Preoperative statin use and outcomes following cardiac surgery

Background: Cardiac surgery carries a 2-3% early mortality due in part to perioperative myocardial infarction (PMI), low-output syndrome (LOS), and arrhythmias. Statins attenuate thrombogenesis, normalize endothelial dysfunction, and mitigate the oxidative stress and reperfusion injury characteristic of such complications. We sought to determine whether preoperative statin use is associated with reduced early mortality and major morbidity following cardiac surgery. Methods: Patients having isolated coronary artery bypass grafting (CABG), valve, or combined CABG/valve surgery between May 1998 and June 2003 (n=5469) were identified. A logistic regression model was generated to determine the association of preoperative statin use with in-hospital mortality (IHM). Propensity score analysis was used to match two subgroups of patients (Group I, on statins, n=1443; Group II, not on statins, n=1443) on multiple factors known to impact cardiac surgical outcome. Outcomes assessed were IHM, intra-aortic balloon pump (IABP) use, PMI, prolonged (>24 h) ventilation (p-vent), stroke, and a composite end point (comp) defined as any one or more of the above. Results: Of the 5469 patients, 3555 were on statins and 1914 were not. Unadjusted rates of IHM (2.6% vs. 5.0%), stroke (1.9% vs. 3.3%), p-vent (10.2% vs. 16.6%), and comp (12.7% vs. 19.5%) were lower (p=0.0001) in patients receiving statins. After adjustment, statin use was not associated with a reduction in IHM (OR=0.9, 95% CI=0.6-1.2, p=0.36) or comp (OR=0.9, 95% CI=0.8-1.1, p=0.31). After matching two subgroups using propensity score for statin, no significant differences were found in any of the adjusted outcomes for Group I vs. Group II: IHM (4.0% vs. 4.6%), PMI (1.5% vs. 1.1%), p-vent (15.8% vs. 15.7%), IABP use (2.0% vs. 2.3%), stroke (3.0% vs. 3.3%), and comp (19.1% vs. 18.8%). Conclusions: Preoperative statin use is not associated with a reduction in IHM or major morbidity following cardiac surgery.