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A left bundle-branch block (LBBB) contraction pattern identified from longitudinal-strain analysis predicts outcomes following cardiac resynchronization therapy (CRT). We investigated the use of an LBBB-contraction pattern identified from radial- or circumferential-strain analysis in the prediction of CRT benefits. Eighty CRT candidates were prospectively enrolled. Before CRT implantation, speckle-tracking analyses in three deformation directions were performed to determine whether an LBBB-contraction pattern was present. The study endpoints were reverse remodeling at 6 months, and adverse outcomes including death or heart failure hospitalization. At 6 months, 49 (61%) patients had reverse remodeling. An LBBB-contraction pattern identified from the radial strain in the mid-ventricular short-axis view or longitudinal strain in the four-chamber view provided excellent true-positive (86%) and false-negative (8%) rates for predicting reverse remodeling. During a median follow-up of 30 months, 31 patients (39%) had adverse outcomes. Absence of an LBBB-contraction pattern in radial (hazard ratio 3.74; 95% confidence interval 1.83-7.62) or longitudinal strain (hazard ratio 3.49; 95% confidence interval 1.71-7.13) was significantly associated with an increased risk of adverse outcomes. Adding the LBBB-pattern assessment by radial-(model χ 2 from 8.2 to 18.5, p = 0.005), or longitudinal-strain analysis (model χ 2 from 8.2 to 16.9, p = 0.011) to a risk model significantly improved the model, including QRS duration and ischemic etiology. In conclusion, an LBBB-contraction pattern identified from radial-strain analysis in the mid-ventricular short-axis view predicted reverse remodeling and outcome following CRT, similarly to the longitudinal-strain analysis.

Aims: Previous studies have identified four baseline characteristics associated with a favourable response to cardiac resynchronization therapy (CRT): female, non-ischaemic aetiology of heart failure, left bundle-branch block (LBBB), and QRS duration ≥150 ms. This study evaluated the incremental value of discoordination and dyssynchrony indices over these characteristics for the prediction of the response to CRT., Methods and Results: The speckle-tracking strain analysis was performed in 120 CRT candidates. Patients were divided into subgroups according to the gender (male vs. female), aetiology of heart failure (ischaemic vs. non-ischaemic), QRS morphology (LBBB vs. non-LBBB), and QRS duration (≥150 vs. <150 ms), respectively. Discoordination was measured using the mid-ventricular radial discoordination index (RDI-M), the ratio of the average mid-ventricular thinning to thickening during ejection. Patients with one of the four favourable characteristics were more likely to exhibit other favourable characteristics and had greater amounts of average myocardial thinning during ejection and RDI-M than those without (all P< 0.05). In contrast, dyssynchrony indices failed to demonstrate significant differences between male and female and between ischaemic and non-ischaemic subjects. Of 39 patients who had 6-month follow-up data after CRT, left ventricular reverse remodelling was found in 22 patients (56%). Combining the favourable characteristics and RDI-M provides the best ability to predict reverse remodelling after CRT (area under the curve = 0.85, 95% confidence interval 0.73-0.98, P < 0.001)., Conclusion: Mechanical discoordination rather than mechanical dyssynchrony provides a significant incremental value over the baseline characteristics for the prediction of the response to CRT.

Background: Previous studies have identified four clinical characteristics associated with a favorable response to cardiac resynchronization therapy (CRT): female gender, left bundle branch block (LBBB), QRS duration ≥ 150 msec, and nonischemic etiology of heart failure. The aim of this study was to evaluate the incremental value of baseline inefficient deformation and time delay indices over clinical characteristics for predicting CRT response., Methods: Speckle-tracking longitudinal strain was analyzed in 119 CRT candidates. Patients were divided into subgroups according to sex (male vs. female), QRS morphology (LBBB vs. non-LBBB), QRS duration (≥150 vs. <150 msec), and heart failure etiology (ischemic vs nonischemic). Inefficient deformation was indexed by the septal systolic stretching that occurred after prematurely terminated shortening (systolic rebound stretch in the septal wall) and the absolute differences between peak strain and end-systolic strain across 16 segments (strain delay index). Time to peak strain was measured to derive the septal-to-lateral delay and the 12-segment standard deviation of time to peak strain. CRT response was defined as 6-month end-systolic volume reduction ≥ 15%., Results: Patients with one of the four favorable characteristics were more likely to exhibit other favorable characteristics and had greater amounts of inefficient deformation than those without. In contrast, time delay indices were not significantly different in any pairwise comparison except for that between patients with and those without LBBB. Of the 43 patients for whom 6-month follow-up data were available, CRT response was found in 26 (60%). Systolic rebound stretch in the septal wall and strain delay index rather than time delay indices provided significant incremental value over clinical characteristics when predicting CRT response., Conclusions: Combined systolic rebound stretch in the septal wall (or strain delay index) and favorable characteristics may help identify CRT responders., (Copyright © 2013 American Society of Echocardiography. Published by Mosby, Inc. All rights reserved.)

Aims Previous studies have identified four baseline characteristics associated with a favourable response to cardiac resynchronization therapy (CRT): female, non-ischaemic aetiology of heart failure, left bundle-branch block (LBBB), and QRS duration ≥150 ms. This study evaluated the incremental value of discoordination and dyssynchrony indices over these characteristics for the prediction of the response to CRT. Methods and results The speckle-tracking strain analysis was performed in 120 CRT candidates. Patients were divided into subgroups according to the gender (male vs. female), aetiology of heart failure (ischaemic vs. non-ischaemic), QRS morphology (LBBB vs. non-LBBB), and QRS duration (≥150 vs. <150 ms), respectively. Discoordination was measured using the mid-ventricular radial discoordination index (RDI-M), the ratio of the average mid-ventricular thinning to thickening during ejection. Patients with one of the four favourable characteristics were more likely to exhibit other favourable characteristics and had greater amounts of average myocardial thinning during ejection and RDI-M than those without (all P< 0.05). In contrast, dyssynchrony indices failed to demonstrate significant differences between male and female and between ischaemic and non-ischaemic subjects. Of 39 patients who had 6-month follow-up data after CRT, left ventricular reverse remodelling was found in 22 patients (56%). Combining the favourable characteristics and RDI-M provides the best ability to predict reverse remodelling after CRT (area under the curve = 0.85, 95% confidence interval 0.73–0.98, P < 0.001). Conclusion Mechanical discoordination rather than mechanical dyssynchrony provides a significant incremental value over the baseline characteristics for the prediction of the response to CRT. [ABSTRACT FROM PUBLISHER]