Abstract 9104: Identifying Determinants of Aortic Allograft Durability following Valve/Root Replacement - A Single Instituitional Follow-up Study of 852 Cryopreserved Allograft Implanted in the Last 35 years
Background: Use of biological valve substitute for aortic valve/root surgery is limited by structural deterioration, which is suggested to be associated with immune response and atherosclerosis-like inflammatory process. While young age is a known contributor to structural deterioration, other factors are not fully understood, in part due to insufficient follow-up and limited use of contemporary biological valve substitute in young population. Cryopreserved allograft is a single biological valve substitute which has been used with a consistent quality for a variety of age groups in the last 35 years. We hypothesized that durability of cryopreserved aortic allograft might be affected by multiple factors.
Methods: Since 1975, 852 cryopreserved aortic allografts have been implanted in 818 patients, including 292 patients (34%) below 40 years of age, by using sub-coronary (n=449), full-root (n=368) and inclusion-cylinder (n=35) implantation techniques in our institution. Primary end points are death or reintervention for allograft.
Results: By December 2009, 240 deaths (28%), including 22 early postoperative deaths (3%), occurred prior to reintervention, while 252 allografts (30%) were reinterventioned for structural deterioration (91%), non-structural deterioration (8%) or end stage heart failure (1%). Actuarial survival and freedom from reintervention was 84% and 84% at 10 years, 62% and 56% at 20 years and 37% and 45% at 30 years, respectively. Independent contributors to reintervention, analysed by Cox proportional hazard model, were body mass index >35 (P=0.01, hazard ratio (HR); 2.3), aortic annular calcification extending into the mitral valve (P<0.001, HR; 2.1), history of blood transfusion (P=0.02, HR; 1.8), younger patient age (P<0.001, HR; 1.02) and donor age >50 years (P=0.04, HR; 1.6), whereas implantation techniques, blood-group mismatch or other atherosclerotic risk factors were not independent contributors.
Conclusions: Severe obesity, extensive annular calcification and history of blood transfusion, in addition to reported factors, independently contributed to aortic allograft deterioration, suggesting possible preventive and/or therapeutic targets for structural deterioration of biological valve substitute.
- © 2010 by American Heart Association, Inc.