Use of echocardiography to stratify the risk of atrial fibrillation: comparison of left atrial and ventricular strain

Aims: Although both left atrial (LA) and ventricular (LV) dysfunction has been accepted as an important risk factor of atrial fibrillation (AF), usefulness of LA and LV strain has not been fully compared for prediction of AF. The aims of this study were to clarify the associations of both LA and LV strain with AF and to compare their predictive values in the risk stratification for AF.

Methods and Results: We evaluated 531 consecutive patients (median age 67 years, 56% male), with no history of AF who underwent echocardiography after cryptogenic stroke. Standard echocardiographic parameters were measured, and speckle-tracking was used to measure LA (reservoir, pump, and conduit strain) and LV strain (global longitudinal strain, GLS). The baseline clinical and echocardiographic parameters of the patients who developed AF and those who did not were compared. Median 36 months of follow-up, 61 patients (11%) had newly diagnosed AF. LA pump strain and GLS were significantly and independently associated with AF and provided incremental predictive value over clinical and standard echocardiographic parameters. Areas under the receiver-operating curves for GLS (0.841) were comparable to LA pump (0.825) and reservoir (0.851) strain. However, predictive value of both strains was different between patients with and without LA enlargement at the time of transthoracic echocardiography screening. LA strain was more useful than LV strain in patients with normal LA volumes, while LV strain was more useful than LA strain in patients with abnormal LA volumes.

Conclusion: Both LA and LV strain are significantly and independently associated with AF and provide incremental predictive value over clinical and standard echocardiographic parameters. However, priorities of strain assessment are different depends on patients' condition at the time of echocardiography.