Ejection fraction/velocity ratio identifies prosthesis-patient mismatches in patients with aortic bioprosthetic valves and left ventricular dysfunction

Objectives. Recently, a new echocardiographic nonflow corrected index (ejection fraction/velocity ratio [EFVR] = percent left ventricular ejection fraction [EF]/maximum aortic gradient) has been introduced and has shown excellent accuracy in quantifying the effective orifice area (EOA) in native aortic valves and bioprostheses. The objective of this study was to assess the utility of the EFVR to quantify the indexed EOA in patients with an aortic bioprosthesis and left ventricular dysfunction considering an indexed EOA value of 0.85 cm²/m² or less to be indicative of a prosthesis-patient mismatch (PPM), defined as an EOA of the inserted prosthetic valve of less than that of the normal human valve. Methods. We studied 100 patients (62 men and 38 women; mean age ± SD, 71 ± 8.6 years) with an aortic bioprosthesis and left ventricular dysfunction (EF ≤49%), and we evaluated the indexed EOA by both the continuity equation (CE) and EFVR. Results. We found a significant linear correlation between the CE and EFVR (r = 0.85; P <.0001) and good agreement between the two methods in identifying patients with an indexed EOA of 0.85 cm²/m² or less; the correlation began to become nonlinear for patients with an indexed EOA of greater than 1.2 cm²/m², which was not clinically relevant. Notably, all 11 patients with a discrepancy between the indexed EOA and EFVR (ie, EFVR ≤1.0 and indexed EOA >0.85 cm²/m ²) also showed an indexed EOA of greater than 0.85 but less than or equal to 1.0 cm²/m² (meaning the presence of a mild PPM). Conclusions. The EFVR can be considered a reliable echocardiographic alternative to the CE, especially in conditions in which that is technically difficult, allowing identification of a PPM (indexed EOA ≤0.85 cm²/m ²) with excellent sensitivity and specificity.