Older adults and women are more likely to develop postoperative infections after cardiac surgery

Older adults and women are more likely to develop postoperative infections after cardiac surgery

One in five older adults will develop an infection up to six months after heart surgery - with women far more likely to develop one, according to studies led by Michigan Medicine.

The two studies examined thousands of cases involving Medicare beneficiaries who underwent coronary artery bypass grafting, also known as CABG or heart bypass or aortic valve replacement.

Women were 60% more likely to develop postoperative infections, the three most common being urinary tract, pneumonia and sepsis.

Black patients also had higher overall infection rates (28%) than white patients (19.2%).

The studies are published inThe Journal of Thoracic and Cardiovascular Surgery.

“Our research highlights persistent disparities in outcomes for patients undergoing cardiac surgery that require multidisciplinary efforts to correct,” said J’undra N. Pegues, MD, MS, first author of the infection disparities study and a T32 Research Fellow in the Department of Cardiac Surgery at UM Health.

In one of the studies involving hospitals in 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 infection rates varied nearly 40% across hospitals.

“Tracking infections over the short time horizon is important because some hospitals are better equipped than others to prevent infections and some patients face disproportionate challenges in the face of social determinants of health,” Pegues said.

Several previous studies have revealed lower infection rates following these procedures.

The higher numbers in the two current studies are probably due to the longer follow-up period of six months.

“Patients who have had heart bypass or valve replacement surgery are at risk of developing other infections that can develop over a long period of time, such as UTIs and gastrointestinal infections,” said Donald Likosky, a graduate student, senior author of the studies and Richard and Norma Sarns Research Professor of Cardiac Surgery at the School of Medicine.

Most national registries do not track these additional infections through surveillance beyond 30 days after the procedure, says Charles Schwartz, chairman of the department of surgery at Trinity Health Oakland and a co-author on both studies.

“This likely results in a large underestimation of the infection burden after cardiac surgery,” Schwartz said.

Heart bypass and aortic valve replacement account for more than half of all cardiac surgical procedures in Michigan. Nationwide, CABG accounts for more than 70% of all heart surgeries.

In one of the Michigan studies, patients who received their services at lower-performing hospitals with higher expected infection rates were more likely to be discharged to longer-term care or rehabilitation facilities.

“The results show that patients are at risk of developing infections early and late after their cardiac surgery,” said co-author of both studies Francis Pagani, Ph.D., the Otto Gago MD Professor of Cardiac Surgery at the Michigan Society and Michigan Society and Cardiocular Surgeular Surges Surge, Surge-Surge-Surge-Surge.

“Other age-related health conditions such as diabetes, high blood pressure and cancer may contribute to later-onset infections in this study.”

Likosky's study team notes that collaborative learning efforts across health systems are needed to reduce disparities in patient outcomes.

Through a nationwide quality improvement intervention from 2012 to 2017, hospitals that adopted infection prevention strategies were able to reduce the risk of pneumonia compared to the rest of the country.

Our study reinforces the importance of bringing hospitals and community stakeholders together to identify and subsequently implement potentially modifiable hospital and community practices to prevent postoperative infections. “

Syed Sikandar Raza, MD, lead author and integrated thoracic surgery resident at UM Health

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