Right ventricular lead location, right-left ventricular lead interaction, and long-term outcomes in cardiac resynchronization therapy patients

Usama A. Daimee, Helmut U. Klein, Michael C. Giudici, Wojciech Zareba, Scott McNitt, Bronislava Polonsky, Arthur J. Moss, Valentina Kutyifa

The effects of right ventricular (RV) lead location and the combination of RV and left ventricular (LV) lead locations on long-term outcomes in patients receiving cardiac resynchronization therapy with defibrillator (CRT-D) are not well understood. Our cohort consisted of 743 CRT-D patients from MADIT-CRT. We evaluated long-term death and combined heart failure or death (HF/death) in patients with non-apical RV vs. apical RV leads. We further assessed these long-term outcomes based on the combination of RV and LV leads, termed "RV-LV lead interaction." Patients with non-apical RV and apical LV leads and those with apical RV and non-apical LV leads were described to have "discordant RV and LV leads." Patients with RV and LV leads that were both non-apical or both apical were defined to have "concordant RV and LV leads." There were no differences in death and HF/death between patients with non-apical RV vs. apical RV leads. However, patients with non-apical RV and apical LV leads had higher mortality risk, relative to those with apical RV and non-apical LV leads (HR = 4.06, 95% CI 1.73-9.53, p = 0.001) as well as those with both leads in the non-apical (HR = 3.82, 95% CI 1.33-10.98, p = 0.013) or apical (HR = 3.40, 95% CI 1.24-9.37, p = 0.018) positions. There was no difference in HF/death by RV-LV lead sub-groups. Among CRT-D patients, long-term outcomes were similar for non-apical RV and apical RV leads. However, mortality risk was increased with discordant RV and LV leads, when a non-apical RV lead was combined with an apical LV lead.