The Mind Matters: Exploring the Brain-Heart Relationship at AHA 2024

A unique educational session at the American Heart Association (AHA) 100th anniversary conference dove into the keen relationship between the brain and cardiovascular health. Maureen Hood, PhD, RN, Uniformed Services University, spread awareness about the affect that stress and/or brain injuries—such as traumatic brain injuries (TBIs) and stroke—have on one’s blood vessels and cardiovascular health. Of particular focus was the role of stress- or injury-induced inflammation that carries implications for heart and vascular wellbeing.

With 30 years of experience working with the military, Hood has witnessed firsthand the consequences that trauma and stress have on the heart and US veteran’s wellbeing. Advocating for more resources, interventions, and awareness to address this issue is great passion of hers, as the needs of impacted veterans have not been well met. The talk centered around the biology of this brain-heart connection and multimodality imaging, Hood’s presentation and begged the question, “Is the brain at the heart of the matter?”

This transcript has been lightly edited for clarity and length.

Transcript

Can you contextualize the implications of stress and brain injuries have on the cardiovascular system? What biomarkers are important to look out for in affected patients?

First of all, the context is that we know that stress is one of the factors that cause atherosclerotic disease–that is well, well known. But what's really not well studied is also the effect of an injury itself. What kind of biomarker effects happen when you get an injury, as opposed to just an acute stress event? And so, it's important to realize that some of those factors overlap. I work for the Department of Defense and Military Health, and we're noticing that our troops that are out in battlefield, they're getting blown up, they're getting head injuries or dealing with stress on the battlefield, or even just stress sleeping at night. And we're seeing similar effects with sleep disorders, anxiety, irritability, things of that nature, depression.

Looking at the biomarkers itself, we think there's some overlap that needs to be investigated. And some of those biomarkers are currently looking on cardiovascular disease, we do our lipid panels, our metabolic panels, we're looking at some of the cytokines, such as IL-6, TNF-α, things like that. And those are fine. The cytokines give us an idea that there's something going on. But the important bio factors that we're looking at, like ck, they're just nonspecific. And I think that's one of the major problems right now, is we have a lot of this data coming in knowing that inflammation is bad, but there's no specific early biomarkers that we've really got a good handle on that we can then take advantage of for treatments. And I think that's the conundrum that we're in right now, but we are seeing that there are elevated biomarkers with a mild traumatic brain injury vs chronic variable stress, and then we add those 2 together. It has a synergistic effect.

And that's one of the reasons why I'm passionate about trying to figure out what is going on in the brain, because we know with an acute injury or acute stress—you've heard of the flight-or-fight type of response that happens. Those immediate neurotransmitters send off a lot of signals that increase the response to help protect our bodies, and that response includes inflammatory cytokines. It includes macrophages to sites of injury, and we haven't studied those areas enough.

What we do know is that we should be able to come back down the baseline after something occurs. We don't always come back down to baseline, and so it's figuring out who comes back to baseline and who doesn't, which is really difficult because you can have the same people have the same experiences, and there's a variety of responses on how they recover. Some don't recover. And we need to figure out why we're not coming back down to baseline. Because we don't come back down to baseline, it sets us up to have this chronic increased cortical steroids, increased neuroinflammation, increased inflammation in general, increased catecholamines in the brain. And so, we know that these are destabilizing the functions within our body because we need what's called the HPA axis, the hypothalamus pituitary adrenal axis. It’s very important to help and stabilize our autonomic system in our body. And when those balances are upset, it causes a cascade of cardiovascular dysfunction, atherosclerosis, things of that nature. So that's why we need to look at these areas together.