Small left atrium and mild mitral regurgitation predict super-response to cardiac resynchronization therapy

Abstract

AimsCardiac resynchronization therapy (CRT) can result in profound reverse remodelling. The goal of this study was to identify factors predictive of such beneficial response.Methods and resultsSuper-response to CRT was defined as normalization or near normalization of left ventricular systolic function without recognized reversible causes of heart failure. In a retrospective study, we compared baseline demographic, electrocardiogram, and echocardiographic characteristics of super-responders (n 21) with a population of unselected consecutive cardiac CRT patients (Control 1, n 330) and another sex-, age-, and aetiology-matched control group (Control 2, n 43). Compared with Control 1, super-responders had significantly smaller left ventricular end-diastolic diameter (65.4 ± 6.4 vs. 73.4 ± 9.3 mm, P 0.0001), higher ejection fraction (0.25 ± 0.05 vs. 0.22 ± 0.04, P 0.004), smaller degree of mitral regurgitation (MR; mean value 1.9 ± 0.9 vs. 2.6 ± 0.8, P <0.0001), and smaller left atrium (LA; 42.8 ± 4.6 vs. 50.0 ± 6.5 mm, P < 0.0001). Septal flash and inter-ventricular mechanical dyssynchrony were both more frequent among super-responders than in Control 2 subjects (93.8 vs. 69.8; P 0.01, and 93.8 vs. 62.8; P 0.01, respectively). In a multivariate analysis, smaller LA diameter and milder MR remained independent predictors of super-response.ConclusionSuper-response to cardiac CRT was associated with less advanced left-sided structural involvement as described by echocardiography. In particular, smaller LA and milder MR were independent predictors of pronounced reverse remodelling. © 2012 Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2012. For permissions please email: journals.permissionsoup.com.