The primary objective of PROGRESS is to determine reliably the efficacy of lowering blood pressure for the prevention of stroke in patients with a history of cerebro-vascular disease.
PROGRESS is a randomized, double-blind, placebo-controlled trial investigating the effects on the incidence of stroke and other major cardiovascular events and dementia of treatment with the angiotensin-converting enzyme inhibitor perindopril, alone or in combination with the diuretic indapamide.
The study population comprises 6000 normotensive or hypertensive patients with a history of stroke or transient ischaemic attack within the previous 5 years. The study is being conducted in over 160 centres in seven regions: Australia and New Zealand, The People's Republic of China, France and Belgium, Italy, Japan, Sweden and the United Kingdom. Computerized randomization to active treatment or placebo is performed by fax direct to Auckland, New Zealand. The primary study outcome is total stroke and secondary outcomes include fatal or non-fatal stroke, total major cardiovascular events and deaths, cognitive function and disability. Patients will be followed for a minimum of 4 years after randomization.
By 16 July 1996, 162 local clinical centres had been registered across the seven regions, and 1682 patients, 49% with a history of hypertension, had been randomly assigned to receive active treatment or placebo, with 65% allocated to the combination of perindopril and indapamide or double placebo, and 35% to perindopril alone or single placebo. Three months after randomization, the blood pressure difference between the treatment and control groups among the first 182 patients randomized was 11.9 mmHg (systolic) and 3.9 mmHg (diastolic). Six strokes and two non-stroke cardiovascular deaths have been recorded after a total of 3174 patient-months of follow-up.
Observations made so far confirm that full recruitment into the study is feasible and that treatment with perindopril and indapamide is well tolerated in the study population. The blood pressure differences between control and treatment groups recorded so far suggest that the study should have the power to achieve its primary objectives, provided compliance with treatment is satisfactory and 6000 patients are successfully recruited and followed for 4–5 years.