Abstract
BACKGROUND: Early recurrence of atrial tachyarrhythmia (ERAF) after radiofrequency catheter ablation (RFCA) for atrial fibrillation (AF) remains a major clinical challenge. While left atrial diameter (LAD) is a known predictor, the role of atrial mechanical function, particularly left atrial appendage emptying velocity (LAAEV), and its integration with other markers needs clarification. METHODS: This single-center retrospective cohort study included 157 drug-refractory non-valvular AF patients undergoing first-time RFCA. Among them, 53 (33.8%) developed ERAF within the 90-day blanking period. Baseline clinical, echocardiographic (including LAD and LAAEV), and biochemical (NT-proBNP) data were collected. The primary endpoint was ERAF (atrial tachycardia/flutter/fibrillation ≥30 s) within the 90-day blanking period. Predictive models were developed using logistic regression. An integrative AF Recurrence Index (AF-RI) was derived and validated internally. RESULTS: Among 157 patients, 53 (33.8%) experienced ERAF. The ERAF group exhibited a distinct "atrial failure" phenotype: larger LAD (43.8 ± 5.6 vs. 39.5 ± 4.3 mm, p < 0.001), lower LAAEV (35.8 ± 9.9 vs. 47.6 ± 11.9 cm/s, p < 0.001), and higher NT-proBNP (median 356.9 vs. 207.2 pg/mL, p = 0.023). LAAEV was a stronger independent predictor (AUC: 0.812, 95% CI: 0.742-0.882) than LAD (AUC: 0.745, 95% CI: 0.665-0.825). The AF-RI, integrating LAD, LAAEV, and NT-proBNP, demonstrated outstanding discrimination (AUC: 0.917, 95% CI: 0.874-0.960), with significantly higher sensitivity (88.7%) and specificity (84.6%) than single-parameter models (all p < 0.05). Correlation network analysis positioned LAAEV as a central hub linking structural and neurohormonal remodeling. Patients stratified by LAAEV tertiles showed dramatically graded ERAF risks (14.8%, 28.3%, 58.5%, p-trend < 0.001). CONCLUSION: LAAEV is a potent, independent predictor of ERAF, central to an "atrial failure" phenotype. The integrative AF-RI score provides a simple, bedside-friendly tool for individualized risk stratification, enabling clinicians to identify high-risk patients (e.g., those with LAAEV < 35 cm/s) who may benefit from intensified monitoring or tailored therapeutic strategies post-ablation.