Retrograde Transarterial Implantation of a Nonmetallic Aortic Valve Prosthesis in High–Surgical-Risk Patients With Severe Aortic Stenosis

Abstract

Background— To assess the feasibility and safety of retrograde transarterial implantation of a novel nonmetallic aortic valve prosthesis (Direct Flow Medical Inc, Santa Rosa, Calif), a prospective single-center study was performed in patients with severe aortic stenosis at high risk for open-heart surgery. Methods and Results— Fifteen patients (intention-to-treat cohort) with an aortic valve area ≤0.8 cm 2 , a ≥35-mm Hg mean transvalvular pressure gradient, and a logistic EuroSCORE ≥20% were enrolled. Percutaneous aortic valve replacement was performed with the patient under general anesthesia. Hemodynamic parameters were assessed before and after implantation by transesophageal echocardiography. Clinical follow-up and transthoracic echocardiographic assessment were obtained at 30 days. Procedural success was achieved in 12 patients (80%). Surgical conversion became necessary at day 2 in 1 patient; 11 patients (73%) were discharged with a permanent implant. In these patients, implantation resulted acutely in a significant increase in aortic valve area (median, 1.64 [interquartile range, 1.27 to 1.74] versus 0.60 [0.46 to 0.69] cm 2 ; P =0.0033) and a concomitant reduction in the mean pressure gradient (14.0 [13.2 to 16.5] versus 54.0 [43.2 to 59.8] mm Hg; P =0.0033). At 30 days, 1 cardiac death (6.7%; 95% CI, 0.2% to 32.0%) and 1 major stroke were observed. The 10 surviving patients with a permanent implant showed marked hemodynamic and clinical improvement at this time point. Conclusions— In this small series of patients, percutaneous implantation of the Direct Flow Medical aortic valve prosthesis in high–surgical-risk patients was feasible and associated with a reasonably low safety profile.