Background: In patients with heart failure cardiac resynchronization therapy (CRT) leads to reverse ventricular remodelling. Aim: To evaluate whether myocardial collagen metabolism in patients with heart failure is implicated in adverse ventricular remodelling and response to CRT. Methods: Collagen synthesis and degradation were assessed from the concentrations of aminoterminal propeptides of type I and type III collagen (PINP and PIIINP) and carboxyterminal telopeptide of type I collagen (ICTP), respectively, in serum of 64 patients with heart failure before and after 6 months of CRT. Forty-six patients (72%) showed a N 10% reduction in LV end-systolic volume at follow-up and were classified as responders to CRT, the other 18 patients (28%) were classified as non-responders. Results: Responders demonstrated a mean (± SEM) increase of serum PINP and PIIINP during follow-up, from 32.9 ± 2.2 to 46.7 ± 4.0 μg/L (p b 0.001) and from 4.59 ± 0.24 to 5.13 ± 0.36 μg/L (p b 0.05), respectively. In non-responders, serum PINP and PIIINP remained unchanged during follow-up. At baseline, responders had significantly lower serum PINP than non-responders (32.9 ± 2.2 vs. 41.8 ± 4.3 μg/L; p b 0.05). ICTP levels of responders at baseline tended to be higher than in non-responders (3.54 ± 0.56 vs. 2.08 ± 0.37 μg/L, p = ns), and in both groups ICTP levels did not change upon CRT. Conclusion: Reverse LV remodelling following CRT is associated with increased collagen synthesis rate in the first 6 months of follow-up.

Background: In heart failure patients, cardiac resynchronization therapy (CRT) leads to reverse ventricular remodelling. Aim: The aim of this study was to evaluate whether changes in levels of circulating biomarkers of extracellular matrix metabolism correlate with the response to CRT. Methods and results: Clinical parameters, left ventricular (LV) volumes, and circulating levels of tenascin-C (TNC), matrix metalloproteinase-2 (MMP-2), MMP-9, and amino-terminal propeptide of brain natriuretic peptide (NT-proBNP) were assessed in 64 patients at baseline and 6 months follow-up. The majority of patients (72%) showed a N 10% reduction in LV end-systolic volume at follow-up, and were classified as responders to CRT. The remaining patients were classified as non-responders. In responders, a significant decrease in circulating levels of TNC (from 60 ± 40 ng/mL to 47 ± 30 ng/mL, p b 0.01), MMP-9 (from 55 ± 30 AU to 44 ± 27 AU, p b 0.01), and NT-proBNP (from 2106 ± 1805 pg/mL to 1132 ± 1289 pg/mL, p b 0.001) were observed at follow-up; MMP-2 levels were unchanged. In non-responders TNC, NT-proBNP, MMP-9 and MMP-2 levels remained unchanged. Conclusion: At 6 months follow-up, CRT was associated with reverse LV remodelling, and a significant decrease in TNC, MMP-9, and NTproBNP levels. This suggests an important role of ECM modulation in the process of reverse ventricular remodelling in patients responding to CRT.

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Rhamnose is one of the sugars regularly used to conduct the dual sugar permeability test. For more than 30 years, it has been assumed that rhamnose is an inert sugar not metabolized by the human body and only fermented by some colonic bacteria into rhamnulose. While conducting an investigation on gut permeability in children undergoing cardiac surgery, increased concentrations of rhamnitol were found in the urine samples. The present report suggests that rhamnose is not an inert sugar and it is partially metabolized into rhamnitol by the human body.

Infants and children undergoing cardiac surgery with cardiopulmonary bypass show a significant reduction in gut permeability when dexamethasone is used during induction of anesthesia. Dexamethasone does not affect the intestinal barrier at the functional level, as assessed on the basis of 3-O-methyl-D-glucose and D-xylose absorption.