Objective: To determine the effects of an angiotensin-converting enzyme (ACE) inhibitor-based blood pressure lowering regimen on the risk of stroke among patients with a history of cerebrovascular disease. Secondary aims include investigation of the effects of treatment on other cardiovascular events, dementia, and disability.
Design and methods: PROGRESS (Perindopril Protection Against Recurrent Stroke Study) is a double-blind, placebo-controlled, randomized trial being conducted in 172 centres in 10 countries (Australia, Belgium, China, France, Italy, Ireland, Japan, New Zealand, Sweden, and the United Kingdom). Patients were randomly assigned to treatment with the ACE inhibitor perindopril (and the diuretic indapamide for those with no definite indication for or contraindication to treatment with a diuretic) or matching placebo(s). Both hypertensive and normotensive patients were eligible for inclusion. Follow-up is scheduled for completion in 2001.
Results: Of 6105 patients randomly allocated to study groups on completion of recruitment in November 1997, 1110 were recruited from Australia and New Zealand, 1520 from China, 713 from France and Belgium, 557 from Italy, 815 from Japan, 675 from Sweden, and 715 from the UK and Ireland. Regional differences in the baseline characteristics included a greater rate of diabetes, lacunar infarction, and cerebral haemorrhage in patients from China and Japan, and a more frequent history of myocardial infarction in Australia and New Zealand. Previous treatment with calcium antagonists was very frequent in Japan and China, whereas diuretic treatment was most often documented in the UK and Ireland.
Conclusions: Analysis of baseline characteristics of patients recruited from seven distinct geographic regions revealed some interesting differences, but more striking was the consistency of characteristics of patients recruited from many different countries across the world.