Undiagnosed renal impairment in patients with and without diabetes with normal serum creatinine undergoing percutaneous coronary intervention

HYPOTHESIS: The recent Dialysis Outcome Quality Initiative publication on the evaluation, classification and stratification of chronic kidney disease (CKD) states that individuals with a reduced glomerular filtration rate (GFR) is at greater risk for cardiovascular diseases and cardiac deaths. AIM: To determine the prevalence of kidney dysfunction in a cohort of 1390 patients with and without diabetes with normal serum creatinine undergoing percutaneous coronary intervention. METHODS: Kidney function was estimated using simplified MDRD, Cockcroft-Gault and Jeliffe formulas. RESULTS: Normal serum creatinine was observed in 93% patients. Mean estimated GFR in 1068 non-diabetic patients was significantly higher than in 322 diabetic patients (all formulas). Diabetic females had significantly lower creatinine and estimated GFR, higher high-density lipoprotein and platelet count than diabetic males. A very high prevalence of CKD up to 77% was found in studied diabetic patients. Clinically significant CKD (as defined by GFR < 60 mL/min) was found in 13.0-33.8% patients depending on the formula used to estimate GFR. CONCLUSION: The prevalence of CKD (stages 2-3) is high in diabetic patients undergoing percutaneous coronary intervention despite normal creatinine. The risk of contrast nephropathy with worse outcomes is enhanced in these patients, particularly in elderly and females. Evaluation of renal function is important in order to select the appropriate strategy to reduce the cardiovascular risk.