Contrast-Induced Acute Kidney Injury in Patients Undergoing Emergency Coronary Angiography: Eighteen Months of Prospective Surveillance, Risk Score Validation, and Thirty-Day Outcomes

Contrast-induced acute kidney injury (CI-AKI) following emergency coronary angiography is associated with prolonged hospitalisation, increased need for renal replacement therapy, and higher 30-day mortality. We prospectively monitored renal function in 302 consecutive patients undergoing emergency angiography for ST-elevation or high-risk non-ST-elevation myocardial infarction across 18 months at a tertiary cardiac centre. CI-AKI, defined by KDIGO criteria, occurred in 44 patients (14.6%), with stage 1 in 28 (9.3%), stage 2 in 12 (4.0%), and stage 3 in 4 (1.3%). The Mehran risk score showed good discrimination in this cohort (AUC 0.81, 95% CI 0.74-0.88), with CI-AKI incidence rising from 3.2% in the lowest risk stratum to 41.7% in the highest. Baseline CKD with eGFR below 60 mL/min/1.73 m² doubled CI-AKI incidence at every Mehran stratum. Patients who developed CI-AKI experienced longer length of stay (median 10 vs 5 days), higher in-hospital mortality (9.1% vs 1.9%), and substantially higher rates of new dialysis requirement (9.1% vs 0%). Pre-procedural risk stratification combined with peri-procedural hydration and minimised contrast volume offers a practical pathway to reduce this burden.