Cano, Óscar

Abstract Aims Conduction system pacing (CSP) has emerged as a physiologic alternative to cardiac resynchronization therapy (CRT) with biventricular pacing (BiVP) in heart failure with reduced ejection fraction (HFrEF), yet its comparative effects remain uncertain. This meta-analysis sought to compare outcomes of CSP vs. BiVP in patients with HFrEF undergoing CRT. Methods and results MEDLINE, Embase, Scopus, and the Cochrane Database were searched through 4 May 2026. Randomized controlled trials (RCTs) were synthesized using random-effects meta-analysis. Thirteen RCTs including 1320 participants were analysed (657 CSP, 663 BiVP). Conduction system pacing was associated with a lower risk of the composite of hospitalization for heart failure (HHF) or all-cause mortality compared with BiVP (46 vs. 83 events; odds ratio [OR] 0.51, 95% confidence interval [CI] 0.28–0.93). No significant differences were observed for HHF alone (OR 0.68, 95% CI 0.36–1.27) or all-cause mortality (OR 0.75, 95% CI 0.36–1.58). Conduction system pacing was associated with greater improvement in the 6-min walk distance (mean difference [MD] 21.53 m, 95% CI 4.33–38.73) and New York Heart Association functional class (standardized mean difference [SMD] −0.27, 95% CI −0.47 to −0.07), but not quality of life. Conduction system pacing also reduced QRS duration compared with BiVP (MD −10.94 ms, 95% CI −17.55 to −4.34), with no significant differences in left ventricular ejection fraction, left ventricular end-systolic volume, overall pacing threshold, total procedure time, fluoroscopy time, any complication, or reintervention. Conclusion In patients with HFrEF undergoing CRT, CSP is associated with lower composite risk of HHF or all-cause mortality compared with BiVP. Conduction system pacing is also associated with improved functional capacity, without significant differences in safety or procedural outcomes.

Abstract Objectives This study aimed to investigate the procedural characteristics, efficacy, and safety of atrioventricular junction (AVJ) ablation for atrial tachyarrythmia (AT) in patients with congenital heart disease (CHD). Background Although AVJ ablation is an established treatment option for intractable AT in the general population, there is no existing data on this treatment in patients with CHD. Methods Data were analyzed from an observational, retrospective, multicenter cohort, initiated jointly by the Pediatric and Congenital Electrophysiology Society and the International Society of Adult Congenital Heart Disease. Eleven centers contributed baseline, procedural and longitudinal data, including vital status, echocardiographic data, QRS duration, and NYHA class. Outcomes were assessed at early (3 months-1 year), and late follow-up (≥2 years) after AVJ ablation. Results A total of 66 patients (46.7 ± 20.2 years) underwent 71 AVJ ablations. In total, 58.5% had moderate or complex CHD, including 17.1% patients with a systemic RV or single ventricular circulation. The cumulative AVJ ablation success rate was 98.5%. An abnormal location of the atrioventricular conduction pathway was successfully targeted in 20.0% of the patients, which was significantly more common in patients with complex CHD compared to moderate or mild CHD (44.4%, 15.8%, and 3.6%, respectively; both P<0.05). Thirty-six patients (54.5%) underwent primary pacemaker implantation as part of the ‘pace and ablate’ strategy; final pacing modes were VVI pacing in 60.9%, and CRT/CSP in 39.1%. The transplant-free survival rates at 2, 5 and 10 years after AVJ ablation were 91.5%, 84.3%, and 69.0%, respectively. The acute and long-term complication rates were 3.0% and 13.6%, respectively. Conclusions AVJ ablation can be successfully performed in CHD patients with a high acute success rate and low complication rate. Anatomical challenges were common, which underscores the need for careful planning and operator experience. Given the acceptable long-term survival, these findings support the consideration of a ‘pace and ablate’ strategy in CHD patients with intractable AT.