Survival advantage of stentless aortic bioprostheses

Background. Bioprostheses (BPs) are used to avoid anticoagulation after aor tic valve replacement (AVR) in patients over 65 years of age. Stentless BPs offer established hemodynamic benefits. We sought to determine whether the se advantages translate into improved survival. Methods. Between 1993 and 1997, follow-up data (for Food and Drug Administr ation submission) were collected prospectively for 160 consecutive, unselec ted hospital survivors who received the Freestyle valve (FS). Equivalent da ta were collected for 247 Carpentier-Edwards (CE) porcine xenograft patient s. Detailed comparative statistical analysis was used to compare events and survival between the groups. Follow-up was 100% complete for the FS (5.2 y ears maximum; mean 3.2 +/- 1.0 years) group and 98% (7.2 pears maximum; mea n 3.8 +/- 2.0 years) for CE. Results. The groups were well matched in age (FS, 73 +/- 6 years; CE, 74 +/ - 6 years), gender (FS, 58% male; CE, 62% male), ventricular function, and number of patients requiring coronary grafts (FS, 41%; CE, 37%). Actuarial survival at 5 years was 84% for FS versus 69% for CE (p = 0.023 Kaplan Meie r, p = 0.009 Cox). Annual mortality rates were 3.6% for FS versus 7.1% for CE (p = 0.001). Thromboembolic rate was 0.8% per year for FS and 2.4% for C E (p = 0.024) without a difference in cardiac rhythm. Incidence of nonstruc tural dysfunction (paravalvular leak) was 0.2% for FS versus 1.3% for CE (p = 0.020). Conclusions. By 5 years, the stentless valve patients had improved survival and reduced adverse events. Though differences in durability are yet to be proved, our findings support the use of stentless bioprostheses in this ag e group. (Ann Thorac Surg 2000;70:785-91) (C) 2000 by The Society of Thorac ic Surgeons.