Clinical and Echocardiographic Risk Factors Predict Late Recurrence after Radiofrequency Catheter Ablation of Atrial Fibrillation

Abstract

The benefits of radiofrequency catheter ablation (RFCA) for patients with atrial fibrillation (AF) significantly decrease with late recurrence (LR). We aimed to develop a scoring system to identify patients at high and low risk for LR following RFCA, based on a comprehensive evaluation of multiple risk factors for AF recurrence, including echocardiographic parameters. We studied 2,352 patients with AF undergoing first-time RFCA in a single institution. The LR-free survival rate up to 5 years was measured using a Kaplan-Meier analysis. The influence of clinical and echocardiographic parameters on LR was calculated with a Cox-regression analysis. Duration of AF ≥4 years (hazard ratio [HR] = 1.75; p < 0.001), non-paroxysmal AF (HR = 3.18; p < 0.001), and diabetes (HR = 1.34; p = 0.015) were associated with increased risk of LR. Left atrial (LA) diameter ≥45 mm (HR = 2.42; p < 0.001), E/e' ≥ 10 (HR = 1.44; p < 0.001), dense SEC (HR = 3.30; p < 0.001), and decreased LA appendage flow velocity (≤40 cm/sec) (HR = 2.35; p < 0.001) were echocardiographic parameters associated with increased risk of LR following RFCA. The LR score based on the aforementioned risk factors could be used to predict LR (area under curve = 0.717) and to stratify the risk of LR (HR = 1.45 per 1 point increase in the score; p < 0.001). In conclusion, LR after RFCA is affected by multiple clinical and echocardiographic parameters. This study suggests that combining these multiple risk factors enables the identification of patients with AF at high or low risk for having arrhythmia recurrence.

Figure 1

Influence of clinical parameters on LR. Kaplan-Meier curve analysis of cumulative incidence of LR for up to 5 years following the last RFCA, according to AF duration (a) age (b) AF type (c) and diabetes (d). AF: atrial fibrillation; CI: confidence interval; HR: hazard ratio; LR: late recurrence; RFCA: radiofrequency catheter ablation.

Figure 2

TTE risk factors for LR. LA diameter ≥45.0 mm (a) LV EF <50% (b) and E/E′ ≥ 10 (c) were significantly associated with increased risk of LR following the last RFCA. CI: confidence interval; HR: hazard ratio; LA: left atrium; LR: late recurrence; LV: left ventricle; RFCA: radiofrequency catheter ablation; TTE: transthoracic echocardiography.

Figure 3

TEE risk factors for LR. The presence of SEC (a) dense SEC (b) and decreased LAA flow velocity (c) were significantly associated with increased risk of LR following the last RFCA. CI: confidence interval; HR: hazard ratio; LAA: left atrial appendage; LR: late recurrence; RFCA: radiofrequency catheter ablation; SEC: spontaneous echocontrast; TEE: trans-esophageal echocardiography.

Figure 4

Predictive value of the LR score. (a) Risk of LR stratified by LR score. (b) ROC curve analysis of the LR score which showed significant predictive value. AUC: area under curve; CI: confidence interval; HR: hazard ratio; LR: late recurrence; RFCA: radiofrequency catheter ablation; ROC: receiver operating characteristic.

Figure 5

Impact of repeat procedures. Repeat procedures were associated with improved outcomes in patients with AF undergoing RFCA (a) regardless of AF type (b,c). AF: atrial fibrillation; CI: confidence interval; RFCA: radiofrequency catheter ablation.