A comparison of definitions of contrast-induced nephropathy in patients with normal serum creatinine.

Contrast-induced nephropathy (CIN) is the third leading cause of acute kidney injury in hospitalized patients. The prevalence of CIN is reported to range from 0% to 50%, depending not only on patient condition and the procedure used but also the definition of CIN applied. We aimed to determine the best diagnostic indicator of CIN in patients with normal serum creatinine. This study included 206 patients with normal serum creatinine who underwent coronary angiography/angioplasty. Serum creatinine level and glomerular filtration rate (GFR) were measured before and on the second and fifth days after contrast administration. The incidence of CIN based on a 25% increase in serum creatinine was calculated and compared with the incidence based on a 25% decrease in GFR or an increase of at least 0.5 mg/dL in serum creatinine. Of 206 patients, 127 were male (61.7%) and 79 were female (38.3%); the mean age was 59.56±10.3 years. The prevalence of CIN was 30% based on a 25% increase in serum creatinine, 23% based on a 25% decrease in GFR (P<0.012) and 3.8% based on a serum creatinine increase of at least 0.5 mg/dL (P<0.0001). The serum creatinine levels remained within the normal range in the majority of patients with CIN based on the different definitions. In patients with normal serum creatinine, the absolute increase in serum creatinine may describe the prevalence of CIN more accurately than the relative increase in serum creatinine or relative decrease in GFR.

Renal artery stenosis in patients with established coronary artery disease: prevalence and predicting factors.

The association between renal artery stenosis (RAS) and other atherosclerotic diseases (particularly coronary artery diseases) is well known. In general, the risk factors for atherosclerosis have been clarified, but whether these risk factors operate equally in all forms of atherosclerotic diseases is not known. The aim of this study was to describe the prevalence of RAS in patients with established coronary artery diseases and then to define the most important risk factors that may help to predict the RAS in this population. In this cross-sectional study, 146 patients with established coronary artery stenosis by angiography simultaneously underwent renal angiography; RAS >50% was considered significant. We found that 25.3% of patients with coronary artery diseases had RAS. The prevalence of significant stenosis was 17.1%. Females were more vulnerable to this disorder than males (47.1% vs. 13.7%, P = 0.001). There was no relationship between the severity and number of stenosed coronary arteries and those of stenosed renal arteries (P = 0.716). Multi-variate logistic regression analysis revealed that among the risk factors for atherosclerosis, female sex (P = 0.001), duration of hypertension (P = 0.032), age (P = 0.046) and serum creatinine (P = 0.018) were strong predictors of the presence of RAS. We concluded that RAS is a common finding in patients with coronary artery disease. We suggest that all older females with deteriorating renal function and long-standing hypertension should be carefully evaluated for early detection of the RAS.