ABSTRACT
When the first antihypertensive agents became available during the 1950s, they were tested on the most severe
form of hypertension, malignant hypertension. These early studies were uncontrolled, and the benefit of BP lowering was established by a historical comparison of the lengthened survival of a cohort of treated patients with the very bad survival of cohorts of patients followed up in the previous years when effective drugs were not available. A study published in 1959 by Leishman4 showed that while up to 90% of untreated patients had died within 5 years, among treated patients 5-year death was less than 30%.
