Moderate Patient-Prosthesis Mismatch Has No Independent Effect on 30-Day Mortality After Isolated Aortic Valve Replacement

Abstract

It is still not clear whether the presence of a moderate patient-prosthesis mismatch after isolated aortic valve replacement can increase 30-day mortality. The aim of this study was to determine whether a moderate mismatch is an independent predictor of early global or cardiac mortality after aortic valve replacement. The study involved 272 adult patients (median age, 72 years; interquartile range, 66-76 years) undergoing isolated aortic valve replacement. Moderate mismatch was considered to be present if the projected indexed effective orifice area was < or =0.85 and >0.65 cm2/m2. Severe mismatch was present if the projected indexed effective orifice area was < or =0.65 cm2/m2. Follow-up to assess survival at 30 days was carried out in 100% of patients. Moderate mismatch was observed in 37.9% of patients. None had a severe mismatch. Multivariate analysis identified the following independent predictors of global mortality at 30 days: left ventricular ejection fraction <50% (P=.03) and age (P=.01). The same variables were identified as predictors of 30-day cardiac survival, but at a higher level of statistical significance: left ventricular ejection fraction <50% (P=.006) and age (P=.008). The analysis did not identify moderate mismatch as a predictor of global or cardiac 30-day mortality in our study population. Our findings indicate that the evidence that inserting a prosthesis of the measured size in a small aortic annulus compromises the patient's survival is far from clear when the patient-prosthesis mismatch is moderate.