Association Between Infection and Thrombosis After Coronary Artery Bypass Grafting: A Cohort Study

Abstract

Objective: Surgery-related infection remains a major complication for patients undergoing cardiac surgery, and its association with thrombosis is unclear. This study aimed to examine the association of postoperative infection with thrombosis and major adverse cardiovascular and cerebral events (MACCEs) in patients undergoing coronary artery bypass grafting (CABG).

Design: Retrospective cohort study. Multiple variable regression analyses were performed.

Setting: The study was performed at a single institution.

Participants: All patients underwent CABG.

Intervention: None.

Measurements and main results: Perioperative and postoperative follow-up data relating to all CABG patients from January 2001 to August 2006 were queried from institutional electronic medical records of Fuwai Hospital, Beijing, China. Patients were divided into 2 groups according to whether they experienced infection. The study population comprised 75 patients who experienced infection and 2,926 control patients. Primary outcomes were a composite outcome of perioperative thrombosis and long-term thrombosis-related complications. Secondary outcomes were 5-year MACCEs postoperatively, including death, myocardial infarction, target vessel revascularization, and stroke. Risk factors for infection included older age, higher level of creatinine, chronic lung disease, cardiopulmonary bypass time, aortic cross-clamp time, history of renal failure, cardiopulmonary bypass, left ventricular assist device or intra-aortic balloon pump, length of stay in the intensive care unit, and duration of tracheal intubation. Infection increased the odds of perioperative thrombosis by 5.132-fold (95% confidence interval [CI] 2.040-12.911; p < 0.0001) compared with control. However, infection was not associated with a significant increase in MACCEs (hazard ratio 1.855, 95% CI 0.929-3.704; p = 0.080). Age was associated with a significant increase in MACCEs (hazard ratio 1.040, 95% CI 1.026-1.054; p < 0.0001).

Conclusion: There is an association between postoperative infection and perioperative thrombosis after CABG. Several specific management modalities were associated with controlling infection risk, which offers targets for future quality improvement.

Keywords: coronary artery bypass grafting; infection; thrombosis.