ON-X Bileaflet Valve in Aortic Position - Early Experience Shows an Improved Hemodynamic Profile

Abstract BACKGROUND: Despite considerable progress during the last decades, mechanical heart valves still have significant disadvantages in Performance compared to native valves. To optimize the hemodynamic profile, a new mechanical bileaflet valve (ON-X) was developed and introduced in 1997. It was the aim of this study to assess the feasibility, safety, and the early postoperative hemodynamics with this new valve in vivo. METHODS: We analyzed 19 patients (11 male, 8 female; 63.2 ± 8.2 years; aortic Stenosis: n = 13; aortic incompetence: n = 2; combined aortic lesion: n = 2), undergoing aortic valve replacement with this prosthesis (valve size 19 mm: n= 1; 21 mm: n = 6; 23 mm: n = 8; 25 mm: n = 4; additional CABG: n = 4). In addition to intraoperative pressure gradient measurements, echocardiography was performed early postoperatively and after 3 months, evaluating pressure loss, effective orifice area, and regression of left-ventricular hypertrophy. RESULTS: No major perioperative complications were observed. The echocardiographic evaluation demonstrated a significantly increased effective orifice area and lower transvalvular gradients in all valve sizes compared with literature values for the St. Jude Medical prosthesis. Effective regression of left-ventricular hypertrophy (-23.6%) was observed over the first three months. CONCLUSIONS: These preliminary data confirm the favorable hemodynamic characteristics of the ON-X valve as compared to standard bileaflet designs. Implantation was feasible and safe, and no major postoperative complications such as thrombembolic events were observed.