Complete left bundle branch block and smaller left atrium are predictors of response to cardiac resynchronization
Teruhiko Imamura1, Koichiro Kinugawa, Daisuke Nitta
1Department of Therapeutic Strategy for Heart Failure, Graduate School of Medicine, University of Tokyo.
Insights
Complete left bundle branch block (CLBBB) and smaller left atrial volume index (LAVI) predict response to cardiac resynchronization therapy with defibrillator (CRT-D) in advanced heart failure patients. These responders may benefit more from CRT-D.
Area of Science:
- Cardiology
- Heart Failure Management
- Electrophysiology
Background:
- Cardiac resynchronization therapy with defibrillator (CRT-D) is often considered, but its efficacy as a rescue strategy in advanced heart failure (HF), particularly in inotrope-dependent patients, remains uncertain.
- Early ventricular assist device (VAD) implantation is suggested as an alternative, but predictors for CRT response in this population are not well-defined.
Purpose of the Study:
- To identify predictors of response to CRT-D in patients with advanced heart failure.
- To evaluate the impact of these predictors on clinical outcomes and VAD-free survival.
Main Methods:
- Retrospective analysis of 67 advanced HF patients (<65 years) who received CRT-D between 2007 and 2014.
- Logistic regression analysis to identify baseline predictors of CRT-D response, defined as >10% improvement in left ventricular ejection fraction (LVEF) at 6 months.
- Comparison of clinical outcomes, including VAD-free survival, between responders and non-responders.
Main Results:
- 16% of patients (11/67) were responders.
- Complete left bundle branch block (CLBBB) and left atrial volume index (LAVI) <43 ml/m² were significant predictors of CRT-D response (OR 6.663, P=0.032 and OR 36.67, P=0.001, respectively).
- Responders showed improved LVEF, reduced B-type natriuretic peptide, and higher 2-year VAD-free survival (86% vs. 52%, P=0.044) compared to non-responders.
Conclusions:
- CLBBB and smaller LAVI are novel predictors of CRT-D response in advanced HF patients in real-world settings.
- Patients with these predictors may be better candidates for CRT-D, potentially delaying the need for cardiac replacement therapy.
- These findings aid in patient selection for CRT-D in advanced HF.
Background:
We previously reported that cardiac resynchronization therapy with defibrillator (CRT-D) is not an appropriate rescue strategy in patients with advanced heart failure (HF), especially those dependent on inotrope infusion, and instead early ventricular assist device (VAD) implantation should be considered. Predictors of response to CRT in such populations, however, remain uncertain.
Methods And Results:
We studied 67 inpatients aged <65 years old with advanced HF, who received CRT-D between 2007 and 2014. Eleven patients (16%) were responders, in whom LVEF improved >10% at 6-month follow up. On logistic regression analysis, LA volume index (LAVI) <43 ml/m(2)(odds ratio (OR), 36.67; P=0.001) and complete left bundle branch block (CLBBB; OR, 6.663; P=0.032) were significant predictors of response to CRT-D among the baseline variables. Patients with both predictors were associated with improvements in LVEF and plasma B-type natriuretic peptide compared with those with none of these predictors during the 6-month follow up period (P<0.05 for both). VAD-free survival rate was significantly higher in the responders compared with the non-responders during the 2-year study period (86% vs. 52%, P=0.044).
Conclusions:
CLBBB and smaller LAVI are novel predictors of response in patients with advanced HF receiving CRT-D in real-world practice. Such responders may be better candidates for CRT-D and delay of cardiac replacement therapy.
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