Aortic stiffness correlates with an increased extracellular matrix turnover in patients with dilated cardiomyopathy

Background: An increased extracellular matrix (ECM) turnover has been associated with poor survival in patients with chronic heart failure (CHF) due to dilated cardiomyopathy (DCM). However, the influence of the accelerated collagen turnover on the progressive large artery stiffening process characterizing CHF has not been clarified. This is relevant because aortic stiffening imposes an additional systolic load and impairs exercise tolerance in CHF patients. Therefore, we investigated whether the serum aminoterminal propeptide of type III collagen (PIIINP), an established marker of ECM turnover and tissue fibrosis in DCM, was associated with aortic stiffness in DCM patients. Methods and Results: A total of 89 patients with clinical diagnosis of DCM (age 62 ± 9 years, 80% men, mean ejection fraction 34% ± 8%) were selected. Aortic pulse-wave velocity (PWV), a well-established marker of aortic stiffness, was measured by Doppler ultrasonography. Serum concentration of PIIINP was determined by radioimmunoassay. Mean aortic PWV was 5.7 ± 2.3 m/s, and PIIINP was 5.0 ± 1.3 μg/L. The variables correlated with aortic PWV were age (r = 0.33, P = .002), PIIINP (r = 0.30, P = .005), heart rate (r = 0.27, P = .02), stroke volume (r = -0.24, P = .03) and New York Heart Association class (r = 0.25, P = .02). In a multivariate analysis, age (P = .02) and PIIINP (P = .01) were independently related with aortic PWV, accounting for 27% of its variance. Conclusions: Higher serum PIIINP levels are independently associated with a stiffer aorta in DCM patients. This suggests that abnormalities in the ECM turnover might involve the proximal elastic vasculature and could partially explain the progressive large artery stiffening process characterizing CHF.