Remote magnetic versus manual catheters: evaluation of ablation effect in atrial fibrillation by myocardial marker levels

Background A remote magnetic navigation (MN) system is available for radiofrequency ablation of atrial fibrillation (AF), challenging the conventional manual ablation technique. The myocardial markers were measured to compare the effects of the two types of MN catheters with those of a manual-irrigated catheter in AF ablation. Methods AF patients underwent an ablation procedure using either a conventional manual-irrigated catheter (CIR, n=65) or an MN system utilizing either an irrigated (RMI, n=23) or non-irrigated catheter (RMN, n=26). Levels of troponin T (TnT) and the cardiac isoform of creatin kinase (CKMB) were measured before and after ablation. Results Mean procedure times and total ablation times were longer employing the remote magnetic system. In all groups, there were pronounced increases in markers of myocardial injury after ablation, demonstrating a significant correlation between total ablation time and post-ablation levels of TnT and CKMB (CIR r=0.61 and 0.53, p<0.001; RMI r=0.74 and 0.73, p<0.001; and RMN r=0.51 and 0.59, p<0.01). Time-corrected release of TnT was significantly higher in the CIR group than in the other groups. Of the patients, 59.6% were free from AF at follow-up (12.2± 5.4 months) and there were no differences in success rate between the three groups. Conclusions Remote magnetic catheters may create more discrete and predictable ablation lesions measured by myocardial enzymes and may require longer total ablation time to reach the procedural endpoints. Remote magnetic non-irrigated catheters do not appear to be inferior to magnetic irrigated catheters in terms of myocardial enzyme release and clinical outcome

N-terminal pro-B-type natriuretic peptide level at longterm follow-up after atrial fibrillation ablation: A marker of reverse atrial remodeling and successful ablation

Aims: We investigated the relationship between arrhythmia burden, left atrial volume (LAV) and N-terminal pro-B-type natriuretic peptide (NT-pro-BNP) at baseline and after long-term follow-up of atrial fibrillation (AF) ablation. Methods: We studied 38 patients (23 paroxysmal, six women, mean age 56±11) scheduled for AF ablation. LAV was calculated on the basis of computed tomography images at baseline and long-term follow-up, and arrhythmia burden was graded from self-reported frequency and duration of AF episodes. Results: After a mean period of 22±5 months, 28/38 patients (11/15 persistent) were free from AF recurrence. At baseline there were no differences in mean LAV (125 vs. 130 cm3, p=0.7) or median NT-pro-BNP (33.5 vs. 29.5 pmol/L, p=0.9) between patients whose ablation had been successful or otherwise. At long-term follow-up there was a marked decrease in LAV (105 vs. 134 cm3, p 25% of baseline value had a specificity of 0.89 and a sensitivity of 0.6 (receiver operator characteristics, accuracy 0.82) for ablation success. Conclusions: NT-pro-BNP correlates with LAV and arrhythmia burden in AF patients and both NT-pro-BNP and LAV decrease significantly after successful ablation. A decrease in NT-pro-BNP of >25% from the baseline value could be useful as a marker of ablation success