Baseline left atrial low voltage area predicts recurrence after pulmonary vein isolation: WAVE-MAP AF results.

BACKGROUND AND AIMS: Electroanatomical mapping may be critical to identify atrial fibrillation (AF) subjects that require substrate modification beyond pulmonary vein isolation (PVI). The objective was to determine correlations between pre-ablation mapping characteristics and 12-month outcomes after a single PVI-only catheter ablation of AF.

METHODS: This study enrolled paroxysmal AF (PAF), early persistent AF (PsAF; 7 days-3 months) and non-early PsAF (>3 months-12 months) subjects undergoing de novo PVI-only radiofrequency catheter ablation. Sinus rhythm and AF voltage maps were created with the Advisor HD Grid™ Mapping Catheter, Sensor Enabled™ for each subject and presence of low voltage area (low voltage cutoffs: 0.1 mV-1.5 mV) was investigated. Follow-up visits were at 3-, 6- and 12-months, with a 24-hour Holter monitor at 12-months. A Cox proportional hazards model identified associations between mapping data and 12-month recurrence after a single PVI procedure.

RESULTS: The study enrolled 300 subjects (113 PAF, 86 early PsAF, 101 non-early PsAF) at 18 centers. At 12-months, 75.5% of subjects were free from AF/atrial flutter (AFL)/atrial tachycardia (AT) recurrence. Univariate analysis found arrhythmia recurrence did not correlate with AF diagnosis, but low voltage area was significantly correlated. Low voltage area (<0.5 mV) greater than 28% of the left atrium in sinus rhythm (HR:4.82, 95% CI:2.08-11.18, p = 0.0003) and greater than 72% in AF (HR:5.66, 95% CI:2.34-13.69, p = 0.0001) was associated with higher risk of AF/AFL/AT recurrence at 12-months.

CONCLUSION: Larger extension of low voltage area was associated with increased risk of arrhythmia recurrence. These subjects may benefit from substrate modification beyond PVI.