Recovery in malignant hypertension presenting as acute renal failure

Malignant hypertension may present occasionally with acute renal failure. Seven patients with this syndrome were admitted to the Renal Unit of the Royal Infirmary, Glasgow, between 1977 and 1981 giving an estimated incidence of one per million of the population per year. All the patients smoked and all had features of microangiopathic haemolytic anaemia. Renal biopsies showed arterial subintimal changes with relative sparing of glomeruli in each case. Good control of blood pressure led to significant recovery of renal function in five of the seven patients after 10-44 days of peritoneal dialysis. Renal function improved progressively over the first year and the improvement has been sustained for an average of 24 months (range 15-62 months). Mean serum creatinine when last measured was 248 mumol/l (range 125-350 mumol/l). These results confirm previous reports of recovery of renal function in patients presenting with acute renal failure and malignant hypertension. The proportion of patients who improve may be higher than has been generally recognised, and recovery may last several years. The pathogenesis of the renal failure is discussed.