Clinical Trial Details
— Status: Not yet recruiting
Administrative data
NCT number |
NCT06410274 |
Other study ID # |
0966 |
Secondary ID |
|
Status |
Not yet recruiting |
Phase |
|
First received |
|
Last updated |
|
Start date |
May 25, 2024 |
Est. completion date |
January 31, 2029 |
Study information
Verified date |
April 2024 |
Source |
University of Leicester |
Contact |
Jatinder Minhas, SFHEA |
Phone |
+44 116 252 3299 |
Email |
jm591[@]leicester.ac.uk |
Is FDA regulated |
No |
Health authority |
|
Study type |
Observational
|
Clinical Trial Summary
The aim of this observational study is to determine how and why inadequate brain blood flow
occurs after bleeding in patients with intracerebral haemorrhage (ICH). Treatment for strokes
caused by burst blood vessels involves reducing blood pressure (BP) to stop the bleeding.
However, this reduction in BP may affect blood flow, causing blockages in blood vessels
within the brain. Fast breathing also affects brain blood flow. Therefore, participants will
be asked to undergo a simple brain blood flow assessment using transcranial Doppler (TCD)
within 48 hours upon admission to hospital. Patients will then have a follow-up TCD
assessment at 4-7 days post-ICH onset, in addition to an MRI scan at >7 days. This research
will help to confirm if blockages after bleeding are caused by reduced blood flow within the
brain.
Description:
Stroke is the second-leading cause of death worldwide, with high mortality and morbidity
rates. One stroke type, intracerebral haemorrhage (ICH), refers to spontaneous, non-traumatic
bleeding, within the brain tissue and is the second most common cause of stroke. Although ICH
can happen at any age, it is more common over the age of 70. The most common cause of ICH is
hypertension, which can cause bursting of cerebral blood vessels, resulting in bleeding
within the brain. National and international guidelines strongly advocate systolic blood
pressure (BP) lowering in ICH as part of "bundled" care, reducing fluctuations in cerebral
blood velocity (CBv). However, despite blood pressure (BP) lowering being deemed clinically
safe, no reduction in death or disability at 90 days was demonstrated in two landmark large
randomised controlled trials. Moreover, reductions in BP may affect CBv to the whole of the
brain, inadvertently causing ischaemic stroke (blockage of the blood supply).
Previous literature has identified that mild-to-moderate ICH stroke severity benefits from
early and stable BP lowering, but those with excessively systolic high BP (>220 mmHg) prior
to lowering suffer significantly higher rates of neurological deterioration. In order to
understand the relationship between BP changes and potential clinical benefit in ICH, it
needs to be determined if there is a global reduction in brain perfusion which is causing
ischaemic lesions in the brain following ICH.
Prospective studies have shown impairments in dynamic cerebral autoregulation (dCA),
cerebrovascular tone, and cerebrovascular resistance in acute ICH. Moreover, meta-analyses
have demonstrated a previously unreported confounder to cerebral autoregulatory function: the
presence of an acute reduction in spontaneous CO2 tension after ICH, potentially reflecting
spontaneous hyperventilation (measured as partial pressure in arterial blood (pCO2) in
patients in intensive care and on the ward). There is no current explanation for the presence
of spontaneous hyperventilation post-ICH. However, it has been shown that across a range of
end-tidal carbon dioxide (EtCO2) values, cerebral blood flow (CBF), dCA, and other core
haemodynamic parameters (arterial BP and heart rate) have a dose-response relationship.
Fast breathing is also known to affect CBv. When EtCO2 is low, rapid acute cerebral
vasoconstriction can occur - risking acute ischaemic injury. Therefore, in the presence of
spontaneous hyperventilation or induced hyperventilation, reductions in brain perfusion
through vasoconstriction could risk new or worsened ischaemic insults, particularly in the
presence of BP lowering. Whilst the presence of cerebral small vessel disease plays a role in
incidence of diffusion-weighted imaging (DWI) lesions after ICH, there have been no
mechanistic association studies to date linking key confounding factors: BP lowering, EtCO2
change, dCA, and ischaemic lesions.
The investigators aim to perform transcranial Doppler (TCD) to measure CBv in patients with
ICH within 48 hours of admission to hospital. These patients would then have a follow-up TCD
assessment at 4-7 days post-ICH onset, in addition to a magnetic resonance imaging (MRI) scan
(>7 days). Data would be collected and analysed to determine the relationship between
cerebral haemodynamics and ischaemic lesions on MRI, post-acute ICH.