Nitrates as adjunct hypertensive treatment.

Isolated systolic hypertension (ISH) is an important cause of strokes and heart failure among the elderly, but it is difficult to control in some elderly patients, even with combination antihypertensive therapy. The presence of a prominent reflection wave in the arterial pulse-wave profile of such patients signifies that adjuvant nitrate therapy may prove effective in lowering pulse pressure. This reflection arises in the muscular arteries and is caused by arterial stiffness associated with hypertension and other cardiovascular risk factors, probably including endothelial dysfunction. By acting directly on the arterial wall, nitrates produce endothelium-independent vasorelaxation. The reflection wave and the contribution this makes to pulse pressure are thereby ablated. Controlled trials of the use of isosorbide mononitrate and isosorbide dinitrate in ISH have shown that these agents decrease systolic blood pressure as well as pulse pressure, and with the mononitrate, efficacy appears to be unimpaired by nitrate tolerance.