In-vivo Evaluation of a Novel Surgical Heart Valve Prosthesis Designed to Be Durable, Anticoagulant-free and Silent

Abstract

Objective: Heart valves prostheses still face limitations: reoperations with tissue valves or lifelong anticoagulation with mechanical valves. The Triflo valve, a tri-leaflet valve made of high-resistant bio-inert materials, aimed at overcoming these limitations. We studied safety and performance in a chronic sheep model. Methods: The Triflo valve (size 21mm) was implanted in two models: 90 days in aortic position (n=7) and 70 days in pulmonary position (n=4). In the pulmonary model, On-X valves (n=2) were used as control. After 7 days of low-molecular-weight heparin, no further anticoagulant was administered. Serial blood testing, echocardiography, acoustic measurements, fluoroscopy and autopsy were done. Results: The Triflo valve demonstrated excellent surgical handling. There were one aborted procedure and one early death in the aortic study, both unrelated to the prosthesis. All other sheep (n=9) recovered fast and remained in excellent clinical condition until the scheduled sacrifice. In aortic position, we observed low peak and mean gradients (8.1+/-2.7 and 4.8+/-1.9 mmHg), high effective orifice area (2.3+/-0.2 cm2), no valvular regurgitation, and perfect left ventricular function. At explantation, the surface of all Triflo valves was clean, without any valve thrombosis. All major organs were free from thrombo-embolic (TE) damage. In pulmonary position, leaflet mobility of all valves remained also normal and no TE-damage was found in the lungs. Hematological parameters were stable without any sign of hemolysis. On-X valves in pulmonary position functioned well, but generated significantly louder acoustic signals (p < 0.05). Conclusions: The Triflo valve showed safety and effectiveness in both aortic and pulmonary position. These favorable in-vivo results, with excellent hemodynamic behavior and stable long-term function even in the absence of anticoagulants, demonstrate that this valve can proceed to first-in-human studies.