Does Early Graft Patency Benefit from Perioperative Statin Therapy? A Propensity Score-Matched Study of Patients Undergoing Off-Pump Coronary Artery Bypass Surgery

Abstract

Background: Decreased graft patency after off-pump coronary artery bypass grafting (OPCAB) leads to substantial increases in cardiac events. However, there is paucity of data on efficacy and safety of perioperative statin therapy for OPCAB populations.

Methods: 582 patients undergoing OPCAB in a single-institution database (October 1, 2009-September 30, 2012) were stratified by perioperative continuation of statin therapy (CS group, n=398) or not (DS group, n=184). Inverse probability weighted propensity adjustment was used to account for treatment assignment bias, resulting in a well-matched cohort. Primary outcomes were graft patency at an average of five days after operation and in-hospital mortality. Secondary outcomes included intraoperative blood loss, liver, and renal functions.

Results: No in-hospital death occurred in this study. Early graft patency rates after OPCAB were 98.4% (1255 of 1275 grafts) in the CS group and 98.0% (583 of 595 grafts, P=0.486) in the DS group. Secondary outcomes showed a reduction in blood loss during operation (438.53 mL versus 480.47 mL, P=0.01). Continuation of statin therapy is associated with alanine transaminase (ALT) elevation (49.67 U/L versus 34.52 U/L, P<0.001), as well as aspartate transaminase (33.54 U/L versus 28.10 U/L, P<0.001). Abnormal ALT elevation was observed in 8.9% of the CS group and 3.1% in DS (odds ratio 3.06, 95% confidence interval, 1.77 to 5.29, P<0.001). There was no significant difference in estimated glomerular filtration rate (76.28 mL/min/1.73m2 versus 76.13 mL/min/1.73m2, P=0.90). Subgroup analyses suggested that graft occlusion was less common in CS than in DS group among smoking patients (odds ratio 0.41, 95% confidence interval, 0.20 to 0.86, P=0.026).

Conclusions: Perioperative continuation of statin therapy did not improve early graft patency in OPCAB patients. A lower risk of graft occlusion was observed among smoking patients. Continuous statin use correlated with liver function elevation (Clinical Trials.gov number, NCT01268917).

Conflict of interest statement

The authors declare that they have no conflicts of interest.

Copyright © 2019 Shanglin Chen et al.

Figures

Figure 1

Effect of Perioperative Statin Therapy on Postoperative Graft Occlusion, Overall and According to Prespecified Subgroups Following IPW Adjustment. Shown are odds ratios for the incidence of graft occlusion after off-pump CABG (assessed by MSCTA) among patients with perioperative continuation of statin therapy (CS group) as compared with those with discontinuation of statin therapy (DS group). For each prespecified subgroup, after IPW propensity-score adjustment, squares represent odds ratios and horizontal lines represent 95% confidence intervals, with values and results of the P for interaction significance test presented alongside. A square to the left of the vertical line indicates a benefit associated with perioperative continuous statin use, but the benefit is significant at the 5% level only if the horizontal line does not overlap the vertical line.