title: Elevated pre-operative serum peptides for collagen I and III synthesis result in post-surgical atrial fibrillation.
abstract: OBJECTIVE
  This study sought to determine if serum markers for collagen I and III synthesis, the carboxyl terminal peptide from pro-collagen I (PICP) and the amino terminal peptide from pro-collagen III (PIIINP), correlate with left atrial (LA) fibrosis and post-operative atrial fibrillation (AF).
  
  
  BACKGROUND
  AF after cardiac surgery is associated with adverse outcomes. We recently demonstrated that LA fibrosis is associated with post-operative AF in patients with no previous history of AF.
  
  
  METHODS
  Fifty-four patients having cardiac surgery without a history of AF consented to left and right atrial biopsies and a pre-operative peripheral blood draw. Picrosirius red staining quantified the percentage of fibrosis, and reverse transcriptase polymerase chain reaction assessed atrial tissue messenger ribonucleic acid transcripts involved in the fibrosis pathway. PICP and PIIINP levels were measured using an enzyme immunosorbent assay.
  
  
  RESULTS
  Eighteen patients developed AF, whereas 36 remained in normal sinus rhythm. LA fibrosis was higher in patients who developed AF versus normal sinus rhythm (6.13 ± 2.9% vs. 2.03 ± 1.9%, p = 0.03). LA messenger ribonucleic acid transcripts for collagen I, III, transforming growth factor, and angiotensin were 1.5- to 2.0-fold higher in AF patients. Serum PICP and PIIINP levels were highest in AF versus normal sinus rhythm (PICP: 451.7 ± 200 ng/ml vs. 293.3 ± 114 ng/ml, p = 0.006; PIIINP: 379 ± 286 pg/ml vs. 191.6 ± 162 pg/ml, p = 0.01). Furthermore, there was a linear correlation between LA fibrosis and serum PICP levels (R(2) = 0.2; p = 0.01), and of the markers, only PICP was independently associated with AF.
  
  
  CONCLUSIONS
  This demonstrates that serum PICP and PIIINP levels correlate with the presence of LA fibrosis and may act as predictors for post-operative AF even in the absence of previous history of AF.
authors.affiliation: Department of Surgery, University of Rochester, Rochester, New York, USA.
authors.forename: Michael F
authors.initials: MF
authors.lastname: Swartz
authors.forename: Gregory W
authors.initials: GW
authors.lastname: Fink
authors.forename: Muhammad F
authors.initials: MF
authors.lastname: Sarwar
authors.forename: George L
authors.initials: GL
authors.lastname: Hicks
authors.forename: Yao
authors.initials: Y
authors.lastname: Yu
authors.forename: Rui
authors.initials: R
authors.lastname: Hu
authors.forename: Charles J
authors.initials: CJ
authors.lastname: Lutz
authors.forename: Steven M
authors.initials: SM
authors.lastname: Taffet
authors.forename: José
authors.initials: J
authors.lastname: Jalife
mesh_terms: D000328:Adult; D000368:Aged; D001281:Atrial Fibrillation / Q000097:blood* / Q000209:etiology*; D001706:Biopsy / Q000379:methods; D024042:Collagen Type I / Q000097:blood*; D024061:Collagen Type III / Q000097:blood*; D004562:Electrocardiography / Q000379:methods; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D005260:Female; D006325:Heart Atria / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010446:Peptide Fragments / Q000097:blood; D011183:Postoperative Complications; D011347:Procollagen / Q000097:blood; D016896:Treatment Outcome
chemical_list: D024042:Collagen Type I; D024061:Collagen Type III; D010446:Peptide Fragments; D011347:Procollagen; C041876:procollagen Type III-N-terminal peptide