Abstract 16920: Accuracy of Echocardiographic Estimation of Left Ventricular Relaxation and Filling Pressure: A Multicenter Study in Japan

Abstract

Background: Mitral annular early-diastolic velocity (e') and the early transmitral velocity to e' ratio (E/e') have been widely used as the indexes of left ventricular (LV) relaxation and filling pressure, respectively. There are, however, a number of clinical settings in which e' and E/e' may not be reliable. Myocardial strain rate (SR) indexes in the longitudinal direction during rapid filling phase or during isovolumic relaxation period (IVR) derived from speckle tracking imaging were also demonstrated to reflect LV relaxation and filling pressure. However, circumferential or radial SR indexes have not yet been tested. We thus conducted a multicenter study in Japan (SMAP) to determine the accuracy of echocardiographic indexes of LV relaxation and filling pressure including SR indexes.

Methods: From 5 institutions, 70 patients with various structural heart diseases and sinus rhythm (60±14 years, 17 females) excluding significant valvular disease and pericardial disease were enrolled. Time constant of LV pressure decay (τ) and LV mean diastolic pressure (LVMDP) were measured using a micromanometer-tipped catheter. Conventional echocardiographic indexes and SR indexes were also measured.

Results: Transmitral E/A (r=0.55, p<0.001), pulmonary venous S/D (r=-0.33, p=0.007), and e' (r=-0.30, p=0.012) weakly correlated with τ (48±12 msec). Global longitudinal, circumferential, and radial SRs during rapid filling phase, circumferential and radial SRs during IVR also significantly correlated with τ. Among those, the correlation of circumferential SR during IVR (C-SR_IVR) was the best (r=-0.40, p=0.001). E/e' weakly correlated (r=0.31, p=0.010) with LVMDP (8.8±6.6 mmHg). In contrast, there was more strong correlation between E/A and LVMDP (r=0.56, p<0.001) or between E/(C-SR_IVR) and LVMDP (r=0.59, p<0.001).

Conclusions: The first multicenter study in Japan demonstrated that e' and E/e' were limited for estimating LV relaxation and filling pressure in patients with various structural heart diseases. Global circumferential SR during IVR may be the best index of LV relaxation among conventional echocardiographic and SR indexes.