Background: The long-term prognostic influence of left atrial diameter (LAD) remodeling on the status of post-radiofrequency catheter ablation (RFCA) atrial fibrillation (AF) is unclear. This study employed a two-stage model from 3-year echocardiographic data to ascertain whether the two-stage model predicts RFCA outcome more favorably than models using the baseline LAD.
Methods: Data were retrospectively collected from 263 consecutive patients with drug-refractory AF undergoing RFCA. Regular echocardiographic measurements of LAD were performed at baseline, 1, 3, 6, and 12 months and then every 6 months after RFCA. Sex, age, type of AF, number of RFCA, and AF status were recorded. We obtain the actual (predicted) 3-year LAD using a longitudinal linear mixed model (1st stage). Logistic regression models based on the baseline LAD (Model 1), actual (predicted) 3-year LAD (Model 2) (2nd stage), and observed 3-year LAD (Model 3) were constructed to predict RFCA outcome. The area under the receiver operating characteristic curve (AUC) were used to assess the performance of models.
Results: The lowess smoothed curve indicated that the LAD declined over the first three months and remained stable up to 36 months after RFCA. The degree of LAD reduction was significantly influenced by the baseline LAD. Non-paroxysmal AF, large LAD and female gender were significant predictors of AF recurrence. Model 2 had the largest AUC among the three models.
Conclusions: This longitudinal study-based two-stage model outperforms the original logistic model using the baseline LAD. Non-paroxysmal AF, larger LAD and female gender are significant predictors of RFCA failure.
Keywords: Atrial fibrillation; Left atrial diameter; Longitudinal data; Radiofrequency catheter ablation; Two-stage model.