Plasma cyclophilin a as a novel predictor of major adverse cardiac events in patients with acute myocardial injury cohort study

BACKGROUND: Cyclophilin A (CypA) is a multifaceted immunophilin implicated in cardiovascular disease; however, its predictive value for Major Adverse Cardiac Events (MACEs) after acute myocardial injury remains poorly defined. PURPOSE: The study aimed to analyze whether admission Plasma CyPA independently predicts MACEs and to assess its predictive feasibility beyond recognized clinical risk factors. METHOD: In this cohort study, 217 adults with an acute myocardial injury diagnosis exhibiting symptom onset within 24 hours and high cardiac troponin 1 were included. Plasma CyPA concentrations were evaluated using enzyme-linked immunosorbent assay. Participants were closely followed up for 6 months to determine MACEs, defined as all-cause mortality, ischemic stroke, nonfatal myocardial infarction, or unexpected heart failure hospitalization. Receiver Operating Characteristic (ROC) analysis, multivariable Cox proportional hazard models, Kaplan-Meier survival curves, and calibration analysis were conducted with adjusted standard covariates. RESULT: 30% of participants experienced MACEs, with significantly higher CyPA concentrations among those with events than among those without (median 1.942 vs. 1.026 ng/mL; p < 0.001). CyPA demonstrated good discriminatory ability (AUC 0.755; 95% CI: 0.680-0.830), with an optimal cutoff of 1.651 ng/mL. Higher CyPA levels were associated with significantly lower event-free survival. In multivariable analysis, CyPA remained an independent predictor of MACEs (HR 1.698; 95% CI: 1.462-1.973; p < 0.001). The overall Brier score was 0.158, reinforcing satisfactory precision of absolute risk prediction. CONCLUSION: Integration of CyPA into the baseline model significantly enhanced analytical performance, improving the C-index from 0.632 to 0.770. These conclusions suggest that CyPA may be a promising biomarker for risk stratification in acute myocardial injury and warrants external validation.