High-Sensitivity Troponin T and Creatine Kinase MB Predict Mortality after Cardiac Surgery

Background: We aimed to determine the relationship between postoperative high-sensitivity cardiac troponin T/creatine kinase MB and the risk of death (all-cause) within 30 days and 5 years after cardiac surgery.

Method: A consecutive series of 8,327 patients who underwent cardiac surgery at our department since the introduction of hs-cTnT in May 2010 was analyzed retrospectively. The primary endpoint was all-cause mortality at 30 days and during the follow-up of 5 years. The median follow-up was 4.3 years (2.1–5.0) and was 100% complete. Cox analysis using a regression spline exploring the relationship between CK-MB/hs-cTnT and 30-day mortality or 5-year mortality adjusted for EuroSCORE II was performed. ROC curves were calculated to compare sensitivity and specificity of ck-MB and hs-cTnT for prognosis of mortality. Patients undergoing isolated CABG or AVR and patients undergoing other cardiac surgery were analyzed separately.

Results: The median peak CK-MB level within 72 hours after surgery was 49 U/L, the median peak hs-cTnT value was 979.9 ng/L. Isolated CABG or AVR was performed in 49% of the patients, while 51% underwent other procedures. Death within 30 days occurred in 2.7% of the patients. Increased postoperative hs-cTnT and CK-MB levels were associated with 30-day mortality even after adjustment for EuroSCORE II. ROC curve analysis showed no significant differences in the predictive value of CK-MB and hs-cTnT for the prediction of 30-day mortality (p = 0.283). Neither CK-MB nor hs-cTnT was proper biomarkers to predict 5-year mortality reliably. Thresholds for hs-cTnT predicting 30-day mortality were calculated at 1,762 ng/L (125.85 × URL) for isolated CABG or AVR and at 2386 ng/L (170.43 × URL) for other cardiac surgery, respectively. These thresholds are clearly above the recommended thresholds of 35 and 70 × URL to detect periprocedural myocardial injury or infarction. CK-MB thresholds were 102 U/L (4.08 × URL) for isolated CABG or AVR and 71 U/L (2.84 × URL) for other cardiac surgery, respectively.

Conclusion: Increased postoperative hs-cTnT and CK-MB levels are associated with 30-day mortality. The association of postoperative cardiac enzyme levels and mortality declines over time. They are not associated with 5-year mortality. Thresholds for hs-cTnT associated with increased risk of death within 30 days are markedly higher than currently suggested levels for the definition of periprocedural myocardial infarction.

Publikationsverlauf

Artikel online veröffentlicht:
28. Januar 2023