AUSTRALIAN COMPARATIVE OUTCOME TRIAL OF ANGIOTENSIN-CONVERTING ENZYMEINHIBITOR-BASED AND DIURETIC-BASED TREATMENT OF HYPERTENSION IN THE ELDERLY (ANBP2) - OBJECTIVES AND PROTOCOL

1, ANBP2 is a comparative outcome trial of angiotensin-converting enzy me inhibitor- and diuretic-based treatment of hypertension in the elde rly using a prospective randomized open-label design with blinding of endpoint assessments, 2. The primary objective is to determine, in hyp ertensive subjects 65-84 years of age, whether there is any difference in total cardiovascular events (fatal and non-fatal) over a 5 year tr eatment period between the two treatment regimens, 3. The study is bei ng conducted in general practices throughout Australia and will recrui t 6000 subjects over 2-3 years (3000 in each arm of the study) to prov ide 30000 years of patient observation. This will allow detection of a 25% difference in the primary outcome variable at the 5% level with a power of 90%. 4. Following randomization to one of the treatment arms , each subject's blood pressure (BP) is managed by the general practit ioner according to his/her usual practice to achieve goal BP with guid elines for drug therapy relevant to each treatment arm. 5, Study endpo int information is gained from a review of practice records every 3 mo nths and these data are then assessed by an Endpoint Committee blinded for treatment randomization. 6, Interim analyses of endpoint data wil l be conducted at the end of randomization and then annually until the final analysis after 5 years of observation in each subject.