More than 3 million persons in the United States over the age of 60 have isolated systolic hypertension. They face an excess risk (2-3 fold) of stroke, other cardiovascular disease and death. Population-based data show that the prevalence rises from approximately 8 percent in the age group 60-69 years to approximately 20 percent over the age of 80. Based on available data, an annual stroke rate of 2.0 percent has been estimated in this population. The full-scale clinical trial followed a pilot study conducted from 1980 to 1983. Recruitment in the trial began in March 1985 and was finished in January 1988. Follow-up ended in February 1991. Data analysis continued through October 1996.
A randomized, double-blind trial in which 2,365 subjects were assigned to active treatment and 2,371 to placebo. For the active treatment group, a stepped-care regimen was used which included chlorthalidone 12.5 or 25 mg/day, and as needed, addition of atenolol 25 or 50 mg/day or reserpine, 0.05 or 0.10 mg/day. Treatment goal was to reduce systolic blood pressure by at least 20 mm Hg from baseline and to below 160 mm Hg with minimal amounts of study medication. The primary endpoint was the incidence of fatal and non-fatal stroke. Secondary endpoints were cardiovascular and coronary morbidity and mortality, all-cause mortality, and quality-of-life measures.