Successful catheter ablation decreases platelet activation and improves endothelial function in patients with atrial fibrillation

BACKGROUND Nonvalvular atrial fibrillation (AF) confers a fivefold increased risk of stroke. Whether catheter ablation (CA) subsequently decreases prothrombotic risk is unknown. OBJECTIVE The purpose of this study was to assess the long-term effects of CA for AF on prothrombotic risk. METHODS Fifty-seven patients undergoing CA for AF were prospectively studied. Platelet activation (CD62P [platelet P-selectin] and PAC-1 Lglycoprotein IIb/IIIai expression) and endothelial function (asymmetric dimethylarginine [ADMA] Levels) were measured at baseline and 6-months postablation. RESULTS Thirty-seven (65%) patients remained in sinus rhythm (SR group) and 20 (35%) sustained AF recurrence (AF recurrence group) at 6-months. Patients with AF-recurrence were older, had a higher proportion of hypertension and long-standing persistent AF. There were no significant differences in CD62P (P = .3), PAC-1 (P = .1) and ADMA (P =.7) levels at baseline between the two groups. In the SR group, markers of platelet activation decreased significantly at 6-month follow-up compared to baseline; Log CD62P % 0.79 +/- 0.28 vs 1.03 +/- 0.27 (P < .05) and Log PAC-1 % 0.22 +/- 0.58 vs 0.89 +/- t 0.31 (P <.01). This was not significant in the AF-recurrence group (P =.8, Log CD62P; P = Log PAC-1). For endothelial function, ADMA Levels decreased significantly at 6-months compared to baseline in the SR group (log ADMA iiM/L 0.15 +/- 0.02 vs 0.17 +/- 0.04; P < .05), but did not alter significantly in the AFrecurrence group (P =.4, log ADMA). CONCLUSION Catheter ablation and successful maintenance of SR leads to a decrease in platelet activation and improvement in endothelial function in patients with AF. These findings suggest that AF is an important determinant of the prothrombotic state and that this may be reduced by successful catheter ablation.