title: Myocardial collagen metabolism in failing hearts before and during cardiac resynchronization therapy.
abstract: BACKGROUND
  In patients with heart failure cardiac resynchronization therapy (CRT) leads to reverse ventricular remodelling.
  
  
  OBJECTIVE
  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 > 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 microg/L (p < 0.001) and from 4.59+/-0.24 to 5.13+/-0.36 microg/L (p < 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 microg/L; p < 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 microg/L, p = ns), and in both groups ICTP levels did not change upon CRT.
  
  
  CONCLUSIONS
  Reverse LV remodelling following CRT is associated with increased collagen synthesis rate in the first 6 months of follow-up.
authors.affiliation: Department of Cardiology, Leiden University Medical Center, Leiden, The Netherlands.
authors.forename: Soban
authors.initials: S
authors.lastname: Umar
authors.forename: Jeroen J
authors.initials: JJ
authors.lastname: Bax
authors.forename: Margreet
authors.initials: M
authors.lastname: Klok
authors.forename: Rutger J
authors.initials: RJ
authors.lastname: van Bommel
authors.forename: Marleen H M
authors.initials: MH
authors.lastname: Hessel
authors.forename: Brigit
authors.initials: B
authors.lastname: den Adel
authors.forename: Gabe B
authors.initials: GB
authors.lastname: Bleeker
authors.forename: Maureen M
authors.initials: MM
authors.lastname: Henneman
authors.forename: Douwe E
authors.initials: DE
authors.lastname: Atsma
authors.forename: Ernst E
authors.initials: EE
authors.lastname: van der Wall
authors.forename: Martin J
authors.initials: MJ
authors.lastname: Schalij
authors.forename: Arnoud
authors.initials: A
authors.lastname: van der Laarse