Abstract 1864: Real-time Three-dimensional Echocardiography: A Novel Imaging Modality That Predicts Acute Left Ventricular Reverse Remodeling After Cardiac Resynchronization Therapy.
Objective. To evaluate the value of real-time 3-dimensional echocardiography (RT3DE) to quantify left ventricular (LV) mechanical dyssynchorny and to predict acute echocardiographic response to cardiac resynchronization therapy (CRT).
Methods. 60 consecutive heart failure patients scheduled for CRT were included. RT3DE was performed before and within 48 hours after pacemaker implantation to calculate both LV volumes and LV dyssynchrony. LV dyssynchrony was defined as the standard deviation of the time taken to reach the minimum systolic volume for 16 LV segments (referred to as the systolic dyssynchrony index, SDI). Patients were subsequently divided into acute responders or non-responders, based on a reduction ≥15% in LV end-systolic volume immediately after CRT.
Results. 4 patients (7%) were excluded from further analysis because either suboptimal apical acquisitions or significant translation artefacts. Out of the remaining 56 patients, 35 patients (63%) were classified as acute responders. Baseline characteristics were similar between responders and non-responders, except for the SDI, which was larger in responders. Moreover, responders demonstrated a significant reduction of SDI immediately after CRT (from 9.7±4.1% to 3.6±1.8%, P < 0.0001), whereas SDI did not change in non-responders (3.4±1.8% versus 3.1±1.1%, NS). ROC curve analysis revealed that a cut-off value for SDI ≥5.6% yielded a sensitivity of 88% with a specificity of 86% to predict acute LV reverse remodeling after CRT (AUC 0.96).
Conclusion. RT3DE is highly predictive for acute echocardiographic response to CRT (sensitivity 88% and specificity 86%). In addition, RT3DE allows assessment of changes in LV volumes and LV ejection fraction in patients before and after CRT implantation.