Effect of Dose and Timing of Preoperative Statins on Mortality After Coronary Artery Bypass Surgery

Abstract

Preoperative statin administration is associated with reduced mortality risk after a coronary artery bypass graft operation. However, the optimal dose and timing are unknown. We retrospectively reviewed data from 3,025 primary isolated coronary artery bypass graft surgery patients at our institution. Patients were divided into three groups, according to timing of their preoperative statin: 24 hours or less (n= 1,788), 24 to 72 hours (n= 452), or more than 72 hours before operation or no dose (n= 781). We then grouped patients by preoperative dose: no statin (n=739), 20 mg or less (n= 920), or more than 20 mg (n=1,284) atorvastatin or equivalent. Primary outcome was 30-day all-cause postoperative mortality. Thirty-day all-cause mortality was significantly lower for patients taking a statin 24 hours or less preoperatively (1.7%) compared with 24 to 72 hours (2.9%), more than 72 hours, or no dose (3.8%). Multivariate analysis of a propensity-matched cohort showed taking statins 24 hours or less preoperatively was associated with reduced 30-day all-cause mortality (odds ratio 0.52, 95% confidence interval: 0.28 to 0.98, p= 0.04) versus more than 24 hours or no dose. For preoperative statin dose, 30-day all-cause mortality was significantly lower when taking 20 mg or less(1.8%) or more than 20 mg atorvastatin or equivalent (2.1%) than when taking none (3.8%). In multivariate analysis of the propensity-matched cohort, more than 20 mg preoperative dose was associated with a 68% reduction of 30-day all-cause mortality (odds ratio 0.32, 95% confidence interval: 0.13 to 0.82, p= 0.02) compared with no preoperative statin. However, a 20 mg or less preoperative dose showed no mortality reduction. Both statin use 24 hours or less preoperatively and preoperative statin dose of more than 20 mg were independently associated with decreased 30-day all-cause mortality after coronary artery bypass graft surgery.