Left Ventricular Lead Location and Long-Term Outcomes in Cardiac Resynchronization Therapy Patients.

Abstract

The authors aimed to evaluate the association of left ventricular (LV) lead location and long-term outcomesin MADIT-CRT (Multicenter Automatic Defibrillator Implantation With Cardiac Resynchronization Therapy). There is limited data on the association of lead location with long-term clinical outcomes in patients with cardiac resynchronization therapy with defibrillator (CRT-D). The LV lead location was classified in 797 patients with CRT-D, in 569 patients with left bundle branch block (LBBB), in 228 patients with non-LBBB, and in 505 patients with an implantable cardioverter-defibrillator (ICD) only. Leads were classified into apical (n= 83) and non-apical (n= 486); with the non-apical LV leads further categorized into anterior (n= 99) and posterior/lateral (n= 387) within LBBB. All-cause mortality and heart failure (HF) events were assessed using Kaplan-Meier and Cox analyses. In CRT-D patients with LBBB and posterior/lateral LV lead location, there was an association with a significant reduction in long-term all-cause mortality (hazard ratio [HR]: 0.54, 95% confidence interval [CI]: 0.37 to 0.79; p=0.001), and HF events (HR: 0.44, 95% CI: 0.33 to 0.60; p< 0.001) compared to an ICD only, accompanied withbetter LV reverse remodeling. CRT-D patients with LBBB and an anterior LV lead location were shown to be associated with a significant reduction in HF events compared to an ICD only (anterior HR: 0.50, 95% CI: 0.30 to 0.82; p= 0.006); however, no association with mortality reduction was observed from CRT-D versus an ICD only. CRT-D wasnot associated with improved outcomes in non-LBBB patients, regardless of LV lead location. In mild HF patients with LBBB and an implanted CRT-D, lateral/posterior, and anterior LV lead locations are similarly associated with reduction in the risk of HF or death events compared to ICD alone. Mortality benefit derived from CRT-D is associated only with patients with lateral/posterior LV lead location. An apical LV lead location should be avoided due to the early risk of death whenever possible. (Multicenter Automatic Defibrillator Implantation With Cardiac Resynchronization Therapy [MADIT-CRT], NCT00180271; Multicenter Automatic Defibrillator Implantation Trial WithCardiac Resynchronization Therapy Post Approval Registry [MADIT-CRT-PAR], NCT01294449; and MADIT-CRT Long-Term International Follow-Up Registry - Europe, NCT02060110).