Unipolar Voltage for Better Characterizing Left Atrium Substrates: Comparing the Predictive Efficacy for Recurrence Post Atrial Fibrillation Ablation in a Post Hoc Analysis of STABLE-SR-III Trial.

Background: While bipolar voltage (BV) is acknowledged as an indicator of viable cardiomyocyte activation, unipolar recording has emerged as an alternative technique due to its advantage of providing a wider field of view. This study aims to compare the efficacy of unipolar voltage (UV) versus BV in predicting ablation recurrence in atrial fibrillation patients.

Methods: In Substrate Ablation in the Left Atrium during Sinus Rhythm Trial III, 375 patients completed the follow-up with preserved mapping data were included in the analysis. For each patient, the mean UV and BV was obtained from the electrograms sampled in left atrium (LA).

Results: Totally 301 patients experience the primary endpoint within 23.0 ± 9.2 months. While both low UV and BV had significant associations with long-term recurrence of atrial tachyarrhythmia (ATa), only mean UV was independently associated with the outcome. The model by UV with ablation feature had higher discriminatory power to predict ATa recurrence compared with BV model (area under the curve [AUC]: 0.858 vs. 0.757, p < 0.001). In subgroup analysis, UV reveals more powerful predictive efficacy compared with BV, with the AUC 0.843 versus 0.751 (p < 0.001) in circumferential pulmonary vein isolation (CPVI) alone cohort and 0.882 versus 0.750 (p < 0.001) in CPVI plus cohort, respectively.

Conclusion: UV exhibits higher efficacy for predicting long-term ATa recurrence after ablation compared with BV in elderly patients with atrial fibrillation regardless of whether the patient accepts substrate modification. The outcome suggests that unipolar recording may better characterize LA fibrosis by capturing more comprehensive transmural features than bipolar signals.

Clinical Trial Registration: ClinicalTrials.gov; URL: https://www.

Clinicaltrials: gov. Unique Identifier: NCT03462628.