Gender differences in the right atrial appendage and right atrium-related structures in patients with atrial fibrillation and their association with ablation outcomes

Objective To quantitatively measure gender-specific anatomical structures of the right atrial appendage (RAA) and right atrium (RA) in atrial fibrillation (AF) patients, and explore their clinical significance for post-radiofrequency ablation (RFA) recurrence using 256-slice spiral Computed Tomography (CT). Method This study included 321 AF patients (184 males and 137 females) undergoing RFA for the first time. All patients underwent a 256-slice spiral CT examination before surgery. The volume of the RA, RAA, and left atrium (LA); RAA height; short diameter, long diameter, area, and circumference of RAA base; RA anteroposterior diameter, tricuspid annulus diameter, crista terminalis, and cavo-tricuspid isthmus (CTI) were measured, and clinical data were collected. Results After body surface area normalization, the RA volume and RA anteroposterior diameter in female patients with AF showed more significant structural remodeling than those in male patients. Both male and female patients with recurrent AF showed larger RAA and RA structural parameters. In females, short diameter of RAA base, crista terminalis thickness and persistent AF were independent recurrence predictors post-RFA, while short diameter of RAA base and AF duration were independent predictors in males (all P < 0.05). ROC analysis showed that short diameter of RAA base served as the strongest predictor of AF recurrence in both genders. The optimal cutoff values were 26.95 mm for females (sensitivity = 0.696, specificity = 0.824, AUC = 0.811, P = 0.000) and 25.55 mm for males (sensitivity = 0.700, specificity = 0.746, AUC = 0.786, P = 0.000). Conclusion The short diameter of the RAA base had the highest predictive value for postoperative recurrence in both male and female patients.