Perioperative factors associated with changes in troponin T during coronary artery bypass grafting

Abstract

Objective Investigate important clinical and operative variables associated with increases in cardiac troponin T (cTnT) as indicators of myocardial injury after coronary artery bypass grafting (CABG). Design Prospective cohort study. Setting Single university hospital. Participants The study comprised 626 patients undergoing isolated CABG from April 2008 through April 2010 with a validation cohort (n = 686) from 2015-2017. Interventions None. Measurements and Main Results Perioperative variables were registered prospectively. The extent of diffuse coronary atherosclerosis and significant stenoses were assessed with preoperative coronary angiography. Mixed model analysis was used to construct a statistical model explaining the course of cTnT concentrations. The model was adjusted for preoperative and intraoperative/postoperative myocardial infarction (MI) for independent assessment of additional variables. Clinical factors associated with increased cTnT concentrations during and after CABG were longer duration of cardiopulmonary bypass (p < 0.001), higher preoperative creatinine (p < 0.001), New York Heart Association functional classification IV (p = 0.006), reduced LVEF (p = 0.034), higher preoperative C-reactive protein (p = 0.049), and intraoperative/postoperative MI (p < 0.001). Factors associated with decreasing cTnT concentrations during CABG were higher BSA (p < 0.001) and a recent preoperative MI (p < 0.001). The extent of diffuse coronary atherosclerosis and significant stenoses were not associated with changes in cTnT (p = 0.35). Results were similar in the validation cohort. Conclusions Left ventricular ejection fraction, New York Heart Association classification, kidney function, inflammation status, duration of cardiopulmonary bypass, body surface area, and preoperative MI were associated with the cTnT rise-and-fall pattern related to myocardial injury after CABG. Information regarding these variables may be valuable when using cTnT in the diagnostic workup of postoperative MI.