High-sensitivity Troponin I and Ablation Effectiveness Quotient after Ablation Index-guided pulmonary vein isolation-markers of arrhythmia recurrence?

Background There are conflicting data regarding the relationship between high-sensitivity cardiac Troponin I (Hs-cTnI) and the ablation effectiveness quotient (AEQ) with arrhythmia recurrence following atrial fibrillation (AF) ablation. Our goals were to evaluate the impact of the Ablation Index (AI) software on Hs-cTnI and AEQ levels and to assess whether these markers are predictors of arrhythmia recurrence. Methods Prospective single-center study of 75 consecutive patients referred for paroxysmal AF ablation from October 2017 to January 2019. Procedural endpoints and 2-year outcomes were assessed and compared to those of 75 propensity score-matched patients submitted to non-AI-guided pulmonary vein isolation (PVI) [control group]. Results Compared to the control group, patients having AI-guided PVI had lower Hs-cTnI values (1580 [IQR 1180-2140] ng/L vs. 2600 [IQR 1840 - 3900], p < 0.001) and a lower AEQ (0.9 [IQR 0.6-1.2] ng/L/s vs. 1.4 [0.8-1.6] ng/L/s, p < 0.001). After a median follow-up of 26 (IQR 20-32) months, there was a significant reduction in arrhythmia recurrence in the AI group (15% vs. 31%, HR 0.67 [95% CI, 0.32-1.40], p = 0.02). However, neither Hs-cTnI nor AEQ was predictors of arrhythmia recurrence in AI-guided PVI. Conclusions The use of the AI software led to reduced levels of Hs-cTnI and lower AEQ in AF patients submitted to PVI. However, none of these markers predicted arrhythmia recurrence.