Abstract 9419: A Novel Global Strain Imaging Diastolic Index for the Estimation of Left Ventricular Filling Pressure

Abstract

Background: Recently, strain imaging diastolic index (SIDI) has been proposed to assess left ventricular (LV) regional abnormal relaxation induced by myocardial ischemia. We aimed to examine whether non-invasive global SIDI obtained using 2D speckle tracking imaging (2DSI) could predict elevated levels of LV filling pressure. Methods: One hundred and twenty patients (age 63±13 years) with suspected coronary artery disease underwent echocardiography and 2DSI during simultaneous cardiac catheterization. Mean LV ejection fraction was 46.3±17.6%. LV pressure curve was obtained to measure pre-atrial contraction (Pre-AC) pressure as a surrogate for LV filling pressure. SI-DI was defined as LV longitudinal changes during the first one-third of diastolic duration. In 2DSI, LV longitudinal SIDI of 18 LV segments were measured from the apical 2-, 3-, and 4-chamber views. Then, longitudinal global SIDI (L-global SIDI) was calculated as a mean SIDI of 18 LV segments. Mitral inflow and tissue Doppler imaging were also assessed. Results: Among 120 patients, 64 cases had Pre-AC pressure > 15 mmHg. L-global SIDI had a significant and better correlation with pre-AC pressure (p<0.001, R=0.47)(Figure 1), than E/e’ (p<0.01, R=0.26) . In multiple stepwise regression analysis, L-global SIDI was the strongest independent determinant of pre-AC pressure (β=-0.66, P<0.001), among E/A, left atrium volume index, E/e’, and e’. In addition, L-global<0.50 was the optimum cutoff value to predict LV pre-AC pressure >15mmHg (sensitivity, 89%; specificity, 51%)(Figure 2), while E/e’>11.2, the optimum cutoff value of E/e’ predicted LV pre-A contraction pressure >15mmHg (sensitivity, 65%; specificity, 75%). Conclusions: L-global SIDI derived from 2DSI can be used to estimate LV filling pressure noninvasively. Global SI-DI may provide more accurate estimation of LV filling pressure, compared with conventional mitral inflow and tissue speckle tracking.