Isolated systolic blood pressure elevation in the elderly: mechanisms, risk, and the need for further studies

Isolated systolic hypertension (ISH) is generally defined as a systolic pressure of 160 mm Hg or more, with a diastolic pressure cutoff point below 95 mm Hg in some studies and 90 mm Hg in others. Its prevalence and incidence vary from 3 to 30% depending on the definition applied, methodology of measurement, as well as the population and the age and sex of the patient. Mechanisms that could lead to the development of isolated systolic hypertension are discussed, especially the role of atherosclerosis. The risks of systolic hypertension on mortality and morbidity in the elderly are considered. The need for further studies to quantify the risk and the effect of treatment is emphasized. The Syst-Eur trial enters patients above the age of 60 years with a diastolic pressure below 95 mm Hg and a systolic of 160 mm Hg or more. The study is a double-blind, placebo-controlled trial and the main purpose is to examine the influence of ISH on morbidity, mortality, and general well-being. Investigation of blood pressure variation over 24 h and its relationship to morbidity and use for planning treatment will be incorporated. Other centers are invited to join in the enlarging project.