Clinical evaluation of the Hydra self-expanding transcatheter aortic valve: 6 month results from the GENESIS trial

Objectives To evaluate the safety and performance of the Hydra transcatheter aortic valve (THV) in the treatment of symptomatic severe aortic stenosis in patients at high or extreme surgical risk. Background The Hydra THV (Vascular Innovations Co. Ltd., Nonthaburi, Thailand) is a novel flexible repositionable self-expanding system with supra-annular bovine pericardial leaflets, available in three sizes, covering aortic annuli between 17 and 27 mm. Methods The GENESIS trial was a prospective, multi-center, single-arm, 6 month follow-up study conducted in India. The primary performance endpoint was device success defined as per VARC-II criteria at 30 days. The primary safety endpoint was all-cause mortality at 30 days. All endpoints were adjudicated by an independent clinical events committee. Results Forty high-risk patients (74.5 +/- 6.7 years, 60% men; STS Score:5.6 +/- 4.2%) were enrolled in 11 centres. Device success was achieved in 92.5%. The effective orifice area improved from 0.7 +/- 0.2 to 2.3 +/- 0.6 cm(2) at 30 days and to 2.2 +/- 0.7 cm(2) at 6 months (p < .0001). Mean aortic valve gradient decreased from 53.5 +/- 18.1 to 8.9 +/- 4.9 mmHg at 30 days and to 7.6 +/- 2.7 mmHg at 6 months (p < .0001). The rate of new permanent pacemaker implantation was 7.5% at 30 days, and no patient had more than mild paravalvular leak at 6 months. The 30 days and 6 month all-cause mortality was 10.0 and 17.5%, cardiovascular mortality 7.5 and 7.5%, device-related mortality 5.0 and 5.0%, respectively. No patients had stroke up to 6 months. Conclusions The GENESIS trial demonstrated high efficacy of the self-expanding Hydra THV. The cardiovascular mortality rate of 7.5% may partly be explained by the inclusion of some centres with no or limited previous experience in transcatheter aortic valve implantation.