Stentless and stented aortic valve replacement in elderly patients: Factors affecting midterm clinical and hemodynamical outcome.

OBJECTIVE: To report on the midterm results of aortic valve replacement (AVR) with stented and stentless bioprosthesis in an elderly population by analyzing the factors affecting survival and hemodynamical performance.

METHODS: In a retrospective study, 145 patients with a Toronto stentless prosthesis are compared with 110 patients with a stented Carpentier-Edwards valve. The 5- to 10-year clinical outcome, transprosthetic gradients, and early and late left ventricular mass (LVM) regression are analyzed in view of specific prosthesis- and patient-related factors.

RESULTS: Actuarial survival at 5 years is 82% after stentless AVR versus 68% after stented AVR (p < 0.001) in elderly patients. However, there was no difference in survival at 8 years, being 55.9% and 59.5%, respectively. Univariate analysis revealed that advanced age at the time of operation, NYHA class IV, use of a stented xenograft, presence of patient-prosthesis mismatch (PPM) (IEOA < or = 0.85 cm2/m2), and severe preoperative left ventricular (LV) hypertrophy (LVMI > 180 g/m2) affected survival adversely. But multivariate analysis determined only age, NYHA class IV and excessive LV hypertrophy as independent predictors of late mortality. Stented and stentless xenografts were equally effective in terms of transprosthetic gradients and LVMI regression. The use of a stentless valve significantly reduced the occurrence of PPM (18% vs 41%, p < 0.01). Early LVMI regression at 1 year was optimized by the avoidance of PPM, indicated by a higher absolute (43.7+/-28.3 g/m2 vs 58.6+/-33.8 g/m2, p = 0.003) and relative (25.0+/-12.7% vs 31.4+/-14.9%, p=0.004) mass regression. However, late LV remodeling was predominantly affected by systemic hypertension and severe preoperative LV hypertrophy, resulting in the incomplete LVMI resolution in 61.3% and 66.7% of these patients, respectively.

CONCLUSION: In elderly patients, aortic valve replacement appears to be equally effective with a stentless or stented bioprosthesis. Midterm clinical outcome is mainly determined by patient-related factors such as age, advanced NYHA class, and severity of preoperative LV hypertrophy. Regarding post-AVR left ventricular remodeling, patient-prosthesis mismatch influences the early phase, whereas arterial hypertension affects the late regression more. However, the left ventricular remodeling is continuously compromised by the preoperative presence of excessive hypertrophy, despite the efficacy of the aortic valve replacement.