Prevention of Decline in Cognition after Stroke Trial (PODCAST): a study protocol for a factorial randomised controlled trial of intensive versus guideline lowering of blood pressure and lipids

Abstract

Background: Stroke is a common cause of cognitive impairment and dementia. However, effective strategies for reducing the risk of post-stroke dementia remain undefined. Potential strategies include intensive lowering of blood pressure and/or lipids.

Design: multi-centre prospective randomised open-label blinded-endpoint controlled partial-factorial phase IV trial in secondary and primary care.

Participants: 100 participants from 30 UK Stroke Research Network sites who are post- ischemic stroke or intracerebral haemorrhage by three to seven months. Interventions--all patients (1:1): intensive versus guideline blood pressure lowering (target systolic < 125 mmHg versus < 140 mmHg).Interventions--ischemic stroke (1:1): intensive versus guideline lipid lowering (target low density lipoprotein-cholesterol (LDL-c) < 1.4 mmol/l versus < 3 mmol/l).

Hypotheses: does 'intensive' blood pressure lowering therapy and/or 'intensive' lipid control reduce cognitive decline and dementia in people with ischemic stroke; and does 'intensive' blood pressure lowering therapy reduce cognitive decline and dementia in patients with hemorrhagic stroke.

Primary outcome: Addenbrooke's Cognitive Examination-Revised.

Secondary outcomes: feasibility of recruitment and retention of participants, tolerability and safety of the interventions, achieving and maintaining the blood pressure and lipid targets, maintaining differences in systolic blood pressure (> 10 mmHg) and low density lipoprotein-cholesterol (> 1 mmol/l) between the treatment groups, and performing clinic and telephone follow-up of cognition measures. Randomisation: using stratification, minimization and simple randomization. Blinding: participants receive open-label management. Cognition is assessed both unblinded (in clinic) and blinded (by telephone) to treatment. Adjudication of events (dementia, vascular, serious adverse events) is blinded to management.

Discussion: The PODCAST trial is ongoing with 78 patients recruited to date from 22 sites. Outcomes of cognitive impairment and dementia are accruing.

Trial registration: ISRCTN85562386.