The potential effect of blood pressure reduction on cardiovascular disease. A cautionary note.

The risk of cardiovascular disease (CVD) at various levels of systolic blood pressure (BP) and the potential benefit of BP reduction have been estimated by constructing probability tables for extended periods based on the Framingham Study data. These estimates demonstrate that systolic BP alone delineates subgroups of persons with widely divergent risk of CVD, depending both on their demographic and clinical characteristic. For example, the disparity in prognosis is such that some persons with a systolic BP of 160 mm Hg are at greater risk of subsequent CVD than others with a systolic BP of 195 mm Hg. The potential benefit to be derived from systolic BP reduction shows similarly wide variation, so initial pressure alone does not precisely predict the gain that might accompany BP reduction. Measures of greater prognostic value are needed to enhance the value of BP determination.