Association between re-elevation of cardiac biomarkers and in-hospital MACE after primary PCI in STEMI patients

Previous studies have indicated that after reperfusion therapy in patients with myocardial infarction, high-sensitivity cardiac troponin T (hs-cTnT) may exhibit a secondary increase following the initial peak decline, presenting a biphasic pattern. The clinical significance of this second peak remains controversial. Meanwhile, whether creatine kinase-MB (CK-MB) demonstrates a similar secondary increase and its clinical implications have been rarely investigated. This retrospective study enrolled patients with ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PPCI). The associations of the second increase in the levels of myocardial markers including CK-MB and hs-cTnT and clinical outcomes were analyzed. The main study outcome was the rate of in-hospital major adverse cardiovascular events (MACE), including cardiac death, recurrent AMI, unplanned revascularization and stroke. A total of 264 patients were included in the study (220 males; average age of 63 ± 12 years). The phenomenon of a second increase in myocardial markers, including hs-cTnT and CK-MB, was observed in a significant subset of patients with STEMI following PPCI: the proportions of patients with isolated hs-cTnT secondary rise, isolated CK-MB secondary rise, and dual secondary rise were 29.9%, 11.7%, and 9.1%, respectively. The incidence of MACE in the isolated hs-cTnT secondary rise group (1.3%) was not significantly different from that in the no secondary rise group (1.5%). In contrast, both the isolated CK-MB secondary rise group (9.7%) and the dual secondary rise group (16.7%) showed higher MACE rates compared to the no secondary rise group. In conclusion, a secondary rise in CK-MB, whether isolated or concurrent with hs-cTnT, is associated with a significantly higher risk of MACE. In contrast, an isolated secondary rise in hs-cTnT does not appear to confer an increased risk. These findings suggest that CK-MB, rather than hs-cTnT, is a more critical biomarker for identifying the biphasic pattern that predicts adverse outcomes in post-MI patients after reperfusion.