Prognostic value of serum cystatin C and its changes in patients with ST-segment elevation myocardial infarction.

BACKGROUND

Serum cystatin C (Cys-C) has been established as a prognostic marker in various cardiovascular settings, but its changes and their relationship with long-term outcomes in ST-segment elevation myocardial infarction (STEMI) patients remain underexplored. Therefore, this study aims to evaluate the prognostic value of serum Cys-C concentration and its changes in predicting all-cause mortality in STEMI patients with normal or mildly impaired renal function.

METHODS

This single-center, retrospective observational study enrolled 753 STEMI patients who underwent emergency percutaneous coronary intervention between February 2019 and December 2024. Serum Cys-C levels were measured at baseline and the last measurement. Patients were categorized into tertiles based on baseline Cys-C, follow-up Cys-C, and the absolute change in Cys-C. The primary endpoint was all-cause mortality.

RESULTS

During follow-up of 627 days, 75 deaths occurred. Non-survivors had significantly higher baseline and follow-up Cys-C levels, as well as greater absolute increases in Cys-C, compared to survivors (all p < 0.001). Kaplan-Meier analysis showed significantly worse survival in the highest tertiles of baseline Cys-C (log-rank p < 0.001), follow-up Cys-C (p < 0.0001), and Cys-C change (p = 0.009). After multivariable adjustment, the highest tertile of baseline Cys-C was associated with a 2.20-fold increased risk of mortality (95% CI: 1.19-3.88, p = 0.012). The highest tertile of follow-up Cys-C was associated with a 3.12-fold increased risk of mortality (95% CI: 1.79-5.99, p < 0.001), while the highest tertile of Cys-C change conferred a 2.10-fold increased risk (95% CI: 1.14-3.68, p = 0.017).

CONCLUSION

Elevated serum Cys-C levels at baseline and the last measurement, as well as an increase in Cys-C over time, are independently associated with higher all-cause mortality in STEMI patients. Serial measurement of Cys-C may enhance risk stratification and serve as a dynamic indicator for monitoring disease progression and treatment response.