Risk reduction associated with lowering systolic blood pressure: review of clinical trial data

Hypertension is very common in adults >/=60 years of age. Isolated systolic hypertension (ISH) in particular is a good predictor of events associated with elevated blood pressure such as stroke, coronary heart disease, and congestive heart failure. Two large studies, the Systolic Hypertension in the Elderly Program (SHEP) and the Systolic Hypertension in Europe study (Syst-Eur), have demonstrated that antihypertensive drug therapy for elderly patients with ISH reduces the risk of stroke and other major cardiovascular events. SHEP demonstrated that antihypertensive drug treatment with a diuretic-based regimen in patients >/=60 years of age with ISH reduced the incidence of total stroke by 36%. SHEP also demonstrated a 32% reduction in the incidence of cardiovascular events for patients receiving active treatment. The 5-year average systolic blood pressure (SBP) was 155 mm Hg in the placebo group (n = 2371) compared with 143 mm Hg for the active treatment group (n = 2365). Results from the recently completed Syst-Eur study also support the benefits of antihypertensive treatment in patients >/=60 years of age with ISH. Active treatment in Syst-Eur consisted of the calcium channel blocker nitrendipine, with the addition of enalapril and hydrochlorothiazide as needed to reduce SBP to <150 mm Hg. In the active treatment group, total stroke decreased by 42%, and all cardiovascular events decreased by 31%. At 2 years, sitting SBP had decreased by 13 mm Hg in the placebo group (n = 2297) compared with 23 mm Hg in the active treatment group (n = 2398).