Association between statins and infections after coronary artery bypass grafting

Background: We determined whether pre-operative statin therapy is associated with a decrease in the incidence of infections after coronary artery bypass grafting (CABG). Methods: A retrospective cohort study of 6253 patients undergoing isolated CABG, from the Texas Heart Institute Database from January 1, 2000 to December 31, 2010 (3869 receiving statins and 2384 not receiving statins) was conducted. Primary outcome was the development of any postoperative infection (composite of deep-sternal wound infection, leg harvest-site infection, pneumonia, or sepsis) after CABG. Secondary outcome was the association between pre-operative statin use and individual incidence of each aforementioned infection. Logistic regression analyses were performed. Results: Incidence of any postoperative infection in patients who received statins pre-operatively was 6.5% compared to 8.3% in patients who did not receive statins. Pre-operative statin therapy was associated with a significant reduction in the primary outcome (odds ratio (OR) 0.74, 95% confidence interval (CI) 0.60-0.90) in adjusted models. Among individual secondary outcomes, pre-operative statin therapy was associated with a reduced incidence of sternal wound infections (2.5% vs. 3.2%, OR 0.6, 95% CI 0.5-0.8) and leg harvest site infections (0.6% vs. 1.3%, OR 0.46, 95% CI 0.2-0.8). Pre-operative statin therapy was not associated with a reduced incidence of pneumonia or sepsis. Conclusion: Pre-operative statin use is associated with a decrease in overall incidence of post-operative infections after CABG. We propose immunomodulatory effects of statins leading to a dampening of inflammatory cascade as the cause of our findings.