title: Sinus rhythm restoration affects collagen turnover in patients with persistent atrial fibrillation.
abstract: OBJECTIVE
  Collagen turnover and atrial fibrosis have been implicated in the generation and perpetuation of atrial fibrillation (AF). We evaluated the importance of serum markers of collagen turnover in predicting the outcome of electrical cardioversion (CV) of persistent AF and the relationship between AF and fibrosis.
  
  
  RESULTS
  Serum C-terminal pro-peptide of collagen type-I (CICP) and C-terminal telopeptide of collagen type-I (CITP) were measured in 164 patients with AF before and 2 months after CV. All the patients were successfully cardioverted to sinus rhythm (SR) although in 38 of them AF recurred. Baseline CICP levels were comparable in patients in SR 60 days after CV and in those who experienced a relapse of AF (85.08 ± 16.99 vs. 87.55 ± 10.43 ng/mL, respectively, P = ns). Baseline CITP levels were significantly higher in patients with AF recurrence compared with those who remained in SR (0.48 ± 0.16 vs. 0.32 ± 0.17 ng/mL, respectively, P < 0.0001). In the 126 patients who maintained the SR, CICP levels were significantly lower at the end of the study as compared with the baseline (63.74 ± 15.92 vs. 85.08 ± 16.99 ng/mL P = 0.003), while there was a mild increase in plasma CITP levels (0.36 ± 0.21 vs. 0.32 ± 0.17 ng/mL, respectively, P = 0.03).
  
  
  CONCLUSIONS
  Atrial fibrillation can result in alterations in atrial structure and architecture that make the atrial myocardium more susceptible to the maintenance of the arrhythmia. Sinus rhythm restoration could affect the fibrotic process occurring or exacerbating during AF course.
authors.affiliation: Department of Cardiology, University Hospital of Heraklion, 71100 Heraklion, Crete, Greece ekallergis@med.uoc.gr.
authors.forename: Eleftherios M
authors.initials: EM
authors.lastname: Kallergis
authors.affiliation: Department of Cardiology, University Hospital of Heraklion, 71100 Heraklion, Crete, Greece.
authors.forename: Christos A
authors.initials: CA
authors.lastname: Goudis
authors.affiliation: Department of Cardiology, University Hospital of Heraklion, 71100 Heraklion, Crete, Greece.
authors.forename: Emmanuel M
authors.initials: EM
authors.lastname: Kanoupakis
authors.affiliation: Department of Cardiology, University Hospital of Heraklion, 71100 Heraklion, Crete, Greece.
authors.forename: Hercules E
authors.initials: HE
authors.lastname: Mavrakis
authors.affiliation: Laboratory of Biochemistry, University Hospital of Heraklion, 71100 Heraklion, Crete, Greece.
authors.forename: Niki E
authors.initials: NE
authors.lastname: Maliaraki
authors.affiliation: Biostatistics Laboratory, University Hospital of Heraklion, 71100 Heraklion, Crete, Greece.
authors.forename: Nikos
authors.initials: N
authors.lastname: Tzanakis
authors.affiliation: Department of Cardiology, University Hospital of Heraklion, 71100 Heraklion, Crete, Greece.
authors.forename: Panos E
authors.initials: PE
authors.lastname: Vardas
mesh_terms: D001281:Atrial Fibrillation / Q000097:blood / Q000175:diagnosis* / Q000517:prevention & control*; D015415:Biomarkers / Q000097:blood; D002908:Chronic Disease; D003094:Collagen / Q000378:metabolism*; D024042:Collagen Type I / Q000097:blood*; D004554:Electric Countershock; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010446:Peptide Fragments / Q000097:blood*; D010455:Peptides / Q000097:blood*; D011347:Procollagen / Q000097:blood*; D012008:Recurrence; D015203:Reproducibility of Results; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D016896:Treatment Outcome
chemical_list: D015415:Biomarkers; D024042:Collagen Type I; D010446:Peptide Fragments; D010455:Peptides; D011347:Procollagen; C052929:collagen type I trimeric cross-linked peptide; C042813:procollagen type I carboxy terminal peptide; D003094:Collagen
keywords: Atrial fibrillation; Cardioversion; Collagen; Fibrosis; Recurrence