Background and aim of the study: There remains a great need for bioprosthetic valves in developing countries where monitoring of anticoagulation therapy is difficult. The study aim was to assess the intermediate outcome following mitral valve replacement with a stentless bovine pericardial quadrileaflet mitral (Quattro) valve. This valve maintains mitral annular-papillary continuity in patients with isolated severe rheumatic mitral valve disease.
Methods: Since December 1996, the Quattro valve has been implanted in 47 patients (mean age 34 +/- 13 years; 16 (34%) aged <25 years) with rheumatic mitral valve disease. All patients were symptomatic, and in NYHA class II (n = 7), III (n = 30) or IV (n = 10). Preoperatively, all patients underwent full clinical and routine echocardiographic assessment, as well as intraoperative transesophageal evaluation after valve implantation. At follow up visits, clinical and echocardiographic evaluations were carried out in each patient.
Results: After a mean follow up of 51 +/- 11 months, the overall mortality was 10.6% (five deaths). Five patients did not return for clinical follow up, but three of these are known to be alive and well. Of the 37 patients who returned for regular follow up, 32 remained symptomatically improved. Valve explantation was performed in two patients (4.2%) for prosthetic valve endocarditis. Two patients have deteriorated as a result of left ventricular dysfunction, and one patient has developed severe mitral regurgitation. Thromboembolism or clinically overt hemolysis has not occurred. One patient, who was receiving coumadin therapy for atrial fibrillation, died following a massive hematemesis. Serial one-year echocardiography data at one, two and three-year follow up intervals were available in 28 patients. These data confirmed no significant change in valve area or in mean diastolic gradient. Varying degrees of valve thickening were detected echocardiographically in 10 patients; four patients had clinically significant mitral stenosis (valve area <1.5 cm2). One valve was explanted for structural deterioration.
Conclusion: Intermediate results after Quattro valve implantation in a relatively young population were satisfactory. However, long-term follow up is mandatory to assess valve durability.