New research from the Perelman School of Medicine at the University of Pennsylvania has shown for the first time that pneumonia is the most common serious infection after heart surgery. The new study, presented at the 2011 American Heart Association Scientific Sessions, also revealed that most infections occur about two weeks after surgery, not one week as physicians previously thought.
"In the past, focus has been on sternal wound infections after heart surgery, rather than other prevalent infections such as pneumonia," said Michael A. Acker, MD, the study's lead researcher and chief of Cardiovascular Surgery at Penn. "This new research should help guide more effective management strategies to reduce overall occurrence of all infections."
In the new study, researchers analyzed more than 5,100 patients in the Cardiothoracic Surgical Trials Network (CTSN). Patients, average age 64, were treated at nine U.S. academic medical centers and one Canadian center. The median time to major infection was 14 days after heart surgeries. Forty-two percent of all major infections occurred after hospital discharge.
"Half of these patients had no evidence of infection before they were discharged from the hospital," Acker said. "Then they had to return because of the new infection. One implication is that patients must be followed more closely after discharge." In this study, which excluded patients who were infected before surgery, researchers found 761 infections: 300 were classified as major infections (occurring in six percent of patients) and 461 were minor (in 8.1 percent of patients). The most commonly performed procedures were isolated coronary artery bypass graft and aortic and mitral valve surgeries.
Several risk factors appeared to increase the risk of developing infection, including congestive heart failure, hypertension, chronic lung disease, corticosteroid use prior to surgery, and length of cardiopulmonary bypass time.