Abstract 10342: Prognostic Implications of Myocardial Contraction Fraction in Patients With Severe Aortic Stenosis Referred for TAVR.

Introduction: The prognostic impact of myocardial contraction fraction (MCF), in patients with severe aortic stenosis (AS) remains unexplored. We investigated the association between MCF and 1-year all-cause mortality in patients with severe AS who underwent a transcatheter aortic valve replacement (TAVR). Hypothesis: MCF, a volumetric measurement of myocardial shortening analogous to strain, may help to improve risk stratification in patients with severe AS referred for TAVR especially in those with preserved left ventricular ejection fraction (LVEF). Methods: Patients with severe AS referred for TAVR were divided into 2 groups according to the estimated MCF (MCF≤30% versus MCF>30%). MCF was assessed as the ratio of stroke volume (SV) to myocardial volume. ROC curves were performed for assessing the best cut-off point of MCF for predicting the primary outcome. The primary endpoint was 1-year all-cause mortality. A Cox regression analysis was performed for independent risk factors of mortality. Baseline patient and echo characteristics were included using a backward stepwise selection method, and variables significant at α= 0.10 were included for adjusted multivariate analysis. Results: Of 126 patients, (mean age 82± 5 years, 45% male), 44% showed MCF≤30%. When comparing against patients with preoperative MCF>30%, these patients showed higher body mass index (28,2±5,7 kg/m2 versus 25,9±4,5 kg/m2, p=0,02), higher surgical Euroscore II (6,2±4,5 versus 4,7±3,2 p=0,032), lower LVEF (54,2±11,9% versus 58,5±10,8%, p=0,042) and more severe AS (AVA index 0,40±0,09 cm2/m2 versus 0,45±0,10 cm2/m2, p=0,03). The median follow-up was of 14 (0-96) months, and 16% of patients died. Patients with MCF≤30% showed significantly increased all-cause mortality (Figure , log-rank p<0.002). In a multivariate model correcting for left atrial volume index (LAVI), MCF≤30% was independently associated with increased risk for all-cause 1-year mortality (HR 3.3, 95% CI [1.1-9.2], p<0.021). Conclusions: In a large population of patients with symptomatic severe AS, MCF≤30% is independently associated with increased mortality. [ABSTRACT FROM AUTHOR]