Ejection fraction-velocity ratio for the assessment of aortic bioprosthetic valves in patients with systolic dysfunction

Abstract

The continuity equation (CE) represents the 'gold standard' for the evaluation of aortic valve area in patients with aortic stenosis, but it is time-consuming and subject to error, and can be technically demanding. Recently, a new echocardiographic nonflow corrected index was introduced and demonstrated excellent accuracy in quantifying the effective orifice area (EOA) in native aortic valves and bioprostheses. This new index, the ejection fraction (EF)-velocity ratio (EFVR), is obtained by dividing the percentage left ventricular EF by the maximum aortic gradient. To assess the usefulness of this echocardiographic index for quantifying the EOA in patients with aortic bioprosthesis and left ventricular dysfunction. A total of 70 patients (25 women and 45 men) with aortic bioprosthesis and left ventricular dysfunction (EF of 49% or less) were studied. The mean (+/- SD) age of the study population was 71.4+/-9 years. The EOA was evaluated, both by the CE and by the EFVR. A significant linear correlation between the CE and the EFVR was found (r=0.80; P<0.0001). The receiver operating characteristic curve analysis showed good agreement between the CE and the EFVR. An EFVR value of 1.15 or less was found to have a good sensitivity (89%) and good specificity (91%) in identifying patients with an EOA of 1.0 cm2 or smaller, with positive and negative predictive values of 79% and 95%, respectively. The EFVR, a simple index that is less time-consuming than the CE, allows the identification of patients with aortic bioprosthesis stenosis with excellent sensitivity and specificity. It may be taken into consideration in clinical practice for the evaluation of patients with aortic bioprosthesis stenosis and left ventricular dysfunction.