Systolic versus diastolic blood pressure versus pulse pressure.

Elevation of systolic blood pressure (BP) has been recognized as an independent risk factor that far exceeds the risk associated with an elevated diastolic BP in older patients with hypertension. Isolated systolic hypertension (ISH) is a disorder typically defined when the systolic BP is greater than 140 mm Hg but with diastolic BP below 90 mm Hg. Pulse pressure (the difference between systolic and diastolic pressure) has recently become an active area of discussion in the literature as an independent factor of cardiovascular risk. An increased pulse pressure nearly always indicates reduced vascular compliance of large arteries and, by definition, is always increased in patients with isolated systolic hypertension. Although the evidence that a widened pulse pressure is an independent marker of cardiovascular risk is quite well established, therapeutic morbidity and mortality studies in ISH have focused on reductions in systolic pressure. At the present time, outcomes data have not been well established for reductions in pulse pressure in older patients with hypertension.