A ten-year study of the Ionescu-Shiley low-profile bioprosthetic heart valve.

Seven hundred and eight adults (age > or = 16 years) with isolated aortic (n = 433) or mitral (n = 275) Ionescu-Shiley Low-Profile (ISLP) pericardial valves were followed at 14 implanting centres 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 operative mortality rate was 3.0% for aortic valve replacement (AVR) and 5.5% for mitral valve replacement (MVR) (p = ns). Actuarial patient survival 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 valve appears to have durability comparable to other contemporary bioprosthetic valves. For aortic prostheses, the freedom from structural deterioration was 96.5% at 5 years and 73.7% at 10 years, and 89.7% at 5 years and 62.4% at 10 years for mitral prostheses. Structural deterioration was significantly more frequent following MVR than after AVR (p < 0.05). Structural deterioration was the principal cause for reoperation, but sudden deterioration precluding safe reoperation was not a dominant 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 tissue valves in its incidence of other valve-related complications. We conclude that ISLP valves now implanted for 7 years or more are entering 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 indications in these patients.