Long‐term follow‐up of patients with a quadripolar active fixation left ventricular lead: An Italian multicenter experience

Abstract

Left ventricular (LV) lead optimal positioning is one of the most important determinant of cardiac resynchronization therapy (CRT) success. LV quadripolar active fixation (QAF) leads have been designed to ensure stable LV pacing in the target area and reduce the likelihood of phrenic nerve stimulation (PNS). The aim of this analysis is to compare performances, safety and clinical outcomes of QAF with those of quadripolar passive fixation (QPL) and bipolar active fixation (BAF) leads in a real-world cohort of CRT patients. This retrospective analysis compared procedure and follow-up data of 117 QAF included in the One Hospital ClinicalService project from 9 Italian hospitals with two historical cohorts of 261 BAF and 124 QPL. QAF enabled basal pacing more frequently than QPL (24.1% vs. 6.5%, p<0.001) but not differently from BAF (p=0.981). At implant, mean QAF LV myocardial threshold (LVMT) was 1.21±0.8V at 0.4 ms, not different from that of BAF (p=0.346) and QPL (p=0.333). At a median follow-up of 22 months, LVMT was 1.37±0.90 V (p=0.036 vs. implant). Acute LV lead dislodgment occurrence was low in all cohorts: 1 (0.9%) in QAF, 4 in BAF (1.5%) and none (0.0%) in QPL. During follow-up, total LV-related complication rate was lower in QAF (0.5/100 patient-years) than in BAF (4.2/100 patient-years, p=0.014) and QPL (3.6/100 patient/years, p=0.055). QAF, BAF and QPL annual rate of heart failure hospitalization were respectively 6.1/100 patient-years, 2.5/100 patient-years (p=0.081) and 3.6/100 patient-years (p=0.346). CRT responders' rate in QAF was 69.9%, with no difference in comparison to BAF (p=0.998) and QPL (p=0.509). During follow-up, mean LVEF of QAF increased from 31.8 ± 10.1% to 40.3 ± 10.7% (p<0.001). The average degree of echocardiographic response (ΔLVEF) did not differ between QAF and other cohorts; however, LVEF CRT responder's distribution of QAF differs from those of BAF (p=0.003) and QPL (p=0.022), due to a higher percentage of super-responders. QAF with short inter-electrode spacing resulted in noninferior clinical outcome and CRT responders' rate in comparison to BAF and QPL, while reducing complication rate during follow-up and increasing the possibilities of electronic repositioning to manage PNS or to optimize resynchronization therapy. This article is protected by copyright. All rights reserved.