Hypertension with Renal Impairment: Influence of Intensive Therapy

Abstract

The influence of effective blood pressure control upon renal function has been examined in a group of 83 patients with severe hypertension and renal impairment. Twenty-seven patients (32.5 per cent) died or were transferred to a dialysis programme within six months of referral. Mean creatinine clearance in this group was 3.6 ml/min and all but two patients had a creatinine clearance of less than 8 ml/min. By contrast, initial mean creatinine clearance in patients who survived more than six months was 28.9 ml/min. A highly significant fall in clearance, associated with poor blood pressure control by conventional agents, could be demonstrated in the 30 patients who had had creatinine clearance measured upon first presentation. This fall was reversed with effective blood pressure control in the 35 patients who were considered to have primary hypertension, and who survived more than six months. In these, clearance rose from 35.1 to 50.5 ml/min. Change of a similar order could be demonstrated in chronic pyelonephritic patients. Follow-up of 56 (67.5 per cent) patients who survived more than six months was extended up to 43 months and confirmed that the improvement in renal function was maintained. Chronic glomerulonephritic patients showed a deterioration in renal function at six months despite good blood pressure control. In most patients there was an initial fall in creatinine clearance with blood pressure control: this was not seen in patients who were in congestive cardiac failure in whom improvement in cardiac function apparently nullifies the fall in renal perfusion pressure. It is concluded that the prognosis of patients with primary hypertension and renal impairment is good when effective blood pressure control is maintained if the initial creatinine clearance exceeds 8 ml/min and if there is no intrinsic, progressive renal disease.