Incremental Benefit of Left Ventricular Global Longitudinal Strain over Clinical and Left Atrial Parameters for Predicting New-Onset Atrial Fibrillation

Abstract

Background: Although LV dysfunction is associated with atrial fibrillation (AF), AF often occurs in the absence of reduced LVEF. The effect of subclinical LV dysfunction on AF has not been fully studied. We sought the association between subclinical LV dysfunction (measured with global longitudinal strain, GLS) and new-onset AF. Methods: We evaluated 531 consecutive pts without a history of AF who underwent strain echo after cryptogenic stroke. Standard echo parameters were measured, and speckle-tracking was used to measure LA and LV strain. Baseline clinical and echo parameters of the pts who developed AF and those who did not were compared. Results: Over 2.5 years of follow-up, 61 pts (11%) had AF. Pts who developed AF were older, larger LA volume, worse LA strain, and worse GLS than those who did not. Area under the receiver-operating curve for GLS (0.84) was comparable to LA pump strain (0.83) and LA reservoir strain (0.85). In the nested Cox models, GLS demonstrated an independent and incremental predictive value over the clinical and LA parameters. Moreover, adding GLS to the combined clinical and LA parameters model resulted in a significantly improved reclassification (net reclassification improvement, 0.32; p = 0.016). Importantly, the predictive value of GLS was confirmed in pts with abnormal LA volumes (LA volume index ≥34 ml/m2) but not in pts with normal LA volumes. Conclusion: GLS is associated with new-onset AF, especially in pts with abnormal LA volumes. This effect is independent of and incremental to the clinical and LA parameters.