Ratio of Acceleration Time to Ejection Time for Assessing Aortic Stenosis Severity

BACKGROUND: Inconsistencies in the grading of aortic valve stenosis are frequent (24-38%). Guidelines highlight the waveform shape when discrepancies are present. Our aim was to evaluate the severity of aortic stenosis by the ratio of acceleration time to ejection time (AT/ET). METHODS: Between January 2011 and January 2013, patients with at least moderate aortic stenosis (valve area < 1.5 cm(2) ) evaluated in our echocardiography laboratory were enrolled. Clinical data were recorded including symptoms attributable to aortic stenosis. Quantitative echocardiographic Doppler parameters as ejection dynamics (ejection time and acceleration time) and conventional parameters, and usual laboratory test including natriuretic peptides (NT-proBNP) were analyzed. RESULTS: One hundred eight patients with aortic valve stenosis were recruited (mean age 77 ± 7 years; 57% women). Comorbidity of the patients was frequent: 85% hypertension, 59% diabetes, 31% chronic renal failure, 26% smokers, mean body mass index 30.0 ± 6.6 kg/m(2) . Ninety-six patients (90%) were symptomatic at the index visit. Using a cutoff of 0.35, AT/ET had a sensitivity of 77% and a specificity of 100% to discriminate symptomatic patients. Serum value of NT-proBNP was higher in patients with AT/ET > 0.35 (9885 ± 3111 vs. 2600 ± 1175, P < 0.001). This ratio showed a good correlation with indexed left ventricle mass (r = 0.60, P < 0.001), DVI (r = -0.56, P < 0.001), and AVA (r = -0.49, P < 0.001). CONCLUSIONS: Ejection dynamics through aortic valve, particularly AT/ET ratio, is a useful tool for assessing aortic stenosis severity, with a good correlation with flow-independent parameters in aortic stenosis.