Impact of optimal heart rate on left ventricular reverse remodeling and functional improvement in patients with systolic heart failure.

Heart rate modulation therapy using ivabradine reduces mortality and morbidity in patients with systolic heart failure, whereas too reduced heart rate seems to worsen the clinical outcome. The optimal heart rate during heart rate modulation therapy remains unknown. Consecutive patients with left ventricular ejection fraction   10 bpm of ideal heart rate). A total of 75 patients (70 years old, 60 men) were included. There were no significant differences in the baseline characteristics among the three groups, except for the higher prevalence of tolvaptan use and higher plasma B-type natriuretic peptide level in the below-optimal heart rate group. Left ventricular end-diastolic diameter (from 55 to 54) and left ventricular ejection fraction (from 39 to 46) improved significantly only in the optimal heart rate group at 1-year follow-up (p < 0.05 for both). Optimal heart rate, which was calculated using a formula consisting of deceleration time, was associated with cardiac reverse remodeling in patients with systolic heart failure. Prospective study to investigate the implication of deceleration time-guided aggressive heart rate optimization is the next concern.