Early release of high-sensitive cardiac troponin during complex catheter ablation for ventricular tachycardia and atrial fibrillation

Background: Radiofrequency ablation results in intentional cardiac injury. We aimed to assess the kinetics of cardiac injury as measured by cardiac troponin release following ventricular ablation and atrial ablation. Methods: Patients undergoing ablation for ventricular tachycardia (VT) with structural heart disease (19 patients) or atrial fibrillation (AF, 24 patients) were prospectively enrolled. High-sensitivity cardiac troponin T (hs-cTnT) and high-sensitivity cardiac troponin I (hs-cTnI) were measured before ablation as well as 30 min, 60 min, 90 min, 120 min, 4 h, 8 h, and 24 h after applying the first ablation lesion. Results: Median ablation time, power used, and energy delivered were 28 min, 39 W, and 69,713 J in VT ablations and 55 min, 29 W, and 95,425 J in AF ablations, respectively. Release of hs-cTnT occurred promptly with both, but reached greater levels earlier for ventricular compared to atrial ablation (hs-cTnT after 30 min 191 vs. 31 ng/l, after 1 h 467 vs. 80 ng/l; hs-cTnI after 30 min 132 vs. 30 ng/l, after 1 h 331 vs. 76 ng/l; p < 0.001 for all comparisons). After 24 h, levels were similar (hs-cTnT 1325 vs. 1303 ng/l, p = 0.92; hs-cTnI 2165 vs. 1996 ng/l, p = 0.55). Levels of hs-cTnT after 24 h correlated well with the energy delivered in AF ablations (r = 0.81 and r = 0.75, p < 0.001), but not in VT ablations (r = 0.35 and r = 0.44, p = ns). Conclusions: Evidence of cardiac injury as indicated by the release of hs-cTnT and hs-cTnI occurs early with atrial and ventricular ablation. Higher early levels are observed in ventricular ablations, but levels are similar after 24 h. The extent of total troponin release seems to correlate well with the amount of energy delivered in AF ablations, but not in VT ablations.