Cardiac Resynchronization Therapy WithaQuadripolar Electrode Lead Decreases Complications at 6 Months: Results of the MORE-CRT Randomized Trial.

Abstract

The aim of this study was to test the hypothesis that a quadripolar left ventricular (LV) lead results in fewer LV lead-related events than a bipolar cardiac resynchronization therapy (CRT) system in a prospective randomized trial. Bipolar LV leads cannot be implanted at the optimal site in up to 10% of patients who need CRT, because of anatomic or technical challenges (pacing threshold, phrenic stimulation, or mechanical instability). The MORE-CRT (More Options Available With a Quadripolar LV Lead Provide In-Clinic Solutions to CRT Challenges) trial enrolled 1,078 patients. Patients with indications for CRT defibrillator therapy were randomized into 2groups in a 1:2 ratio: a group with a bipolar CRT lead system (the BiP group; any manufacturer) and a group with a quadripolar CRT system (the Quad group; Quartet LV lead). The primary endpoint was freedom from a composite endpoint of intraoperative and post-operative LV lead-related events at 6 months. A total of 1,074 of 1,078 patients (99%) were randomized and contributed to the primary endpoint. Freedom from the composite endpoint was significantly greater in the Quad than the BiP group (83.0% vs. 74.4%, p= 0.0002). The intraoperative component of the endpoint was met less frequently by Quad group patients (6.26% Quad vs. 12.1% BiP), whereas there was no difference for the post-operative component (7.1% Quad vs. 7.6% BiP). The Quartet LV system significantly reduced total LV lead-related events at 6 months after implantation compared with a bipolar CRT system. The reduction in events demonstrates the superiority of this quadripolar technology to effectively manage CRT patients. (More Options Available With a Quadripolar LV Lead Provide In-Clinic Solutions to CRT Challenges [MORE-CRT]; NCT01510652).