A 10-YEAR STUDY OF THE IONESCU-SHILEY LOW-PROFILE BIOPROSTHETIC HEART-VALVE

Seven hundred and eight adults (age greater-than-or-equal-to 16 years) with isolated aortic (n = 433) or mitral (n = 275) Ionescu-Shiley Low -Profile (ISLP) pericardial valves were followed at 14 implanting cent res in Canada, the United Kingdom, and the United States for a mean of 6.7 years, providing 4,729 patient-years of clinical data. The operat ive mortality rate was 3.0% for aortic valve replacement (AVR) and 5.5 % for mitral valve replacement (MVR) (p = ns). Actuarial patient survi val following AVR at 5 years was 81.6%, and 62.9% at 10 years; for MVR patients it was 78.1% at 5 years and 59.6% at 10 years. The ISLP valv e appears to have durability comparable to other contemporary bioprost hetic valves. For aortic prostheses, the freedom from structural deter ioration was 96.5% at 5 years and 73.7% at 10 years, and 89.7% at 5 ye ars and 62.4% at 10 years for mitral prostheses. Structural deteriorat ion was significantly more frequent following MVR than after AVR (p < 0.05). Structural deterioration was the principal cause for reoperatio n, but sudden deterioration precluding safe reoperation was not a domi nant feature of this series. The ISLP valve appeared to engender more thrombo-embolic events than would be anticipated from earlier studies of pericardial bioprostheses, but was indistinguishable from other tis sue valves in its incidence of other valve-related complications. We c onclude that ISLP valves now implanted for 7 years or more are enterin g a phase of increasing structural deterioration, indicating the need for regular clinical and echocardiographic surveillance, and that long -term anticoagulation should be instituted for relatively minimal indi cations in these patients.