Cardiac Resynchronization Therapy Using Quadripolar Versus Non-Quadripolar Left Ventricular Leads Programmed to Biventricular Pacing With Single-Site Left Ventricular Pacing: Impact on Survival and Heart Failure Hospitalization

Background-In cardiac resynchronization therapy (CRT), quadripolar (QUAD) left ventricular (LV) leads are less prone to postoperative complications than non-QUAD leads. Some studies have suggested better clinical outcomes. Methods and Results-Clinical events were assessed in 847 patients after CRT-pacing or CRT-defibrillation using either QUAD (n= 287) or non-QUAD (n= 560), programmed to single-site site LV pacing. Over a follow-up period of 3.2 years (median [interquartile range, 1.90-5.0]), QUAD was associated with a lower total mortality (adjusted hazard ratio [aHR]: 0.32, 95% confidence interval [CI], 0.20-0.52), cardiac mortality (aHR: 0.36, 95% CI, 0.20-0.65), and heart failure (HF) hospitalization (aHR: 0.62, 95% CI, 0.39-0.99), after adjustment for age, sex, New York Heart Association class, HF etiology, device type (CRT-pacing or CRT-defibrillation), comorbidities, atrial rhythm, medication, left ventricular ejection fraction, and creatinine. Death from pump failure was lower with QUAD (aHR: 0.33; 95% CI, 0.18-0.62), but no group differences emerged with respect to sudden cardiac death. There were no differences in implant-related complications. Re-interventions for LV displacement or phrenic nerve stimulation, which were lower with QUAD, predicted total mortality (aHR: 1.68, 95% CI, 1.11-2.54), cardiac mortality (aHR: 2.61, 95% CI, 1.66-4.11) and HF hospitalization (aHR: 2.09, 95% CI, 1.22-3.58). Conclusions-CRT using QUAD, programmed to biventricular pacing with single-site LV pacing, is associated with a lower total mortality, cardiac mortality, and HF hospitalization. These trends were observed for both CRT-defibrillation and CRT-pacing, after adjustment for HF cause and other confounders. Re-intervention for LV lead displacement or phrenic nerve stimulation was associated with worse outcomes.