Troponin elevation after radiofrequency catheter ablation of atrial fibrillation: relevance to AF substrate, procedural outcomes, and reverse structural remodeling.

Background: Although radiofrequency ablation creates myocardial necrosis leading to troponin T (TnT) release into the systemic circulation, the significance of TnT elevation after atrial fibrillation (AF) ablation is unknown.
Objective: To demonstrate a possible mechanism of reverse structural remodeling in the left atrium (LA) by evaluating postprocedural TnT elevation.
Methods: This study included 106 patients with an enlarged LA (paroxysmal AF, n = 43; persistent AF, n = 63). All patients underwent pulmonary vein isolation alone in the index procedure. Left atrial volume indexed to body surface area (LAVi) was measured by echocardiography before ablation and 6 months after sinus rhythm restoration. Patients were divided into responders (n = 53) and nonresponders (n = 53) based on a cutoff value of 23% reduction in LAVi. The TnT level was measured 12 hours postprocedure.
Results: LAVi decreased from 43 ± 13 to 33 ± 12 mL/m(2) (P < .0001). The TnT level was higher in responders than in nonresponders (1.31 ± 0.34 μg/L vs 0.88 ± 0.29 μg/L; P < .0001) and correlated linearly with percent reduction in LAVi (R = .54; P < .0001). Also in multivariate analysis, the TnT level was the only independent predictor for responders (odds ratio 90.1; 95% confidence interval 14.95-543.3; P < .0001). The TnT level in patients who required a repeat procedure (n = 30) was lower than that in patients who did not require a repeat procedure only in the persistent AF group (0.92 ± 0.38 μg/L vs 1.16 ± 0.37 μg/L; P = .01).
Conclusion: Greater elevation of the TnT level was related both to favorable outcomes after ablation and to greater reversal of structural remodeling. Postprocedural TnT level may be reflective of the preservation of healthy LA myocardium.
(Copyright © 2014 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)