Brachial arterial flow mediated dilation in acute ischemic stroke

Abstract
Background and purpose: Brachial arterial flow‐mediated dilation (FMD) reflects endothelium‐dependent vasodilation function. FMD is diminished in patients with endothelial dysfunction (ED). Our aim was to investigate the relationship between FMD and outcome for patients with acute ischemic stroke. Methods: We measured FMD in 120 consecutive patients (58.3% male, median age 73 years) with acute ischemic stroke within the first 48 h of onset of the stroke, using high‐resolution ultrasonography. FMD was calculated as the relationship between basal diameter of the brachial artery before (d1) and after (d2) transient vascular occlusion (300 mmHg for 4 min) was measured using a sphygmomanometer (FMD = d2d1/d1 × 100). Poor outcome was defined as modified Rankin Scale at 3 months >2. FMD was categorized according to ROC analysis and we defined ED as FMD ≤ 4.5%. Results: Thirty‐three patients (27.5%) had ED. Median % FMD was 9.12 (7.48). FMD negatively correlated to stroke severity (P = 0.045). Median FMD was significantly lower [4.5 (2.3, 10.3) vs. 9.4 (5.6, 15.1), P = 0.003] for patients with poor outcome (n = 38). The adjusted odds ratio of poor outcome for FMD ≤ 4.5% was 3.03 (95% CI, 1.09–27.3). Conclusions: Impaired FMD in patients with acute ischemic stroke is associated with poor outcome.