Association of quantitative computed tomography-based right atrial appendage and right atrium parameters with postradiofrequency ablation recurrence of atrial fibrillation

BACKGROUND: The significance of the right atrial appendage (RAA) and right atrium (RA) in the recurrence of atrial fibrillation (AF) after radiofrequency ablation (RFA) remains uncertain. This retrospective case-control study aimed to quantitatively evaluate the role of morphological parameters of the RAA and RA in the recurrence of AF after RFA based on 256-slice spiral computed tomography (CT). METHODS: A total of 297 patients with AF who underwent RFA for the first time between January 1 and October 31, 2020, were enrolled in the study, and they were divided into a nonrecurrence group (n=214) and a recurrence group (n=83). The volume of the RA, RAA and left atrium (LA); height of the RAA; long and short diameter, perimeter, and area of the RAA base; right atrial anteroposterior diameter; tricuspid annulus diameter; crista terminalis thickness; and cavotricuspid isthmus (CVTI) were measured, and the clinical data of patients were collected. RESULTS: (I) Multivariable logistic regression analysis followed by univariable logistic regression analysis showed that the height of the RAA [odds ratio (OR) =1.124; 95% confidence interval (CI): 1.024–1.233; P=0.014], short diameter of the RAA base (OR =1.247; 95% CI: 1.118–1.391; P=0.001), crista terminalis thickness (OR =1.594; 95% CI: 1.052–2.415; P=0.028) and duration of AF (OR =1.009; 95% CI: 1.003–1.016; P=0.006) were independent predictors of postradiofrequency ablation AF recurrence. (II) Receiver operating characteristic (ROC) curve analysis showed that the prediction model constructed according to the multivariate logistic regression analysis presented good accuracy [area under the curve (AUC) =0.840; P=0.001]. A short diameter of the RAA base >26.95 mm had the highest predictive value for AF recurrence, with a sensitivity of 0.614 and a specificity of 0.822 (AUC =0.786, P=0.001). Pearson correlation analysis showed that there was a significant correlation between right atrial volume and left atrial volume (r=0.720, P<0.001). CONCLUSIONS: A significant increase in diameter and volume of the RAA and RA and tricuspid annulus diameter may correlate with postradiofrequency ablation AF recurrence. The height of the RAA, short diameter of the RAA base, crista terminalis thickness, and AF duration were independent predictors of recurrence. Among them, the short diameter of the RAA base had the highest predictive value for recurrence.