title: Effect of remote ischemic preconditioning on platelet activation and reactivity induced by ablation for atrial fibrillation.
abstract: BACKGROUND
  Radiofrequency ablation of atrial fibrillation has been associated with some risk of thromboembolic events. Previous studies showed that preventive short episodes of forearm ischemia (remote ischemic preconditioning [IPC]) reduce exercise-induced platelet reactivity. In this study, we assessed whether remote IPC has any effect on platelet activation induced by radiofrequency ablation of atrial fibrillation.
  
  
  RESULTS
  We randomized 19 patients (age, 54.7±11 years; 17 male) undergoing radiofrequency catheter ablation of paroxysmal atrial fibrillation to receive remote IPC or sham intermittent forearm ischemia (control subjects) before the procedure. Blood venous samples were collected before and after remote IPC/sham ischemia, at the end of the ablation procedure, and 24 hours later. Platelet activation and reactivity were assessed by flow cytometry by measuring monocyte-platelet aggregate formation, platelet CD41 in the monocyte-platelet aggregate gate, and platelet CD41 and CD62 in the platelet gate in the absence and presence of ADP stimulation. At baseline, there were no differences between groups in platelet variables. Radiofrequency ablation induced platelet activation in both groups, which persisted after 24 hours. However, compared with control subjects, remote IPC patients showed a lower increase in all platelet variables, including monocyte-platelet aggregate formation (P<0.0001), CD41 in the monocyte-platelet aggregate gate (P=0.002), and CD41 (P<0.0001) and CD62 (P=0.002) in the platelet gate. Compared with control subjects, remote IPC was also associated with a significantly lower ADP-induced increase in all platelet markers.
  
  
  CONCLUSIONS
  Our data show that remote IPC before radiofrequency catheter ablation for paroxysmal atrial fibrillation significantly reduces the increased platelet activation and reactivity associated with the procedure.
authors.affiliation: Institute of Cardiology, Università Cattolica del Sacro Cuore, Rome, Italy.
authors.forename: Alessandra
authors.initials: A
authors.lastname: Stazi
authors.forename: Giancarla
authors.initials: G
authors.lastname: Scalone
authors.forename: Marianna
authors.initials: M
authors.lastname: Laurito
authors.forename: Maria
authors.initials: M
authors.lastname: Milo
authors.forename: Gemma
authors.initials: G
authors.lastname: Pelargonio
authors.forename: Maria Lucia
authors.initials: ML
authors.lastname: Narducci
authors.forename: Rossella
authors.initials: R
authors.lastname: Parrinello
authors.forename: Stefano
authors.initials: S
authors.lastname: Figliozzi
authors.forename: Gianluigi
authors.initials: G
authors.lastname: Bencardino
authors.forename: Francesco
authors.initials: F
authors.lastname: Perna
authors.forename: Gaetano A
authors.initials: GA
authors.lastname: Lanza
authors.forename: Filippo
authors.initials: F
authors.lastname: Crea
mesh_terms: D000328:Adult; D000368:Aged; D001281:Atrial Fibrillation / Q000097:blood / Q000601:surgery*; D001792:Blood Platelets / Q000502:physiology; D017115:Catheter Ablation; D005260:Female; D005542:Forearm / Q000098:blood supply; D006801:Humans; D019157:Ischemic Preconditioning, Myocardial / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009000:Monocytes / Q000502:physiology; D017202:Myocardial Ischemia / Q000517:prevention & control*; D015539:Platelet Activation / Q000502:physiology*; D011183:Postoperative Complications / Q000097:blood / Q000517:prevention & control*; D013927:Thrombosis / Q000097:blood / Q000517:prevention & control
keywords: atrial fibrillation; blood platelets; catheter ablation; ischemic preconditioning; platelet activation