Abstract 17557: Programmed Lower Rate Limit in Cardiac Resynchronization Therapy Defibrillators: Is There One Best Approach?

Introduction: Recent remote follow-up data analysis suggests that Lower Rate Limit (LRL) programming at 40 beats per minute (bpm) is associated with lower mortality than higher LRL in patients receiving cardiac resynchronization defibrillators (CRT-d) devices. Purpose: We evaluated: 1. if LRL programming in CRT-d devices is based on implanting center or if it varies from patient-to-patient within centers and 2. if LRL programming is associated with survival. Method: The ALTITUDE remote follow-up database was analyzed for dual-chamber CRT-d devices implanted 2006-2011. LRL programming near implant was assessed. Patients were included if LRL remained constant during follow-up. Centers were included with >25 implants. Mortality was determined from the Social Security Death Index. Results: Of 64,482 patients receiving CRT-d devices (not in chronic atrial fibrillation), 56,501 were from centers implanting >25 devices. Of these, 4,683 were implanted in centers where most patients (>75%) received the same LRL (homogeneous); 51,818 were implanted in centers with variable LRL programming (heterogeneous). No difference in overall survival existed between the two approaches to LRL programming. However, in centers that varied LRL programming, LRL<60 bpm was associated with better 5-year survival (p<0.001) (figure). Conclusion: Most patients in the ALTITUDE database received CRT-D devices from centers that vary LRL programming. At these centers, LRL <60 bpm programming is associated with better survival but the mechanism of benefit is unknown. Alternatively, LRL <60 bpm programming for all patients does not confer survival benefit.