Effect of Antihypertensive Treatment on Morbidity

Clinical trials evaluating the effects of treatment with antihypertensive drugs on the prevention of the complications of hypertension have been limited almost exclusively to patients with severe hypertension. In malignant hypertension the life expectancy of the untreated patient seldom exceeds one or two years. The prolongation of life of many patients to five years or longer with antihypertensive drug treatment has provided convincing evidence of the benefits of drugs in this condition.1-6 The course of the disease, however, is much more variable in the lesssevere forms of hypertension. Therefore, the effectiveness of treatment with respect to morbidity and mortality is more difficult to evaluate, In the absence of adequately controlled, prospective trials some authorities have questioned the benefit from antihypertensive drugs on mortality.7-9 Recently, this need for definitive data on the efficacy of treatment in essential hypertension has been partially fulfilled by several prospective controlled clinical trials. The first is a study by Hamilton in EnglandlO and the second is the Cooperative Study on Antihypertensive Agents carried out by the Veterans Administration.ll In Hamilton’s study 61 patients without evidence of prior cardiovascular complications, but with diastolic blood pressures of 110 mm Hg or higher as measured in the clinic, were alternately assigned to antihypertensive drug treatment or placebos. Over an eight-year period of follow-up, 16 of the untreated patients had complications as compared to five of the treated group. Of the latter, the blood pressure was poorly controlled in four patients. Thus, of the treated patients whose