Clinical Superiority of Active Fixation Quadripolar Leads in Cardiac Resynchronization Therapy

The effectiveness of cardiac resynchronization therapy (CRT) depends on stable and optimal left ventricular (LV) lead placement. The Attain Stability Quadripolar (ASQ) lead uses active fixation to improve performance. We aimed to assess the clinical superiority of ASQ leads over conventional quadripolar leads.

This single-center retrospective cohort study included 65 CRT recipients (31 ASQ, 34 non-ASQ). Primary endpoints were lead stability and CRT response at 6 months (relative LVESV reduction and absolute LVEF increase); secondary endpoints included pacing thresholds, QRS changes, and LV functional parameters.

No intraoperative dislodgement occurred with ASQ leads, versus six cases (17.6%) in the non-ASQ group (p = 0.014). At 6 months, pacing thresholds were lower with ASQ (1.35 ± 0.81 V vs. 1.80 ± 0.77 V, p = 0.047). In patients with left bundle branch block, reverse remodeling as assessed by LVESV reduction was more frequent with ASQ (≥15%: 82% vs. 29%, p = 0.008; ≥30%: 64% vs. 21%, p = 0.032), and this was accompanied by greater improvement in LVEF (≥10 percentage points: 73% vs. 21%, p = 0.01; ≥20 points: 64% vs. 21%, p = 0.032). ASQ leads provided stable fixation across vessel diameters from 1.9-5.4 mm, including large veins >4.0 mm.

ASQ leads offer superior stability, lower pacing thresholds, and higher CRT response, supporting wider use of active fixation technology in CRT.