Long-term follow-up of patients undergoing aortic root enlargement for insertion of a larger prosthesis

OBJECTIVES To evaluate the long-term survival of patients undergoing aortic root enlargement (ARE) compared with those with small aortic root (SAR), exploring risk factors for late mortality as well as the influence of patient-prosthesis mismatch (PPM). METHODS From January 1999 through December 2010, a total of 3724 patients underwent isolated or combined aortic valve replacement at our institution. From these, 239 (6.4%) had transannular ARE with a pericardial patch, to permit implantation of a larger prosthesis. This study population was compared with a control group of 767 patients (20.6%) who were considered to have SAR, as a prosthesis of size 21 or less was implanted. Mean age was comparable: 70.4 ± 12.5 vs 69.9 ± 9.6 years for ARE and SAR groups, respectively (P = 0.552). Female sex predominated in the control group (81.6 vs 88.0%; P = 0.011). Patients of the ARE group tended to have higher mean body surface area (1.59 ± 0.15 vs 1.57 ± 0.13 m(2); P = 0.061) and were less symptomatic (NYHA III-IV: 49.4 vs 57.9%; P = 0.021). RESULTS Implantation of bioprostheses was more frequent in the ARE group (76.2 vs 52.3%; P < 0.001), while concomitant procedures were more frequent in the SAR group (25.5 vs 32.2%; P = 0.050). Patients in the SAR group had higher moderate PPM (29.7 vs 50.1%; P < 0.001), but no patient was left with severe PPM. Hospital mortality was not statistically different between ARE and SAR groups (0.8 vs 0.5%; P = 0.632). The overall survival rate for ARE group patients at 5, 10 and 15 years was 82.7 ± 2.5, 64.8 ± 3.8 and 36.0 ± 7.5%, respectively, in comparison with 86.2 ± 1.3, 62.9 ± 2.3 and 38.4 ± 4.3% for the SAR group (P = 0.741). There was no significant difference in long-term survival of ARE patients compared with the age- and gender-matched general population (P = 0.794). Long-term survival was not affected by the presence of PPM. Increasing age, male sex, atrial fibrillation, LV end-systolic dimension, preoperative creatinine and NYHA class III-IV were significant predictors of late mortality. CONCLUSIONS ARE can be done safely, effectively reducing PPM. Although no difference was found in early and late mortality compared with the SAR group, long-term survival rates of ARE patients was comparable with that of the general population, unlike those of the SAR group.