To determine if left atrial appendage flow velocity can enhance stroke risk assessment in atrial fibrillation patients with or without cerebrovascular disease.

The left atrial appendage (LAA) is a common site for clot formation in patients with atrial fibrillation (AF). Thrombus formation is a significant contributor to stroke risk in AF patients. Lower blood flow velocity in the LAA (LAA-FV) has been associated with higher risk of thrombus formation. However, little is known about the utility of LAA-FV in estimating stroke risk in conjunction with the CHA₂DS₂-VASc score.

We conducted a retrospective study of AF patients undergoing catheter ablation over 4 years to identify an association between CHA₂DS₂-VASc score and LAA-FV in those with and without cerebrovascular disease. Primary predictive measurements were CHA₂DS₂-VASc score and LAA-FV, which was classified as low (LAA-FV < 40 cm/s) or normal (LAA-FV ≥ 40 cm/s). The outcome of the study was to identify if patients had cerebrovascular disease, defined as a history of stroke, TIA, or cortical brain infarction prior to ablation. Statistical analysis was performed using SPSS. Results with p < 0.05 were deemed significant.

We identified 408 patients (mean age 62.5 ± 10.3 years), and 73.5% were women. The rate of cerebrovascular disease was 9.6% (10 patients with TIA, 13 with ischemic stroke, 16 with brain infarct). In patients with cerebrovascular disease, mean CHA₂DS₂-VASc score was higher among those with low LAA-FV vs. normal LAA-FV (2.9 ± 1.3 vs. 1.4 ± 0.9, p = 0.009). However, in patients without cerebrovascular disease, low LAA-FV was not associated with higher CHA₂DS₂-VASc score (2.2 ± 1.3 vs. 2.1 ± 1.4, p = 0.934).

There appears to be discordance between CHA₂DS₂-VASc score and LAA-FV in AF patients without underlying cerebrovascular disease. This group of patients may benefit from LAA-FV measurement to fully assess their stroke risk.