PACED-PI
Research type
Research Study
Full title
Targeting prevention of vascular dementia by modifying paced heart rate to improve cerebral pulsatility and haemodynamics
IRAS ID
364681
Contact name
Alastair Webb
Contact email
Sponsor organisation
Imperial College Healthcare NHS Trust
Duration of Study in the UK
2 years, 0 months, 1 days
Research summary
There is an increased risk of dementia in people requiring a pacemaker. Vascular dementia and its commonest cause, cerebral small vessel disease, is associated with increased cerebral pulsatility. This is inversely associated with concurrent heart rate, and our pilot study demonstrated that increasing paced heart rate at the time of pacemaker implantation was associated with decreased cerebral pulsatility. However it is unclear whether this relationship is affected by the site or duration of pacing.
PACED-PI assesses whether the relationship between paced heart rate and cerebral pulsatilty is affected by site and duration of pacing. At each visit, participants will be monitored with continuous BP monitoring (Finometer), ECG, end-tidal CO2 and bilateral middle cerebral artery blood flow velocity (transcranial ultrasound). Paced heart rate will be increased from 50 to 100 bpm in 10 bpm increments for 30-40s, to measure the relationship between heart rate and cerebral pulsatility, performed at each available pacing site in two groups:
Phase A – 12 patients from the PROTECT-UP trial, at ventricular and septal pacing leads at one visit, to test if the heart rate–pulsatility relationship is affected by ventricular vs septal pacing.
Phase B – 24 patients with dual chamber or atrial pacing for sinus node disease or atrial bradycardias, before and after 6 weeks of atrial pacing at a minimum rate of 50bpm or 80 bpm, delivered in a randomised order. They will undergo blood biomarkers, cognitive testing and echocardiography at each visit. This will test whether prolonged pacing at an increased rate affects the heart rate–pulsatility relationship, whether it improves quality of life and whether it is associated with signs of increased cardiac strain.
This study aims to lay the groundwork for a future phase 2 / phase 3 trial to test whether pacing at increased heart rates reduces the risk of dementia.
REC name
East of England - Cambridge South Research Ethics Committee
REC reference
26/EE/0082
Date of REC Opinion
21 Apr 2026
REC opinion
Further Information Favourable Opinion