Procedural performance and safety of a helix locking tool for left bundle branch pacing: a prospective multicenter study

PURPOSE Helix retraction during septal lead deployment can complicate left bundle branch pacing (LBBP) procedures performed with extendable-retractable helix leads. A helix locking tool (HLT) has been developed to stabilize the helix of a stylet-driven lead during implantation, but clinical performance data remain limited. This study aimed to evaluate the acute safety and procedural performance of this tool in a multicenter setting. METHODS In this prospective multicenter registry, 87 consecutive patients who underwent LBBP were enrolled in eight centers in Spain. Implantation was performed using a stylet-driven Tendril STS lead and CPS Direct 3D sheath, with the HLT used during septal deployment. The primary endpoint was freedom from acute adverse events related to the HLT. Secondary endpoints included procedural success, lead repositioning, and acute electrical parameters. RESULTS LBBP was successfully achieved in 79 of 87 patients (90.8%). Lead repositioning was required in 36 cases (41.4%), with a mean of 2.3 ± 1.3 attempts. No cases of helix retraction were observed. Three intraprocedural lead dislodgements (3.4%) occurred and were managed without clinical consequences. No acute complications related to the HLT were reported. Electrical parameters were compatible with conduction system capture. CONCLUSIONS In this prospective multicenter registry, left bundle branch capture was achieved in 79 of 87 patients (90.8%). No helix retraction or acute adverse events considered related to the HLT by site investigators were observed during 24-hour follow-up. In the absence of a comparator group, the study cannot determine whether the HLT reduces helix retraction or improves procedural outcomes.