Comparison of Risks and Clinical Predictors of Contrast‐Induced Nephropathy in Patients Undergoing Emergency versus Nonemergency Percutaneous Coronary Interventions

Abstract

Contrast nephropathy (CIN) increases adverse clinical outcomes. We examine risks and clinical predictors of CIN in patients undergoing percutaneous coronary intervention (PCI) and effectiveness of prophylactic therapy. A cohort of 8,798 patients who underwent PCI from May 2000 to April 2008 was enrolled. We divided patients into 3 groups. A: STEMI patient undergoing primary PCI; B: UA/NSTEMI patients undergoing early PCI; C: Patients without MI undergoing elective PCI. Pre-PCI saline hydration was given to group B and C if baseline glomerular filtration rate (GFR) <60 ml/min/1.73 m². Mean age was 57.4 years; 35.9% was diabetics. Incidence of CIN were 12.0%, 9.2%, and 4.5%, in group A, B and C (P = <0.0005). CIN correlated with higher mortality (15.5% vs. 1.3%, P < 0.0005) at 1 month. The important predictors of CIN were age >70, female gender, anemia, low systolic BP < 100 mmHg, high creatinine kinase level, abnormal LVEF, baseline renal impairment, MI and insulin dependent diabetes. Incidence of CIN in patients with GFR >60 were 8.2%, 9.2%, and 4.3% in group A, B, and C respectively (p < 0.0005). Incidence of CIN in patients with GFR = 30-60 were 19.1%, 4.5%, and 2.4% (p < 0.0005) and in patients with GFR < 30 were 34.4%, 40.0%, and 25.9% (p = 0.510). Pre-hydration prophylaxis was effective in preventing CIN in mild renal impaired patients (GFR 30-60) but are less so in more severely renal impaired patients (GFR < 30). STEMI patients undergoing primary PCI regardless of baseline GFR were at high risk. Accelerated prophylactic regime can be considered in this cohort.