The conundrum of contrast-induced acute kidney injury

Predictors for Irreversibility of Contrast-Induced Acute Kidney Injury in Patients with Obesity After Contrast-Enhanced Computed Tomography Coronary Angiography

INTRODUCTION

Although contrast-induced (CI) acute kidney injury (AKI) is a common complication in high-risk individuals requiring evaluation with contrast-enhanced angiography, the possible predictors of CI-AKI in patients with obesity are not fully understood. The aim of this study was to elucidate plausible factors associated with the irreversibility of CI-AKI in individuals with obesity undergoing contrast-enhanced computed tomography coronary angiography.

METHODS

A total of 96 adult patients with obesity and the KDIGO criteria of CI-AKI (increase of serum levels of creatinine ≥ 25% or ≥ 500 µmol/L at 48 h after procedure) were retrospectively screened from the cohort of 1833 patients who underwent iodine contrast medium (ICM)-enhanced computed tomography coronary angiography, and were included in the study. The patients were divided into two cohorts: 96 adult patients with obesity and recovery of CI-AKI in 7 days after initiating of the event, and 57 individuals with irreversibility of CI-AKI. Serum concentrations of conventional biochemistry and urine biomarkers [i.e., hemoglobin, creatinine, high-sensitivity C-reactive protein, urinary albumin/creatinine ratio (UACR)] as well as natriuretic peptide, adropin, apelin, irisin, tumor necrosis factor-alpha (TNF-alpha), were determined at baseline. The levels of creatinine were measured at baseline, at the event, and in 7 days after the event.

RESULTS

We identified 12 variables, which were associated with irreversibility of CI-AKI: age > 75 years [odds ratio (OR) = 1.22. P = 0.001], male gender (OR = 1.03, P = 0.042), stable coronary artery disease (OR = 1.06, P = 0.048), chronic kidney disease (CKD) 1-3 grade (OR = 1.60, P = 0.001), heart failure with preserved ejection fraction (HFpEF) (OR = 1.07, P = 0.046), baseline estimated GFR < 80 mL/min/1.73 m2 (OR = 1.10, P = 0.040), UACR > 17.5 mg/g Cr (OR = 1.05, P = 0.048), TNF-alpha > 3.11 pg/mL (OR = 1.12, P = 0.001), and adropin < 2.43 ng/mL (OR = 1.18, P = 0.001). After adjustment for CKD and UACR > 17.5 mg/g Cr, only HFpEF (OR = 1.06, P = 0.042) and adropin < 2.43 ng/mL (OR = 1.11, P = 0.001) remained independent predictors of CI-AKI irreversibility. Yet, adropin < 2.43 ng/mL at baseline exerted sufficiently better predictive ability than both HFpEF and preexisting CKD 1-3 grade.

CONCLUSION

In a multivariate prediction model adjusted for CKD and urinary albumin/creatinine ratio > 17.5 mg/g Cr, low levels of adropin (< 2.43 ng/mL) in individuals with non-morbid obesity together with the presence of HFpEF were independent predictors of CI-AKI irreversibility after ICM-enhanced computed tomography coronary angiography.

The usefulness of arylesterase in predicting contrast-induced nephropathy in ST-segment elevation myocardial infarction patients undergoing percutaneous coronary intervention

Aim: Oxidative stress is one of the causes of contrast-induced nephropathy (CIN). Paraoxonase1 (PON1), is one of the oxidative stress markers. The most sensitive method that has been in use to measure PON1 enzyme activity is the measurement of arylesterase (AREase) activity. To explore relationship between AREase activity and CIN development. Material and Method: A total of 58 STEMI patients were included in our study. The patients were divided into two groups as CIN (+) and CIN (-). The success of AREase activity level in predicting the development of CIN was also examined by using ROC analysis. Results: Out of the study patients, 13 were CIN (+) and 45 were CIN (-). AREase activity was found to be statistically significantly lower in the CIN (+) group (875 U/L vs 819 U/L, p= 0.004). In the regression analysis, diabetes mellitus, contrast volume and AREase activity were determined as independent risk factors in the development of CIN. As a result of the ROC analysis, we concluded that the AREase activity level

Specificity of severe AKI aetiology and care in the elderly. The IRACIBLE prospective cohort study

INTRODUCTION

Acute Kidney Injury (AKI) is increasingly common in people over 65 years of age, but its causes and management are poorly described. The purpose of this study was to describe the causes, management and prognosis of patients over 65 hospitalised for severe acute kidney injury (AKI) in all departments of a tertiary centre.

METHOD

The prospective IRACIBLE (IRA: AKI in French; CIBLE: target in French) cohort included 480 patients hospitalised at a university hospital over 18 months for severe AKI or subgroup of AKIN3 (Acute Kidney Injury Network classification) defined by an acute creatinine increase > 354 μmol/L or managed with acute renal replacement therapy (RRT). The history, aetiology of AKI, management, and prognosis were compared in three age groups: < 65, 65-75, and > 75 years.

