A pair of new studies from Michigan Medicine has revealed that one in five older adults develops an infection within six months of heart surgery.
The findings, published in The Journal of Thoracic and Cardiovascular Surgery, highlight important concerns about long-term recovery and the disparities that exist in patient outcomes.
The research focused on people undergoing two of the most common types of heart surgery: coronary artery bypass grafting (CABG), also known as heart bypass surgery, and aortic valve replacement.
These procedures are performed on thousands of patients every year, and together account for more than half of all cardiac surgeries in Michigan. Nationally, CABG alone makes up over 70% of all heart surgeries.
The results showed that women were at much greater risk than men. In fact, women had 60% higher odds of developing an infection after surgery. The three most common types of infections were urinary tract infections (UTIs), pneumonia, and sepsis. Black patients also faced higher infection rates, with 28% affected compared to 19.2% of white patients.
One of the studies, which included hospitals across Michigan, found that 21.2% of Medicare patients developed an infection within six months of surgery. Pneumonia and UTIs accounted for nearly 17% of all infections.
Infection rates also varied widely, with nearly 40% differences observed between hospitals. These gaps point to important differences in how hospitals prevent infections and in the social factors that shape patients’ recovery.
The researchers explained that their findings show higher infection rates than those found in past studies. One reason, they say, is that many studies and national registries only track infections for 30 days after surgery.
By extending the follow-up to six months, the Michigan Medicine team uncovered infections that appear later in recovery, such as UTIs and gastrointestinal infections. These are often missed by shorter studies.
Dr. Donald Likosky, senior author of both studies, emphasized that heart surgery patients remain at risk for months after their procedures. Other age-related conditions, such as diabetes, high blood pressure, or cancer, may also increase the risk of later infections.
Co-author Dr. Francis Pagani added that patients at lower-performing hospitals, where infection rates were higher, were more likely to be discharged to extended care or rehabilitation facilities. This shows how hospital quality can shape outcomes long after the surgery itself.
The studies also point to important disparities. Women and Black patients face much greater risks of infection, raising concerns about health equity. First author Dr. J’undra Pegues noted that solving these disparities will require cooperation across specialties and healthcare systems.
Collaborative learning programs may help. In fact, from 2012 to 2017, a statewide quality improvement project in Michigan reduced pneumonia risk for cardiac surgery patients relative to the national average.
The research team says the next step is to keep building partnerships between hospitals, communities, and policymakers. Preventing infections is not just about the hospital stay—it also involves the patient’s environment and support system after discharge.
By combining medical strategies with broader community support, they hope to reduce disparities and improve recovery for all patients.
In summary, the new findings show that one in five older adults is at risk of infection months after heart surgery, and that women and Black patients are especially vulnerable.
While progress has been made in reducing some infection risks, the studies call for continued work to make recovery safer, more equitable, and more consistent across hospitals.
The study is published in The Journal of Thoracic and Cardiovascular Surgery.
Copyright © 2025 Knowridge Science Report. All rights reserved.
