Risk factors for contrast-induced nephropathy after coronary angiography.

Contrast-induced nephropathy (CIN) is of concern after the use of radiocontrast media for coronary angiography (CAG) and percutaneous coronary intervention (PCI). We studied the incidence of CIN and its risk factors in patients undergoing CAG. In this prospective study, we included all patients with normal renal parameters undergoing CAG with nonionic radiocontrast media. We excluded patients with known chronic kidney disease, baseline creatinine more than 1.5 mg/dL, significant hypotension, anemia, and patients with acute myocardial infarction undergoing emergency PCI. Serum creatinine was done at baseline and serially for seven days after the procedure. Appropriate statistical tests were used to analyze the results and P <0.05 was considered statistically significant. The study population (n = 500, 348 males and 152 females) had a mean age of 56.6 ± 12.5 years. Twelve patients (2.4%) developed CIN and were equally distributed irrespective of the age, diabetes, or PCI procedure. CIN was observed to be more common in patients with hypertension than in those without hypertension (P = 0.0158). The total volume of contrast administered to CIN group (175 ± 59.3) was not significant as compared to that of non-CIN (159.1 ± 56) group (P = 0.334). None of the patients in our study required renal replacement therapy, and there was no mortality. CIN is observed in 2.4% of patients undergoing CAG and had a self-limiting course. Hypertension is the only observed risk factor, and further large-scale studies are necessary to delineate the novel risk factors for CIN in the general population with normal kidney function.