What’s the Real Half-Life of Troponin Elimination?
November 19, 2024
Written by Catherine Burger
Spoon Feed
Authors used a novel method to determine cardiac troponin (cTn) elimination and found the half-life median range was 134 to 239 minutes, which is 5-16 hours shorter than results previously reported.
Return of the troponin – final elimination
This study included 25 patients admitted to an ICU in Denmark after revascularization for a STEMI (>90% stenosis on cardiac catheterization). Consenting participants had plasmapheresis performed within 24 hours of revascularization. At least 3 weeks later, participants returned for autologous retransfusion with their own high-concentration-cTn plasma. Blood samples were drawn before transfusion, then every 10 minutes for 1.5 hours after transfusion, followed by every 30 minutes for 4.5 hours, followed by every 60 minutes for 2 hours. All samples were analyzed using 5 separate high-sensitivity troponin assays. Five participants dropped out prior to retransfusion. Four participants were women and one participant had CKD. Of the 440 samples planned, 3.9% were not done due to lack of time during the planned 10-minute intervals and 3.1% failed due to hemolysis. An exponential two-phase (distribution of cTn and elimination of cTn) model was used to describe the data. After retransfusion, the median elimination half-life ranged from 134.1 minutes (95%CI 117.8-168.0) to 239.7 minutes (CI 153.7-295.1). This is 5-16 hours shorter than previous clinical observation studies after myocardial injury. Authors postulate these differences may be due to ongoing release of cTn into the blood stream during these prior observational studies. Due to limited numbers and exclusion criteria, this study was unable to examine difference between men and women, and those with medical comorbidities, such as liver or kidney disease.
How will this change my practice?
I will have higher concern for continued myocardial injury in my patients when they exhibit continued cTn elevation (or further rise) over the span of 2 to 5 hours.
Source
Half-Life and Clearance of Cardiac Troponin I and Troponin T in Humans. Circulation. 2024 Oct 8;150(15):1187-1198. doi: 10.1161/CIRCULATIONAHA.123.066565. Epub 2024 Sep 10. PMID: 39253802