Incremental value of right atrial strain analysis to predict atrial fibrillation recurrence after electrical cardioversion

Abstract Funding Acknowledgements Type of funding sources: None. Background Atrial fibrillation (AF) is the most frequent cardiac arrhythmia, associated with elevated risks of cardiovascular events and death. The assessment of left atrial (LA) mechanics has been reported to refine AF risk prediction, however it does not completely predict AF relapse. The potential added role of right atrial (RA) function in this setting is unknown. Purpose This study sought to evaluate the added value of RA longitudinal reservoir strain (RARS), on top of LA longitudinal reservoir strain (LARS) analysis, for the prediction of AF recurrence after electrical cardioversion (ECV). Methods We retrospectively studied 132 consecutive adult patients (men 55%, 72±10 years) with persistent AF undergoing ECV in hospital setting. Exclusion criteria were: pregnancy, previous cardiac surgery, pacemaker or implantable cardioverter defibrillator, severe valvular regurgitation/stenosis, ventricular systolic dysfunction, poor apical acoustic window, unsuccessful ECV, early recurrent AF and lack of follow-up. LA and RA size and function were analyzed by conventional 2D and speckle-tracking echocardiography before ECV. The endpoint was AF recurrence. Results After a total follow-up of 12 months, 63 patients (48%) showed AF recurrence. Both LA and RA reservoir strain were significantly lower in patients experiencing AF recurrence than in patients with persistent sinus rhythm (LARS 10±6 vs 13±7%, RARS 14±10 vs 20±9 %, respectively, p<0.001 for both). By receiving operating curve (ROC) analysis, the best cut-offs associated to AF recurrence after ECV were 15% for RARS [AUC 0.77 (95%CI 0.69–0.84), p<0.0001] and 10% for LARS [AUC 0.69 (95%IC 0.60–0.77), p<0.0001]. Kaplan-Meier curves showed that patients with both LARS≤10% and RARS ≤15% had a significant risk for AF recurrences (log-rank, p<0.001) (Figure 1). However, at multivariable Cox regression, RARS [HR 3.26, 95%CI (1.73–6.13), p< 0.001] was the only parameter independently associated with the AF recurrence. RARS provided incremental prognostic value over LARS, LA and RA volumes concerning the prediction of AF relapse after ECV (Figure 2). Conclusions RARS was independently associated with AF recurrence after ECV and provided an incremental prognostic value over LARS. This study highlights the importance of assessing the functional remodeling of both RA and LA in patients with persistent AF. Figure 1. Atrial fibrillation recurrence freedom according to left and right atrial reservoir longitudinal strain. Kaplan-Meier plots of patients grouped according to the threshold levels of left (left panel) and right (right panel) values of reservoir longitudinal strain identified by the Receiver Operating Curve analyses.