The study was renewed in 1998 for an additional three years through June, 2003. The study continued to investigate the prevalence and prognostic value of subclinical atherosclerosis in the Pittsburgh SHEP cohort and a cohort of normotensive controls. Annual telephone follow-up of the remaining 178 SHEP participants and 168 controls continued. A final clinic visit included measures of coronary and aortic calcification using electron beam computed tomography (CT), pulse wave velocity as a measure of aortic stiffening and cognitive function testing. For the Pittsburgh SHEP cohort, the antihypertensive treatment effect was striking with event rates for the active and placebo groups continuing to diverge beyond the end of SHEP. Successful demonstration of a treatment effect on coronary calcium scores would be the first randomized data showing an antihypertensive effect directly in the coronary arteries. Risk factors for coronary calcification were evaluated, producing data of a type not yet available in the literature for older adults and not being collected in any other ongoing studies of the elderly. The added measures of vascular stiffness supplemented the extensive data on subclinical atherosclerosis already available for this cohort. The extent to which these measures predicted cardiovascular events was evaluated.