Reduced Mortality Associated With Quadripolar Compared to Bipolar Left Ventricular Leads in Cardiac Resynchronization Therapy

ObjectivesThe study sought to compare survival, lead deactivation, and lead replacement with quadripolar versus bipolar leads using a retrospective cohort of patients with newly implanted cardiac resynchronization therapy (CRT) systems.BackgroundIn CRT, quadripolar left ventricular (LV) leads offer alternative pacing sites and vectors not available with bipolar LV leads, which may improve the effectiveness of the therapy.MethodsUsing nationwide data from device implant registration records of a single manufacturer, we identified patients with a de novo cardiac resynchronization therapy with defibrillation (CRT-D) implanted between November 30, 2011, and May 31, 2013. Patients were followed for up to 24 months. The primary predictor was LV lead type (quadripolar Quartet [St. Jude Medical, St. Paul, Minnesota] LV lead or bipolar LV lead). The primary outcome was death and the secondary outcomes were LV lead replacement and deactivation.ResultsAmong 23,570 patients (69.5 ± 11.1 years of age; 28% female; median follow-up time 1.14 years), 18,406 had quadripolar and 5,164 had bipolar LV leads. The quadripolar and bipolar groups had 5.04 and 6.45 deaths per 100 patient-years, respectively (p < 0.001). After multivariate adjustment, the quadripolar lead was associated with a lower risk of deactivation (hazard ratio [HR]: 0.62; 95% confidence interval [CI]: 0.46 to 0.84; p = 0.002), replacement (HR: 0.67; 95% CI: 0.55 to 0.83; p < 0.001), and death (HR: 0.77; 95% CI: 0.69 to 0.86; p < 0.001).ConclusionsIn this observational study of CRT-D devices, use of a quadripolar, compared to a bipolar LV lead, was associated with a reduction in LV lead deactivation, replacement, and mortality.