Failure to initiate statin therapy during and after percutaneous coronary interventions negatively affects coronary artery bypass graft outcomes

Abstract

Studies have shown that patients who have had a previous percutaneous coronary intervention (PCI) and subsequently require coronary artery bypass graft (CABG) surgery have increased perioperative morbidity and mortality and decreased long-term survival. 1-4 Tran and colleagues 3 found that patients with diabetes mellitus who had previously undergone a PCI and subsequently underwent CABG surgery had nearly a 3-fold increase in operative mortality, increased risk of developing a major adverse cardiac event (MACE), and significantly reduced 2-year survival compared with patients without a previous PCI. In an editorial accompanying this study, it was noted that the use of statin therapy in both groups was especially low (<40%). 5 The question was raised on whether the outcomes would have improved in the PCI cohort undergoing CABG if these patients had received statin therapy after their PCI and before their surgery. This issue is now addressed in the study by Mannacio and colleagues in this issue of The Journal of Thoracic and Cardiovascular Surgery. 6 In this study of 2501 patients who had undergone a previous PCI and now required CABG surgery, 1528 patients were on continuous statin therapy and 973 patients did not receive a statin until immediately before their surgery. A propensity-matched conditional logistic regression analysis showed that continued statin therapy significantly reduced the risk for in-hospital and 2-year mortality and MACE. Statins were particularly effective in those patients who had prolonged crossclamp times and patients with previous multivessel PCI. Patients on continuous statin therapy had significantly lower lowdensity lipoprotein cholesterol (LDL-c) levels at the time of surgery (120 28 mg/dL vs 159 39 mg/dL; P<.001). There were several limitations in this study. It was retrospective and urgent and emergency patients were excluded. Different types of statins were used and the dosages varied widely. Adherence was assessed by the rates of prescription refills and not by actual documentation that patients took their medication. Nearly 35% of the patients had diabetes mellitus but no mention was made of the use of perioperative glycemic control or the preoperative glycated hemoglobin values between the groups. The use of other cardioprotective agents was poor; only 22% of patients received an angiotensin-converting enzyme (ACE) inhibitor and only 70% were on a b-blocker at the time of surgery. Cardiac catheterization data were not available at the time of the PCI so that the completeness of the revascularization performed during PCI for both groups was unknown.