VALVE-REPLACEMENT WITH THE ATS OPEN PIVOT BILEAFLET PROSTHESIS

Objective. We sought to evaluate the ATS open pivot bileaflet valve wi th respect to haemodynamics and thromboembolism. Methods. We prospecti vely studied 200 consecutive patients aged 13-80 years. One hundred an d nineteen aortic, 103 mitral and 11 tricuspid valves were replaced in 172 single, 23 double and 5 triple valve procedures, Thirty-eight wer e re-operations and 51 underwent coronary bypass. Transvalvular gradie nts were determined by transoesophageal and transthoracic echocardiogr aphy. Patients were followed for 13 months to 3 years. Results. There were four hospital (2%) and three late deaths, each non-valve related. Two patient were reoperated for partial valve dehiscence. One aortic re-operation patient suffered a potential transient thrombo-embolic ev ent. One tricuspid prosthesis thrombosed after anticoagulation was dis continued but thrombolysis resolved this problem. There were no other thromboembolic events. Valve gradients were equivalent or better than those for other bileaflet valves.Conclusions. The ATS valve has excell ent haemodynamic characteristics and a very low thromboembolic fate, p robably related to the convex self-washing hinge mechanism. Consequent ly, we have reduced anticoagulant levels to INR (international normali sed ratio) 1.5 to 2.0 for aortic valve patients in sinus rhythm. Early experience suggests that the ATS valve functions well in the tricuspi d position.