Do patients with de novo hypertension differ from patients with previouslyknown hypertension when malignant phase hypertension occurs?

Malignant phase hypertension (MHT) represents the most severe form of hyper tension, and many consider that this condition only occurs in poorly manage d patients with previously known hypertension. To investigate this further, we studied 350 patients with MHT on the West Birmingham MHT database: 195 (55.7%) of these presented de novo, without any known past history of hyper tension (Group 1), and 146 (41.7%) were previously known hypertensives (Gro up 2), of whom 86 were receiving antihypertensive therapy; in 9 patients, t he status was uncertain. Median duration of clinical followup was similar in both groups (36.0 v 37. 5 months, Mann-Whitney test P = .795). Patients presenting de novo with MHT (Group 1) were younger, with a predominance of whites and men. Nevertheles s, the clinical features, blood pressures, and renal function at presentati on were similar to MHT patients with previously known hypertension. Renal f unction at follow-up was also similar in both groups. There was an excess o f women and nonwhites in MHT patients with previously known hypertension (G roup 2), who also had higher mean follow-up blood pressures. On univariate life-table analysis, there was no statistically significant difference in s urvival time between Groups 1 and 2 (mean 57.5 v 63.5 months, median 36.0 v 37.0 months; log-rank test, P = .456). Using a multivariate Cox analysis o f baseline variables, the independent predictors of outcome (death or dialy sis) were age at presentation (P = .0019), diastolic blood pressure (P = .0 466), serum urea (P = .006), and serum creatinine (P < .001). Whether the p atient had presented de novo, without any known history of hypertension (Gr oup 1) or had previously known hypertension (Group 2) did not independently predict outcome (P = .6549). We suggest that MHT can occur de novo in patients without previously known hypertension, and the clinical characteristics and prognosis in such patien ts were similar to MHT patients with previously known hypertension. (C) 200 0 American Journal of Hypertension, Ltd.