Abstract 13489: Diastolic Strain Parameters Predict Outcome in High Risk Heart Failure Patients Referred for LVAD or Heart Transplantation

Abstract

Background and Objectives: Global longitudinal strain by speckle tracking echocardiography is a promising measurement of LV (left ventricular) systolic function and predicts outcome in patients with heart failure (HF). But, there is a paucity of data about diastolic strain parameters as they relate to outcome in this population. We sought to evaluate whether diastolic strain indices provide independent prognostic information in patients with advanced HF.

Methods: We included 365 HF patients referred for cardiac transplantation or LVAD at our center between 2004 and 2009 (age 54±12 yrs, 23% females, LVEF 24 ±10%, and ischemic cardiomyopathy in 49%). All patients had echocardiographic imaging within 7-10 days of presentation. In addition to conventional 2D and Doppler measurements, Velocity vector imaging (VVI) was used to measure longitudinal (LS) in 3 apical views, circumferential (CS) and radial strain (RS). Strain imaging diastolic parameters were derived as peak diastolic strain, strain at one-third of diastolic duration, and diastolic index (DI) as: (Strain at aortic valve closure-Strain at 1/3 diastolic duration)/strain at aortic valve closure. 34 patients were excluded due to suboptimal images and 331 were included in the final analysis. The primary end point was the occurrence of death, LVAD implantation or cardiac transplantation.

Results: There were 154 events (46.5%) during follow-up (mean time to event: 236±154days). In univariable analysis, age, LVEF, mitral E/A ratio, pulmonary artery systolic pressure, time to peak CS, end systolic CS, CS diastolic parameters (peak, 1/3 diastole, and DI), time to peak LS, end systolic LS, and LS diastolic parameters (from the 3 apical views) were significant predictors of events. On multivariable analysis, age (odds ratio [OR]: 1.04, 95% confidence interval [CI]: 1.014 to 1.067, p = 0.002), mitral E/A ratio (OR: 1.25, 95% CI: 1.006 to 1.56, p = 0.04), and CS at 1/3 diastolic duration (OR: 1.33, 95% CI: 1.15 to 1.527; p <0.001) were independently associated with cardiac events.

Conclusion: Circumferential diastolic strain at 1/3 diastolic duration is an independent predictor of clinical events in HF patients referred for cardiac transplantation or LVAD implantation.