Is hypoalbuminemia a prognostic risk factor for contrast-induced nephropathy in peritoneal dialysis patients?

Iodinated Contrast and Nephropathy: Does It Exist and What Is the Actual Evidence?

Iodinated contrast material (ICM) is a critical component for many radiologic examinations and procedures. However, ICM has often been withheld in the past out of concern for its potential nephrotoxicity and increased risk of morbidity and mortality, often at the expense of diagnostic accuracy and timely diagnosis. Evidence from controlled studies now suggest that most cases of acute kidney injury (AKI) caused by ICM were instead due to contrast-independent causes of AKI or normal variation in renal function. This study will discuss current knowledge of contrast-induced AKI, including the incidence, sequelae, risk factors, and prevention strategies of this potential complication.

Risk of Acute Kidney Injury Following IV Iodinated Contrast Media Exposure: 2023 Update, From the AJR Special Series on Contrast Media

Iodinated contrast material (ICM) has revolutionized the field of diagnostic radiology through improvements in diagnostic performance and the expansion of clinical indications for radiographic and CT examinations. Historically, nephrotoxicity was a feared complication of ICM use, thought to be associated with a significant risk of morbidity and mortality. Such fears often precluded the use of ICM in imaging evaluations, commonly at the expense of diagnostic performance and timely diagnosis. Over the past 20 years, the nephrotoxic risk of ICM has become a topic of debate, as more recent evidence from higher-quality studies now suggests that many cases of what was considered contrast-induced acute kidney injury (CI-AKI) likely were cases of mistaken causal attribution; most of these cases represented either acute kidney injury (AKI) caused by any of myriad other known factors that can adversely affect renal function and were coincidentally present at the time of contrast media exposure (termed "contrast-associated AKI" [CA-AKI]) or a manifestation of the normal variation in renal function that increases with worsening renal function. This Special Series Review discusses the current state of knowledge regarding CI-AKI and CA-AKI, including the incidence, risk factors, outcomes, and prophylactic strategies in the identification and management of these clinical conditions.

Dynamic thiol-disulphide homeostasis as a biomarker for predicting the development of contrast medium-associated acute kidney injury in the endovascular treatment of peripheral arterial disease: should intravenous N-acetylcysteine be given before the procedure?

AIM

To determine the predictive ability of serum thiol-disulphide levels for contrast medium-associated acute kidney injury (CA-AKI) after endovascular treatment (EVT) of peripheral arterial disease (PAD) and evaluate the efficacy of intravenous N-acetylcysteine (NAC) in preventing CA-AKI.

MATERIAL AND METHODS

This double-blind, randomised controlled study included 85 consecutive adult patients who underwent EVT for PAD. Patients were divided into NAC negative (NAC-) and positive (NAC+) groups. While the NAC- group received only 500 ml saline, the NAC + group received 500 ml saline plus intravenous 600 mg NAC before the procedure. Intra- and intergroup patient characteristics, procedural details, preoperative thiol-disulphide levels, and ischaemia-modified albumin (IMA) levels were recorded.

RESULTS

There was a significant difference between NAC- and NAC + groups regarding native thiol, total thiol, disulphide/native thiol ratio (D/NT), and disulphide/total thiol ratio (D/TT). There was also a significant difference between the NAC- (33.3%) and NAC+ (13%) groups in CA-AKI development. Logistic regression analysis showed that the D/TT (OR 2.463) and D/NT (OR 2.121) were the most influential parameters for CA-AKI development. In the receiver operating characteristic (ROC) curve analysis, the sensitivity of native thiol to detect the development of CA-AKI was 89.1%. The negative predictive values of native thiol and total thiol were 95.6% and 94.1%, respectively.

CONCLUSION

The serum thiol-disulphide level can be used as a biomarker to detect CA-AKI development and reveal patients with a low risk for CA-AKI development before EVT of PAD. Furthermore, thiol-disulphide levels allow for the indirect quantitative monitoring of NAC. Preprocedural intravenous NAC administration significantly inhibits CA-AKI development.

Revised Swedish guidelines on intravenous iodine contrast medium-induced acute kidney injury 2022: A summary

The Swedish Society of Uroradiology has revised their computed tomography (CT) guidelines regarding iodine contrast media-induced acute kidney injury (CI-AKI). They are more cautious compared to the European Society of Urogenital Radiology and the American College of Radiology since the actual risk of CI-AKI remains uncertain in patients with moderate to severe kidney damage due to a lack of prospective controlled studies and mainly based on retrospective propensity score-matched studies with low-grade evidence. Another source of uncertainty is the imprecision of glomerular filtration rate (GFR) estimating equations. However, randomized hydration studies indictae an upper limit risk of CI-AKI of about 5% for outpatients with a GFR in the range of 30-44 or 45-59 mL/min/1.73m² combined with multiple risk factors. Apart from GFR limits, the guideline also includes limits for systemic contrast medium exposure expressed in gram-iodine/GFR ratio.

