Contrast-Associated Acute Kidney Injury and Mortality Risk After Coronary Angiography for Acute Coronary Syndromes: A Retrospective Cohort Study

Background/Objectives: Contrast-associated acute kidney injury (CA-AKI) is a frequent complication after coronary angiography (CAG) that may adversely affect outcomes in patients with acute coronary syndrome (ACS). We aimed to estimate the incidence of CA-AKI and evaluate its association with 30-day all-cause mortality in adults with ACS undergoing CAG. Methods: We conducted a retrospective cohort study; CA-AKI was defined as an increase in serum creatinine ≥0.5 mg/dL or ≥25% from baseline within 72 h after contrast exposure, according to KDIGO criteria. The primary outcome was 30-day all-cause mortality. Survival analyses were performed using Kaplan–Meier curves and Cox proportional hazards models. Results: Including 374 consecutive adults with ACS who underwent diagnostic or therapeutic CAG at a tertiary referral center. The mean age was 68.8 ± 11.2 years, and 72.6% were male. CA-AKI occurred in 17.4% of patients, and 11.7% died within 30 days. In multivariable analysis, age (HR 1.04; 95% CI 1.00–1.07), CA-AKI (HR 2.81; 95% CI 1.48–5.33), stress hyperglycemia ≥180 mg/dL (HR 2.88; 95% CI 1.54–5.38), and delirium (HR 7.20; 95% CI 2.40–20.92) were independent predictors of mortality. Conclusions: age, CA-AKI, stress hyperglycemia, and delirium independently predict short-term mortality after CAG in ACS, supporting integrated risk-stratified peri-procedural management. These observations suggest that mortality in these patients may be related to an inflammatory process secondary to ischemia/reperfusion, which is probably induced by dysregulation of the central autonomic network and activation of the hypothalamic–pituitary–adrenal axis which is currently underdiagnosed.