High-sensitive cardiac troponins and CK-MB concentrations in patients undergoing cardiac surgery

Prognostic Value of High-Sensitivity Troponin T After On-Pump Coronary Artery Bypass Graft Surgery

INTRODUCTION

High-sensitivity troponin T (hs-TnT), as a single or serial measurement to predict postoperative mortality and morbidity, appears to be attractive due to its direct relationship in assessing myocardial damage and the widespread availability of hs-TnT testing. Therefore, this study aimed to identify any prognostic value of hs-TnT in predicting in-hospital outcomes after coronary artery bypass graft (CABG) surgery.

METHOD

We identified all consecutive patients who underwent on-pump CABG between July 2011 and December 2018. To evaluate the prognostic value of hs-TnT after CABG, we assessed the probability and odds ratio (OR) of adverse events concerning the maximum value of postoperative hs-TnT (measured within 24 hrs). TnT was routinely collected at 0, 6, 12 and 72 hours postoperatively. Values were categorised into intervals of 200 for analysis. A fully Bayesian logistic regression of the adverse event with the troponin T interval (0-200) as the reference level was used. A subgroup analysis was performed in patients with normal and elevated preoperative hs-TnT (< or ≥30 ng/L). The pre-specified primary outcome was a major adverse cardiac or cerebrovascular event (MACCE), defined as a composite of death within 30 days of operation for any cause, myocardial infection (MI), or stroke.

RESULTS

1,318 people underwent on-pump CABG during this period. One hundred and twenty-three (123) (9.3%) experienced MACCE, 14 (1.1%) experienced death within 30 days, 105 (8.0%) experienced MI and 14 (1.1%) experienced stroke. Compared to the reference category (hs-TnT ≤200 ng/L) we found there was an increase in OR with increasing level of hs-TnT for MACCE (p<0.001), 30-day mortality (p=0.003), MI (p<0.001) and ICU stay >48 hours (p<0.001). However, there was no statistically significant association present between hs-TnT and stroke, readmission to the intensive care unit (ICU), return to theatre for bleeding, or new-onset renal dysfunction.

CONCLUSION

Peak hs-TnT level, greater than 400 ng/L, measured within 24 hours after CABG surgery is associated with MACCE, 30-day mortality, MI and ICU stay >48 hours. Prospectively designed trials, with clear prognostic and outcome variables, may provide further insight into the prognostic value of hs-TnT post-CABG.

High-sensitivity troponin T release profile in off-pump coronary artery bypass grafting patients with normal postoperative course

BACKGROUND

The aim of the study was to investigate the high-sensitivity troponin T (hs-TnT) release profile in off-pump coronary artery bypass grafting (OPCABG) patients with normal postoperative course.

METHODS

From January 2015 to October 2016, 398 consecutive OPCABG patients who had normal postoperative courses were enrolled. Blood samples for hs-TnT were collected at several time points and the comparisons among different time points grouped by various factors were further analyzed.

RESULTS

There were 317 male and 81 female patients, with a median age of 64. For 66.1% of the patients, peak hs-TnT occurred at the 24th hour after OPCABG, regardless of the groups divided by different factors. In total, the hs-TnT values were much higher in male group (P = 0.035), in patients who need 5 or more bypass grafts (P = 0.035) and in patients with high-risk EuroSCORE II assessment (P = 0.013). However, we failed to find any significant differences between different age groups (P = 0.129) or among different coronary heart disease classifications (P = 0.191).

CONCLUSIONS

The hs-TnT values were affected by various factors and culminated around the first 24 h following OPCABG. It may provide some useful information for future clinical studies of myocardial biomarkers after OPCABG.

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 72hours 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.