Freestyle Aortic Root Bioprosthesis Is a Suitable Alternative for Aortic Root Replacement in Elderly Patients: A Propensity Score Study

Abstract

The aim of this retrospective study was to compare the early and midterm clinical outcomes of aortic root replacement in elderly patients receiving the Freestyle stentless bioprosthesis (FSB) (Medtronic Inc, Minneapolis, MN) with younger patients receiving a mechanical valve conduit. From January 2001 to December 2010, 185 consecutive patients underwent aortic root replacement. Of these, 79 (43%) patients received the Freestyle bioroot (Medtronic Inc, Minneapolis, MN) (group F) and 106 (57%) patients received a mechanical valve conduit (group M). Target endpoints were 30-day mortality, 5-year survival, 5-year freedom from cardiac death, and 5-year freedom from major adverse valve-related and cardiovascular events (MAVCE) (cardiac death, cerebrovascular accident, myocardial infarction, heart failure, valve prosthesis dysfunction requiring reoperation, and thromboembolic and hemorrhagic events). A propensity score model was built to adjust the results according to preoperative and operative characteristics of both groups. Thirty-day mortality was similar in both groups (F group, 2.5% versus M group, 5.7%; p=0.407). Unadjusted analysis showed no differences between groups, whereas adjusted analysis showed a significantly higher 5-year freedom from cardiac death and MAVCE in group F (group F, 98.6±1.9 versus group M, 88.0%±3.0%; p=0.038; group F, 97.4%±2.6% versus group M, 81.2%±3.6%; p=0.010). Multivariate analysis confirmed a significantly higher risk for 5-year MAVCE in patients who did not undergo implantation with the Freestyle bioprosthesis (hazard ratio [HR], 6.87; 95% confidence limit [CL], 1.43-15.09; p=0.016). In elderly patients, the FSB seems to be as safe as mechanical composite grafts in the perioperative period but results in superior freedom from MAVCE at 5 years postoperatively.