Ejection fraction-velocity ratio in predicting symptoms in severe aortic stenosis

Background. Ejection fraction-velocity ratio (EFVR), the ratio between ejection fraction and peak aortic gradient (4Vmax²), was proposed and validated some years ago as a simplified index of aortic stenosis (AS) severity. Valvulo-arterial impedence (Zva) has been recently introduced as prognostic measure in AS patients (pts). According to current guidelines, AS is defined severe if aortic valve area (AVA) is = 1.0 cm2, or AVA index (AVAi) is = 0.6 cm2/m2 or mean gradient is = 40mmHg or peak velocity is = 4.0m/s. In pts with AS, the onset of symptoms represents the cornerstone that changes natural history and drives to appropriate approaches and treatments. Purpose. To evaluate the power of conventional indices of AS severity, EFVR and Zva in predicting symptoms in a consecutive series of pts with severe AS. Methods. We studied 143 patients (50% males), aged 76.4 ± 8.9 years, with severe AS according to guidelines. Pts were defined as symptomatic in presence of angina or sincope or NYHA class >2. In all patients we measured conventional indexes of severity, EFVR and Zva (as the ratio of systolic LV pressure to LV stroke volume index). Receiver operating characteristic (ROC) curve analysis was performed for each parameter to identify symptomatic status. Results. Mean left ventricular EF was 59.1 ± 10.4%, mean peak aortic velocity (Vmax) was 4.0 ± 0.7 m/s, transaortic mean pressure gradient (meanG) was 40.1 ± 4.7 mmHg, mean aortic valve was 0.77 ± 0.17 cm2, mean aortic area valve index (AVAi) was 0.42 ± 0.11 cm/m2. Zva was 4.9 ± 1.3 mmHg/ml/m2 and EFVR was 0.93 ± 0.31. Fifty-four patients (38%) were symptomatic. EFVR showed the largest area under curve (AUC, 0.72, p <0.001); followed by meanG (0.69, p<0.001), Vmax (0.64, p<0.01), AVAi (0.63, p<0.05) and AVA (0.62, p<0.05). The smallest and non significant AUC in predicting symptoms was found using Zva (AUC 0.56, p= NS). Conclusions. EFVR, a simple and not time-consuming index, demonstrated the best performance in predicting symptoms in patients with severe AS. Further studies are needed to evaluate the real prognostic role of EFVR in asymptomatic AS. Save as PDF