Purpose: Recent observational studies have suggested that statins can decrease the incidence and severity of various infections including pneumonia and bacteremia. However, the effect of statins on post-cardiac surgery infection has not been adequately evaluated. Therefore we sought to determine whether preoperative statin use resulted in a reduction in infection following cardiac surgery.
Methods: This was a cohort evaluation of all consecutive patients who underwent coronary artery bypass graft (CABG) and/or valve surgery at our institution between January 1, 2004 and August 31, 2006. Our primary outcome measure was the occurrence of at least one of the following postoperative infectious complications (pneumonia, bacteremia, sternal wound, leg vein harvest site infection, urinary tract infection, or tracheotomy site infection). We used multivariable logistic regression to control for potential confounding and to calculate adjusted odds ratios (AORs) and 95% confidence intervals (CIs).
Results: A total of 1934 patients were included in this evaluation of which 1248 received a statin preoperatively and 686 did not. Our study population was 66.3 +/- 11.6 years of age, 71.3% male; 37.2% underwent complex surgery, 3.6% were morbidly obese, and 32.0% were diabetic (each being previously identified as an independent predictor of infection following cardiac surgery). Patients receiving a statin preoperatively and not receiving a statin preoperatively varied in respect to a number of important pre- and peri- operative characteristics. Patients receiving preoperative statin therapy were more likely to have had a history of diabetes, chronic obstructive pulmonary disease or high cholesterol and to be smokers, but less likely to be undergoing urgent/emergent surgery or surgery utilizing a cardiopulmonary bypass pump (p < 0.05 for all comparisons). In total, 151 (7.8%) patients developed an infectious complication. Upon multivariable logistic regression, preoperative statin use was associated with a significant reduction in the development of infection (AOR; 0.67 (95% CI 0.46-0.99), p = 0.04). The use of a statin was not associated with a statistically significant reduction in any individual infection on its own (p > 0.08 for all).
Limitations: Patients were not randomized to receive statins or not. We did not have adequate power to evaluate individual infections.
Conclusions: Preoperative statin use is associated with a reduction in patients' odds of developing a postoperative infection following cardiac surgery.