Role of high-sensitivity troponin T as a sensitive biomarker for postoperative myocardial infarction and outcome after isolated coronary artery bypass grafting surgery

BackgroundUncertainty exists about the diagnosis of post-coronary artery bypass grafting (CABG) Perioperative myocardial infarction (PMI) owing to nonconsensus for elevated biomarkers diagnostic levels and associated criteria. Post-CABG studies concerning high-sensitivity troponin (hs-TnT) and its role in the diagnosis of postoperative MI are few.AimWe are aiming to figure out the diagnostic and prognostic role of hs-TnT in individuals undergoing isolated coronary artery bypass graft surgery and whether it has relations to other diagnostic criteria.Patients and methodsA total of 50 patients with multivessel coronary artery disease who elected for isolated CABG were enrolled in the study. Our exclusion criteria included individuals with chronic renal impairment, sepsis, and pre-existing high level of hs-TnT (unless >50% increment significantly raises its postoperative difference). Moreover, patients who experienced marked intraoperative hypotension (mean arterial blood pressure <80 for >5 min) were excluded. Levels of 140 ng/l (10 times 99th percentile upper reference limit) and 500 ng/l (10 times coefficient of variation of 10% for fourth-generation troponin T applied to hs-TnT) were predetermined.ResultsWe enrolled 50 patients who underwent elective CABG. Their mean age was 59.8 ± 6.5 years, and there were 30 (60%) males. hs-TnT level was significantly associated with a higher incidence of off-pump CABG, higher cardiopulmonary bypass time, and higher aortic cross-clamp time. The composite morbidity was significantly higher in patients with hs-TnT level more than 500 (P < 0.001). The mortality rate was significantly higher among patients with hs-TnT level more than 500 than those with hs-TnT level 141–500 (P < 0.001). No mortality was found in patients with hs-TnT level less than 140. Both hs-TnT more than 140 ng/l with ECG and/or echocardiographic criteria and ECG and/or echocardiographic criteria alone predicted 30-day mortality. The most predictive criteria for postoperative mortality was hs-TnT more than 140 ng/l + ECG and/or echocardiographic criteria (odds ratio: 4.9; 95% confidence interval: 1.6–16.1; P = 0.00).ConclusionThe occurrence of post-CABG MI is associated with a higher level of hs-TnT as well as a higher incidence of morbidity and mortality. The use of hs-TnT to diagnose post-CABG MI with a cut point of 10 times 99th percentile upper reference limit especially if associated with ECG and/or echocardiographic criteria predicts 30-day mortality.