Prevention of Commplications in Hypertension

Summary. Hypertension occurs in more than one in 10 adult persons. It is the leading risk factor in stroke, heart failure and renal failure (in adults) and along with hypercholesterolemia it is the leading risk factor in myocardial infarction and sudden death. Hypertension along with atherosclerosis are probably the most important causes of death in modern man. Fortunately hypertension is to a considerable extent a controllable kisease. Present day evidence indicates that most of the complications are the result of the elevated blood pressure. As demonstrated in the U.S. Veterans Administration Cooperative Study on Antihypertensive Agents control of the hypertension using antihypertensive drugs greatly reduces the incidence of major compliations. In this prospective trial patients with essential hypertension were randomly assigned, double blind to either active antihypertensive drugs or toplacebos. In 143 modetately severe patients with initial diastolic blood pressures in the range of 115–129 mm Hg, 27 in the placebo group developed major cardiovascular complications as compared to only one in the treatment group. In 380 patients with mild and moderate hypertension and initial diastolic blood pressure averaging between 90–114 mm Hg there were over a maximum 5.5 year follow-up 19 deaths in the placebo group as compared to 8 in the treatedpatients. In addition the risk of developing a major complication, fatal or nonfatal, over a 5 year period was 55% in the control patients and 18% in the treated group. Further analysis of these results indicated that most of the benefit of treatment was achieved in the patients with initial diastolic blood pressures of 105–114 mm Hg. In this subgroup the treated patients sustained only one fourth the number of complications as those in the placebo group. Among mild hypertensives with diastolic levels of 90–104 mm Hg the difference between the control and treated groups was not significant. This negative result cannot be regarded as definitive, however. The numbers of mild patients were relatively small, the follow-up was not long, the average of the patients was 50 years and the patients already had known hypertension for an average of 5 years. Thus considerable coronary atherosclerosis could have been present and indeed almost all of the complications in this mild group were secondary to atherosclerosis. Further trials are needed in younger patients with early mild hypertension to determine whether such atherosclerotic complications can be prevented. Nevertheless, it has been conclusively demonstrated at least in males that treatment is effective in greatly reducing morbidity and mortality in hypertensive patients with diastolic blood pressures averaging 105 mm Hg or more over several clinic visits. All such patients should be treated. In patients with diastolic levels of 90–104 the decision to treat will depend on clinical judgement. Risk factors other than the hypertension alone such as young age, male sex, lack of lability of the blood pressure, presence of hypercholesterolemia or diabetes mellitus or history of severe hypertension in one or more parents need to be assessed in making decision. Even if patients are not treated because they are at low risk they should be followed periodically in order to detect those whose hypertension worsens.