Arrhythmic Risk in Biventricular Pacing Compared With Left Bundle Branch Area Pacing: Results From the I-CLAS Study
Bengt Herweg1, Parikshit S Sharma2, Óscar Cano3
1University of South Florida Morsani College of Medicine, Tampa (B.H., R.B., M.M.).
Insights
Left bundle branch area pacing (LBBAP) significantly reduced ventricular arrhythmias and new atrial fibrillation compared to biventricular pacing (BVP). LBBAP offers a potentially safer alternative for cardiac resynchronization therapy patients.
Area of Science:
- Cardiology
- Electrophysiology
- Medical Devices
Background:
- Cardiac resynchronization therapy (CRT) aims to improve heart function in patients with heart failure.
- Left ventricular ejection fraction (LVEF) ≤35% is a common indication for CRT.
- Left bundle branch area pacing (LBBAP) is an alternative pacing strategy to biventricular pacing (BVP).
Purpose of the Study:
- To compare the incidence of sustained ventricular tachycardia/ventricular fibrillation (VT/VF) and new-onset atrial fibrillation (AF) between LBBAP and BVP.
- To evaluate the safety and efficacy of LBBAP versus BVP in patients undergoing CRT.
Main Methods:
- The I-CLAS study included 1778 patients undergoing CRT (BVP or LBBAP) between 2018 and 2022.
- Propensity score-matched analysis (1:1 ratio) was performed on 1414 patients.
- Incidence of VT/VF and new-onset AF was assessed using Cox proportional hazards survival models.
Main Results:
- LBBAP showed significantly lower rates of VT/VF (4.2% vs 9.3%) and VT storm (0.8% vs 2.5%) compared to BVP.
- New-onset AF was also significantly lower with LBBAP (2.8% vs 6.6%) compared to BVP.
- These findings remained significant after adjusting for baseline characteristics.
Conclusions:
- LBBAP is associated with a lower incidence of VT/VF and new-onset AF compared to BVP.
- Physiological resynchronization achieved by LBBAP may contribute to a reduced risk of arrhythmias.
- LBBAP represents a promising alternative pacing strategy for CRT.
Background:
Left bundle branch area pacing (LBBAP) may be associated with greater improvement in left ventricular ejection fraction and reduction in death or heart failure hospitalization compared with biventricular pacing (BVP) in patients requiring cardiac resynchronization therapy. We sought to compare the occurrence of sustained ventricular tachycardia (VT) or ventricular fibrillation (VF) and new-onset atrial fibrillation (AF) in patients undergoing BVP and LBBAP.
Methods:
The I-CLAS study (International Collaborative LBBAP Study) included patients with left ventricular ejection fraction ≤35% who underwent BVP or LBBAP for cardiac resynchronization therapy between January 2018 and June 2022 at 15 centers. We performed propensity score-matched analysis of LBBAP and BVP in a 1:1 ratio. We assessed the incidence of VT/VF and new-onset AF among patients with no history of AF. Time to sustained VT/VF and time to new-onset AF was analyzed using the Cox proportional hazards survival model.
Results:
Among 1778 patients undergoing cardiac resynchronization therapy (BVP, 981; LBBAP, 797), there were 1414 propensity score-matched patients (propensity score-matched BVP, 707; propensity score-matched LBBAP, 707). The occurrence of VT/VF was significantly lower with LBBAP compared with BVP (4.2% versus 9.3%; hazard ratio, 0.46 [95% CI, 0.29-0.74]; P<0.001). The incidence of VT storm (>3 episodes in 24 hours) was also significantly lower with LBBAP compared with BVP (0.8% versus 2.5%; P=0.013). Among 299 patients with cardiac resynchronization therapy pacemakers (BVP, 111; LBBAP, 188), VT/VF occurred in 8 patients in the BVP group versus none in the LBBAP group (7.2% versus 0%; P<0.001). In 1194 patients with no history of VT/VF or antiarrhythmic therapy (BVP, 591; LBBAP, 603), the occurrence of VT/VF was significantly lower with LBBAP than with BVP (3.2% versus 7.3%; hazard ratio, 0.46 [95% CI, 0.26-0.81]; P=0.007). Among patients with no history of AF (n=890), the occurrence of new-onset AF >30 s was significantly lower with LBBAP than with BVP (2.8% versus 6.6%; hazard ratio, 0.34 [95% CI, 0.16-0.73]; P=0.008). The incidence of AF lasting >24 hours was also significantly lower with LBBAP than with BVP (0.7% versus 2.9%; P=0.015).
Conclusions:
LBBAP was associated with a lower incidence of sustained VT/VF and new-onset AF compared with BVP. This difference remained significant after adjustment for differences in baseline characteristics between patients with BVP and LBBAP. Physiological resynchronization by LBBAP may be associated with lower risk of arrhythmias compared with BVP.
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