PO-02-011 SHORT TERM OUTCOME OF DIFFERENT LOWER PACING RATES IN PATIENTS WITH RECENTLY IMPLANTED CRT

Abstract

CRT is a well-established treatment for patients with congestive heart failure, impaired ejection fraction and QRS duration more than 130 msec. Around one third of patients remains to be non-responders. We aim at comparing the effect of two bi-ventricularly base pacing rates (DDD 60 Bpm vs DDD 80 Bpm) on the composite endpoint of mortality and hospitalization due to heart failure. We included patients with recently implanted CRT, all patients had LBBB, QRS duration more than 130 msec and ejection fraction less than 35%. Patients who had more than 80% of their heart rate at the 6th week follow up visit less than 80 beats/minute as evidenced by the heart rate histograms of the implanted device were randomized using randomization table into two groups (DDD 60 bpm and DDD 80 bpm). Patients with atrial fibrillation or active coronary artery disease . Patients were followed 3 months after randomization and then every 6 months thereafter. `Fifty-one patients were enrolled, 45 patients were included in the final analysis (one died before the randomization, two patients were excluded due to average heart more than 80 beats/min at the time of randomization and three were lost to follow up). Mean age was 51.67 ± 11.1 years, 23 patients (51.1%) were females. Thirty-seven patients (82.2%) had dilated Cardiomyopathy, 16 patients (35.6%) had New York heart association (NYHA) functional class (FC) III heart failure (HF) and 29 patients (64.4%) had NYHA class IV (ambulant) HF. At baseline, Minnesota living with heart failure questionnaire score was (52.56 ± 14.3), six minutes-walk distance was 242 ± 95.9 meters and EF was 24.6± 7.4%. Patients were followed for mean duration of 23.2 ± 11.5 months. More patients reached the primary endpoint of death or hospitalization due to heart failure in the DDD 80 bpm group [ 3 (13.6%) vs 13 (56.5%), P=0.003]. This was driven mainly by hospitalization due to heart failure. Death was numerically higher in the DDD 80 group but this was not statistically significant [1 (4.5%) vs 4 (17.4%), P=0.18]. Patients in DDD 60 group had significant improvement in the 6MWD, NYHA functional class, EF % and Minnesota living with heart failure score compared to non-significant improvement in the DDD 80 group. In CRT recipients, Base pacing rate 60 beats/min shows less incidence of the composite endpoint of mortality and hospitalization due to heart failure and base pacing rate 80 beats/min could potentially be harmful.Tabled 1DDD- 60 (22 patients)DDD-80 (23 patients)P ValueΔ Minnesota living with heart failure score-19 ± 1-4 ± 30.01Δ Six minutes Walking distance (meters)185±7410 ± 630.001Δ EF%6 ± 42 ± 30.01NYHA class improvement20 (90%)14 (60%)0.001 Open table in a new tab