Clinical Trial Details
— Status: Not yet recruiting
Administrative data
NCT number |
NCT06262061 |
Other study ID # |
PRO-TBI-FS |
Secondary ID |
|
Status |
Not yet recruiting |
Phase |
Early Phase 1
|
First received |
|
Last updated |
|
Start date |
March 2024 |
Est. completion date |
September 2025 |
Study information
Verified date |
February 2024 |
Source |
London Health Sciences Centre |
Contact |
Mohammad Hmidan Simsam |
Phone |
5196397499 |
Email |
mhmidansimsam2024[@]meds.uwo.ca |
Is FDA regulated |
No |
Health authority |
|
Study type |
Interventional
|
Clinical Trial Summary
Traumatic brain injury (TBI) is a leading cause of global disease and directly affects over
1.5 million Canadians, with 165 000 TBIs occurring yearly in Canada. Despite the burden of
TBIs, there are limited treatment options available and current treatments generally focus on
supportive care. The aim of TBI treatment is reduce inflammation and damage occurring after
the TBI (secondary injury).
Beta- blockers (BBs) are medications commonly used to block the actions of endogenous
catecholamines- hormones that are thought to contribute to secondary injury within brain
tissue. This reduces metabolic demand in the vulnerable, injured brain. BBs have been studied
in several retrospective trials and one single-center, non- blinded randomized controlled
study. These results point towards a benefit to the use of BBs in TBI but need to be
confirmed in a rigorous manner before they are widely adopted.
The current study aims to assess the feasibility of a single centre randomized controlled
trial of BBs versus placebo to treat moderate to severe TBI. This feasibility trial will
inform the planning of a large multi-center study powered to detect a difference in cognitive
outcomes and mortality. It also will allow the investigators to gather biologic samples for
measuring serum catecholamines and inflammatory mediators to better understand the basic
science mechanisms of BBs in this patient population; and to assess the feasibility of using
the Cambridge Battery to assess cognitive outcomes of trial participants.
Description:
Traumatic brain injury is a spectrum of illness ranging from mild concussive symptoms to
debilitating and even life-threatening injury. Between 2002 and 2016, there were 3550 deaths
per year due to TBI. Between 2006 and 2018 there were 17 500 hospitalizations per year due to
TBI. As TBIs often affect youth and working- age adults they are responsible for a very large
economic burden, costing Canada $7.3 billion in 2011 and rising to a projected $8.2 billion
in 2031.
TBI causes morbidity and morbidity in two phases. The primary (initial) injury results in
damage to brain tissue, and is only preventable with injury prevention programs. The
cornerstone of medical TBI management hinges on avoidance of secondary injury to vulnerable
brain tissue. This translates to supportive care for these patients, such as normalization of
vital signs, blood glucose and treatment of seizures, if present. Any abnormalities such as
low blood pressure or oxygen levels do not provide an appropriate environment for the
recovery of brain function and negatively impact recovery. There are few targeted medications
that can be given in the initial management of TBI patients. One of these groups of
medications is osmotic agents that help to reduce intracranial pressure in cases of elevated
intracranial pressure. Osmotic agents, such as mannitol or hypertonic saline, act transiently
and as a bridging therapy to surgical intervention. Medications to reduce bleeding, such as
TXA, have been studied but have not been shown to reduce mortality. Given the limitations and
equivocal role of these medications, additional therapies to reduce the devastating sequelae
in TBI patients are necessary.
Beta-blockers are a class of medications which act on various b adrenergic receptors in the
body, either b1 or b2. b1 receptors are located primarily in the heart and to a lesser extent
the kidneys and adipose tissue; while b2 receptors are located in the lungs, vasculature and
liver. Depending on which b receptors are inhibited, different beta-blockers exert variable
physiologic effects. There are non-selective beta-blockers (bind to both b1 and b2) as well
as selective beta-blockers (solely bind to b1 receptors) available. Propranolol is an example
of a non-selective beta-blocker - it will lower heart rate and blood pressure by its cardiac
effects on b1 receptors but also acts peripherally. Propranolol can uniquely cross the
blood-brain barrier and is able to bind to b receptors that are also present in the central
nervous system. TBI patients commonly develop episodes of elevated heart rate, blood pressure
and agitation secondary to overactivation of the sympathetic nervous system. Administration
of beta-blockers helps mitigate these events, thereby reducing the metabolic demand in
vulnerable, injured brain. It is because of these mechanisms that propranolol is the
beta-blocker that has been postulated to be most beneficial for patients with TBI. Blocking
these receptors leads to decreased metabolic demand and inflammation in neuronal cells. An
important objective of this feasibility trial is for the investigator team to collaborate
with Dr. Allan and her team to measure differences in serum catecholamines and inflammatory
mediators between participants in the Propranolol group as compared to the placebo group.
There have been several retrospective analyses of patients with TBI on at-home beta-blocker
therapy or who received beta-blockers during the course of their hospital stay, many of which
demonstrated improved outcomes. In a meta-analysis combining prospective and retrospective
cohorts, beta- blocker administration was associated with a reduction in in-hospital
mortality. The only randomized control study of propranolol in TBI examined early
administration of propranolol to TBI patients and its impacts on plasma catecholamine levels
and physiologic parameters. The authors found lower levels of plasma catecholamines and
improved vital signs, including Glasgow Coma Scale (GCS) scores at 7 days. This study was
unblinded and occurred in a single, center and as such is at risk of bias.
While most studies of propranolol in TBI have focused on mortality as the outcome of choice,
this is not ideal for several reasons. Mortality is a crude marker of function in TBI,
whereas functional outcomes are the patient-centered outcome of choice in neurologic injury.
The Glasgow Outcomes Scale (Extended) is a validated measure of neurologic function and is
the standard for assessment of recovery following neurological injury.
Additionally, the investigators propose to evaluate the feasibility of using the Cambridge
Battery developed by Dr. Adrian Owen to evaluate short and longer term cognitive outcomes in
trial participants. This neuropsychologic measure has been used in a variety of neurologic
testing studies evaluating CNS disorders and medication, but has not to date been applied to
TBI patients. This represents an exciting opportunity to develop a new tool for the
assessment of the traumatically brain injured patient, with the advantage of a strong record
of safety and reliability in other populations.
In order to change practice, an adequately powered, multi-center RCT is necessary to evaluate
the role of beta-blockers in patients with TBI. The investigators propose a feasibility study
of beta-blockers in TBI at London Health Sciences Center (LHSC) as a first step towards a
future multi-center RCT.