Serum C-reactive protein to albumin ratio and mortality associated with peritoneal dialysis

Background: Serum C-reactive protein to albumin ratio (CAR) was recently identified as a poor marker of prognosis among various populations. The current study aimed to examine the association between CAR and all-cause mortality among patients undergoing peritoneal dialysis (PD).Methods: A total of 758 patients with PD were included in this study during the period from 1 November 2005 to 28 February 2017 and followed up until 31 May 2017. The primary outcome was all-cause mortality. We used multivariate Cox proportional hazard models and Kaplan-Meier survival curves to assess the relationship between CAR and all-cause mortality in these patients.Results: Among 758 participants, mean age was 49.1 ± 14.2 years, with 56% males and 18.6% prevalence of diabetes. Median CAR was 0.13 (interquartile range [IQR], 0.07-0.34). After 27 months (IQR, 14-40 months) of follow-up, 157 deaths had been reported. After adjusting for confounding factors, we found a significant association between serum CAR and all-cause mortality among those in the highest CAR group (hazard ratio 1.91, 95% confidence interval 1.05- 3.47, p = 0.034).Conclusions: In patients undergoing PD, an increase in serum CAR is independently associated with increased risk for all-cause mortality.

The Impact of Serum Creatinine, Albumin, Age, and Gender on the Development of Contrast-Induced Nephropathy in Patients Exposed to Contrast Agent Upon Admission to the Emergency Department

Background and objectives

As the stage progresses in chronic kidney disease (CKD), the risk of contrast-induced nephropathy (CIN) also increases. Serum albumin level is the strongest predictor of CIN development in patients with CKD. It is widely known that females of age 75 are at risk for the development of CIN. Our study aims to investigate the impact of age, gender, serum creatinine, and albumin levels on the development of CIN in patients who were admitted to the emergency department and have had contrast-enhanced computerized tomography (CECT) for diagnosis.

Materials and methods

The study was planned retrospectively. Patients who applied to the emergency department between January 1, 2018, and January 1, 2020, and had CECT were included in the study. A 25% or 0.5 mg/dL increase in serum basal creatinine level within 72 hours following the implementation of contrast agent was accepted as CIN. The patients were divided into two groups: CIN (+) and CIN (-).

Results

One-hundred twenty-two patients (53 female and 69 male), whose average age was 72.27± 12, were included in the study. Forty-five of the patients were found to be CIN (+) and 77 CIN (-). There was no significant difference between the groups (p> 0.05) in terms of age. It was found that the serum creatinine level during admission to the emergency department was the determinant for the development of CIN (p = 0.024). In addition, it was observed that serum albumin levels during the admission had no impact on the development of CIN (p = 0.326). When the serum albumin values of female and male patients diagnosed with CIN measured at the first admission to the emergency service were compared, the mean values were found to be lower in male patients (p = 0.027).

Conclusion

Serum creatinine and albumin levels, age, and gender parameters should be considered in terms of the risk of CIN development in patients who are admitted to the emergency department and given contrast agents.

Population attributable risk estimates of risk factors for contrast-induced acute kidney injury following coronary angiography: a cohort study

Background

Contrast-induced acute kidney injury (CI-AKI) is a common complication with poor outcomes following coronary angiography (CAG) or percutaneous coronary intervention (PCI). However, no study has explored the population attributable risks (PARs) of the CI-AKI risk factors. Therefore, we aimed to identify the independent risk factors of CI-AKI and estimate their PARs.

Methods

We analyzed 3450 consecutive patients undergoing CAG/PCI from a prospective cohort in Guangdong Provincial People’s Hospital. CI-AKI was defined as a serum creatinine elevation ≥50% or 0.3 mg/dL from baseline within the first 48 to 72 h after the procedure. Independent risk factors for CI-AKI were evaluated through stepwise approach and multivariable logistic regression analysis, and those that are potentially modifiable were of interest. PARs of independent risk factors were calculated with their odds ratios and prevalence among our cohort.

Results

The overall incidence of CI-AKI was 7.19% (n = 248), which was associated with increased long-term mortality. Independent risk factors for CI-AKI included heart failure (HF) symptoms, hypoalbuminemia, high contrast volume, hypotension, hypertension, chronic kidney disease stages, acute myocardial infarction and age > 75 years. Among the four risk factors of interest, the PAR of HF symptoms was the highest (38.06%), followed by hypoalbuminemia (17.69%), high contrast volume (12.91%) and hypotension (4.21%).

Conclusions

These modifiable risk factors (e.g., HF symptoms, hypoalbuminemia) could be important and cost-effective targets for prevention and treatment strategies to reduce the risk of CI-AKI. Intervention studies targeting these risk factors are needed.