RESULTS

The study population included 480 subjects (73% men) with a median body mass index (BMI) of 26.6 kg/m² [23.3, 30.9], 176 (37%) diabetic patients, 124 (26%) patients < 65 years, 150 (31%) 65-75 years and 206 (43%) > 75 years. Increasing age class was associated with more comorbidities, a significantly lower median estimated glomerular filtration rate (eGFR) 6 months before inclusion (82; 62; 46 ml/min/1.73 m², p < 0.05) and aetiology of AKI, which was more often obstructive (12%; 15%; 23%, p = 0.03) or part of a cardio-renal syndrome (6%; 9%; /15%, p = 0.04). Older patients were less often managed in the intensive care unit  (54%; 47%; 24%, p < 0.0001), were less frequently treated by RRT (52%; 43%; 31%, p < 0.001) and received fewer invasive treatments  (6%; 9%; 22%, p < 0.0001). Older survivors returned home less often (80%; 73%; 62%, p = 0.05) in favour of transfers to rehabilitation services (10%; 13%; 22%) with higher mortality at 3 months (35%; 32%; 50%, p < 0.0001).

CONCLUSION

Older patients hospitalised for severe AKI have a specific profile with more comorbidities, lower baseline renal function, an aetiology of AKI of mainly extra-parenchymal causes and a complex pathway of care with an overall poor prognosis.

A multiple-metabolites model to predict preliminary renal injury induced by iodixanol based on UHPLC/Q-Orbitrap-MS and 1H-NMR

BACKGROUND & AIMS

There are some problems, such as unclear pathological mechanism, delayed diagnosis, and inaccurate therapeutic target of Contrast-induced acute kidney injury (CI-AKI). It is significantly important to find biomarkers and therapeutic targets that can indicate renal injury in the early stage of CI-AKI. This study aims to establish a multiple-metabolites model to predict preliminary renal injury induced by iodixanol and explore its pathogenesis.

METHODS

Both UHPLC/Q-Orbitrap-MS and ¹H-NMR methods were applied for urine metabolomics studies on two independent cohorts who suffered from a preliminary renal injury caused by iodixanol, and the multivariate statistical analysis and random forest (RF) algorithm were used to process the related date.

RESULTS

In the discovery cohort (n = 169), 6 metabolic markers (leucine, indole, 5-hydroxy-L-tryptophan, N-acetylvaline, hydroxyhexanoycarnine, and kynurenic acid) were obtained by the cross-validation between the RF and liquid chromatography-mass spectrometry (LC-MS). Secondly, the 6 differential metabolites were confirmed by comparison of standard substance and structural identification of ¹H-NMR. Subsequently, the multiple-metabolites model composed of the 6 biomarkers was validated in a validation cohort (n = 165).

CONCLUSIONS

The concentrations of leucine, indole, N-acetylvaline, 5-hydroxy-L-tryptophan, hydroxyhexanoycarnitine and kynurenic acid in urine were proven to be positively correlated with the degree of renal injury induced by iodixanol. The multiple-metabolites model based on these 6 biomarkers has a good predictive ability to predict early renal injury caused by iodixanol, provides treatment direction for injury intervention and a reference for reducing the incidence of clinical CI-AKI further.

Predictive value of combining the level of fibrinogen and CHA2DS2-VASC Score for contrast-induced acute kidney injury in patients with acute coronary syndromes undergoing percutaneous coronary intervention

OBJECTIVE

The present study aimed to investigate the value of preprocedural fibrinogen (FIB) combined with CHA2DS2-VASC scores in the risk prediction of contrast-induced acute kidney injury (CI-AKI) after percutaneous coronary intervention (PCI) in patients with acute coronary syndromes (ACS).

METHOD

A total of 934 patients (mean age 63.9 ± 11.5 years, and 32.1% female), who were admitted to our hospital for ACS and underwent PCI, were retrospectively enrolled. The patients were divided into two groups: non-CI-AKI group (n = 787) and CI-AKI group (n = 147). Contrast-induced acute kidney injury was defined as an increase of ≥ 0.5 mg/dL or ≥ 25% serum creatinine within 48-72 h after PCI. Spearman correlation analysis was used to determine the relationship between FIB and CHA2DS2-VASC scores.

RESULTS

Patients with high baseline FIB levels and high CHA2DS2-VASC scores had higher CI-AKI incidence. On spearman correlation analysis, FIB and CHA2DS2-VASC scores were positively correlated (R = 0.236, P < 0.001). The ROC statistical analysis showed that the combination had 63.3% sensitivity with 72.6% specificity for the development of CI-AKI (area under the curve: 0.727, 95% CI 0.697-0.755, P < 0.001). A total of 934 ACS patients were divided into low-risk group (404 cases), medium-risk group (383 cases) and high-risk group (147 cases) according to the cut-off values of FIB and CHA2DS2-VASC scores. The incidence of CI-AKI was higher in the high-risk group than in the low-risk and medium-risk groups (Log-rank χ2 = 104.505, 56.647. P < 0.001). Multivariate analysis revealed that albumin (OR = 0.913, 95% CI 0.867-0.962), FIB (OR = 1.451, 95% CI 1.185-1.77), CHA2DS2-VASC score (OR = 1.271, 95% CI 1.504-1.78) were the independent risk factors of CI-AKI (p < 0.05).

