BACKGROUND AND AIM OF THE STUDY

Bioprostheses in heart surgery have been investigated in recent years to reduce the long-term anticoagulant administration associated with mechanical devices. Positive results have been achieved, particularly in elderly patients who have a supposed delayed fibrocalcification and reduced life expectancy. Herein are reported 17-year data on the ongoing long-term study of the Biocor porcine prosthetic heart valve, an improved bioprosthesis with reduced stiffness and improved flexibility of the valve cusps designed to resolve issues of reduced lifespan of previous biological valves.

METHODS

Data were presented for 1,455 patients who underwent aortic valve replacement (AVR) or mitral valve replacement (MVR) in Sweden with glutaraldehyde-preserved Biocor bioprostheses between 1983 and 2000. Follow up after surgery was evaluated on alternate years using hospital records, interviews, questionnaires and the Cox regression model of multivariate analysis.

RESULTS

At 17 years, the cumulative follow up was 6,540 and 989 patient-years (pt-yr) for AVR and MVR, respectively. Late mortality accounted for 357 (28%) and 65 (38%) patients, respectively, and actuarial survival was 28.2% and 35.4%, respectively. Thromboembolic events occurred in 82 AVR (1.25%/pt-yr) and 18 MVR (1.82%/pt-yr) patients, respectively, with freedom from thromboembolism decreasing with age; 181 AVR and 44 MVR patients received anticoagulants. Reoperations due to structural valve deterioration (SVD) were required in 63 AVR and nine MVR patients. Freedom from reoperation due to SVD increased with age in both groups; actuarial freedom from reoperation was 73.9% and 81.3%, respectively.

CONCLUSION

Seventeen-year data confirm the low incidence of valve-related complications and improved valve durability reported at the 15-year follow up after both AVR and MVR using Biocor porcine bioprostheses.