Pathogenesis of atherosclerosis and its complications: effects of antihypertensive drugs.

Since hypertension is an important risk factor for atherosclerosis, it is logical to assume that treatment to lower blood pressure will prevent atherosclerosis. However, the relationship between hypertension and atherosclerosis is indirect and complex. Drugs that lower pressure will prevent heart failure and arteriolar complications such as renal failure or strokes caused by lacunar infarction or brain haemorrhage due to rupture of microaneurysms. However, there is little evidence that atherosclerotic complications can be reduced by lowering pressure. It is important to understand the pathogenesis of atherosclerosis and its complications, which are related to lipoproteins and arterial flow disturbances, in order to develop an approach to selecting those antihypertensive drugs which may prevent atherosclerotic complications related not only to initiation and progression of atherosclerotic plaques, but to the embolisation of platelet clumps or atherosclerotic debris, or events such as intraplaque haemorrhages, that lead to myocardial or cerebral infarction. Antihypertensive drugs have different effects on lipoproteins and on arterial flow disturbances that may have important implications for prevention. Alpha-blockers and drugs with beta 2 agonist activity have beneficial effects on lipoprotein profiles, ACE inhibitors and calcium channel antagonists have some anti-atherosclerotic effects in animal models, while beta-blockers have beneficial effects on flow disturbances and are anti-atherosclerotic in animal models and man. Future studies to determine how to prevent atherosclerotic complications in hypertensive patients will require methods for noninvasive measurement of atherosclerosis.