Risk Factors and Clinical Outcomes for Contrast-induced Nephropathy After Percutaneous Coronary Intervention in Patients with Normal Serum Creatinine

Abstract

Introduction: We aim to examine the risk predictors of contrast-induced nephropathy (CIN) in patients with normal baseline serum creatinine (Cr). CIN is an important complication post percutaneous coronary intervention (PCI). Previous studies examined CIN predictors in patients with chronic renal impairment. No large studies investigated patients with normal renal function which constitute the majority undergoing PCI. We aim to identify risk predictors in this cohort and examine the clinical outcomes. Materials and Methods: A total of 3036 patients with normal baseline Cr (<1.5 mg/dL) who did not receive prophylaxis while undergoing PCI were enrolled. We examined the occurrence of CIN and the mortality outcome at 1 and 6 months. Results: CIN occurred in 7.3% of patients. The median age was 59.5 years (range, 26 to 86), 78.7% men, 34.6% diabetics. Risk predictors for CIN include age [odds ratio (OR), 6.4; 95% CI, 1.01-13.3; P = 0.042], female gender (OR, 2.0; 95% CI, 1.5-2.7; P = 0.001), abnormal left ventricular ejection fraction (LVEF) <50%(OR,1.02; 95% CI, 1.01-1.04; P = 0.01), anaemia with haemoglobin <11 mg/dL (OR, 1.5; 95% CI, 1.01-2.4; P = 0.044) and systolic hypotension with blood pressure <100 mmHg (OR, 1.5; 95% CI, 1.01-2.2; P = 0.004). Diabetics on insulin therapy were at the highest risk compared with diabetics on oral hypoglycaemics and diet control (18.9% vs 6.8% vs 3.6%; P = 0.001). Patients who developed CIN had higher mortality at 1 month (14.5% vs 1.1%; P <0.001) and 6 months (17.8% vs 2.2%; P <0.001). Conclusions: Subgroups of patients with normal baseline Cr undergoing PCI are at risk of developing CIN with resultant higher mortality. Age, female gender, insulin dependent diabetes mellitus, presence of hypotension, anaemia and low LVEF are predictors of CIN. Prophylaxis may be considered in these patients. Key words: Anaemia, Female gender, Haemoglobin, Left ventricular ejection fraction