Kidney Function Alters the Relationship between Postoperative Troponin T Level and Death

Area of Science:

• Cardiology
• Nephrology
• Perioperative Medicine

Background:

• Elevated cardiac troponin T (cTnT) post-noncardiac surgery is a known mortality risk factor.
• The impact of impaired kidney function on the prognostic value of cTnT is not well understood.

Purpose of the Study:

• To evaluate the relationship between cTnT concentration, kidney function, and 30-day mortality after noncardiac surgery.

Main Methods:

• Post hoc analysis of a prospective cohort study involving 14,037 patients undergoing noncardiac surgery.
• Cardiac troponin T (cTnT) was measured for 3 days post-surgery; abnormal levels were defined as peak ≥0.02 ng/ml.
• Estimated glomerular filtration rate (eGFR) was used to categorize kidney function.

Main Results:

• An abnormal cTnT concentration was associated with increased 30-day mortality across different eGFR categories.
• The adjusted hazard ratio for death with abnormal cTnT was significantly lower for patients with eGFR 15 to <30 ml/min/1.73 m² (interaction P=0.02).
• Altering the definition of abnormal cTnT did not change the study's main findings.

Conclusions:

• The prognostic significance of postoperative cTnT may differ in patients with severely reduced kidney function (eGFR <30 ml/min/1.73 m²).
• Further research is needed to establish appropriate interpretation of perioperative cTnT values in patients with impaired kidney function.