Thorac Cardiovasc Surg 2008; 56 - P18
DOI: 10.1055/s-2008-1037751

Atrial fibrillation and cardiac progenitor cells: Observations in atrial specimens from 73 patients undergoing cardiac surgery

M Arnold 1, B Reiter 2, T Fischlein 3, V Kufer 1, A Schütz 1, H Reichenspurner 2, WG Daniel 1, CD Garlichs 1
  • 1Friedrich-Alexander-Universität Erlangen, Medizinische Klinik II Kardiologie, Angiologie, Erlangen, Germany
  • 2Universitäres Herzzentrum Hamburg, Klinik für Herz- und Gefäßchirurgie, Hamburg, Germany
  • 3Friedrich-Alexander-Universität Erlangen, Klinik für Herzchirurgie, Erlangen, Germany

Aims: Electrical und structural remodeling is part of the pathophysiology of atrial fibrillation (AF). The purpose of our study was to investigate if AF leads to an increase in proliferative activity in atrial myocardium and to changes of resident cardiac stem cell numbers in patients with or without ACE inhibitor therapy.

Methods: Atrial myocardium of 73 patients was examined by immunohistochemistry. Proliferating cardiomyocytes (i.e. cardiac progenitor cells) were identified by their morphology and presence of Ki67 (a nuclear protein which is only expressed in cells actively undergoing the cell cycle). C-kit+CD34-CD45- cells were counted as resident cardiac stem cells. Cell numbers of patients with or without atrial AF and with or without ACE inhibitor therapy were compared.

Results: In patients with AF a significantly higher number of Ki67 positive cells was found (AF overall: 5,3±2,6*10-6/µm2; AF and ACE-inhibitor: 6.9±3,0*10-6/µm2; AF without ACE inhibitor: 4,8±2,1*10-6/µm2) as compared to patients without AF (no AF: 3,6±1,9*10-6/µm2; no AF with ACE inhibitor: 3,8±2,0*10-6/µm2; no AF without ACE inhibitor 3,2±1,6*10-6/µm2) (p=0,0097, p=0,0028, p=0,039). There was no difference in patients without AF with regard to ACE inhibitor therapy (4,3±2,4*10-6/µm2 vs. 3,6±2,0*10-6/µm2).

Summary: Atrial fibrillation is related to a higher proliferative activity of atrial cardiac progenitor cells. Numbers of C-kit+CD34-CD45- resident cardiac stem cells in specific are not changed. ACE inhibitors seem not to affect this process in our study.