Aims: About one-third of patients receiving cardiac resynchronization therapy (CRT) are not responders, due to either patient selection or technical issues. Left ventricular quadripolar passive fixation leads (QPL) and bipolar active fixation (BAF) leads have been designed to ensure a targeted left ventricular stimulation area, minimizing lead dislodgments and phrenic nerve stimulation (PNS). The aim was to compare real-world safety and efficacy of BAF (Attain Stability, Medtronic Plc.) and QPL (Attain Performa, Medtronic Plc.).
Methods: We performed a retrospective analysis examining procedural and follow-up data of 261 BAF and 124 QPL (programmed to single-site left ventricular pacing), included in the ClinicalService project from 16 Italian hospitals.
Results: At median follow-up of 12 months, no difference in left ventricular pacing threshold was recorded between BAF and QPL (1.3 ± 0.9 V @0.4 ms vs. 1.3 ± 1.0 V @0.4 ms; P = 0.749). Total left ventricular lead dislodgement rate was 1.43/100 patient-years in BAF vs. 2.9/100 patient-years in QPL (P = 0.583). However, no dislodgements occurred among BAF after hospital discharge. Events requiring repeated surgery or permanently turning CRT off occurred in 0.8% of BAF, as compared with 4.0% of QPL (P = 0.025). There was no difference between groups in the echo CRT responders' rate (70% of BAF and 66% of QPL; P = 0.589) or in the annual rate of heart failure hospitalization (P = 0.513).
Conclusions: BAF resulted in noninferior clinical outcome and CRT responders' rate in comparison to QPL. Moreover, BAF ensured more precise and stable placement in cardiac veins, with comparable electrical performance and less than 1% patients with unsolved PNS.