Effects of implantation of quadripolar left ventricular leads on CRT response

BackgroundThe use of quadripolar (QP) left ventricular leads for cardiac resynchronization therapy (CRT) is intended to improve outcomes compared with conventional bipolar leads (BP). Hence, the number of implanted quadripolar CRT systems is increasing despite limited long-term data.PurposeThe aim of this study is to evaluate clinical response and long-term outcomes of CRT recipients who were implanted with quadripolar versus bipolar left ventricular leads.MethodsData from consecutive patients receiving a CRT defibrillator in one German and one Hungarian tertiary referral center were retrospectively collected. Long-term survival and response to CRT were analyzed.ResultsA total of 536 patients with structural heart disease and a mean left ventricular ejection fraction (LVEF) of 25% received a CRT defibrillator (CRT-D) system for primary (79%) or secondary (21%) prevention of sudden death. Comorbidities did not differ significantly between patients receiving a QP (n=123) or a BP lead (n=413). Procedure (101 vs. 120min) and fluoroscopy times (14 vs. 20min) were shorter in patients implanted with QP compared with BP (both p<0.001). At 6months follow-up, QP patients were more likely to respond to CRT measured as improvement in the New York Heart Association (NYHA) functional class (77% vs. 63%; p<0.001). Use of QP left ventricle/left ventricular (LV) leads was associated with greater reduction in QRS duration compared with patients implanted with BP LV leads (-2130 vs. -8 +/- 35ms, p=0.004). Mortality was not significantly different between patients with QP and patients with BP LV leads at a mean follow-up of 39 +/- 31months.ConclusionImplantation of quadripolar left ventricular leads was associated with better CRT response compared with bipolar left ventricular leads.