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Updated: May 9, 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
Complete atrioventricular block does not reduce long-term mortality in patients with permanent atrial fibrillation
José M Tolosana1, Emilce Trucco, Malek Khatib
1Thorax Institute, Cardiology Department, Hospital Clinic, Universitat de Barcelona, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Catalonia, Spain.
Insights
Atrioventricular junction block did not improve survival in patients with atrial fibrillation receiving cardiac resynchronization therapy (CRT). Key mortality predictors include advanced heart failure symptoms, reduced kidney function, and lower left ventricular ejection fraction (LVEF).
Area of Science:
- Cardiology
- Electrophysiology
- Heart Failure Management
Background:
- Cardiac Resynchronization Therapy (CRT) efficacy in atrial fibrillation (AF) patients is linked to maximizing ventricular pacing.
- Atrioventricular junction (AVJ) ablation is a strategy to achieve high ventricular pacing rates in AF patients undergoing CRT.
Purpose of the Study:
- To evaluate if complete AVJ block improves survival in permanent AF patients treated with CRT.
- To identify independent predictors of mortality in these patients.
Main Methods:
- Retrospective analysis of 155 permanent AF patients treated with CRT.
- Comparison of survival outcomes between patients with and without AVJ block (spontaneous or induced).
- Multivariate analysis to determine mortality predictors.
Main Results:
- No significant difference in overall or cardiovascular mortality between AF patients with and without AVJ block (HR 0.85, P=0.51; HR 0.94, P=0.82).
- Independent predictors of mortality identified: NYHA class IV (HR 2.25, P=0.03), glomerular filtration rate (HR 0.98, P=0.03), and LVEF (HR 0.94, P=0.02).
Conclusions:
- AVJ block does not enhance survival for AF patients undergoing CRT.
- Mortality risk is significantly associated with severe heart failure symptoms (NYHA IV), impaired renal function, and reduced LVEF.
Aims:
A maximum percentage of ventricular pacing is mandatory to obtain a good response to CRT. Atrioventricular junction (AVJ) ablation has been recommended to attain this objective in patients with AF.
The Aims Of Our Study Were:
(i) to determine whether the presence of complete AVJ block (induced or spontaneous) improves survival in patients with permanent AF treated with CRT and (ii) to analyse the predictors of mortality in AF patients treated with CRT.
Methods And Results:
From a series of 608 patients treated with CRT in our centre from 2000 to 2011, a cohort of 155 patients with permanent AF was analysed. Patients in AF were divided into two groups, AF + AVJ block [76 (49%)] and AF non-AVJ block [79 (51%)]. Mean follow-up was 30 months (interquartile range 13-51 months). During the follow-up, 62 patients died. Overall and cardiovascular mortality were similar between both groups: hazard ratio (HR) 0.85, 95% confidence interval (CI) 0.51-1.39, P = 0.51 and HR 0.94, 95% CI 0.52-1.68, P = 0.82. Multivariate analysis identified three independent predictors of mortality: basal NYHA functional class IV (HR 2.25, 95% CI 1.12-4.22, P = 0.03), glomerular filtration rate (HR 0.98, 95% CI 0.96-0.99, P = 0.03), and LVEF (HR 0.94, 95% CI 0.89-0.99, P = 0.02).
Conclusions:
AVJ block did not improve survival for patients in AF treated with CRT. Basal NYHA functional class IV, poor renal function, and LVEF were the independent predictors of mortality.
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