Grant: Team Grant: Cardiac Arrest: Optimize Brain Recovery After Cardiac Arrest

Every year, more than 80,000 Canadians experience cardiac arrest—a sudden event where the heart stops beating without warning. Thanks to advances in emergency care, we have become better at restarting the heart. Today, however, survival depends more on the brain than on the heart alone. When the heart stops, blood flow to the brain stops as well. Within minutes, the brain is deprived of oxygen and injury begins. This injury, called post-cardiac arrest brain injury (PCABI), is the leading cause of death and long-term disability after cardiac arrest and costs the Canadian healthcare system approximately $2 billion annually. Survivors frequently experience anxiety, depression or post-traumatic stress, and families are also profoundly affected. Despite this major burden, effective treatments to protect the brain after cardiac arrest remain limited. To improve these devastating outcomes, we aim to study and intervene across the entire course of PCABI, from when blood flow stops to long-term recovery. We propose an integrated research platform that examines how brain injury occurs, how early treatments can be developed and delivered, how recovery can be improved in survivors and caregivers and how PCABI care can be more equitable. First, we will study what happens in the brain in the first moments after blood flow stops. When the heart stops, brain cells release large amounts of a chemical called glutamate. Glutamate is normally important for brain function, but in excess it can overwhelm and damage brain cells. Most of what we know about brain injury after cardiac arrest comes from animal studies, which limits applicability and drug development. Using advanced bedside monitoring in critically ill patients, we will measure brain chemistry in real time to better understand how this injury unfolds in humans. We will also examine whether biological sex influences vulnerability. Evidence suggests that women may experience worse survival and neurological outcomes after cardiac arrest. Second, we will test whether early medications that block harmful glutamate signaling can protect the brain when given during resuscitation or immediately after circulation returns. Working closely with emergency medical services across Vancouver, paramedics will deliver these treatments during real-world cardiac arrest care, aiming to intervene before irreversible injury occurs. Third, we will examine the factors that influence how doctors predict neurological recovery in intensive care units. These predictions guide decisions about whether to continue or withdraw life sustaining treatment, yet there is uncertainty about how and when they are made and whether some patients may be unintentionally disadvantaged like marginalized groups. By studying provincial data and interviewing healthcare provider perspectives, we aim to improve equity in PCABI decision making. Finally, recognizing that recovery extends beyond survival, we will address the mental health needs of cardiac arrest survivors and caregivers. We will test an innovative noninvasive brain stimulation therapy to treat post-traumatic stress and improve long-term quality of life. Together, this Neuron-to-Patient research platform brings scientists, clinicians, patients, families and emergency responders together to improve treatments, recovery and equity in cardiac arrest care. Our ultimate goal is simple: to improve survival after cardiac arrest and help more people return to meaningful lives.