Isolated Mitral Valve Replacement With Carpentier-Edwards Bioprosthesis: Independent Risk Factors for Long-Term Survival and Prosthesis Failure

From 1976 through 1986, 188 patients (female/male ratio: 2/1, age 20-77 years, mean 58 years) with isolated mitral valve disease underwent valve replacement using the Carpentier-Edwards porcine bioprothesis (CEPB). Nine hospital deaths (4.8%) were excluded from further analysis. Follow-up was 0.2-11.3 years (mean 5.2 years); preoperatively, 74% had atrial flutter/fibrillation, and 75% were in NYHA-classes III-IV. All patients were put on life-long coumadin treatment. Preoperative predictability of long-term survival and prosthesis-related complications was examined using Cox regression analysis. Five preoperative variables were found to have independent predictive value as regards long-term survival: myxomatous degeneration of the valve (p = 0.002), chronic regurgitation (p = 0.003), age (p = 0.004), NYHA-class III-IV (p = 0.05), and atrial flutter/fibrillation (p = 0.05). A prognostic index calculated form the final Cox model identified six risk groups (I-VI) having cumulative 10-year survivals +/- SE of: I (n = 9) 100%, II (n = 10) 90 +/- 9%, III (n = 30) 73 +/- 10%, IV (n = 70) 51 +/- 9%, V (n = 43) 17 +/- 10%, and VI (n = 17, 7-year survival) 16 +/- 13% (p less than 0.0001). The incidence of late valve-related complications (%/patient-years) were: hemorrhage, 1.2; thromboembolism, 0.5; Endocarditis, 1.0; paravalvular leak, 0.2; and primary tissue failure, 1.5. Previous closed comissurotomy adversely influenced the occurrence of hemorrhage, while calcified mitral annulus were predictive of endocarditis. Younger age (less than or equal to 45 years) had a strong predictive influence of primary tissue failure.(ABSTRACT TRUNCATED AT 250 WORDS)