Is Increased Aortic Stiffness Associated with Advanced Ischemic Stroke?

Abstract

REFER TO THE PAGE 12-17 Survivors of a transient ischemic attack (TIA) or stroke have an increased risk of another stroke, which is a major source of increased mortality and morbidity. Among the estimated 700,000 people with stroke in the United States each year, 200,000 of them are among persons with a recurrent stroke. The number of people with TIA, and therefore at risk for stroke, is estimated to be much greater.1) Therefore, efforts that identify the risk and determinants of recurrent stroke, might be helpful to provide the data to generate evidence-based recommendations to reduce this risk. One of the efforts to identify those risks might be an investigation for marker of disease progression. Aortic stiffness has been known as an independent predictor of all cause and cardiovascular mortality in hypertensive patients.2) Aging and genetic factors are responsible for structural and functional changes of the arterial wall, leading to decreased elasticity and increased stiffness.3),4) The plausible explanation about relationship between arterial stiffness and stroke is that the increased arterial stiffness responsible for increase in systolic blood pressure and decrease in diastolic blood pressure, thus increasing pulse pressure (PP).5) Although PP has been associated with stroke in some longitudinal studies,6),7) aortic stiffness, non-invasively measured with pulse wave velocity is an independent predictor of fatal stroke in patients with essential hypertension.8) Also, aortic stiffness is associated with ischemic stroke, independent of thickness of aortic arch plaques and other stroke risk factors. This suggests that aortic stiffness may add prognostic information when assessing the risk of ischemic stroke in the elderly.9) There are evidences that aortic stiffness increase in subjects of increased cardiovascular risks. Eren et al.10) found that aortic stiffness is increased in patients with hypertension, diabetes, or both even after the exclusion of coronary artery disease. Aortic stiffness and left ventricular diastolic dysfunction are also associated in these patients. In a longitudinal study, aortic stiffness is an independent predictor of progression to hypertension in non-hypertensive individuals.11) Therefore, aortic stiffness could provide useful information as a surrogate marker not only for cardiovascular risk but also for future development of cardiovascular risk itself. In recent study, Yoon et al.12) found that increased aortic stiffness is associated with advanced cerebrovascular ischemia. Although there was no information about the current medication that might affect arterial stiffness and about whether presence of target organ damage such as microalbuminuria or left ventricular hypertrophy, and even the research was cross-sectional design, it is decisive that increased aortic stiffness represents more aggressive disease manifestation. We need future investigation about usefulness of aortic stiffness as a predictor of future ischemic stroke or as a predictor of recurrent cerebrovascular event in patients with previous TIA or stroke. Furthermore development of its cut-off value for prediction of development or recurrence of ischemic stroke might helpful for real clinical practice.