Improving Cardiac Resynchronization Therapy Re- sponse with Multipoint Left Ventricular Pacing: 12- month Follow-up Study

Background: Cardiac resynchronization therapy (CRT) with multipoint left ventricular (LV) pacing (MultiPointTM Pacing [MPP], St. Jude Medical) improves acute LV function and LV reverse remodeling at 3 months. Objective: We hypothesized that MPP can also improve LV function at 12 months. Methods: Consecutive patients receiving a CRT implant (Unify Quadra MPTM or Quadra Assura MPTM CRT-D and QuartetTM LV lead, St. Jude Medical) were randomized to receive pressure-volume (PV) loop optimized biventricular pacing with either conventional CRT (CONV) or MPP. CRT response was defined by a reduction in end-systolic volume (ESV) of ≥15% relative to BASELINE as determined by a blinded observer and alive status. Results: Forty-four patients (NYHA III, ejection fraction [EF] 29±6%, QRS 152±17 ms) were enrolled and randomized to either CONV (N=22) or MPP (N=22). During the observation period, two patients died from non-cardiac causes and two patients were lost to follow-up. After 12 months, 12/21 (57%) patients in the CONV group and 16/21 (76%) patients in the MPP group were classified as CRT responders (p=0.33). ESV reduction and EF increase relative to BASELINE were significantly greater with MPP than with CONV (ESV: median -25% [IQR -39 to -20%] vs. median -18% [IQR: -25 to -2%], p=0.03; EF: median +15% [IQR 8 to 20%] vs. median +5% [IQR: -1 to 8%], p<0.001). Conclusion: Sustaining the trend observed 3 months post-implant, PV loop guided multipoint LV pacing resulted in greater LV reverse remodeling and increased LV function at 12 months compared to PV loop guided conventional CRT.