Echocardiographic Predictors of Reverse Remodeling After Cardiac Resynchronization Therapy and Subsequent Events

Abstract

Studies of echocardiographic predictors of response after cardiac resynchronization therapy (CRT) have largely involved single parameters. We hypothesized that combining parameters would be more robust and sought to develop a multiparametric echocardiographic score for predicting CRT response. Global longitudinal strain of left ventricle was added to standard echocardiographic measurements in 334 consecutive patients (224 men; mean, 65±12 years) who underwent baseline echocardiography before CRT and underwent follow-up echocardiograms at 1 year. Regression analysis was performed to create an echocardiographic score for prediction of LV reverse remodeling (defined as ≥15% reduction in the LV end-systolic volume). Cox proportional hazards models were used to identify the association of the score with death, transplantation or LV assist device implantation, and heart failure hospitalization during 57±22 months of follow-up. LV reverse remodeling (n=161; 48%) was associated with pre-CRT LV end-diastolic dimension index <3.1 cm/m(2), global longitudinal strain of left ventricle <-7%, left atrial area <26 cm(2), right ventricular end-diastolic area index <10.0 cm(2)/m(2), right atrial area <20 cm(2), and right ventricular fractional area change ≥35%. Combination of these into an echocardiographic score allowed prediction of LV reverse remodeling with a sensitivity of 84% and a specificity of 79%. During follow-up, there were 134 deaths, 18 heart transplantations/LV assist device implantations, and 93 heart failure admissions. The score was associated with heart failure admission, heart transplantation/LV assist device, or death (hazard ratio, 0.97; 95% confidence interval, 0.95-0.98; P<0.001) and all-cause death (hazard ratio, 0.97; 95% confidence interval, 0.96-0.98; P<0.001), independent of age, sex, ischemic cause, and initial functional class. A multiparametric echocardiographic score is helpful in selecting patients likely to undergo reverse remodeling after CRT and predicts clinical outcomes.