@article {Liue021219, author = {Hanning Liu and Zhengxi Xu and Cheng Sun and Qianlong Chen and Ning Bao and Wen Chen and Zhou Zhou and Xiaoqi Wang and Zhe Zheng}, title = {Perioperative urinary thromboxane metabolites and outcome of coronary artery bypass grafting: a nested case-control study}, volume = {8}, number = {8}, elocation-id = {e021219}, year = {2018}, doi = {10.1136/bmjopen-2017-021219}, publisher = {British Medical Journal Publishing Group}, abstract = {Objective As a marker of in vivo thromboxane generation, high-level urinary thromboxane metabolites (TXA-M) increase the occurrence of cardiovascular events in high-risk patients. To investigate whether perioperative urinary TXA-M level is associated with major adverse cardiac and cerebrovascular events (MACCE) after coronary artery bypass graft (CABG) surgery, we designed a nested case-control study.Design Observational, nested case-control study.Setting Single-centre outcomes research in Fuwai Hospital, Beijing, China.Participants One thousand six hundred and seventy Chinese patients undergoing CABG surgery from September 2011 to October 2013.Methods We obtained urinary samples from 1670 Chinese patients undergoing CABG 1 hour before surgery (pre-CABG), and 6 hours (post-CABG 6 hours) and 24 hours after surgery (post-CABG 24 hours). Patients were followed up for 1 year, and we observed 56 patients had MACCE. For each patient with MACCE, we matched three control subjects. Perioperative urinary TXA-M of the three time spots was detected in these 224 patients.Results Post-CABG 24 hours TXA-M is significantly higher than that of patients without MACCE (11 101vs8849 pg/mg creatine, P=0.007). In addition, patients in the intermediate tertile and upper tertile of post-CABG 24 hours urinary TXA-M have a 2.2 times higher (HR 2.22, 95\% CI 1.04 to 4.71, P=0.038) and a 2.8 times higher (HR 2.81, 95\% CI 1.35 to 5.85, P=0.006) risk of 1 year MACCE than those in the lower tertile, respectively.Conclusions In conclusion, post-CABG 24 hours urinary TXA-M elevation is associated with an increase of 1 year adverse events after CABG, indicating that the induction of cyclo-oxygenase-2 by surgery-related inflammatory stimuli or platelet turnover may be responsible for the high levels of post-CABG urinary TXA-M.Trial registration number NCT01573143.}, issn = {2044-6055}, URL = {https://bmjopen.bmj.com/content/8/8/e021219}, eprint = {https://bmjopen.bmj.com/content/8/8/e021219.full.pdf}, journal = {BMJ Open} }