Echocardiographic strain imaging and progression of atrial fibrillation in low-risk individuals

Left atrial (LA) and left ventricular (LV) strain are sensitive parameters characterizing left ventricular diastolic dysfunction and atrial remodeling. We aimed to assess the association of LA and LV strain and clinical AF progression in two pooled European prospective clinical cohorts.

Individuals were examined at baseline, with LV global longitudinal strain (GLS), LA reservoir strain (LASr), LA conduit strain (LAScd) and LA contraction strain (LASct) measured by speckle-tracking analysis in transthoracic echocardiography. AF progression was defined as a change from paroxysmal to persistent or persistent to permanent AF. Binary logistic regression was performed to assess the association of baseline strain parameters with AF progression.

Of 316 individuals, 29 (9.2%) had AF progression over a median follow-up of 12 months. Restricted cubic spline modelling suggested non-linear associations between GLS and LASr with AF progression. For LASr only the unadjusted spline model reached statistical significance (p = 0.0498), whereas the adjusted spline model did not (p = 0.074). For GLS, the spline fit indicated a U-shaped curve with a slight trend towards non-linearity (p = 0.072 unadjusted; p = 0.13 adjusted). In unadjusted logistic regression, LASr was significantly associated with AF progression (odds ratio (OR) per standard deviation 0.65, 95% CI 0.42-0.99; p = 0.047).

Our data suggest a potential non-linear association for GLS and LASr as a marker of diastolic function with higher predicted probability of AF progression at lower strain values. However, the test for non-linearity did not reach statistical significance after adjustment.