Prognostic Impact of the Ratio of Acceleration Time to Ejection Time in Patients With Low Gradient Severe Aortic Stenosis and Preserved Ejection Fraction

The clinical management of patients with low gradient severe aortic stenosis (LG-SAS) and preserved left ventricular ejection fraction (LVEF) remains challenging owing to their heterogeneity. The aim to this study was to evaluate the relation between an ejection dynamic parameter linked to AS severity and outcome, the ratio of acceleration time (AT) to ejection time (ET), in a cohort of patients with LG-SAS and preserved LVEF. Three hundred and fifty-six patients with LG-AS (defined by AVA ≤1 cm² and/or AVAi ≤0.6 cm²/m² and mean aortic pressure gradient <40 mm Hg) and preserved LVEF ≥50% were studied. The relation between AT/ET and all-cause and cardiac mortality during follow-up was studied. Median follow-up was 41 months (interquartile range, 35 to 47 months). Median AT/ET was 0.32 (interquartile range, 0.29 to 0.36). The 5-year estimates of all-cause and cardiac mortality were respectively 57 ± 7%, 36 ± 7% for patients with AT/ET >0.36 versus 43 ± 4%, 16 ± 3% for patients with AT/ET ≤0.36 (p = 0.024 and p <0.001, respectively). After adjustment on known predictors of outcome including aortic valve replacement used as a time-dependent covariate, there was a significant increase in all-cause mortality risk for patients with AT/ET >0.36 (adjusted hazard ratio 2.04 [95% confidence interval, 1.32 to 3.13]; p = 0.001) and cardiac mortality risk (adjusted hazard ratio 2.89 [95% confidence interval, 1.54 to 5.43]; p<0.001) compared with patients with AT/ET ≤0.36. The association of AT/ET >0.36 and all-cause or cardiac mortality risk was consistent in subgroups of patients with LG-SAS and preserved EF. In conclusion, an AT/ET ratio of more than 0.36 is an independent predictor of mortality in patients with LG-SAS and preserved EF.