Kinetics of High-Sensitive Cardiac Troponin I in Patients with ST-Segment Elevation Myocardial Infarction and Non-ST Segment Elevation Myocardial Infarction

<b>Background/Objectives:</b> Existing data regarding the kinetics of cardiac troponin I (cTnI) are limited. The aim of the current study was to evaluate the kinetics of highly sensitive (hs) cTnI following acute myocardial infarction (MI) in a large-scale, real-world cohort. <b>Methods:</b> A prospective observational cohort study included all consecutive patients admitted to the intensive cardiovascular care unit (ICCU) with ST-segment elevation MI (STEMI) and non-ST-segment elevation MI (NSTEMI) who underwent percutaneous coronary intervention (PCI) between January 2020 and April 2024. Hs-cTnI concentrations were measured at the time of presentation and daily thereafter. <b>Results:</b> A total of 1174 STEMI patients [191 females (16.3%)] with a mean age of 63 years and 767 NSTEMI patients [137 females (17.9%)] with a mean age of 66.7 years were enrolled. The average hs-cTnI peak levels were 77,937.99 ng/L and 24,804.73 ng/L for STEMI and NSTEMI patients, respectively. A single peak of hs-cTnI was observed in 83% and 78% of STEMI and NSTEMI patients, respectively, while two peaks were observed in 11% and 19% and three or more peaks were observed in 6% and 3% of STEMI and NSTEMI patients, respectively. A higher number of peaks was associated with a lower ejection fraction and more in-hospital complications. Additionally, a higher number of peaks correlated with a higher in-hospital mortality rate among NSTEMI patients. <b>Conclusions:</b> Most STEMI and NSTEMI patients displayed a monophasic kinetic pattern of hs-cTnI peak levels. However, a greater number of hs-cTnI peaks was linked to a higher incidence of clinical complications, lower ejection fraction, and increased mortality.