Aortic Closure Signal Length On Doppler Echocardiography Differentiates Aortic Patient-Prosthesis Mismatch From Prosthetic Stenosis

Purpose The purpose of this study was to investigate the diagnostic potential of the aortic closure (A2) signal length on Doppler echocardiography in distinguishing aortic patient-prosthesis mismatch (PPM) from prosthetic stenosis among patients with elevated gradients over bioprosthetic valves.Methods The A2 signal length was retrospectively measured for 150 patients with bioprosthetic aortic valves (50 with PPM, 50 with prosthetic stenosis, and 50 with normally functioning valves) from transthoracic echocardiograms performed at NYU Langone Health between 01/01/2012 and 08/01/2018.Results Mean A2 signal length was shorter among patients with PPM (11.1 ms +/- 5.2 ms), than among those with prosthetic stenosis (21.1 ms +/- 6.0 ms), P < .001 and controls (21.7 ms +/- 7.4 ms), P < .001. There was no difference in A2 signal length between prosthetic stenosis and controls. The A2 signal length yielded an AUC of 0.89 (95% CI 0.82-0.95) for predicting PPM over prosthetic stenosis.Conclusion Among patients with bioprosthetic aortic valves, the length of the A2 signal on Doppler echocardiography is shorter in PPM than in prosthetic stenosis and normally functioning valves. The A2 signal length may represent a novel metric to distinguish PPM from prosthetic stenosis.