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A prospective study of atrial fibrillation and stroke
L D'Olhaberriague1, A Hernández-Vidal, L Molina
1Department of Neurology, Hospital del Mar, Autonomous University of Barcelona, Spain.
Insights
Certain clinical factors predict cardioembolic stroke in patients with atrial fibrillation. Previous infarcts and prolonged transient ischemic attacks are key indicators, not left atrial size alone.
Area of Science:
- Neurology
- Cardiology
- Medical Diagnostics
Background:
- Atrial fibrillation is a common cause of stroke.
- Distinguishing cardioembolic stroke from other stroke types is crucial for effective treatment.
- Clinical predictors for cardioembolic stroke require further elucidation.
Purpose of the Study:
- To identify clinical characteristics associated with cardioembolic stroke in patients with atrial fibrillation.
- To develop a predictive model for cardioembolic stroke.
- To investigate the relationship between left atrial size, mitral valve disease, and stroke mechanism.
Main Methods:
- Prospective study of 72 patients with stroke and atrial fibrillation.
- Arterial assessment using Doppler sonography and angiography to classify stroke type.
- Analysis of 18 clinical characteristics and logistic regression modeling.
- Echocardiography to compare left atrial size in patients and controls.
Main Results:
- Four clinical characteristics were initially associated with cardioembolic stroke: stroke onset during activity, peak deficit at onset, previous infarct in a different vascular territory, and transient ischemic attack (TIA) lasting >1 hour.
- Logistic regression identified previous infarct in a different vascular territory (OR=7.38) and TIA lasting >1 hour (OR=7.89) as significant predictors.
- Left atrial size was larger in patients with mitral valvulopathy but did not differ between cardioembolic and noncardioembolic stroke groups without valvular disease.
Conclusions:
- Specific clinical features are strongly linked to cardioembolic stroke in atrial fibrillation patients.
- Left atrial enlargement in atrial fibrillation is more indicative of underlying heart disease than of emboli-forming potential.
- These findings aid in identifying patients at higher risk for cardioembolic stroke.
Abstract:
In a prospective study of 72 patients with stroke and atrial fibrillation, we classified strokes as cardioembolic or noncardioembolic based on arterial assessment using Doppler sonography and angiography. We analyzed and cross-tabulated 18 clinical characteristics and found four to be significantly associated with a cardioembolic mechanism: stroke with onset during activity and peak deficit at onset (p less than 0.008), previous infarct in a different vascular territory (p less than 0.01), previous transient ischemic attack in a different vascular territory (p less than 0.01), and transient ischemic attack lasting greater than 1 hour (p less than 0.02). Starting with these four characteristics, we used a step-down procedure to select variables for a logistic regression model. Only previous infarct in a different vascular territory (odds ratio = 7.38) and transient ischemic attack lasting greater than 1 hour (odds ratio = 7.89) were selected by the model. Using M-mode and two-dimensional echocardiography, we compared left atrial size in 46 patients with that in 78 controls who had atrial fibrillation without stroke. Left atrial size in patients and controls with mitral valvulopathy was significantly larger than that in patients and controls without mitral valve disease. There was, however, no difference in left atrial size between patients with nonvalvular atrial fibrillation and cardioembolic stroke and controls or patients with nonvalvular atrial fibrillation and noncardioembolic stroke. We concluded that some clinical characteristics are closely related to cardioembolic stroke and that left atrial enlargement reflects underlying cardiopathy rather than atrial emboli-forming capability.