumbai, India) in the treatment of symptomatic severe AS in patients at high or extreme surgical risk, were published online Monday and in the Jan. 10 issue of JACC: Cardiovascular Interventions. Led by Audrius Aidietis, MD, PhD, from Vilnius University Hospital Santaros Clinics, Lithuania, the authors noted that the Hydra THV is a novel repositionable, self-expanding aortic valve with supra-annular position of leaflets. They added that the device “is designed for high flexibility, superior hemodynamics, easy access to the coronary arteries, low interference with the conduction system, and mitigating the risk for paravalvular leak.” “Post implantation with Hydra THV, there were significant improvements in the effective orifice area and mean aortic valve gradient, which were maintained at up to one-year follow-up,” they said. “Importantly, these hemodynamic improvements were observed in the presence of acceptable rates of new pacemaker implantations for a self-expandable THV (11.7%) and moderate or severe paravalvular leak (5.3%).” The authors added that future large-scale studies with longer-term follow-up are already underway to validate the results of the Hydra CE study in a wider population. Study details Aidietis and colleagues noted that the Hydra CE Study sought to evaluate the 30-day and 1-year safety and performance of the Hydra THV in the treatment of symptomatic severe aortic stenosis in patients at high or extreme surgical risk. The pre-market, prospective, multi-center, single-arm study was conducted across 18 study centers in Europe and Asia-Pacific countries, with a primary endpoint of all-cause mortality at 30 days. The team reported that a total of 157 patients were enrolled in the study, with successful implantation achieved in 94.3% of cases. The study reported significant improvement of effective orifice area (from 0.7 cm2 to 1.9 cm2) and mean aortic valve gradient (from 49.5 mmHg to 8.1 mmHg) at 30 days, which were sustained up to one year. At 30 days, there were 11 (7.0%) deaths, including nine (5.7%) cardiovascular deaths, of which five (3.2%) were device related, said Aidietis and colleagues. Meanwhile, at 1 year, there were 23 (14.6%) deaths, including 13 (8.3%) cardiovascular deaths, they noted. Moderate or severe paravalvular leak was observed in 6.3% of patients at 30 days and 6.9% of patients at 1 year, the researchers added, noting that the rate of new permanent pacemaker implantation was 11.7% at 30 days and 12.4% at 1 year. More data needed Writing in an accompanying editorial, Rüdiger Lange, MD, and Keti Vitanova, MD, from the Technical University, Munich, said the study presents “promising” hemodynamic results. However, they noted that device success was lower (94%), and the 30-day device-related death rate was somewhat higher, compared with the latest generation of established self-expanding TAVR prostheses (3% versus 1%). “Considering that TAVR has become a mature and well-established therapy with established repositionable devices, the device-related deaths need more attention for further comprehension of device safety,” they said, adding that the presence of moderate or severe paravalvular leak of 5.3% after Hydra implantation is higher than the previously reported rate of 3.5% in the recent Evolut low-risk trial. The editorialists warned that “the advantages of the claimed higher flexibility of the delivery system and the varying radial force of the Hydra prosthesis needs to be investigated in long-term studies and randomized comparison trials.” Moreover, they noted that because the indication for TAVR is “continuously” being expanded to younger and healthier patients, the question of valve durability “becomes more pressing.” “A more active lifestyle and thus presumed higher valve stress may result in a more rapid deterioration,” they commented. “Technical improvements, not only in valve design, crimping manner, delivery sheath, and system, as well as implantation techniques, have an unknown impact on valve durability.” The study was supported by Vascular Innovations (Nonthaburi, Thailand), an indirect foreign subsidiary of Sahajanand Medical Technology. The corresponding author, Lars Søndergaard, MD, DMSc, of Rigshospitalet, Copenhagen University Hospital, Denmark, reports having received consultant fees from Vascular Innovations and Sahajanand Medical Technology. Lange reports having received royalties and consulting fees from Medtronic, and having been a consultant for Highlife and Abbott. Vitanova reports having received speaker honoraria from Medtronic. Sources: Aidietis A, Srimahachota S, Dabrowski M, et al. 30-Day and 1-Year Outcomes With HYDRA Self-Expanding Transcatheter Aortic Valve: The Hydra CE Study. JACC Cardiovasc Interv 2022;15:93-104. Lange R, Vitanova K. A Novel Transcatheter Heart Valve for an Overcrowded TAVR Market: What Should We Focus On? JACC Cardiovasc Interv 2022;15:105-106. Image Credit: Pitchy – stock.adobe.com