The Study on Cognition and Prognosis in the Elderly (SCOPE): principal results of a randomized double-blind intervention trial

Abstract

BACKGROUND: The prognostic benefits of blood pressure lowering treatment in elderly hypertensive patients were established more than a decade ago, but are less clear in those with mildly to moderately elevated blood pressure. OBJECTIVE: To assess whether candesartan-based antihypertensive treatment in elderly patients with mildly to moderately elevated blood pressure confers a reduction in cardiovascular events, cognitive decline and dementia. DESIGN: Prospective, double-blind, randomized, parallel-group study conducted in 1997-2002. SETTING AND PARTICIPANTS: The study was of 4964 patients aged 70-89 years, with systolic blood pressure 160-179 mmHg, and/or diastolic blood pressure 90-99 mmHg, and a Mini Mental State Examination (MMSE) test score >or= 24. A total of 527 centres in 15 countries participated in the study. INTERVENTION: Patients were assigned randomly to receive the angiotensin receptor blocker candesartan or placebo, with open-label active antihypertensive therapy added as needed. As a consequence, active antihypertensive therapy was extensively used in the control group (84% of patients). Mean follow-up was 3.7 years. MAIN OUTCOME MEASURES: The primary outcome measure was major cardiovascular events, a composite of cardiovascular death, non-fatal stroke and non-fatal myocardial infarction. Secondary outcome measures included cardiovascular death, non-fatal and fatal stroke and myocardial infarction, cognitive function measured by the MMSE and dementia. RESULTS: Blood pressure fell by 21.7/10.8 mmHg in the candesartan group and by 18.5/9.2 mmHg in the control group. A first major cardiovascular event occurred in 242 candesartan patients and in 268 control patients; risk reduction with candesartan was 10.9% [95% confidence interval (CI), -6.0 to 25.1, P = 0.19]. Candesartan-based treatment reduced non-fatal stroke by 27.8% (95% CI, 1.3 to 47.2, P = 0.04), and all stroke by 23.6% (95% CI, -0.7 to 42.1, P = 0.056). There were no significant differences in myocardial infarction and cardiovascular mortality. Mean MMSE score fell from 28.5 to 28.0 in the candesartan group and from 28.5 to 27.9 in the control group (P = 0.20). The proportions of patients who had a significant cognitive decline or developed dementia were not different in the two treatment groups. CONCLUSIONS: In elderly hypertensive patients, a slightly more effective blood pressure reduction during candesartan-based therapy, compared with control therapy, was associated with a modest, statistically non-significant, reduction in major cardiovascular events and with a marked reduction in non-fatal stroke. Cognitive function was well maintained in both treatment groups in the presence of substantial blood pressure reductions. Both treatment regimens were generally well tolerated.