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.