By IDSE News Staff
One in 5 older adults develops an infection up to six months after cardiac surgery—especially women—according to studies led by Michigan Medicine (J Thorac Cardiovasc Surg 2025 Jan 15:S0022-5223[25]00017-0).
The two studies examined thousands of cases involving Medicare beneficiaries who underwent coronary artery bypass grafting (CABG) or aortic valve replacement. They found that women had a 60% greater odds of developing postoperative infections, with the three most common being urinary tract infections (UTIs), pneumonia and sepsis. In addition, Black patients also had higher rates of overall infection (28%) compared with white patients (19.2%).
“Our investigations highlight persistent disparities in outcomes for patients undergoing cardiac surgery that will require multidisciplinary efforts to correct,” said J'undra N. Pegues, MD, MS, the first author of the study on infection disparities and a T32 research fellow in the Department of Cardiac Surgery at University of Michigan (U-M) Health, in Ann Arbor.
In one of the studies, which covered hospitals across the state of Michigan, 21.2% of Medicare beneficiaries developed an infection up to six months after surgery. Pneumonia and UTIs accounted for nearly 17% of all infections, and rates of infection varied nearly 40% across hospitals.
“Tracking infections beyond the short time horizon is important, as some hospitals are better equipped than others to prevent infections, and some patients face disproportionate challenges given social determinants of health,” Dr. Pegues said.
Several past studies have uncovered lower rates of infection after these procedures.
The higher numbers found in the two current studies, investigators said, are likely due to the longer follow-up period of six months.
“Patients who have a heart bypass or valve replacement surgery are at risk for developing other infections that may come about over a longer period of time, such as UTIs and gastrointestinal infections,” said Donald Likosky, PhD, the senior author of both studies and the Richard and Norma Sarns Research Professor of Cardiac Surgery at U-M Medical School, in Ann Arbor.
Most national registries neither track these additional infections nor conduct surveillance beyond 30 days after the procedure, according to Charles Schwartz, MD, the chair of the Department of Surgery at Trinity Health Oakland Hospital, in Pontiac, Mich., and a co-author on both of these studies. “This likely results in a vast underestimation of the burden of infections following cardiac surgery,” Dr. Schwartz said.
CABG and aortic valve replacement account for more than half of all cardiac surgical procedures in Michigan. Nationwide, CABG accounts more than 70% of all heart surgeries.
In one of the Michigan studies, patients receiving their operation at low-performing hospitals, with higher expected rates of infection, were more likely to be discharged to extended care or rehabilitation facilities.
“The findings highlight that patients are at risk for developing infections early and late after their cardiac surgical procedure,” said co-author of both studies Francis Pagani, MD, PhD, the Otto Gago M.D. Endowed Professor in Cardiac Surgery at U-M Medical School, and an associate director of the Michigan Society of Thoracic and Cardiovascular Surgeons Quality Collaborative.
“Other age-related health conditions, such as diabetes, high blood pressure and cancer, may contribute to later-occurring infections identified in this study.”
Dr. Likosky’s study team noted that collaborative learning efforts between healthcare systems are needed to reduce disparities in patient outcomes. Through a statewide quality improvement intervention spanning from 2012 to 2017, hospitals that adopted infection prevention strategies lowered the risk for pneumonia relative to the rest of the country.
Having an infectious disease consult can also be important. An older study found having an ID department at a tertiary care hospital was associated with improved management, better clinical outcomes and reduced embolic events in patients with infective endocarditis admitted to the hospital (Ann Thorac Surg 2021;112[4]:1228-1234).
The Agency for Healthcare Research and Quality provided study-related funding (R01HS029026). The National Heart, Lung, and Blood Institute supports Dr. Pegues under Award Number T32HL166113.
