Hemodynamic and clinical outcomes with the Biocor valve in the aortic position: an 8-year experience

Abstract

Objectives: The aim of this study was to analyze the 8-year experience, survival, prosthetic complications, and hemodynamics of patients who received the Biocor valve, a new-generation tissue valve, in the aortic position.

Methods: From May 1992 through May 2001, 257 consecutive patients (129 women and 128 men; mean age, 75 +/- 6 years; age range, 45-91 years) received 258 aortic Biocor porcine prostheses. One female patient who received 2 Biocor valves in the aortic position during 2 consecutive operations was entered twice in the statistical analysis. Twelve (4.6%) patients had previous aortic valve operations. Preoperatively, 82 (32%) patients were in New York Heart Association functional class III or IV. Associated surgical procedures included coronary artery bypass grafting in 56 (21.7%) patients, aortic annular enlargement or aortoplasty in 20 (8%) patients, and others in 8 (3%) patients. Echocardiography was performed in the majority of long-term survivors (91.6%). Follow-up included 1215 patient-years and was 100% complete, with a median time of 5 patient-years (range, 0.4-10.5 years).

Results: There were 16 (6.2%) early deaths. According to a univariate analysis, New York Heart Association functional class III or IV, concomitant procedures, ejection fractions of less than 40%, and urgent operations were identified as significant perioperative risk factors. At follow-up, 75 patients died; 8-year actuarial Kaplan-Meier survival was 48% +/- 5%. At 8 years, the actuarial freedom from valve-related death was 92% +/- 2.6%, the freedom from thromboembolism was 93% +/- 2%, the freedom from anticoagulant-related hemorrhage was 95% +/- 2%, the freedom from endocarditis was 99% +/- 0.6%, the freedom from paravalvular leak was 96% +/- 1.5%, the freedom from all valve-related complications was 78% +/- 4.5%, and the freedom from structural valve deterioration was 95% +/- 3.7%. At 8 years, the actuarial freedom from structural valve deterioration was 89% +/- 10% and 95.8% +/- 4% in patients younger and older than 65 years, respectively. At 10 years, in patients older than 65 years, the actual freedom from structural valve deterioration was 97.9% +/- 2.1%, and the freedom from reoperation was 97% +/- 1.3%. New York Heart Association status was I or II in 90% of patients at the end of follow-up. The mean echocardiographic follow-up time was 4.6 +/- 2 years. By using Doppler echocardiography, the peak and mean transprosthetic gradients were determined to be 30.8 +/- 9.3 mm Hg and 16.6 +/- 5.3 mm Hg, respectively. Mean mass/volume ratio and left ventricular end-diastolic volume were 1.37 +/- 0.17 g/mL and 63.4 +/- 22.6 mL/m(2), respectively. The majority of patients showed a persistent left ventricular hypertrophy.

Conclusion: The Biocor is an effective bioprosthesis with a low incidence of valve-related complications comparable with that of other second-generation bioprostheses. This stented porcine prosthesis provides satisfactory results in terms of hemodynamics, valve durability, and freedom from reoperation.