Ejection fraction velocity ratio as an indicator of aortic stenosis severity

Background: Despite the widespread use of the continuity equation in the estimation of aortic value area (AVA) in patients with aortic stenosis, it is subject to errors, time consuming, and can be technically demanding. As such, simpler methods of assessing aortic stenosis severity have been pursued. Methods: The ejection fraction velocity ratio [EFVR = ejection fraction (%) / maximal aortic velocity (m/sec)] was compared to AVA determined with the continuity equation in 857 patients with aortic stenosis and varying degrees of LV systolic dysfunction. Severe aortic stenosis was defined as an AVA < 1.0 cm(2). Results: There was good to excellent correlation between our index and aortic valve area (P < 0.001 for each ejection fraction subgroup). Receiver operating characteristic analysis showed that the EFVR functioned well with areas under the curve between 0.893 and 0.938. Conclusion: The EFVR is a simple noninvasive method for screening patients for an AVA of 1 0 cm(2). It could be used as a screening test or in lieu of the continuity equation particularly when there is problematic measurement of either the LVOT diameter or velocity. (ECHOCARDIOGRAPHY, Volume 22, March 2005).