Speckle tracking-derived left atrial stiffness predicts adverse events after successful electrical cardioversion

Abstract

Abstract Background Atrial fibrillation (AF) impairs cardiac mechanics and leads to adverse remodelling. Increased left atrial (LA) stiffness reflecting LA reservoir function and left ventricular (LV) filling pressure is one of the symptoms of LA remodelling. Purpose To analyse LA stiffness within 24 hours after successful electrical cardioversion and its prognostic value during 2-years follow-up. Methods Prospective study involved 71 patients with nonvalvular AF (mean age 64±13 years, 61% male). All patients underwent echo during 24 hours after conversion to sinus rhythm. We analysed standard echocardiographic and Doppler parameters. Using speckle-tracking method we assessed peak LA longitudinal strain in 4- and 2-chamber view. LA stiffness was calculated as the quotient of peak LA longitudinal strain (LA reservoir function) and mean E/E' ratio. The clinical endpoints were predefined as AF recurrence and cardiovascular hospitalization. Results Median time of current AF episode was 2 (IQR 0.4–5) months. Standard echo measurements revealed median of LV ejection fraction 55% (IQR 45–58) and median of LA volume indexed to body surface area 42 ml/m2 (IQR 34–51). During follow-up we noticed AF recurrence in 48 (68%) patients and cardiovascular hospitalization in 43 (61%) patients. Median time-to-event was 2.4 (IQR 1 to 6.9) and 7 (IQR 2.1–11) months, respectively. Receiver operating characteristic curve analysis revealed that LA stiffness >0.53 (AUC=0.821; p<0.0001) and >0.95 (AUC=0.788; p<0.0001) were the optimal cut-off values for predicting AF recurrence and cardiovascular hospitalization. Figure presents Kaplan-Meier survival analysis for AF recurrence (A) and for hospitalization (B). Moreover LA stiffness remain statistically significant in multivariate Cox regression analysis even after adjustment for betablockers, antiarrhythmic drugs, coronary artery disease, heart failure and mitral regurgitation. Relative risk was 1.51 (95% CI 1.09–2.09), p=0.01 for AF recurrence and 1.49 (95% CI 1.05–2.13) for cardiovascular hospitalization. Conclusions Speckle tracking-derived LA stiffness assessed early after the restoration of sinus rhythm independently predicts AF recurrence and cardiovascular hospitalization. Funding Acknowledgement Type of funding sources: None.