CONCLUSION

The preprocedural fibrinogen combined with CHA2DS2-VASC score is independently associated with the risk of CI-AKI in ACS patients treated by PCI.

Incidence and Risk Factors of Contrast-Induced Acute Kidney Injury in Sudanese Patients Undergoing Coronary Angiography: A Descriptive Prospective Study

BACKGROUND

Contrast-induced acute kidney injury (CI-AKI) has been reported to be the third most common cause of hospital-acquired acute kidney injury (AKI) and is associated with significant morbidity and mortality.

OBJECTIVES

This study aimed to assess the incidence and risk factors of CI-AKI in Sudanese patients undergoing coronary angiography.

METHODS

The study was a descriptive, prospective, hospital-based study conducted at Alshaab Hospital between January and April 2019. A total of 163 patients undergoing coronary angiography were enrolled, and a checklist was used to collect data. Chi-square and regression analyses were performed to identify the risk factors of CI‑AKI. CI‑AKI was defined as a rise in serum creatinine ≥25% above baseline within three days after percutaneous coronary angiography (PCA).

RESULTS

CI‑AKI incidence in patients undergoing coronary angiography was 31.9% (52/163). Among independent variables, diabetes mellitus, the type of coronary angiography, and the volume of contrast medium were statistically significantly (p-value ˂ 0.05) associated with CI-AKI development. Logistic analysis showed that diabetes (odds ratio (OR): 15.2; 95% CI: 6.771-33.974; p = 0.001), percutaneous coronary intervention (PCI) (OR: 2.4; 95% CI: 1.168-4.901; p = 0.017), and the volume of contrast medium (OR 2.1; 95% CI: 1.440-3.054; p = 0.001) were independent predictors correlated to CI‑AKI development.

CONCLUSION

The incidence of CI-AKI is 31.9%, and diabetes mellitus, PCI, and high volume of contrast medium are associated with a higher risk of CI-AKI in patients undergoing coronary angiography.

Contrast-induced nephropathy and oxidative stress: mechanistic insights for better interventional approaches

Contrast-induced nephropathy (CIN) or contrast-induced acute kidney injury (CI-AKI) is an iatrogenic acute kidney injury observed after intravascular administration of contrast media for intravascular diagnostic procedures or therapeutic angiographic intervention. High risk patients including those with chronic kidney disease (CKD), diabetes mellitus with impaired renal function, congestive heart failure, intraarterial intervention, higher volume of contrast, volume depletion, old age, multiple myeloma, hypertension, and hyperuricemia had increased prevalence of CIN. Although CIN is reversible by itself, some patients suffer this condition without renal recovery leading to CKD or even end-stage renal disease which required long term renal replacement therapy. In addition, both CIN and CKD have been associated with increasing of mortality. Three pathophysiological mechanisms have been proposed including direct tubular toxicity, intrarenal vasoconstriction, and excessive production of reactive oxygen species (ROS), all of which lead to impaired renal function. Reports from basic and clinical studies showing potential preventive strategies for CIN pathophysiology including low- or iso-osmolar contrast media are summarized and discussed. In addition, reports on pharmacological interventions to reduce ROS and attenuate CIN are summarized, highlighting potential for use in clinical practice. Understanding this contributory mechanism could pave ways to improve therapeutic strategies in combating CIN.

Molecular Mechanisms of AKI in the Elderly: From Animal Models to Therapeutic Intervention

Acute kidney injury (AKI), a critical syndrome characterized by a sudden reduction of renal function, is a common disorder among elderly patients particularly in Intensive Care Unit (ICU). AKI is closely associated with both short- and long-term mortality and length of hospital stay and is considered a predictor of chronic kidney disease (CKD). Specific hemodynamic, metabolic, and molecular changes lead to increased susceptibility to injury in the aged kidney; therefore, certain causes of AKI such as the prerenal reduction in renal perfusion or vascular obstructive conditions are more common in the elderly; moreover, AKI is often multifactorial and iatrogenic. Older patients present several comorbidities (diabetes, hypertension, heart failure) and are exposed to multiple medical interventions such as the use of nephrotoxic contrasts media and medications, which can also trigger AKI. Considering the emerging relevance of this condition, prevention and treatment of AKI in the elderly should be crucial in the internist and emergency setting. This review article summarizes the incidence, the risk factors, the pathophysiology, the molecular mechanisms and the strategies of prevention and treatment of AKI in elderly patients.