Outcomes of stylet-driven leads compared to lumenless leads for left bundle branch are pacing: systematic review and meta-analysis.

Background: Most initial experience with Left bundle branch are pacing (LBBAP) has involved lumenless leads (LLLs). Recently, stylet-driven leads (SDLs) have also been introduced for LBBAP. This study examined the clinical success rates, outcomes, and complication rates between SDLs and LLLs.

Methods and results: A systematic review of randomized clinical trials and observational studies comparing LLL and SDL up to November 30, 2024, was conducted. Random- and fixed-effects meta-analyses assessed the impact of implant technology on outcomes, including pacing metrics, lead complications, and procedural parameters. In total, 11 studies with 12,916 patients (SDLs: 3920; LLLs: 8996) were included. Implant success rates were comparable between SDL and LLL (RR 1.00, 95% CI 0.96-1.04, P = 0.96). SDL was associated with shorter procedure time (MD - 11.94 min, 95% CI - 19.48 to - 4.40, P = 0.002) and shorter fluoroscopy times, though this differences was not statistically significant (MD - 1.27 min, 95% CI - 2.92 to 0.39, P = 0.13). Pacing metrics, including impedance, pacing threshold, and R-wave amplitude, also showed no significant differences during follow-up (up to 28 months). However, SDLs were associated with a significantly higher risk of lead-related complications compared to LLLs (RR 1.89, 95% CI 1.47-2.41, P < 0001).

Conclusion: LBBAP using SDL is feasible and demonstrates comparable success rates with a shorter procedure duration. A higher incidence of lead-related complications was observed in the SDL group; however, due to potential confounding factors and the absence of randomized head-to-head comparisons, no definitive conclusions can be drawn regarding causality. Further prospective studies are warranted to clarify this association.