Role of tissue C-reactive protein in atrial cardiomyocytes of patients undergoing catheter ablation of atrial fibrillation: pathogenetic implications

Aims Histological studies support the important role of inflammation in the initiation and maintenance of atrial fibrillation (AF). We describe a novel and safe technique of atrial biopsy during AF radiofrequency catheter ablation (RFCA) to investigate the role of atrial tissue inflammation. Methods and results We enrolled 70 consecutive patients (age 60 +/- 12 years, 49 males) undergoing RFCA for AF. The control group was represented by 10 patients with Wolff-Parkinson-White syndrome undergoing trans-septal puncture. Atrial biopsies were obtained by washing the dilator and needle used for trans-septal puncture with 20 mL sterile phosphate-buffered saline. The presence of intracytoplasmic C-reactive protein was assessed in formalin-fixed atrial specimens by immunohistochemistry. A sufficient amount of atrial tissue was obtained in 23/70 (32%) patients with AF and in 4/10 (40%) of the control group. Intracytoplasmic localization of C-reactive protein was found in isolated atrial cardiomyocytes in 11 (73%) of 15 patients with paroxysmal AF as compared with 2 (25%) of eight patients with persistent AF (P = 0.02). Conclusion In this study, we demonstrate the safety and feasibility of a novel technique to obtain atrial specimens during routine trans-septal puncture. Local inflammation assessed by atrial tissue localization of C-reactive protein is more likely involved in paroxysmal rather than in persistent AF.