Effects of Low Blood Pressure in Cognitively Impaired Elderly Patients Treated With Antihypertensive Drugs

Abstract

The prognostic role of high blood pressure and the aggressiveness of blood pressure lowering in dementia are not well characterized. OBJECTIVE To assess whether office blood pressure, ambulatory blood pressure monitoring, or the use of antihypertensive drugs (AHDs) predict the progression of cognitive decline in patients with overt dementia and mild cognitive impairment (MCI). DESIGN, SETTING, AND PARTICIPANTS Cohort study between June 1, 2009, and December 31, 2012, with a median 9-month follow-up of patients with dementia and MCI in 2 outpatient memory clinics. MAIN OUTCOMES AND MEASURES Cognitive decline, defined as a Mini-Mental State Examination (MMSE) score change between baseline and follow-up. RESULTS We analyzed 172 patients, with a mean (SD) age of 79 (5) years and a mean (SD) MMSE score of 22.1 (4.4). Among them, 68.0% had dementia, 32.0% had MCI, and 69.8% were being treated with AHDs. Patients in the lowest tertile of daytime systolic blood pressure (SBP) (Յ128 mm Hg) showed a greater MMSE score change (mean [SD], −2.8 [3.8]) compared with patients in the intermediate tertile (129-144 mm Hg) (mean [SD], −0.7 [2.5]; P = .002) and patients in the highest tertile (Ն145 mm Hg) (mean [SD], −0.7 [3.7]; P = .003). The association was significant in the dementia and MCI subgroups only among patients treated with AHDs. In a multivariable model that included age, baseline MMSE score, and vascular comorbidity score, the interaction term between low daytime SBP tertile and AHD treatment was independently associated with a greater cognitive decline in both subgroups. The association between office SBP and MMSE score change was weaker. Other ambulatory blood pressure monitoring variables were not associated with MMSE score change. CONCLUSIONS AND RELEVANCE Low daytime SBP was independently associated with a greater progression of cognitive decline in older patients with dementia and MCI among those treated with AHDs. Excessive SBP lowering may be harmful for older patients with cognitive impairment. Ambulatory blood pressure monitoring can be useful to help avoid high blood pressure overtreatment in this population.

An Expert Opinion From the European Society of Hypertension–European Union Geriatric Medicine Society Working Group on the Management of Hypertension in Very Old, Frail Subjects

“…15 Likewise, Mossello et al 16 found a more pronounced cognitive decline in treated old hypertensive patients having mild cognitive impairment or dementia in whom SBP was low (<128 mm Hg). Such an effect was not observed in subjects with low SBP but without antihypertensive treatment.…”

Blood Pressure Is Not Associated With Cerebral Blood Flow in Older Persons

“…17,18 It has even been proposed that lowering BP in older persons using antihypertensive medication may decrease CBF. 3,[19][20][21] These observations have led to the suggestion that low BP in old age could result in cerebral hypoperfusion, initiated by impaired cerebral autoregulation. Nevertheless, in older persons with low BP at risk of impaired cerebral autoregulation, limited data are available as to whether CBF is in fact impaired.…”

New horizons: the management of hypertension in people with dementia

“…The PARTAGE study, conducted on French and Italian nursing home residents (mean MMSE 23), found higher mortality in those with low SBP (defined as <130mmHg) receiving multiple BPlowering medications (HR 1.78 95% CI 1.34 to 2.37), after adjustment for cardiovascular comorbidities [33]. For individuals with established cognitive impairment, recent cross-sectional data identified an association between low daytime SBP (< 128mmHg) and greater decline in MMSE score (mean -2.8 [SD 3.8]), in those treated with antihypertensive medications [34].…”