Cardiac extra-cellular matrix (ECM) fibrosis plays an important role in the pathophysiology of heart failure (HF). It may provide electrical heterogeneity and substrate for arrhythmogenicity, which may cause sudden cardiac death (SCD).
Twenty-one Patients with HF manifestations, and left ventricular ejection fraction (LVEF) ≤ 50% were enrolled. The median age was 62 years and median LVEF was 33 %. Time- and frequency-domain analysis of heart rate variability (HRV) on 24-hour ambulatory electrocardiography recording was assessed. Serum markers of ECM turnover including type I and III aminoterminal propeptide of procollagen (PINP and PIIINP), matrix metalloproteinase-2 and 9 (MMP-2 and MMP-9), and tissue inhibitor of metalloproteinase 1 (TIMP-1) were analyzed.
The serum PIIINP level was significantly correlated with standard deviation of all normal RR intervals (SDNN) (r=−0.722, p=<0.001), percentage of adjacent NN interval differences >50 ms (pNN50) (r=−0.528, p=0.014), percentage of adjacent NN interval differences >20 ms (pNN20) (r=−0.545, p=0.002), very low frequency (VLF) (r=−0.490, p=0.024), low frequency (LF) (r=−0.491, p=0.024), high frequency (HF) (r=−0.513, p=0.018). PINP, MMP-2, 9, TIMP-1 were not correlated with time- and frequency-domain analysis of HRV.
PIIINP was significantly correlated with time- and frequency-domain analysis of HRV in HF patients. PIIINP is a potential serological marker to evaluate cardiac autonomic control and risk of SCD in HF patients.