BACKGROUND: Left bundle branch pacing (LBBP) has emerged as a promising pacing modality to preserve physiological left ventricular activation; however, prospective data evaluating its long-term safety and efficacy in pacemaker-dependent patients following atrioventricular junction (AVJ) ablation are lacking. This study aimed to examine the feasibility, safety, and efficacy of LBBP in patients with atrial fibrillation and heart failure (HF) after AVJ ablation and compare LBBP with His bundle pacing (HBP) through a propensity score (PS) matching analysis. METHODS: We prospectively enrolled patients with atrial fibrillation and HF referred for AVJ ablation and LBBP between July 2017 and December 2019. The control group was patients selected from HBP implants performed from 2012 to 2019 using PS matching with a 1:1 ratio. RESULTS: A total of 99 patients were enrolled in the study. The LBBP implant success rate was 100%. Left ventricular ejection fraction improved from baseline 30.3±4.9 to 1-year 47.3±14.5 in HF patients with reduced ejection fraction and from baseline 56.3±12.1 to 1-year 62.3±9.1 in HF patients with preserved ejection fraction (both P <0.001), and left ventricular ejection fraction in both groups remained stable for up to 3 years of follow-up. A threshold increase >2 V at 0.5 ms occurred in only one patient. Of 176 (81.9%) of 215 patients who received permanent HBP post-AVJ ablation, 86 were matched to the LBBP group by 1:1 PS (propensity score matched His bundle pacing, N=86; propensity score matched left bundle branch pacing, N=86). No significant differences in echocardiographic or clinical outcomes were observed between the 2 groups ( P >0.05), whereas lower thresholds, greater sensed R-wave amplitudes, and fewer complications were observed in the propensity score matched left bundle branch pacing group ( P <0.05). CONCLUSIONS: LBBP is feasible, safe, and effective in patients with atrial fibrillation and HF post-AVJ ablation and has similar clinical benefits, a higher implant success rate, better pacing parameters, and fewer complications compared with HBP.

Background and Objective: Acute kidney injury (AKI) is a common complication associated with adverse outcomes among patients with ST-segment elevation myocardial infarction (STEMI). This is conflicting information about the relationship between hyperuricemia and AKI in STEMI. This work aims to investigate the effect of the interaction between hyperuricemia and lactate on the risk of AKI. Methods: We analyzed 2,008 consecutive STEMI patients between January 2014 and January 2019. Hyperuricemia was defined as a serum uric acid (SUA) level >7 mg/dl for males and >6 mg/dl for females. AKI was defined based on the Kidney Disease: Improving Global Outcomes (KDIGO). Logistic regression models were applied to establish the relationship between hyperuricemia and AKI in the overall population and subgroups stratified as per lactate levels at admission (≤ 2.2 mmol/L or > 2.2 mmol/L). Results: In total, we included 1,887 STEMI patients. Multivariate analysis showed that hyperuricemia is associated with the risk of AKI (OR: 1.34; 95% CI: 1.01-1.77; P =0.045). Nonetheless, the predictive effect of hyperuricemia was only observed in patients with lactate level > 2.2mmol/L (OR: 2.05; 95% CI: 1.36-3.10; P < 0.001), but not in those with lactate level ≤ 2.2mmol/L (OR: 0.86, 95% CI: 0.56-1.32, P = 0.493). The interaction between hyperuricemia and lactate levels demonstrated a significant effect on AKI. Conclusions: In summary, hyperuricemia increases the risk of AKI in STEMI patients with lactate levels> 2.2mmol/L, but not those with lactate levels ≤ 2.2 mmol/L.