Abstract 13472: Association of Changes in Heart Rate and Collagen Metabolism by Beta-Blocker Therapy With Improvement in Left Ventricular Diastolic Function in Patients With Chronic Heart Failure
Introduction: Beta-blocker therapy (BBT) improves LV stiffness constant assessed with mitral deceleration time (DT) in patients with chronic heart failure (CHF). Heart rate (HR) decrease in those patients is reported to be more important for LV functional improvement and survival than the dosage of BBT. On the other hand, animal studies showed inhibition of collagen degradation by BBT leads to the prevention of LV dysfunction.
Objectives: We aimed to examine the association between HR decrease, collagen metabolism and LV stiffness constant during BBT for CHF patients.
Methods: 56 patients with reduced EF were studied. DT was measured before, at 1, 6, and 12 months after reaching the maximum dose of bisoprolol. A serum marker for collagen synthesis, C-terminal propeptide of collagen type-I (PICP), and markers for collagen degradation, C-terminal telopeptide of collagen type-I (CITP) and Matrix Metalloproteinase- 2 (MMP-2) were evaluated at each time point. We divided patients into 2 groups according to the increases in DT: Group A, above the average (≧41msec), n = 30; Group B, below the average, n = 26.
Results: The decreases in HR from the baseline were greater in Group A than in Group B in the first month. Two-way analysis of variance revealed that CITP and MMP-2 significantly decreased at 12 months greater in Group A than in Group B (Figure 1, 2). The decreases in HR did not correlate with the changes in the CITP.
Conclusions: LV stiffness constant improved greater in patients with greater inhibition of collagen degradation. Both HR decreases and inhibition of collagen degradation contribute to LV diastolic function recovery by BBT somewhat independently from each other.
- © 2013 by American Heart Association, Inc.