The malignant phase of essential hypertension in Johannesburg Blacks. A prospective study.

During a 1-year period all Black patients admitted to two medical wards in the Johannesburg General Hospital were screened for malignant hypertension. Of the 62 patients eligible for inclusion in the study, 51 were thought to have essential malignant hypertension (hospital prevalence 2,2%). There was a striking absence of the cardiovascular and hypertensive risk factors usually described -- excessive smoking, alcohol consumption and obesity. The presenting features and complications were similar to those described in other series. Cardiac failure was present in 45% of the patients, neurological complications in 33%, and advanced renal failure in 47%. Twenty patients required dialysis. No evidence of ischaemic heart disease or atheromatous vascular disease was found. Red cell fragmentation was present in 25% of the patients. The hospital mortality rate was 25%. Only 24% of the patients had previously been diagnosed as having hypertension, although 43% had been examined by a doctor during the preceding 2 years. Of the patients discharged to the hypertension clinic, only 28% returned for short-term follow-up. Malignant hypertension is therefore a major medical and social problem in the Johannesburg Black community.