4. Carotid flow Velocity Difference as a Surrogate for Ischemic Stroke

Background Carotid flow peak velocity is increased in carotid artery stenosis. Carotid intima-media thickness (IMT) have been associated with an increased risk of ischemic stroke. We performed this study to evaluate the relationship between carotid flow velocity and carotid IMT in ischemic stroke without significant carotid stenosis. Methods A total of 559 patients with acute ischemic stroke were enrolled in this study. We evaluated the association of carotid IMT and carotid flow velocity difference from peak systolic to end diastolic velocity with age, sex, potential vascular risk factors, and cardiac function by echocardiography. Results Age and common carotid IMT was significantly associated with carotid flow velocity difference (r=−0.106, p=0.014). We did not found a significant relationship between carotid flow velocity difference and gender or traditional cardiovascular risk factors such as hypertension, diabetes, smoking and dyslipidemia. Left ventricle end diastolic dimension and diastolic parameter e/e’ from echocardiography was also related with carotid blood flow velocity (r=0.107, p=0.015, r=0.108, p=0.016). Linear regression analysis demonstrate that carotid flow velocity difference was independently associated with carotid IMT (β=−0.094, p=0.040) and e/e??(β=0.116, p=0.011). Conclusion The present results indicated that carotid flow velocity difference was independently associated with carotid IMT and left ventricle diastolic function. We further suggest that carotid flow velocity difference is another surrogate for ischemic stroke in the spite of absence of significant carotid stenosis.