The stentless quadrileaflet bovine pericardial mitral valve: Early clinical results

Background and aims of the study: Although bioprosthetic valves currently i n use have low thrombogenicity, durability remains very unsatisfactory. Val ve failure occurs early from calcification, and later from tissue wear. Ste ntless design lessens the latter, and anticalcification treatments the form er. Recently, a stentless chordally supported quadrileaflet mitral valve (Q MV) bioprosthesis made of selected tanned bovine pericardium, treated to mi nimize calcification, has become available for clinical study. The aim of t his study was to report the early results relating to valve performance, an d patient outcome. Methods: Since December 1996, the QMV has been implanted in 23 patients (me an age 38 +/- 12 years) requiring isolated mitral valve replacement for val ve lesions not suited for repair. All patients were symptomatic (three in N YHA functional class II, 16 in class III, four in class IV). Preoperatively , all underwent full clinical and echocardiographic assessment, and intraop erative transesophageal evaluation immediately after valve implantation. Bl ood tests for hemolysis were performed preoperatively and at 3 months after surgery. Results: After a mean follow up of 8.3 months (range: 1 to 18 months), 22 p atients were alive and symptomatically improved (NYHA class I or II). One p atient died of sternal sepsis soon after surgery. There have been no reoper ations, nor cases of infective endocarditis or thromboembolism. Subclinical hemolysis was shown pre- and postoperatively in 35% and 32% of cases, resp ectively. Intraoperative transesophageal echocardiography post valve implan tation demonstrated mitral regurgitation which was trivial in 15 patients ( 78%) and mild in five (22%). Conclusions: The QMV can be implanted safely, and the early clinical result s relating to patient outcome and valve performance are encouraging.