Left atrial mechanics for secondary prevention from embolic stroke of undetermined source

Aims: Anticoagulation is not justified unless atrial fibrillation (AF) is detected in cryptogenic stroke (CS) patients. We sought to explore whether left atrial (LA) remodelling is associated with embolic stroke of undetermined source (ESUS).

Methods and results: In this prospective study, we evaluated consecutively 186 patients in sinus rhythm who presented with an acute ischaemic stroke (embolic and non-embolic) and sex- and age-matched controls. We performed continuous electrocardiogram (ECG) monitoring to capture paroxysmal AF episodes as recommended by the guidelines. After 12 months of follow-up, continuous ECG monitoring was repeated in patients with undetected AF episodes. We quantified LA reservoir and contraction strain (LASr and LASct) by speckle-tracking, LA volumes by 3D echocardiography. Out of 186 patients, 149 were enrolled after comprehensive investigation for the source of ischaemic stroke and divided into other cause (OC) (n = 52) and CS (n = 97) groups. CS patients were also subdivided into AF (n = 39) and ESUS (n = 58) groups. Among CS patients, LA strain predicted AF independently from CHARGE-AF score and LA volume indices. ESUS group, despite no captured AF, had significantly worse LA metrics than OC and control groups. AF group had the worst LA metrics. Moreover, LASr predicted both CS (embolic stroke with and without AF) and ESUS (embolic stroke with no detected AF) independently from LAVImax and CHA2DS2-VASc score. LASr >26% yielded 86% sensitivity, 92% specificity, 92% positive, and 86% negative predictive values for the identification of ESUS (areas under curve: 0.915, P < 0.0001, 95% confidence interval: 0.86-0.97).

Conclusion: Echocardiographic quantification of LA remodelling has great potential for secondary prevention from ESUS.