Relationship Between the Ratio of Acceleration Time/Ejection Time and Mortality in Patients With High-Gradient Severe Aortic Stenosis
Résumé
Background The ratio of acceleration time/ejection time (AT/ET) is a simple and reproducible echocardiographic parameter that integrates aortic stenosis severity and its consequences on the left ventricle. No study has specifically assessed the prognostic impact of AT/ET on outcome in patients with high-gradient severe aortic stenosis (SAS) and no or mild symptoms. We sought to evaluate the relationship between AT/ET and mortality and determine the best predictive AT/ET cutoff value in these patients. Methods and Results A total of 353 patients (median age, 79 years; 46% women) with high-gradient (mean pressure gradient >= 40 mm Hg and/or aortic peak jet velocity >= 4 m/s) SAS, left ventricular ejection fraction >= 50%, and no or mild symptoms were studied. The impact of AT/ET <= 0.35 or >0.35 on all-cause mortality was retrospectively studied. During a median follow-up of 39 (25th-75th percentile, 23-62) months, 70 patients died. AT/ET >0.35 was associated with a considerable increased mortality risk after adjustment for established prognostic factors in SAS under medical and/or surgical management (adjusted hazard ratio [HR], 2.54; 95% CI, 1.47-4.37; P<0.001) or conservative management (adjusted HR, 3.29; 95% CI, 1.70-6.39; P<0.001). Moreover, AT/ET >0.35 improved the predictive performance of models including established risk factors in SAS with better global model fit, reclassification, and discrimination. After propensity matching, increased mortality risk persisted when AT/ET >0.35 (adjusted HR, 2.10; 95% CI, 1.12-3.90; P<0.001). Conclusions AT/ET >0.35 is a strong predictor of outcome in patients with SAS and no or only mild symptoms and identifies a subgroup of patients at higher risk of death who may derive benefit from earlier aortic valve replacement.