Acute performance of stylet driven leads for left bundle branch area pacing: a comparison with lumenless leads

FUNDING ACKNOWLEDGEMENTS: Type of funding sources: None. BACKGROUND: Lumen-less leads (LLL) and stylet driven leads (SDL) are currently used for left bundle branch area pacing (LBBAP). We sought to evaluate the acute performance of SDL during LBBAP in comparison with LLL. METHODS: This is an observational retrospective study including consecutive patients undergoing LBBAP at our institution.Acute lead performance was evaluated including implant success rate,electrical parameters,ECG characteristics and lead related complications (intraprocedure LBBAP lead dislodgment after having being penetrated into the septum in an stable position needing lead repositioning, septal perforation, coronary venous fistula, development of complete AV block not previously present and LBBAP lead damage during implant).Conduction system capture criteria were assessed before patient discharge during asynchronous ventricular pacing. Ventricular lead position within the septum was evaluated using paced QRS axis, fluoroscopic orthogonal views and post-procedure TTE, and classified as basal,mid or apical septum. RESULTS: 451 consecutive LBBAP implants were included, 333 using LLL and 118 using SDL. LBBAP acute success was significantly higher with LLL (91.6% for LLL vs 79.7% for SDL,p=0.001).Among patients with successful LBBAP,LBB capture criteria were achieved in 53.2% for LLL vs 36.4% for SDL,while left ventricular septal pacing (LVSP) was achieved in 39% vs 44.1%,respectively (p<0.0001). A basal lead position was more frequently obtained with LLL (19.8% for LLL vs 13.3% for SDL),while SDL were more frequently located at mid to apical septal positions (86.7% for SDL vs 80.1% for LLL, p=0.003).Paced ECG axis was inferior in 43.9% of LLL vs 28.9% of SDL and superior in 24.5% vs 42.1%, respectively,p=0.001.Intraprocedure lead dislodgment occurred in 9.3% of SDL vs 2.1% of LLL,p=0.001.In 5 cases of SDL (4.2%),lead damage occurred during lead implant needing lead replacement due to helix entrapment or malfunction with no such cases registered among LLL patients.Acute LBBAP lead-related complications were significantly higher for SDL vs LLL (29.1% vs 12.6%, respectively, p<0.0001,table 1),none of them needing additional interventions.Among patients with LBBAP criteria at the end of the procedure,34 (7.5%) experienced loss of r prime wave in V1 with paced QRS widening before hospital discharge,more frequently in patients with SDL (17.8% vs. 9.4%, respectively,p<0.0001) indicative of lead microdislodgment. CONCLUSIONS: In our experience,acute lead performance is different between LLL and SDL.LBBAP implant success rate is significantly higher with LLL with higher percentage of patients with LBB capture criteria in comparison with SDL.SDL are associated with a more mid to apical and inferior lead position in the septum.A significantly higher rate of lead related complications during the implant procedure as well as higher rates of acute microdislodgment after implantation were also seen in SDL,none of them needing acute re-intervention. [Figure: see text] [Figure: see text]