Higher Acceleration/Ejection Time Ratio Predicts Impaired Outcome in Aortic Valve Stenosis

Abstract

Background: Acceleration time (AT)/ejection time (ET) ratio is a marker of aortic valve stenosis (AS) severity and predicts outcome in moderate-severe AS.

Methods: We explored the association of increased AT/ET ratio on prognosis in 1530 asymptomatic patients with presumably mild-moderate AS, normal ejection fraction, and without known diabetes or cardiovascular disease. Patients were part of the SEAS study (Simvastatin Ezetimibe Aortic Stenosis). Patients were grouped according to the optimal AT/ET ratio threshold to predict cardiovascular death and heart failure hospitalization. Low-gradient severe AS was identified as combined valve area ≤1.0 cm² and mean gradient <40 mm Hg. Outcome was assessed in Cox regression analyses, and results are reported as hazard ratio and 95% CI.

Results: Higher AT/ET ratio was significantly associated with lower systolic blood pressure, lower left ventricular ejection fraction, lower stress-corrected midwall shortening, low flow, and with higher left ventricular mass and higher peak aortic jet velocity. AT/ET ratio ≥0.32 provided the optimal cutoff for predicting incident cardiovascular death and heart failure hospitalization in the total study sample. In patients with low-gradient severe AS, this threshold was >0.32. AT/ET ratio ≥0.32 had a 79% higher risk of cardiovascular death and heart failure hospitalization (hazard ratio, 1.79 [95% CI, 1.20-2.68]). In patients with low-gradient severe AS, AT/ET ratio >0.32 was associated with a 2-fold higher risk of cardiovascular death and heart failure hospitalization (hazard ratio, 2.15 [95% CI, 1.22-3.77]).

Conclusions: In asymptomatic nonsevere AS and low-gradient severe AS, higher AT/ET ratio was associated with increased cardiovascular morbidity and mortality. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT00092677.

Keywords: aortic valve stenosis; blood pressure; heart failure; prognosis; stroke volume.