Myocardial collagen turnover after surgical ventricular restoration in heart failure patients

Surgical ventricular restoration (SVR) aims to normalize left ventricular (LV) volume and shape in patients with ischaemic cardiomyopathy and anterior wall scar. The chronic effects on LV function may depend on alterations in myocardial collagen metabolism. The present study evaluated myocardial collagen synthesis and degradation rates at baseline and at 6 months follow-up after SVR. We hypothesize that the chronic effects of SVR on LV function and clinical outcome depend on alterations in myocardial collagen metabolism.

Serum levels of aminoterminal propeptides of type I and III collagen (PINP, PIIINP), carboxyterminal telopeptide of type I collagen (ICTP), and tenascin-C (TNC) were measured at baseline and 6 months after SVR in 24 patients. In addition, New York Heart Association (NYHA) functional class, LV volumes and function were evaluated. At follow-up, a significant improvement in NYHA class (from 3.2 ± 0.8 to 1.4 ± 0.6, P< 0.001) and LV ejection fraction (from 28 ± 9 to 35 ± 7%, P< 0.001) was found, whereas E/A ratio tended to increase (from 1.4 ± 1.1 to 1.9 ± 1.1, P= 0.064). Serum levels of PINP, PIIINP, ICTP, and TNC increased significantly (PINP: from 37 ± 15 to 67 ± 26 μg/L, P< 0.001; PIIINP: from 4.9 ± 1.7 to 7.9 ± 4.0 μg/L, P< 0.001; ICTP: from 5.9 ± 3.7 to 10.0 ± 5.3 μg/L, P< 0.001; TNC: from 30 ± 20 to 44 ± 23 μg/L, P= 0.020). At follow-up, an LV ejection fraction <34% and E/A ratio ≥ 2.0 were significantly associated with increased serum levels of PIIINP and ICTP.

In patients who underwent SVR, myocardial collagen metabolism was significantly enhanced 6 months after surgery. Serum levels of myocardial collagen turnover biomarkers were related to post-surgical LV systolic and diastolic function.