Impact of troponin I level on coronary artery bypass grafting outcomes

Purpose: The effect of preoperative cardiac troponin level on outcomes after coronary artery bypass grafting (CABG) is unclear. We investigated the impact of preoperative cardiac troponin I (cTnI) level as well as the time interval between maximum cTnI and surgery on CABG outcomes.

Methods: All patients who underwent isolated CABG at our institution between 2009 and 2016 and had preoperative cTnI level available were identified using our Society of Thoracic Surgeons registry. Receiver operating characteristic (ROC) analysis was performed to identify a cTnI threshold level. Subjects were divided into groups based on this value and outcomes compared.

Results: A total of 608 patients were included. ROC analysis identified 5.74 µg/dL as the threshold value associated with worse postoperative outcomes. Patients with peak cTnI >5.74 µg/dL underwent CABG approximately 1 day later, had twice the risk of adverse postoperative events, and had 2.8 day longer postoperative length of stay than those with peak cTnI ≤5.74 µg/dL. cTnI level was not associated with mortality or 30-day readmission. Time interval between peak cTnI and surgery did not affect outcomes.

Conclusion: Elevated preoperative cTnI level beyond a certain threshold value is associated with adverse postoperative outcomes but is not a marker for increased mortality. Time from peak cTnI does not affect postoperative outcomes or mortality and may not need to be considered when deciding timing of CABG.