Abstract 15274: Left Atrial Cross Sectional Area is a Novel Risk Factor for Cardioembolic Stroke and Recurrence of Ischemic Stroke Within 90 Days
Background: Approximately 20% of ischemic strokes are considered cardioembolic (CE). However many patients with suspected CE stroke do not have clear cardiac etiology or risk factors. Echocardiography is an important imaging modality used to assess for CE stroke etiologies and risk factors. Left atrial (LA) size has been reported as a potential CE risk factor, yet measures of LA size have been inconsistently assessed.
Aim: Examine echocardiographic measures that may help improve identification of patients at risk of CE stroke
Methods: Consecutive patients presenting to our institution with ischemic stroke (2009-10) were prospectively recruited and followed-up for 90 days for recurrence of stroke. Patients were classified into 7 groups based on etiology using the Causative Classification of Ischemic Stroke. A range of clinical and echocardiographic variables, including a novel echocardiographic measure, LA cross sectional area (LA CSA), were examined in all groups. LA CSA which reflects both LA size and shape was calculated using the formula π/4 x largest LA diameter x smallest LA diameter, where mid LA diameter was measured in the parasternal long axis, 4 chamber and 2 chamber views at end systole.
Results: Of the variables tested in our cohort of 556 patients (mean age 68.1±15.8 years; 47% females), increased LA CSA was significantly associated with CE stroke compared to all other groups (8.5 ± 2.6 vs 5.9 ± 1.6 cm2/m2; p <0.001). Multivariate analysis identified the independent predictors of CE stroke as LA CSA and the presence of atrial fibrillation (LA CSA in SR vs AF; 6.0 ± 1.6 vs 8.4 ± 2.6; p<0.001). 38 patients had recurrence within the follow up period. In the univariate analysis, LA volume indexed (p= 0.003), LA CSA indexed (p=0.001), and hypertension (p=0.001) were among factors associated with significant risk of recurrence but only LA CSA (HR 1.241; 95% CI 1.085-1.419; p=0.002) and hypertension (HR 3.701; 95% CI 1.120-12.230; p=0.032) were significantly associated with stroke recurrence in the multivariate analysis.
Conclusion: In patients with ischemic stroke, increased LA cross sectional area is associated with CE stroke and is also a predictor of recurrence at 90 days, potentially providing prognostic value in the stratification of stroke risk.
- © 2013 by American Heart Association, Inc.