Background: The current risk stratification schemes for stroke in patients with atrial fibrillation (AF) are insufficient for an accurate assessment of stroke risk.
Aims: This study evaluates the association between the mechanical function of the left atrial appendage (LAA), as assessed by angiography, and the risk of stroke.
Methods: We conducted a cross-sectional study to assess the mechanical function of the LAA by measuring the left atrial appendage ejection fraction (LAAEF) and grading the contrast retention (CR) using angiography.
Results: A total of 746 patients referred for a left atrial appendage occlusion (LAAO) procedure with (n=151; stroke group) or without (n=595; control group) a history of stroke were included in the analysis. LAAEF was significantly lower (14% [9-19] vs 20% [12-33]; p<0.001) and grade 3 CR was more common (66.9% vs 33.9%; p<0.001) in patients with a history of stroke. Multivariable analysis showed that CR was independently associated with stroke in patients with AF (grade 2 vs grade 1=7.29; 95% confidence interval [CI]: 2.84-21.65; p<0.001; grade 3 vs grade 1=16.45; 95% CI: 6.16-51.02; p<0.001). The receiver operating characteristics curve demonstrated that CR identified patients with stroke more accurately than the CHA2D-VASc score (C-statistic 0.712 vs 0.512; p<0.001), and the combination of CR and the CHA2DS2-VASc score provided the best performance (C-statistic 0.871 vs 0.829 [CHA2DS2-VASc score alone]; p=0.048) Conclusions: Impaired mechanical function of the LAA, indicated by a low LAAEF and CR, is associated with a history of stroke in patients with AF. Assessment of CR using LAA angiography helps improve the stratification scheme for stroke risk prediction.