Abstract
Funding Acknowledgements
Type of funding sources: None.
Introduction
Ablation Index (AI) software has been associated with better freedom from atrial arrhythmias after pulmonary vein isolation (PVI) for paroxysmal atrial fibrillation (AF). There is conflicting data regarding the relationship between high sensitivity cardiac Troponin I (Hs-cTnI) and arrhythmia recurrence. The objective was to evaluate the impact of AI on Hs-cTnI level and on ablation effectiveness quotient (AEQ) and to assess if these markers are predictors of arrhythmia recurrence.
Methods
Prospective observational study of consecutive patients referred for PVI for paroxysmal AF ablation from October 2017 to June 2018 according to a pre-specified AI protocol. Procedural endpoints and 2-year follow-up outcomes were assessed and compared to a retrospective cohort of conventional PVI contact-force-guided group .
Results
A total of 56 patients were included: 29 patients the AI group and 27 patients in the control group. The mean age was 60.5 ± 10.3 years, 48% males. Left ventricular ejection fraction (60 ± 6 % AI vs 61 ± 5 % control, P = 0.07) and left atrium diameter (43 ± 7 mm AI vs 44 ± 6 mm control, P = 0.58) were comparable between groups. First-pass isolation was shown to be higher in the AI group (79% AI vs 44%, p= 0.01). Mean number of radiofrequency applications was lower in the AI group (93 ± 24 vs 111 ± 30, P = 0.02). Average contact-force was similar between groups (17.6 ± 4.1 g vs 22.6 ± 10.7 g, P =0.166). Patients that performed PVI guided by the AI had lower Hs-cTnI (1815 ± 1146 ng/L vs 3274 ± 1696 ng/L, p < 0.001) and lower AEQ (1.01 ± 0.7 ng/L/s vs 1.51 ± 0.7 ng/L/s, P = 0.011) compared to patients in the control group. During a mean follow-up of 26 ± 11 months, AF recurrence was documented in 10.3% of patients in the AI group and 22.2% in the control group (P = 0.223). Neither Hs-cTnI nor AEQ levels were predictors of arrhythmia recurrence.
Conclusions
These data suggest that AI-guided catheter ablation is associated with reduced levels of of Hs-cTnI and AEQ. Neither Hs-cTnI and AEQ should be used to predict arrhythmia recurrence. Abstract Figure.