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This Journal feature begins with a case vignette highlighting a common clinical problem. Evidence supporting various strategies is then presented, followed by a review of formal guidelines, when they exist. The article end with the authors' clinical recommendations.

To determine whether low-osmolality contrast media (LOCM) are less nephrotoxic than high-osmolality contrast media (HOCM), the authors searched MEDLINE and EMBASE databases and other sources to find randomized trials with data collected on changes in glomerular filtration rate or serum creatinine (SCr) level with LOCM and HOCM. Forty-five trials were found. Data were unavailable from 14 trials. When the P values from the other 31 trials were pooled, an overall P value of .02 was found. Among 24 trials with available data, the mean change in SCr was 0.2-6.2 mumol/L less with LOCM than HOCM. Among 25 trials with available data, the pooled odds of a rise in SCr level of more than 44 mumol/L with LOCM was 0.61 (95% confidence interval [CI], 0.48-0.77) times that after HOCM. For patients with existing renal failure, this odds ratio was 0.5 (CI, 0.36-0.68), while it was 0.75 (CI, 0.52-1.1) in patients without prior renal failure. Greater changes in SCr level occurred only in those with existing renal failure and were less common with LOCM (odds ratio, 0.44; CI, 0.26-0.73). Use of LOCM may be beneficial in patients with existing renal failure.

Key points• Chronic kidney disease is common and is associated with increased cardiovascular risk.• Attention to cardiovascular risk factors remains the cornerstone of care to delay progression of chronic kidney disease and prevent cardiovascular events.• Randomized clinical trials are lacking; thus, recommendations in the guidelines are based on a synthesis of the best available evidence.• Shared care of patients with chronic kidney disease by general practitioners and specialists is encouraged.

Background-Atheroembolic renal disease (AERD) is caused by showers of cholesterol crystals released by eroded atherosclerotic plaques. Embolization may occur spontaneously or after angiographic/surgical procedures. We sought to determine clinical features and prognostic factors of AERD. Methods and Results-Incident cases of AERD were enrolled at multiple sites and followed up from diagnosis until dialysis and death. Diagnosis was based on clinical suspicion, confirmed by histology or ophthalmoscopy for all spontaneous forms and for most iatrogenic cases. Cox regression was used to model time to dialysis and death as a function of baseline characteristics, AERD presentation (acute/subacute versus chronic renal function decline), and extrarenal manifestations. Three hundred fifty-four subjects were followed up for an average of 2 years. They tended to be male (83%) and elderly (60% Ͼ70 years) and to have cardiovascular diseases (90%) and abnormal renal function at baseline (83%). AERD occurred spontaneously in 23.5% of the cases. During the study, 116 patients required dialysis, and 102 died. Baseline comorbidities, ie, reduced renal function, presence of diabetes, history of heart failure, acute/subacute presentation, and gastrointestinal tract involvement, were significant predictors of event occurrence.

Background and objectives:The relationship of contrast-induced nephropathy (CIN) to long-term adverse events (AEs) is controversial. Although an association with AEs has been previously reported, it is unclear whether CIN is causally related to these AEs.Design, setting, participants, & measurements: We obtained long-term (>1 yr) follow-up on 294 patients who participated in a randomized, double-blind comparison of two prevention strategies for CIN (iopamidol versus iodixanol). A difference in the incidence of AEs between patients who had developed CIN and those who had not was performed using a 2 test and Poisson regression analysis. A similar statistical approach was used for the differences in AEs between those who received iopamidol or iodixanol. Multiple definitions of CIN were used to strengthen and validate the results and conclusions.Results: The rate of long-term AEs was higher in individuals with CIN (all definitions of CIN). After adjustment for baseline comorbidities and risk factors, the adjusted incidence rate ratio for AEs was twice as high in those with CIN. Randomization to iopamidol reduced both the incidence of CIN and AEs.Conclusions: The parallel decrease in the incidence of CIN and AEs in one arm of this randomized trial supports a causal role for CIN.

To determine the risk of nephrotoxicity induced by the infusion of radiographic contrast material, we undertook a prospective study of consecutive patients undergoing radiographic procedures with intravascular contrast material. There were three study groups: patients with diabetes mellitus and normal renal function (n = 85), patients with preexisting renal insufficiency (serum creatinine level, greater than or equal to 150 mumol per liter) without diabetes (n = 101), and patients with both diabetes and renal insufficiency (n = 34). The control group consisted of patients undergoing CT scanning or abdominal imaging procedures without the infusion of contrast material who had diabetes mellitus (n = 59), preexisting renal insufficiency (n = 145), or both (n = 64). Clinically important acute renal failure (defined as an increase of greater than 50 percent in the serum creatinine level) attributable to the contrast material did not occur in nondiabetic patients with preexisting renal insufficiency or in diabetics with normal renal function. The incidence of clinically important contrast-induced renal failure among the diabetic patients with preexisting renal insufficiency was 8.8 percent (95 percent confidence interval, 1.9 to 23.7 percent), as compared with 1.6 percent for the controls. The incidence of acute renal insufficiency, more broadly defined as an increase of greater than 25 percent in the serum creatinine level after the infusion of contrast material, was 11.8 percent among all patients with preexisting renal insufficiency. After the exclusion of patients whose acute renal insufficiency could be attributed to other causes, the incidence was 7.0 percent (95 percent confidence interval, 3.2 to 12.8 percent), as compared with 1.5 percent in the control group. The risk of acute renal insufficiency attributable to the contrast material was therefore 5.5 percent, and the relative risk associated with the infusion of contrast material was 4.7. These rates were similar whether the osmolarity of the contrast material was high or low. We conclude that there is little risk of clinically important nephrotoxicity attributable to contrast material for patients with diabetes and normal renal function or for nondiabetic patients with preexisting renal insufficiency. The risk for those with both diabetes and preexisting renal insufficiency is about 9 percent, which is lower than previously reported.