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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
Myocardial contractile reserve predicts improvement in left ventricular function after cardiac resynchronization
Claudia Ypenburg1, Allard Sieders, Gabe B Bleeker
1Department of Cardiology, Leiden University Medical Center, Leiden, The Netherlands.
American Heart Journal
|November 24, 2007
Summary
Myocardial contractile reserve, measured by dobutamine stress echocardiography, predicts left ventricular reverse remodeling in heart failure patients receiving cardiac resynchronization therapy (CRT). A greater increase in ejection fraction indicates successful remodeling.
Area of Science:
- Cardiology
- Cardiac Imaging
- Heart Failure Management
Background:
- Myocardial contractile reserve is a significant prognostic indicator in heart failure patients.
- Cardiac resynchronization therapy (CRT) aims to improve left ventricular (LV) function.
- The predictive value of contractile reserve for LV reverse remodeling post-CRT is under investigation.
Purpose of the Study:
- To investigate if myocardial contractile reserve can predict left ventricular reverse remodeling after CRT.
- To assess global and local contractile reserve using echocardiography during dobutamine infusion.
- To determine the threshold of contractile reserve indicative of successful remodeling.
Main Methods:
- Echocardiography with low-dose dobutamine infusion was performed in 31 heart failure patients before CRT.
- Global contractile reserve was assessed by the change in LV ejection fraction (LVEF).
- Local contractile reserve was evaluated using radial strain in the LV pacing lead region; responders showed >15% decrease in LV end-systolic volume after 6 months.
Main Results:
- Responders to CRT exhibited a significantly greater increase in LVEF during dobutamine infusion compared to non-responders (13% vs 3%, P < .001).
- Contractile reserve strongly correlated with LVEF improvement post-CRT (r = 0.80, P < .001).
- A dobutamine-induced LVEF increase >7.5% predicted CRT response with 76% sensitivity and 86% specificity (AUC 0.87). Local contractile reserve was present only in responders.
Conclusions:
- Myocardial contractile reserve, specifically a >7.5% increase in LVEF during dobutamine infusion, is a reliable predictor of LV reverse remodeling following CRT.
- Assessing contractile reserve pre-CRT can help identify patients likely to benefit from the therapy.
- Echocardiographic assessment of contractile reserve offers valuable prognostic information for heart failure management.
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