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Abstract-Presentation, response to therapy, and clinical outcome in hypertension differ according to race, and these observations could relate to differences in microvascular function. We examined forearm microvascular function in age-matched black (nϭ56) and white subjects (nϭ62) using intra-arterial agonist infusion and venous occlusion plethysmography. In normotensive subjects (nϭ70; 34 black and 36 white normotensives), methacholine-, sodium nitroprusside-, and verapamil-induced vasodilation was equivalent in black and white subjects. In hypertensive subjects (nϭ48; 22 black and 26 white hypertensives), the vasodilator response to methacholine was markedly lower in black subjects compared with white subjects (PϽ0.001). The vasodilator responses to sodium nitroprusside and verapamil, however, were equivalent in black and white hypertensive subjects. Acute ascorbic acid infusion improved the methacholine response equally in black and white hypertensive patients, suggesting that a difference in a rapidly reversible form of oxidative stress does not explain these findings. Thus, the present study demonstrates important racial differences in vascular function and a marked impairment in endothelial vasomotor function in black patients with hypertension. Further studies will be required to elucidate the mechanisms and determine whether these insights will lead to more appropriately tailored management of hypertension and its complications.

Echocardiography frequently identifies lesions of the heart or aortic arch that can act as potential sources for retinal ischemia or embolism. Further studies are needed to evaluate the prognostic and therapeutic relevance of these findings.

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Echocardiography frequently identifies lesions of the heart or aortic arch that can act as potential sources for retinal ischemia or embolism. Further studies are needed to evaluate the prognostic and therapeutic relevance of these findings.