Screw-in attempts and success rates in left bundle branch area pacing lead implantation

Type of funding sources: None.

Left bundle branch area pacing (LBBAP) represents a novel cardiac pacing approach that overcomes limitations of conventional right ventricular (septo-) apical pacing. Feasibility and early safety have been shown previously. However, technical limitations (non-dedicated leads, limited availability of suitable implantation sheats) still may preclude successful conduction system pacing (CSP) lead implantation. So-called drilling and entanglement effects can prevent lead implantation at a suitable site and multiple screw-in attempts may be required. However, lead implantation may ultimately still be unsuccessful.

To evaluate the number of total screw-in attempts until abandonment of LBBAP lead implantation during the procedure.

We prospectively assessed 170 consecutive LBBAP lead implantation attempts at our center from 09/2021 to 11/2022. All implanters had previous experience with His-bundle pacing lead implantation. Successful conduction system pacing was established according to standard criteria (R-wave peak time in V6, V1-V6-interpeak interval, programmed stimulation or visibility of a left bundle potential) and pacing thresholds <2V/0.5ms. The number of screw-in attempts and decision of LBBAP lead implantation abandonment was at the operator’s discretion.

Patient baseline characteristics and procedural outcomes are shown in the table (percentages and median values with interquartile range in brackets). Overall CSP lead implantation success rate was 91%. Two patients (1%) experienced complications (one atrial lead dislodgement, one pneumothorax). Median number of screw-in attempts in all interventions was 2 (interquartile range [IQR] 1-4, maximum 12). If implantation was successful, a maximum of four attempts provided already 90% of the overall chance of success (figure). Additional lead implantation attempts rarely provided an additional benefit but prolonged overall implantation duration.

To balance implantation success rates with procedure duration, the number of screw-in attempts during LBBAP lead implantation may be limited to 4-5 attempts. Bail-out strategies (implantation of a cardiac resynchronization pacemaker or a conventional pacemaker) may be considered if CSP lead implantation is unsuccessful after 4-5 attempts.