High-sensitivity troponin release profile after cardiac surgery

Background Postoperative serum troponin levels and perioperative myocardial infarction (MI) rates correlate with mortality and morbidity following cardiac surgery. The objective of this study was to document the release profile of high sensitivity troponin T (hsTnT) following different cardiac operations. Methods Patients undergoing one of five different isolated cardiac surgical procedures (eligible preoperative hsTnT <29ng/L, serum creatinine < 0.2mmol/L) were recruited prospectively. Serum hsTnT was measured at 0, 4, 6, 8, 10, 12, 24 and 72 hours after the first surgical insult to myocardium, together with daily electrocardiographs. Results There were 10 patients in the on-pump coronary artery bypass group and 5 each in the remaining groups (off-pump coronary artery bypass, open aortic valve replacement, transcutaneous aortic valve implantation and mitral valve replacement). Five additional patients were excluded due to perioperative MI or renal failure. Median [range] of peak hsTnT was 241[99–566], 64[50–136], 353[307–902], 115[112–275], and 918[604–1166] ng/L, respectively. Operations with the lowest peak hsTnT values peaked earliest (four hours) while those with highest values peaked latest (eight hours). Conclusion After cardiac surgery, the hsTnT profile peaks four to eight hours after the initial surgical insult. The magnitude and timing of the peak correlates to the expected degree of surgically-induced myocardial injury.