Vascular changes in hypertension.

Hypertension can directly damage blood vessels, and leads to renal failure, intracranial bleeds, and lacunar infarctions. Of equal importance is the effect of hypertension on the development of atherosclerosis. Specific changes in both the microvasculature and macrovasculature vary depending on the degree and rapidity of blood pressure elevation. Changes in the intima and media can lead to significant narrowing of vessels and ischemia in various tissues. In addition, changes in small-resistance vessels contribute to changes in peripheral-vasculature resistance and thus affect blood pressure regulation. Treatment of moderate to severe elevation in blood pressure clearly results in a decrease in the incidence of stroke. However, evidence that treating mild hypertension reduces coronary events is less convincing. Antihypertensive therapy may result in partial regression of vascular changes, especially fibrinoid necrosis seen in malignant hypertension, but more work needs to be done to clearly define the roles of specific drugs in preventing or regressing hypertensive vascular disease.