Changes in collagen metabolism account for ventricular functional recovery following beta-blocker therapy in patients with chronic heart failure

While beta blockade improves left ventricular (LV) function in patients with chronic heart failure (CHF), the mechanisms are not well known. This study aimed to examine whether changes in myocardial collagen metabolism account for LV functional recovery following beta-blocker therapy in 62 CHF patients with reduced ejection fraction (EF). LV function was echocardiographically measured at baseline and 1, 6, and 12 months after bisoprolol therapy along with serum markers of collagen metabolism including C-terminal telopeptide of collagen type I (CITP) and matrix metalloproteinase (MMP)-2. Deceleration time of mitral early velocity (DcT) increased even in the early phase, but LVEF gradually improved throughout the study period. Heart rate (HR) was reduced from the early stage, and CITP gradually decreased. LVEF and DcT increased more so in patients with the larger decreases in CITP ( r = −0.33, p < 0.05; r = −0.28, p < 0.05, respectively), and HR ( r = −0.31, p < 0.05; r = −0.38, p < 0.05, respectively). In addition, there were greater decreases in CITP, MMP-2 and HR from baseline to 1, 6, or 12 months in patients with above-average improvement in LVEF than in those with below-average improvement in LVEF. Similar results were obtained in terms of DcT. There was no significant correlation between the changes in HR and CITP. In conclusion, improvement in LV systolic/diastolic function was greatest in patients with the larger inhibition of collagen degradation. Changes in myocardial collagen metabolism are closely related to LV functional recovery somewhat independently from HR reduction.