A CARDIAC CT-derived imaging marker may help identify patients with non-paroxysmal atrial fibrillation (AF) who are more likely to experience recurrence following radiofrequency ablation, according to a study.
The findings suggest that measuring myocardial changes before treatment could improve risk prediction and help identify patients who may need closer monitoring.
Researchers investigated whether the myocardial extracellular volume fraction (ECV), measured using delayed-phase dual-energy cardiac computed tomography (CT), could predict recurrence.
The retrospective study included 399 patients with non-paroxysmal AF who underwent radiofrequency ablation. All patients had cardiac CT before the procedure, with delayed-phase imaging performed five minutes after contrast administration. Patients were followed for an average of 10.1 months.
During follow-up, 91 patients (22.8%) experienced AF recurrence. These patients had significantly higher mean ECV values than those who remained free from recurrence (37.6% compared with 32.6%).
researchers identified an ECV threshold of 34.69% for distinguishing patients at higher risk. After accounting for other clinical and imaging factors, higher ECV remained independently associated with recurrence.
Researchers also assessed whether adding ECV to existing clinical risk models improved prediction. A model combining traditional risk factors, left atrial volume, left ventricular ejection fraction, and ECV achieved a concordance index of 0.82, compared with 0.71 when ECV was not included.
Researchers concluded that CT-derived ECV could provide a non-invasive way to identify patients with non-paroxysmal AF at greater risk of recurrence following ablation. They suggested that the measurement could complement existing clinical assessments and support more individualised risk stratification.
However, the study was retrospective and conducted at a single centre. ECV was measured in the left ventricle rather than the left atrium, where AF primarily develops, meaning it may not fully reflect the extent or distribution of atrial fibrosis. Researchers called for larger, multicentre studies to validate the findings and investigate direct measurement of atrial ECV.
Reference:
Lin et al. Pre-ablation dual-energy CT-derived extracellular volume fraction predicts recurrence after radiofrequency ablation in non-paroxysmal atrial fibrillation. Br J Radiol.2026;99 (1187): 2277–85.
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