Retrograde transarterial implantation of a nonmetallic aortic valve prosthesis in high-surgical-risk patients with severe aortic stenosis: a first-in-man feasibility and safety study

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 < or = 0.8 cm(2), a > or = 35-mm Hg mean transvalvular pressure gradient, and a logistic EuroSCORE > or = 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.