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

Abstract

Background: Preoperative statin administration is associated with reduced mortality risk after a coronary artery bypass graft operation. However, the optimal dose and timing are unknown.

Methods: 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.

Results: 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.

Conclusions: 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.