High Blood Pressure

Several randomized, double-blind, placebo-controlled intervention studies have provided strong evidence in favor of treating hypertension in elderly patients. Reports of first outcome trials published in 1985 and 1991 that focused attention on systolo-diastolic hypertension showed a reduction in cardiovascular and cerebrovascular morbidity and mortality in patients over sixty-five years old (Amery et al.; Dahlöf et al.; Medical Research Council).

More recent trials have specifically addressed the problem of isolated systolic hypertension. A meta-analysis by Staessen et al. (2000) showed that in 15,693 patients with isolated systolic hypertension who were included in eight trials, antihypertensive treatment reduced stroke by 30 percent. Total mortality decreased by 13 percent, cardiovascular mortality by 18 percent, all cardiovascular complications by 26 percent, and coronary events by 23 percent. Treatment prevented strokes more effectively than it prevented coronary events.

An important finding in the investigation of systolic hypertension in Europe (Syst-Eur; Forette et al., 1998) was that in older people with isolated systolic hypertension, antihypertensive treatment that started with the calcium-channel blocker nitrendipine significantly reduced the incidence of dementia, from 7.7 to 3.8 per 1000 person-years. The incidence of Alzheimer's disease dropped even more after such treatment than that of vascular or mixed dementia. By contrast, in the Systolic Hypertension in the Elderly Program (SHEP), active treatment based on diuretics and beta-blockers failed to reduce the incidence of dementia significantly. These negative results argue against conferring protection simply by lowering blood pressure. In the mechanism of dementia prevention, calcium-channel blockers might have a neuroprotective effect. The potential importance of the Syst-Eur results for public health policies warrants confirmation by other trials.