Left Atrial Stiffness Index as a Non–invasive Measure to Predict Atrial Fibrillation Recurrence After Catheter Ablation

Abstract Background Catheter ablation (CA) is an effective option for the management of patients with atrial fibrillation (AF), albeit burdened with a recurrence rate that needs to be taken into account. To date, strong echocardiographic parameters able to predict the maintenance of sinus rhythm after CA are lacking. Objective To investigate if left atrial stiffness index (LASI), as the ratio of E/e’ and peak atrial longitudinal strain (PALS) could be a predictor of AF recurrence after CA. Methods and Results This is a multicenter prospective study enrolling patients with paroxysmal or persistent AF referred for CA. A total of 118 patients were included in the study (mean age 65.8 ± 7.9 years, 28% female, mean left ventricular ejection fraction LVEF 57.1±7.9%). The median value of LASI was 0.4. The subgroup of patients with high LASI (≥0.4) did not show any difference in baseline clinical characteristics compared to those with low LASI, except for higher frequency of history of peripheral vascular disease and chronic heart failure (p= 0.043 and p= 0.018, respectively). Besides, the former group had significantly higher values of NTproBNP (686±707.0 pg/mL vs. 220.6±306.2 pg/mL, p0.001), mean LA pressure (17.5±5.9 mmHg vs. 14.0±6.2 mmHg, p= 0.012), LA volume index LAVi (41.1±11.9 ml/m2 vs. 34.3±9.9 ml/m2, p 0.001), and lower value of LVGLS (14.7±4.0% vs 18.5±4.0%, p 0.001) and RVGLS of the free wall (21.2 ± 5.1% vs. 24.9±5.6%, p 0.001). During a follow–up period of 3 months, LASI showed a correlation with the probability of AF recurrence (for each increase of 0.1: OR 1.23; 95% CI 1.00, 1.50; p = 0.045), also after adjustment for other variables. The ROC curve showed an area under the curve (AUC) of 0.69 for the prediction of AF recurrence. When compared with other LA parameters, LASI exhibited a slightly larger AUC (0.69 for LASI vs. 0.68 for LAVi, 0.33 for PALS and 0.45 for LA ejection fraction). Conclusion LASI is a novel non–invasive and useful parameter to predict AF recurrence after CA. It is potentially more accurate than other echocardiographic features routinely used in clinical practice.