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Updated: Aug 5, 2026
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
Synergistic Value of Combined Electrical, Structural, and Functional Response Metrics in the Prediction of Long-Term
Amr Yosry Emam1, Ahmad Samir2, Karimeldeen Hafez1
1Department of Adult Cardiology, Aswan Heart Centre, 1242770 Aswan, Egypt.
Insights
Cardiac resynchronization therapy (CRT) improves outcomes for heart failure patients. A combined assessment of QRS duration, left ventricular end-systolic volume (LVESV), and left ventricular ejection fraction (LVEF) predicts 2-year survival post-CRT.
Area of Science:
- Cardiology
- Heart Failure Management
- Medical Imaging
Background:
- Cardiac resynchronization therapy (CRT) is crucial for heart failure with reduced ejection fraction (HFrEF) patients with electrical dyssynchrony.
- Identifying predictors of CRT success is vital for optimizing patient outcomes and resource allocation.
Purpose of the Study:
- To identify clinical, electrocardiographic (ECG), biomarker, echocardiographic, and cardiac magnetic resonance (CMR) parameters predicting 2-year all-cause mortality and hospitalization after CRT.
- To evaluate the combined predictive value of multiparametric assessments for CRT efficacy.
Main Methods:
- Retrospective analysis of CRT patient data.
- Assessment of baseline and 6-12 month follow-up parameters including biomarkers (NT-proBNP), ECG (QRS duration), echocardiography (LVEF, LVESV, RVEF, LV GLS), and CMR.
- Univariate and multivariate regression analyses to determine predictors of 2-year event-free survival.
Main Results:
- Baseline predictors of adverse outcomes included higher NT-proBNP, creatinine, impaired RVEF, increased RVESV, and reduced LV GLS.
- Event-free patients showed improved follow-up NT-proBNP, LVEF, and LVESV.
- Significant improvements in QRS duration (≥20 ms), LVEF (≥10%), and LVESV (≥15%) were associated with better survival.
- A multivariate model combining QRS shortening, LVESV reduction, and LVEF improvement accurately predicted 2-year event-free survival (AUC 0.835).
- QRS duration response (≥20 ms) was the strongest independent predictor (adjusted OR 0.111).
Conclusions:
- Combined improvements in QRS duration, LVESV, and LVEF are strong predictors of 2-year event-free survival after CRT.
- A multiparametric approach enhances the evaluation of CRT efficacy and guides clinical management decisions.
- QRS duration shortening is a key independent predictor of positive CRT outcomes.
Background:
Cardiac resynchronization therapy (CRT) is a cornerstone in the management of patients with heart failure with reduced ejection fraction (HFrEF) and electrical dyssynchrony. This study aimed to identify clinical, electrocardiographic (ECG), biomarker, echocardiographic, and cardiac magnetic resonance (CMR) imaging parameters predictive of 2-year all-cause mortality and hospitalization following CRT implantation.
Methods:
We retrospectively analyzed data from patients undergoing CRT. Baseline characteristics and 6-12-month follow-up data, including biomarkers, ECG parameters, echocardiographic measures, and CMR parameters, were assessed. Univariate and multivariate regression analyses were performed to identify predictors of 2-year event-free survival, defined as freedom from all-cause mortality or hospitalization.
Results:
At baseline, higher N-terminal pro-B-type natriuretic peptide (NT-proBNP) and creatinine levels, impaired right ventricular ejection fraction (RVEF), increased right ventricular end-systolic volume (RVESV), and reduced left ventricular global longitudinal strain (LV GLS) were significantly associated with adverse outcomes. At follow-up, event-free patients had lower NT-proBNP levels, higher left ventricular ejection fraction (LVEF), and lower left ventricular end-systolic volume (LVESV). Response rates for QRS complex (QRS) shortening (≥20 ms), LVEF improvement (≥10% absolute increase), and LVESV reduction (≥15%) were significantly higher in the event-free group. Univariate predictors of 2-year event-free survival included baseline RVEF (odds ratio (OR) 0.958; p = 0.015), baseline LV GLS (OR 1.256; p = 0.047), and follow-up LVEF (OR 0.932; p = 0.006). In contrast, higher follow-up Right Ventricular End-systolic Volume Indexed (RVESVi) (OR 1.013; p = 0.048) was associated with increased risk. A multivariate model incorporating QRS duration shortening (≥20 ms), LVESV reduction (≥15%), and LVEF improvement (≥10%) was highly predictive of 2-year event-free survival (p = 0.006; area under the curve (AUC) 0.835, accuracy 84%, specificity 97.5%, sensitivity 30%), with a QRS duration response ≥20 ms emerging as the strongest independent predictor (adjusted OR 0.111; p = 0.02).
Conclusion:
Combined improvement in QRS duration, LVESV, and LVEF after CRT implantation is a strong predictor of 2-year event-free survival. These findings support a comprehensive, multiparameter approach to evaluating CRT efficacy and guiding clinical management.
