Peri-Coronary Adipose Tissue Attenuation and Atrial Fibrillation Recurrence After Catheter Ablation: A Systematic Review and Meta-Analysis.

backgroundCatheter ablation is an established rhythm-control strategy for atrial fibrillation (AF), but arrhythmia recurrence after the procedure remains a major clinical challenge. Reliable pre-procedural biomarkers reflecting the underlying inflammatory substrate may improve risk stratification and patient selection. Peri-coronary adipose tissue (PCAT) attenuation, measured on coronary computed tomography angiography (CCTA), is a noninvasive imaging marker of coronary perivascular inflammation. This study evaluated the association between PCAT attenuation and AF recurrence after catheter ablation.

methodsWe systematically searched PubMed, Embase, and the Cochrane Central Register of Controlled Trials through October 2024, following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 guidelines, for studies comparing PCAT attenuation between patients with and without AF recurrence after catheter ablation. Pooled mean differences (MDs) with 95% confidence intervals (CIs) were calculated separately for each coronary territory using random-effects models with restricted maximum likelihood estimation of the between-study variance and Knapp-Hartung-Sidik-Jonkman-corrected confidence intervals, an approach recommended when the number of available studies is small. DerSimonian-Laird estimates with Wald intervals are reported alongside for comparison. Standardized MDs were calculated in parallel. Heterogeneity was assessed using the I² statistic, and leave-one-out analysis was performed as a descriptive check.

resultsThree retrospective cohort studies enrolling 852 patients (239, 28%, with AF recurrence) met the inclusion criteria. PCAT attenuation was numerically higher in patients with AF recurrence across all three major coronary territories, but under the small-sample-corrected model, none of the associations reached statistical significance: right coronary artery (RCA)-PCAT (MD 2.62 HU; 95% CI -2.41 to 7.65), left anterior descending artery (LAD)-PCAT (MD 1.53 HU; 95% CI -1.45 to 4.50), and left circumflex artery (LCx)-PCAT (MD 2.48 HU; 95% CI -0.70 to 5.66). Corresponding standardized MDs were 0.30, 0.23, and 0.36. Conventional DerSimonian-Laird estimates with Wald intervals were nominally significant in all three territories despite identical point estimates, reflecting the degree to which precision is overstated when the between-study variance is estimated from three studies. Because each patient contributed correlated measurements across territories, no overall pooled estimate combining territories was calculated. Heterogeneity was moderate (I² 34-65%) but imprecisely estimated.

conclusionPre-ablation PCAT attenuation was consistently higher in patients who subsequently experienced AF recurrence after catheter ablation, but the pooled differences of approximately 1.5-2.6 HU did not reach statistical significance once appropriate small-sample corrections were applied and are of a magnitude comparable to reported technical variability in PCAT measurement across CT acquisition protocols. The consistent direction of effect across three independent cohorts is of interest and supports further investigation, but these data do not establish PCAT attenuation as a predictor of post-ablation recurrence and provide no basis for clinical application. Prospective multicenter studies with standardized acquisition and segmentation protocols are needed.