Randomised controlled decentralised feasibility trial of a fixed low-dose combination antihypertensive drug strategy to attenuate cognitive decline in high-risk adults.

OBJECTIVES

The Action To promote brain HEalth iN Adults study aimed to determine the feasibility and applicability of recruitment using home blood pressure (BP) monitoring, routine blood biochemistry and videoconference measures of cognition, in adults at high risk of dementia.

DESIGN

A decentralised double-blind, placebo-controlled, randomised feasibility trial with a four-stage screening process.

SETTING

Conducted with participants online in the state of New South Wales, Australia.

PARTICIPANTS

Participants were aged 50-70 years with moderately elevated BP (systolic >120 and <160 mm Hg or diastolic >80 and <95 mm Hg) and ≥1 additional enrichment risk factor of monotherapy treatment of hypertension, diabetes mellitus, elevated low-density lipoprotein cholesterol, obesity, current smoking or a first degree relative with dementia, which indicated an elevated risk for future cognitive decline.

INTERVENTION: Triple Pill (active antihypertensive treatment of telmisartan 20 mg, amlodipine 2.5 mg and indapamide 1.25 mg) or placebo Triple Pill (blinded study capsules).

PRIMARY AND SECONDARY OUTCOME MEASURES: Primary outcome was feasibility of the study expressed as the percentage of participants randomised from those who were screened. Secondary outcomes were the applicability of videoconference measures of cognition and the overall trial, tolerability of the Triple Pill, safety outcomes and medication adherence.

RESULTS

The proportion (95% CI) of patients randomised to those screened was 5% (2%-10%). The applicability of the trial expressed as percentage of those who completed all remote assessments over the number of randomised participants was 67% (95% CI 05 to 22%). There were no serious adverse events or withdrawals from treatment. All participants adhered to study medication, except for one person who had two capsules left at the end of the study period.

CONCLUSIONS

The feasibility of this decentralised trial on BP lowering in patients at high risk for dementia is low. However, the applicability of remote assessments of cognitive function is acceptable.

TRIAL REGISTRATION NUMBER: Australian New Zealand Clinical Trials Registry (ANZCTR): ACTRN12621000121864.