Nearly half of patients who receive heart surgery experience some cognitive changes after the operation such as delirium, decreased attention, or “brain fog.” These changes are typically temporary, but preventing them from happening in the first place could have a simple solution: taking daily walks prior to surgery.
That’s according to new research from Jessica Rove, MD, associate professor in the Division of Cardiothoracic Surgery in the University of Colorado Anschutz Department of Surgery. Published in June in the journal JTCVS Open, the study finds that patients who walked more before surgery had better cognitive outcomes than those who walked less.
“Every week in clinic, I hear from patients who are worried they should stop exercising until their heart is fixed,” Rove says. “The opposite is true. We actually want them to move, because we know from experience across different types of surgeries that the stronger patients are going into surgery, the better they're going to recover. But we have no practical exercise guidelines for patients before heart surgery — other than to stop if they have chest pain or shortness of breath.”
Counting steps
For the observational study, Rove and her research team took a baseline measure of patients’ cognition levels at least five days before prescheduled heart surgery, then gave them step counters to see how many steps they walked prior to the operation. Cognition levels were checked again at discharge, on postoperative day 30, and on postoperative day 90.
“We performed a sensitivity analysis to identify a daily step count cutoff that was associated with cognitive changes after heart surgery. This allowed us to separate the participants into high-steps and low-steps groups,” Rove says. “The low-steps participants had a statistically significant drop in their cognition score at discharge.”
Fewer than 7 percent of patients in the high-steps group showed signs of postoperative decline, vs. 41.7% in the low-steps group.
Outside of step count, Rove says, the groups looked nearly identical — same age, similar comorbidities, similar risk factors, surgical procedures, and postoperative length of stay. The step count seemed to make the difference — not a surprise, given the well-researched benefits of walking.
“The reason we started not just looking at steps, but cognition and well-being, was because there are a lot of data that walking is tied to all of these things — not just health outcomes, but also dementia risk, cognition, and mood,” Rove says. “We thought that walking would be a good target for an intervention, given that it affects so many of these things.”
Walking also is ideal for patients prior to heart surgery because it doesn’t require any special equipment or a trip to the gym, Rove says. That’s especially important for patients in rural or remote locations where access to athletic facilities may be difficult or nonexistent.
“It's hard to get people to suddenly go to the gym or commit to exercises that they don't routinely do in a one-month period before a big operation,” she says. “But everybody knows how to walk. All you need is an activity tracker to count how many steps you're walking in a day. We did not track heart rate or gait speed —just the number of steps you take in a day, and however you get those steps in is up to you.”
Looking for the magic number
The results of the observational study have led to an upcoming clinical trial in which Rove will be looking to see if there is a “magic number” of steps patients need to walk prior to surgery to see a difference in their cognition scores. The trial also will test different methods of encouraging patients to walk a larger number of steps.
“It's a multi-component intervention that we're developing — can we as heart surgeons motivate participants to walk more? Will it actually raise their step count? If somebody's not walking a certain number of steps a day, there might be more barriers than just knowledge,” Rove says. “Most people, before heart surgery, want to do well. They're motivated to do something that's going to help their recovery. We just need to give them an evidence-based intervention that they know will actually help them. That's what we're trying to develop here.”
