Left atrial reservoir strain is a superior discriminator of cardioembolism in ischaemic stroke.

ABSTRACT

Aims: Echocardiographic measures of left heart size and function have long been associated with cardioembolic mechanisms of stroke development, however, the diagnostic performance and comparison of measures of atrial function in this context has not been well studied. We sought to evaluate the diagnostic performance of left atrial reservoir strain (LASr) in identification of cardioembolism in the ischaemic stroke population relative to traditional measures of left heart size and function. Methods and results: Consecutive patients admitted to our institution with ischaemic stroke or transient ischaemic attack were recruited and underwent comprehensive transthoracic echocardiography. Strokes were classified by aetiology with comparison undertaken between cardioembolic and non-cardioembolic types. Four hundred and eighteen consecutive stroke patients with a cardioembolic (n = 229) or non-cardioembolic (n = 189) stroke aetiology were analysed. LASr was impaired in cardioembolic compared with non-cardioembolic strokes (16.7 ± 8.2% vs. 26.0 ± 5.5%, P < 0.01) and provided greatest discrimination [area under the curve (AUC) 0.813, 95%CI 0.773-0.858] in differentiating stroke subtypes when compared with LVEF (AUC difference 0.150, P < 0.01), LAVI (AUC difference 0.083, P < 0.01), and E/e' (AUC difference 0.163, P < 0.01). Inclusion of LASr in a model with conventional left heart echocardiographic factors improved model performance with a net reclassification improvement of 1.083 (95%CI 0.945-1.220, P < 0.01). Further, a proposed user-defined model-based clinical algorithm with LASr demonstrated improved diagnostic accuracy of the identification of cardioembolic stroke subtypes which was best appreciated in patients without atrial fibrillation. Conclusion: LASr may provide enhanced diagnostic accuracy beyond conventional echocardiographic measures to discriminate cardioembolic from non-cardioembolic stroke mechanisms, in particular amongst those without comorbid atrial fibrillation.