Title : A propensity score-matching cohort study comparing the immediate effects between left bundle branch area pacing and right ventricular pacing on blood pressure
Abstract:
Background: Left bundle branch area pacing (LBBAP) is an emerging physiological pacing modality. LBBAP can preserve intraventricular and interventricular electrical and mechanical synchrony by directly stimulating the cardiac conduction system. However, little attention focused on its acute hemodynamic effects. Although prior studies have investigated the potential blood pressure (BP) variations in patients undergoing right ventricular pacing (RVP), the association between LBBAP and BP change remains unknown. The objective of our study was to explore the acute BP variations in both LBBAP and RVP receivers. Methods: We conducted a retrospective cohort study that included all patients who underwent de-novo dual-chamber pacemaker implantation at a high-volume center in China, from January 2019 to June 2021. Patients were divided into two groups according to their pacing strategy, namely LBBAP and RVP, and we used propensity score-matching (PSM) to balance confounding factors. Given the dynamic nature of blood pressure, BP variations were analyzed over three time periods: baseline (within 24 hours before implantation), hyper-acute period (0-24 hours after implantation), and acute period (24-48 hours after implantation). The primary outcome was the change in systolic BP after the implantation. We extracted and analyzed BP data for each time period. In the PSM cohort, we used repeated measures ANOVA to examine the overall SBP changes across all three time points, and Tukey’s method was used for multiple comparisons. An independent sample t-test was used to compare the LBBAP and RVP groups. Furthermore, we performed subgroup analyses within each group to explore potential factors that could influence the BP variations. Subgroup categories were specified by baseline SBP, hypertension status, and use of AHDs. Results: From an entire cohort including 898 patients, 193 LBBAP receivers were propensity matched to 193 RVP controls. A gradual decrease in systolic BP after the implantation was observed in overall populations, from its baseline of 137.3 ± 9.2mmHg to the hyper-acute period of 133.4 ± 10.3mmHg, and then to the acute period of 127.7 ± 9.4mmHg (P < 0.001). A similar decreasing trend was observed in both LBBAP and RVP groups. The LBBAP group exhibited a greater reduction than the RVP group (11.6 ± 6.2mmHg vs. 7.6 ± 5.8mmHg, P < 0.001). In further subgroup analysis, LBBAP receivers who had a high baseline SBP (P < 0.001) and those without using anti-hypertensive drugs (P = 0.045) appeared to have a higher magnitude of BP variations. Likewise, a similar trend was also found in RVP receivers. However, there was no significant difference between patients with or without HTN in either group (P = 0.045 in LBBAP group and P = 0.005 in RVP group). Conclusions: Permanent pacemaker implantation may contribute to an acute decrease in systolic BP shortly after the procedure, which was more pronounced in LBBAP receivers. baseline SBP and the use of antihypertensive drugs were potentially associated with the magnitude of BP variation. Future experimental and clinical investigations are necessary to explore the underlying mechanisms and the long-term hemodynamic effects of LBBAP versus RVP
