Perioperative aspirin and long-term survival in patients undergoing coronary artery bypass graft

Qian Ding,Zugui Zhang,Jordan Goldhammer,Douglas Boyd,Jianzhong Sun,Linong Yao,Zhongmin Li,William Weintraub,Eric Yuen,Nilas Young,Rohinton Morris,Hong Liu

doi:10.1038/s41598-018-35208-7

Abstract

This study aimed to examine association between perioperative uses of aspirin and long-term survival in patients undergoing CABG. A retrospective cohort study was performed in 9,584 consecutive patients receiving cardiac surgery from three tertiary hospitals. Of all the patients, 4,132 patients undergoing CABG met inclusion criteria and were divided into four groups: with or without preoperative or postoperative aspirin respectively. 30-day postoperative and long-term mortality were compared with the use of propensity scores and inverse probability weighting adjustment to reduce the treatment-selection bias. The patients taking preoperative aspirin presented significantly more with comorbidities. However, the results of this study showed that preoperative aspirin (vs. no preoperative aspirin) was associated with significantly reduced the risk of 30-day mortality in the patients undergoing CABG. Further, the results of long-term mortality showed that the patients taking preoperative aspirin and postoperative aspirin (vs. not taking) were associated with significantly reduced the risk of 4-year mortality (14.8% vs. 18.1%, RR: 0.82, 95% CI: 0.75–0.89, P = 0.005; 10.7% vs. 16.2%, RR: 0.66, 95% CI: 0.50–0.82, P = 0.003). In conclusion, this cohort study showed that perioperative (before and after surgery) use of aspirin was associated with significant reduction in 30-day mortality without significant bleeding complications, also improved long-term survival in patients undergoing CABG.

Highlights

Aspirin is one of the most common used drugs in preventing and treating cardiovascular disease (CVD) and its complications
Before adjusted with using inverse probability weighting (IPW), more patients taking aspirin than not taking one had smoking, diabetes, peripheral vascular disease, angina, hypertension, previous myocardial infarction (MI), required urgent surgery and underwent CABG, but less underwent CABG + valve surgery and took shorter time on bypass and cross-clamp; they were more with family history of CAD, more taking lipid lowering drugs, ACE inhibitors or beta blockers, but less with history of congestive heart failure, bypass time and cross clamp time
We considered the assumed prevalence of the binary unmeasured confounder in non-preoperative at 5%, 10%, 20%, 30%, and 40%, respectively; and we calculated corresponding hazard ratio related to the unmeasured confounder to explain the observed decreased risk

Summary

Introduction

Aspirin is one of the most common used drugs in preventing and treating cardiovascular disease (CVD) and its complications. Several meta-analyses in the area have showed that preoperative aspirin reduced perioperative MI, but was associated with an increased risk of reoperation, transfusion and bleeding These meta-analyses were based upon early RCTs that were small and underpowered for efficacy outcomes[2,3,4]. In 2016, a large RCT led by Myles et al showed that among 2,100 patients undergoing CABG with or without valve surgery, preoperative aspirin (100 mg) given on the day of surgery did not reduce risk of primary outcome including 30-day death, MI, stroke, renal failure, pulmonary embolism or bowel infarction, nor did increase the risk of bleeding[13]. The length of follow-up is one of major limitations in most previous studies in the area of aspirin effects on cardiac surgery It remains unknown about perioperative aspirin’s effect on the long-term survival in patients undergoing CABG surgery. This study aimed to examine association between perioperative (before and after surgery) use of aspirin and long-term survival in patients undergoing CABG

Objectives

Methods

Results

Conclusion