Impact of High-Density Mapping on Pulmonary Vein Isolation Durability: A Randomized, Single-Center Study.

Background: Despite technical progress and novel ablation strategies, pulmonary vein (PV) reconnection still occurs in a substantial proportion of patients. The aim of the study was to determine the impact of the elimination of antral low-voltage, fragmented electrograms (LFEGMs) identified by high-density (HD) mapping on the rate of pulmonary vein isolation (PVI) durability.

Methods: Sixty patients with paroxysmal atrial fibrillation (PAF) were randomly assigned to a verification of PV entrance block and presence of LFEGMs on antral isolation lines with an HD mapping catheter (HD group) or to a verification of PV entrance block with a circumferential mapping catheter alone (CM group). In the HD group, LFEGMs were additionally ablated. Mandatory reassessment procedure to assess PVI durability and the presence of LFEGMs was performed 12 months after the index procedure or earlier in case of arrhythmia recurrence.

Results: A total of 107 out of 116 (92.2%) PVs were found durably isolated in the HD group, and 97 out of 120 (80.8%) PVs in the CM group (p = 0.02). At the reassessment procedure, a total of 7 [3, 12] and 34 [24, 44] LFEGMs were found in the HD and CM groups, respectively (p = 0.00002). Elimination of LFEGMs at the index procedure reduced the likelihood of antral conduction gaps in the same segments at the reassessment. Arrhythmia recurrence rate was similar between the HD and the CM group (7/29, 24.1% vs. 10/30, 33.3%), p = 0.62, respectively.

Conclusion: Additional elimination of LFEGMs identified by HD mapping of antral isolation lines after PVI resulted in a significantly higher rate of PVI durability.

Trial registration: ClinicalTrials.gov identifier: (NCT04466358).