Assessment of the left atrial appendage morphology in patients after ischemic stroke - The ASSAM study

Background: The ASSAM study was designed to evaluate the association between left atrial appendage (LAA) morphology and stroke risk in patients with atrial fibrillation (AF).

Methods: The study included 85 randomly chosen AF patients with acute ischemic stroke matched with 84 AF without stroke. All patients had left atrial (LA) computed tomography performed to analyze LAA anatomy.

Results: Patients in the stroke group had a larger LAA volume (10.22 [7.83-13.62] vs. 9.33 cm³ [7.33-11.47], p = 0.046], greater distance from LAA ostium to the first LAA bend (9.25 ± 3.85 vs. 7.23 ± 2.95 mm, p = 0.0002), and more frequently had round LAA ostium shape (11.8 vs. 1.2%, p = 0.005). According to a multivariable model, significant predictors of ischemic stroke were distance from LAA ostium to the first LAA bend (OR 1.202 [1.065-1.356], p = 0.003), LAA ostium round shape of (OR 16.813 [1.857-152.231], p = 0.012), LAA ostium surface area (OR 0.612 [0.457-0.819], p = 0.009), and cactus LAA morphology (OR 2.739 [1.176-6.380], p = 0.016). After adjusting for CHA₂DS₂-VASc score, only the distance from LAA ostium to the first LAA bend remained a significant risk factor for stroke (OR 1.154 [1.014-1.314], p = 0.03).

Conclusions: The distance from LAA ostium to the first bend of the LAA was independently associated with stroke risk in patients with AF. Whether this parameter may help improve identification of patients at risk of ischemic stroke, needs to be confirmed in larger studies.