Review of primary prevention trials of antihypertensive treatment
Epidemiologic studies of the role of hypertension in the evolution of cardiovascular disease stimulated large multicenter trials to evaluate the efficacy of antihypertensive treatment in the prevention of cardiovascular disease. These trials have convincingly demonstrated the efficacy of anti-hypertensive treatment in reducing overall mortality, stroke, cardiac failure and renal insufficiency. The evidence for coronary heart disease is weak and inconsistent despite two-thirds of trial endpoints due to CHD. Trials of mild hypertension lacked the power to detect a 50% reduction in CHD events. Even so, with fewer events they did show a clear benefit for stroke, left ventricular hypertrophy and hypertension progression. There is clear evidence that progression in severity of hypertension can be slowed by drug treatment. For any outcome treatment benefits for women and persons under age 50 were not demonstrated. A number of possible reasons for failure to show efficacy against CHD have been postulated. Trials may have been too short in duration to affect progression of atherosclerosis and started too late in life. Sample sizes were too small to detect even sizeable reductions in CHD. No attention was paid to whether the CHD risk profile was improved. The drugs used can adversely affect lipids, glucose tolerance and uric acid offsetting the benefits of the lowered blood pressure. Diuretics also may predispose to sudden death in susceptible persons. Trials suggest that for CHD prevention in hypertension, control of smoking and serum lipids are particularly important. The Gothenberg Trial demonstrates the importance of concomitant lowering of lipids. Existing trials suggest that we need to examine the efficacy of antihypertensive agents which do not adversely affect the CHD risk profile. Also, the efficacy of non-pharmacologic control of mild hypertension with obesity control, salt and alcohol restriction need to be tested.
KeywordsCoronary Heart Disease Uric Acid Antihypertensive Treatment Mild Hypertension Cardiovascular Risk Profile
Unable to display preview. Download preview PDF.
- Kannel, W.B. (1989) ‘Hypertension: Impact of risk factors’, J Med Consultation 29, 104–114.Google Scholar
- Kaplan, N. (1978) ‘Factors affecting blood pressure’, In, Clinical Hypertension, 2nd Edition, Williams & WiIking Co., Baltimore, HD, pp. 14–18.Google Scholar
- Thompson, S.G. (1985) ‘An appraisal of the large-scale trials of antihypertensive treatment’, In, Handbook of Hypertension, Epidemiology of Hypertension, Ed. C. J. Bulpitt, Elsevier Science Publishers, B.V., 6, 331–343.Google Scholar
- Kannel, W.B., Cupples, L.A., D’Agostino, R.B., Stokes, J. III. (1988) ‘Hypertension, antihypertensive treatment and sudden death: The Framingham Study’, Hypertension 11, (suppl. 11), 1145–1150.Google Scholar