High Blood Pressure and End-organ Damage

Background: Findings from numerous epidemiologic and clinical studies worldwide attest to a strong, graded, consistent relationship between blood pressure level and cardiovascular-renal diseases, subclinical and clinical, nonfatal and fatal.

Objective: This review summarizes results from selected prospective observational studies, primarily from US populations, and from randomized clinical trials. Review Analyses from the Multiple Risk Factor Intervention Trial (MRFIT) subjects (middle-aged men) and the Framingham Heart Study (middle-aged and elderly men and women) clearly establish that systolic blood pressure is a more powerful predictor of cardiovascular events than diastolic pressure. Wherever the full range of blood pressure has been examined, for example for systolic pressure in the MRFIT subjects and for diastolic pressure in pooled data from nine epidemiologic studies, the associations for coronary heart disease and stroke are seen to extend over the whole range, including 'normotensive' levels. In MRFIT, this continuous relationship has also recently been shown for end-stage renal disease and both systolic and diastolic pressure. Data from Framingham document further associations with peripheral vascular disease, congestive heart failure, and both electrocardiographic and echocardiographic left ventricular hypertrophy. Several studies are row available demonstrating a relationship between hypertension and carotid wall intimal-medial thickness. Finally, the causal nature of the relationships with major cardiovascular events is supported by the results of 17 large-scale randomized trials of blood-pressure-lowering using primarily diuretic- and beta-blocker-based drug regimens.

Conclusions: These trials have demonstrated highly significant reductions in fatal and nonfatal stroke and major coronary heart disease. There are few trial data, however, on health benefits from further reducing blood pressure among normotensive persons.