Impaired vascular responses to nitroglycerin in subjects with coronary atherosclerosis.

To study smooth muscle function in atherosclerosis, we calculated dose-response curves in patients with coronary artery disease and in controls by measuring changes in brachial artery diameter after incremental sublingual doses of nitroglycerin. The doses required to produce a 50% maximal dilator response were significantly higher in patients with coronary artery disease than in controls (p <0.002), suggesting smooth muscle dysfunction in atherosclerosis.