Long-Term Durability of Stylet-Driven Leads for Left Bundle Branch Area Pacing

Quantify the long-term mechanical durability of Abbott stylet-driven leads for left bundle branch area pacing (LBBAP) using a combination of computational modeling and fatigue bench test.

Intracardiac lead curvatures were simulated in a 3D computational heart model across a range of lead implant scenarios and cardiac electro-mechanical scenarios over a complete cardiac cycle to determine the range of induced stresses. Safety factor was determined using the bending curvature and mechanical properties of the conductor. A benchtop fatigue physical test was implemented at higher stress levels, thus lower safety factors, than the computational modeling cohort.

Computer simulation modeling showed that maximum curvature and safety factor (SF) were comparable for LBBA implants (0.06 ± 0.02 mm^-1 and 4.7 ± 1.6) vs. other traditional implant locations (0.05 ± 0.03 mm^-1 and 5.0 ± 0.7). Lead durability was verified through successful fatigue bench testing at max curvatures of 0.12 ± 0.01 mm^-1 and safety factor of 2.2 ± 0.2. These test conditions represented approximately a twofold increase in maximum curvature and a 2.1-fold reduction in safety factor relative to simulated cases, over a test duration representative of 10 years of service.

Abbott stylet-driven leads were demonstrated to be safe for LBBAP, even at stresses far exceeding those which may be clinically observed for 400 million cardiac cycles. No differences in long-term safety were observed between LBBAP and traditional pacing locations.