Endothelial dysfunction of the peripheral vascular bed in the acute phase after ischemic stroke.

BACKGROUND: Endothelial dysfunction (ED) is relevant for the development of cerebrovascular and cardiovascular diseases. Asymmetric dimethylarginine (ADMA) competes with L-arginine and has been implicated in the development of ED. Increased levels of ADMA have been found in chronic heart failure (CHF). We hypothesized that peripheral ED in acute ischemic stroke is associated with increased ADMA levels.
METHODS: We evaluated 60 patients with acute stroke in the territory of the middle cerebral artery. Stroke patients were classified according to the Trial of ORG 10172 in Acute Stroke Treatment (TOAST) classification. We compared these patients with patients of similar age without known cardiovascular disease (negative controls, n = 23) and patients with stable, ambulatorily treated CHF (n = 46, left ventricular ejection fraction = 33.8 ± 10.9) with known ED (positive controls). Peripheral endothelial function was assessed by EndoPAT2000 technology using the reactive hyperemia index (RHI).
RESULTS: RHI was significantly decreased in stroke and in CHF compared to controls (1.8 ± 0.3 vs. 1.8 ± 0.4 vs. 2.2 ± 0.4, respectively, ANOVA p = 0.01). A decreased RHI was observed in cardioembolic and lacunar infarcts and stroke of undetermined etiology (1.7 ± 0.4, 1.8 ± 0.5 and 1.7 ± 0.3, p < 0.0001). The L-arginine/ADMA ratio was significantly decreased in stroke and in CHF (147.6 ± 31.7 and 126.1 ± 37.9 vs. controls: 161.5 ± 26.1, p < 0.0001) and was lowest in stroke patients in the cardioembolic group (133.0 ± 29.4, p < 0.0001). A lower L-arginine/ADMA ratio was associated with ED in cardioembolic stroke and CHF (r = 0.324, p < 0.05 and r = 0.429, p < 0.0001).
CONCLUSION: Peripheral ED occurs to a similar degree in acute ischemic stroke and CHF. The impaired vasodilator capacity of peripheral arteries reflects the TOAST classification. ADMA may play a role in ED in both acute ischemic stroke and CHF.