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Benefits of Cardiac Resynchronization Therapy in an Asynchronous Heart Failure Model Induced by Left Bundle Branch Ablation and Rapid Pacing
Published on: December 11, 2017
Incremental value of radial discoordination index for the prediction of response to cardiac resynchronization therapy
Yi-Hsin Chan1, Chi-Tai Kuo, Yung-Hsin Yeh
1First Division of Cardiovascular Department, Chang Gung Memorial Hospital, Linkou, 5 Fu-shin street, Kweishan Hsiang, Taoyuan, Taiwan.
Insights
Mechanical discoordination, not dyssynchrony, significantly improves prediction of cardiac resynchronization therapy (CRT) response. Combining baseline factors with discoordination indices offers the best prediction for CRT success.
Area of Science:
- Cardiology
- Medical Imaging
- Heart Failure Management
Background:
- Four baseline characteristics predict cardiac resynchronization therapy (CRT) response: female sex, non-ischaemic heart failure, left bundle-branch block (LBBB), and QRS duration ≥150 ms.
- Predicting CRT response remains crucial for optimizing patient outcomes.
Purpose of the Study:
- To assess the added value of mechanical discoordination and dyssynchrony indices in predicting CRT response.
- To compare the predictive power of these indices against established baseline characteristics.
Main Methods:
- Speckle-tracking strain analysis was performed on 120 CRT candidates.
- Mechanical discoordination was quantified using the radial discoordination index (RDI-M).
- Predictive models were developed combining baseline characteristics and mechanical indices.
Main Results:
- Patients with favorable baseline characteristics showed greater myocardial thinning and higher RDI-M.
- Mechanical discoordination indices, particularly RDI-M, significantly improved CRT response prediction (AUC=0.85).
- Dyssynchrony indices did not show significant predictive value across all subgroups.
Conclusions:
- Mechanical discoordination offers incremental predictive value for CRT response beyond baseline characteristics.
- RDI-M is a promising marker for identifying patients likely to benefit from CRT.
- This approach enhances personalized treatment strategies for heart failure patients.
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.
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Pre-Procedural Preparation
01:11Assessment of radial pulse
The radial pulse, located at the wrist, is often the preferred site for assessing peripheral pulse because of its accessibility and dependability. The process of determining the radial pulse involves several steps: