Contrast-induced acute kidney injury: A review of practical points

Temporal trends of acute kidney injury in patients undergoing percutaneous coronary intervention over a span of 12 years

BACKGROUND

AKI is a known complication of PCI and is associated with higher rates of adverse events. We assessed temporal trends in rates of AKI, factors associated with risk of AKI and prognosis.

METHODS

From a prospective registry of patients undergoing PCI at two hospitals of the Rabin Medical Center, 15,153 consecutive patients were assessed at two time periods: 2006-2012 and 2012-2018. AKI was defined as either a relative elevation of ≥25% in serum creatinine or an absolute elevation of ≥0.5 mg/dl in serum creatinine at 48 h post PCI.

RESULTS

Data for 7913 patients from 2006 to 2012 and 7240 during 2012-2018 was available for analysis. Mean age was 65.0 ± 11.9y and 66.0 ± 12.3y (p < 0.001) and baseline creatinine was 1.08 ± 0.87 mg/dl and 1.15 ± 0.97 mg/dl, respectively (p < 0.001). Rates of AKI were 11.1% in the early and 7.3% in the late period (p < 0.001). Following adjustment, risk of AKI was lower in the late period (OR- 0.72; 95% CI 0.61-0.85, p < 0.001). AKI was associated with increased MACE (HR 1.62; 95% CI 1.44-1.82, p < 0.001 for the early period and HR 2.11; 95% CI 1.80-2.46, P < 0.001 for the late period) and death (HR 1.86; 95% CI 1.64-2.11, p < 0.001; HR 2.4; 95% CI 2.02-2.86; p < 0.001) in both time periods.

CONCLUSIONS

Over time, there was an improvement in the rates of post-PCI AKI. Increased adverse outcomes were evident at both periods. Further research is warranted, to further reduce peri-procedural AKI which is associated with impaired prognosis.

Elevated D-dimers and lack of anticoagulation predict PE in severe COVID-19 patients

Background

Coronavirus disease 2019 (COVID-19) may predispose to venous thromboembolism. We determined factors independently associated with computed tomography pulmonary angiography (CTPA)-confirmed pulmonary embolism (PE) in hospitalised severe COVID-19 patients.

Methods

Among all (n=349) patients hospitalised for COVID-19 in a university hospital in a French region with a high rate of COVID-19, we analysed patients who underwent CTPA for clinical signs of severe disease (oxygen saturation measured by pulse oximetry ≤93% or breathing rate ≥30 breaths·min⁻¹) or rapid clinical worsening. Multivariable analysis was performed using Firth penalised maximum likelihood estimates.

Results

162 (46.4%) patients underwent CTPA (mean±sd age 65.6±13.0 years; 67.3% male (95% CI 59.5–75.5%). PE was diagnosed in 44 (27.2%) patients. Most PEs were segmental and the rate of PE-related right ventricular dysfunction was 15.9%. By multivariable analysis, the only two significant predictors of CTPA-confirmed PE were D-dimer level and the lack of any anticoagulant therapy (OR 4.0 (95% CI 2.4–6.7) per additional quartile and OR 4.5 (95% CI 1.1–7.4), respectively). Receiver operating characteristic curve analysis identified a D-dimer cut-off value of 2590 ng·mL⁻¹ to best predict occurrence of PE (area under the curve 0.88, p<0.001, sensitivity 83.3%, specificity 83.8%). D-dimer level >2590 ng·mL⁻¹ was associated with a 17-fold increase in the adjusted risk of PE.

Conclusion

Elevated D-dimers (>2590 ng·mL⁻¹) and absence of anticoagulant therapy predict PE in hospitalised COVID-19 patients with clinical signs of severity. These data strengthen the evidence base in favour of systematic anticoagulation, and suggest wider use of D-dimer guided CTPA to screen for PE in acutely ill hospitalised patients with COVID-19.

We studied predictors of pulmonary embolism in severe COVID-19 and found that D-dimer level and lack of any anticoagulant therapy were associated with a 17-fold and four-fold increase in PE, respectively, in COVID-19 patients with clinical signs of severityhttps://bit.ly/2ETfAfo

A novel risk assessment model of contrast-induced nephropathy after percutaneous coronary intervention in patients with diabetes

The purpose of our study was to develop a simple clinical pre-procedure risk model based on clinical characteristics for the prediction of contrast-induced nephropathy (CIN) and major adverse cardiac events (MACEs) after percutaneous coronary intervention (PCI) in patients with diabetes. A total of 1113 patients with diabetes who underwent PCI with contrast exposure were randomized into a development group (n = 742) and a validation group (n = 371) in a 2:1 ratio. CIN was defined as an increase of either 25% or 0.5 mg/dL (44.2 μmol/L) in serum creatinine within 72 hours after contrast infusion. A simple CIN risk score based on independent predictors was established. Four variables were identified for our risk score model: LVEF < 40%, acute coronary syndrome (ACS), eGFR < 60, and contrast volume > 300 mL. Based on this new CIN risk score, the incidence of CIN had a significant trend with increased predicting score values of 5.9%, 32.9% and 60.0%, corresponding to low-, moderate- and high-risk groups, respectively. The novel risk assessment exhibited moderate discrimination ability for predicting CIN, with an AUC of 0.759 [95% CI 0.668-0.852, P = .001] in the validation cohort. It also had similar prognostic values for one-year follow-up MACE (C-statistic: 0.705 and 0.606 for new risk score and Mehran score, respectively). This novel risk prediction model could be effective for preventing nephropathy in diabetic patients receiving contrast media during surgical procedures.

Hepatocyte Growth Factor Mimetic ANG-3777 for Cardiac Surgery-Associated Acute Kidney Injury

Introduction

Nearly one-third of patients undergoing cardiac surgery involving cardiopulmonary bypass (CPB) experience cardiac surgery–associated (CSA) acute kidney injury (AKI); 5% require renal replacement therapy. ANG-3777 is a hepatocyte growth factor mimetic. In vitro, ANG-3777 reduces apoptosis and increases cell proliferation, migration, morphogenesis, and angiogenesis in injured kidneys. In animal models, ANG-3777 mitigates the effects of renal damage secondary to ischemia reperfusion injury and nephrotoxic chemicals. Phase 2 data in AKI of renal transplantation have shown improved renal function and comparable safety relative to placebo. The Guard Against Renal Damage (GUARD) study is a phase 2 proof of concept trial of ANG-3777 in CSA-AKI.

Methods

GUARD is a 240-patient, multicenter, double-blind, randomized placebo-controlled trial to assess the efficacy and safety of ANG-3777 in patients at elevated pre-surgery risk for AKI undergoing coronary artery bypass graft (CABG) or heart valve repair/replacement requiring CPB. Subjects are randomized 1:1 to receive ANG-3777 (2 mg/kg) or placebo. Study drug is dosed via 4 daily intravenous 30-minute infusions. The first dose is administered less than 4 hours after completing CPB, second at 24 ± 2 hours post-CPB, with two subsequent doses at 24 ± 2 hours after the previous dose.

Results

The primary efficacy endpoint is percent change from baseline serum creatinine to mean area under the curve from days 2 through 6. Secondary endpoints include change in estimated glomerular filtration rate from baseline to day 30, the proportion of patients diagnosed with AKI by stage through day 5, and the length of CSA-AKI hospitalization. Safety will include adverse events and laboratory measures.

Conclusion

This phase 2 study of ANG-3777 provides data to develop a phase 3 registrational study in this medically complex condition.

Impact of renal function on patients with acute coronary syndromes: 15,593 patient-years study

Introduction

Coexistence of chronic kidney disease (CKD) in the case of acute coronary syndromes (ACS) significantly worsens the outcomes.

Aim

The aim of our study was to assess renal function impact on mortality among patients with ACS.

Materials and methods

The study was based on records of 21,985 patients hospitalized in the Medical University of Bialystok in 2009–2015. Inclusion criteria were ACS. Exclusion criteria were: death within 24 h of admission, eGFR <15 ml/min/1.73 m², hemodialysis. Mean observation time was 2296 days.

Results

Criteria were met by 2213 patients. CKD occurred in 24.1% (N = 533) and more often affected those with NSTEMI (26.2 (337) vs. 21.2 (196), p = .006). STEMI patients had higher incidence of post-contrast acute kidney injury (PC-AKI) (5 (46) vs. 4.1 (53), p < .001). During the study, 705 people died (31.9%), more often with NSTEMI (33.2% (428) vs. 29.95% (277), p < .001). However, from a group of patients suffering from PC-AKI 57.6% died. The risk of PC-AKI increased with creatinine concentration (RR: 2.990, 95%CI: 1.567–5.721, p < .001), occurrence of diabetes mellitus (RR: 2.143, 95%CI: 1.029–4.463, p = .042), atrial fibrillation (RR: 2.289, 95%CI: 1.056–4.959, p = .036). Risk of death was greater with an increase in postprocedural creatinine concentration (RR: 2.254, 95%CI: 1.481–3.424, p < .001).

Conclusion

PC-AKI is a major complication in patients with ACS, occurs more frequently in STEMI and may be a prognostic marker of long-term mortality in patients undergoing percutaneous coronary intervention (PCI). More attention should be given to the prevention and diagnosis of PC-AKI but necessary PCI should not be withheld in fear of PC-AKI.

Association between contrast-induced nephrotoxicity and contrast enhanced computed tomography followed by endoscopic retrograde cholangiopancreatography

PURPOSE

To determine if endoscopic retrograde cholangiopancreatography (ERCP) performed within 72 h after contrast enhanced computed tomography (CECT) increases contrast-induced nephrotoxicity (CIN) risk in patients with abdominal complaints.

METHOD

This single-center retrospective cohort study included consecutive adult patients with abdominal complaints who underwent CECT between October 1, 2016, and June 30, 2019 at an emergency department (ED). CIN was diagnosed based on serum creatinine (SCr) level >0.5 mg/dL within 72 h after CECT or that increased >25 % compared to pre-CECT level. Logistic regression analysis was performed to determine independent risk factors for CIN, including age, sex, body mass index, comorbidities, medication, pre-CECT SCr level >1.5 mg/dL, and ERCP performed within 72 h after CECT. For persistent CIN, SCr level was obtained after 3 months at the earliest and compared to data obtained within 72 h after ERCP and CECT.

RESULTS

Of 1457 patients with CECT, 90 (6.2 %) underwent ERCP within 72 h after CECT and 93 (6.4 %) developed CIN. Multivariate analysis revealed that ERCP performed within 72 h after CECT (odds ratio, 3.31; 95 % confidence interval, 1.74, 6.29; p < 0.001) and pre-CECT SCr level >1.5 mg/dL (odds ratio, 9.86; 95 % confidence interval, 5.08, 19.2; p < 0.001) were independent risk factors for CIN. Of 93 patients with CIN, 10 (11 %) had persistent CIN. No specific factors were correlated with persistent CIN in the 3-month time frame.

CONCLUSION

ERCP performed within 72 h after CECT and pre-CECT SCr level >1.5 mg/dL are associated with CIN development.

Incidence of contrast-induced acute kidney injury (CI-AKI) in high-risk oncology patients undergoing contrast-enhanced CT with a reduced dose of the iso-osmolar iodinated contrast medium iodixanol

Objectives

To determine the incidence of post-contrast acute kidney injury (PC-AKI) and presumed contrast-induced acute kidney injury (CI-AKI) following contrast-enhanced CT (CECT) with intravenous application of a reduced dose of the iso-osmolar contrast agent iodixanol in cancer patients with chronic kidney disease.

Methods

198 oncology patients with a baseline estimated glomerular filtration rate (eGFR) <60ml/min/1.73m² undergoing a total of 237 CECTs using a reduced dose of 60ml iodixanol were retrospectively analyzed. Statistical analysis was performed for the entire cohort and subgroups. The effect of additional risk factors on the occurrence of PC-AKI was evaluated.

Results

The overall PC-AKI incidence was 6.3%. Excluding patients with concurrent medical conditions known to directly and independently impact kidney function and patients with AKI preceding the CT-scan resulted in a presumed CI-AKI incidence of 3.8%. No permanent post-contrast worsening of renal function and no AKI treatment were required. Subgroups considering baseline eGFR yielded PC-AKI incidences of 4.6% (eGFR 45-60ml/min/1.73m², n = 130), 7.4% (eGFR 30-45ml/min/1.73m², n = 95) and 16.7% (eGFR <30ml/min/1.73m², n = 12). Additional patient related risk factors did not show any significant effect on the occurrence of PC-AKI.

Conclusions

Low incidences of PC-AKI/CI-AKI suggest that a reduced dose of an iso-osmolar contrast agent is safe in high-risk oncological patients with impaired renal function.

Higher Mortality in Case of Small Left Atrium on Nongated Computed Tomography Pulmonary Angiography Is Associated With the Presence of Malignancy

PURPOSE

The purpose of this study was to evaluate the association between small left atria (LA) according to computed tomography pulmonary angiography (CTPA) and mortality among individuals without pulmonary embolism, and to examine which volumes begin to portend adverse outcomes.

MATERIALS AND METHODS

Left atrial volume indices (LAVIs) of 752 consecutive patients who underwent CTPA, in which pulmonary embolism were ruled out, were measured retrospectively using an automatic 4-chamber volumetric analysis software. Groups of 5 percentiles within the lower quartile were investigated, and the interquartile range (25th to 75th percentiles) was regarded as the control group.

RESULTS

Patients within the lower 25th LAVI percentiles (<33 mL/m2; n=188) were younger and had less cardiovascular morbidities, while malignancies were less common in the control group (LAVI: 33 to 54 mL/m2; n=376). Percentiles 5th to 25th did not demonstrate an independent association with mortality. After adjustment for baseline characteristics, the risk for 30-day and 1-year mortality was 5.6 (95% confidence interval: 2.1-14.8, P=0.001) and 6.1 (95% confidence interval: 2.4-15.1, P<0.001) times higher, respectively, among the lowest five LAVI percentiles (<24 mL/m2) compared with the control group. Among patients with small LA who died within 1 year, 83% had a diagnosis of malignancy. Albeit, only a minority (3%) of patients with malignancies had small LA.

CONCLUSIONS

Individuals undergoing CTPA whose LAVI is within the lowest five percentiles have a markedly increased risk for short-term and long-term mortality. The risk can probably be attributed to an underlying malignancy. The feasibility of 4-chamber volumetric analysis while avoiding a time-consuming process due to the automatic properties enables the introduction of this feature to clinical practice.

Serum levels of neutrophil Gelatinase associated Lipocalin (NGAL) predicts hemodialysis after coronary angiography in high risk patients with acute coronary syndrome

Background

Contrast-induced nephropathy (CIN) following a percutaneous coronary intervention (PCI) is the third most common cause of acute kidney injury (AKI) worldwide. Patients who require hemodialysis secondary to CIN have an elevated mortality rate as high as 55%. The current definition of CIN is based on an elevation of creatinine and decrease in urinary output. Creatinine typically increases 48 h after the contrast exposure, which delays the diagnosis and treatment of CIN. The neutrophil gelatinase associated lipocalin (NGAL) has emerged as a sensitive and specific biomarker of renal injury. Limited data exists about the effectiveness of NGAL to predict CIN in high-risk patients with acute coronary syndrome (ACS) that underwent PCI. The primary aim of this study was to determine the association of serum NGAL levels and the need for hemodialysis after PCI.

Methods

This is a prospective, observational study. NGAL levels were measured using ELISA. Blood samples were obtained within the first 6 h of hospital admission, and 12 and 24 h after contrast exposure from angiography. The primary outcome was the requirement of hemodialysis. The non-parametric Mann-Whitney U test was used to test for differences in median serum levels of NGAL. A receiver operating characteristic (ROC) curve was developed to assess the accuracy of NGAL to predict the need for hemodialysis after PCI.

Results

A total of 2875 were screened; however, 45 patients with ACS that underwent PCI were included. All patients were at high risk of developing CIN defined by Mehran score > 11 points. The median (IQR) serum concentration of NGAL was significantly higher in patients that required versus did not require hemodialysis (340 [83–384] vs. 169 [100–210], p = 0.01). Elevated serum levels of NGAL with a cut-off at 6 h post PCI of 281 mg/dL predicted the need for hemodialysis with an area under the curve of 0.86 (95% CI, 0.66–1.00).

Conclusions

In patients with ACS undergoing PCI; and high risk of developing CIN, an elevated serum level of NGAL 6 h after contrast exposure predicts the development of acute kidney injury requiring hemodialysis.

The conundrum of contrast-induced acute kidney injury

More than sixty years have elapsed since contrast induced nephropathy (CIN) was first described in the medical literature. This term has since been extensively explored, with a variety of studies conducted to investigate its incidence and various mechanisms examined to explain its pathophysiology. However, the topic of CIN remains one of controversy with a widely variable and often questionable incidence derived from various studies. The past two decades have seen a surge in reports questioning the existing of CIN altogether and if more harm is actually being caused to patients out of fear of this potential complication. We have attempted to review relevant studies regarding CIN and highlight the key points of its surmised understanding. The review has a higher focus on more recent literature and updates, in order to determine if an accurate estimate can be made on the incidence of CIN. While there was certainly no lack of material available, practically all the studies reviewed were limited by one or more significant drawbacks that limited the reliability of their conclusions regarding CIN. Based on the information reviewed, the strengths and the flaws encountered in other studies can be used to design a randomized control trial that may help in concluding the longstanding debate on this topic. However due to time, financial, and perhaps even ethical constraints such a trial will be difficult to arrange, and so a definitive answer on CI-AKI, and whether it really exist, may continue to elude clinicians.

Contrast-induced Acute Kidney Injury

Contrast-induced acute kidney injury (CI-AKI) is the third common cause of kidney injury in hospitalized patients. It describes a wide spectrum of kidney injury from mild and reversible to permanent and irreversible. The mechanism of contrast-induced AKI and strategies to prevent it are not clearly understood. This review discusses the various contrast agents, pathophysiology of CI-AKI and different preventive strategies.

HOW TO CITE THIS ARTICLE

Ramachandran P, Jayakumar D. Contrast-induced Acute Kidney Injury. Indian J Crit Care Med 2020;24(Suppl 3):S122-S125.

The effect of time between angiography and coronary artery bypass grafting on postoperative acute kidney injury in patients with diabetes mellitus

Background

This study aims to investigate the effect of time interval between coronary angiography and coronary artery bypass grafting surgery on postoperative acute kidney injury in patients with diabetes mellitus.

Methods

Between December 2013 and November 2016, a total of 421 diabetic patients (274 males, 147 females; mean age 60±9.2 years; range, 31 to 84 years) who underwent coronary artery bypass grafting were included in the study. Data including demographic characteristics of the patients, comorbidities, medical, and surgical histories, previous coronary angiographies, and operative and laboratory results were retrospectively analyzed. The patients were divided into two groups as those with acute kidney injury (n=108) and those without acute kidney injury (n=313). The Risk, Injury, Failure, Loss, End-Stage Kidney Disease (RIFLE) criteria were used to define acute kidney injury. The patients were further classified into three subgroups according to the time interval: 0-3 days, 4-7 days, and >7 days.

Results

There was no statistically significant difference in the median time between coronary angiography and coronary artery bypass grafting between the patients with and without acute kidney injury (11.5 and 12.0 days; respectively p=0.871). There was no significant difference in the risk factors for acute kidney injury among the subgroups. Multivariate analysis revealed that previous myocardial infarction (odds ratio [OR]: 5.192, 95% confidence interval [CI]: 2.176-12.38; p<0.001) and the increase in the creatinine levels in the first postoperative day (OR: 4.102 and 95% CI: 1.278- 13.17; p=0.018) were independent predictors of acute kidney injury.

Conclusion

Coronary artery bypass grafting can be performed without any delay after coronary angiography without an increase in the postoperative risk of acute kidney injury in patients with diabetes mellitus.

tert-Butylhydroquinone Treatment Alleviates Contrast-Induced Nephropathy in Rats by Activating the Nrf2/Sirt3/SOD2 Signaling Pathway

Oxidative stress plays a critical role in the pathophysiology of contrast-induced nephropathy (CIN). Since the specific treatment of CIN remains an unmet medical need, it is imperative to find an effective strategy against the clinical management of CIN. The transcription factor Nrf2 is known to regulate antioxidative stress response. The aim of the present study was to assess the effects of tert-butylhydroquinone (t-BHQ), an activator of Nrf2, in the prevention of CIN and elucidate the underlying mechanism of its action in vitro and in vivo. We established a rat model of CIN and treated the animals with t-BHQ (25 mg/kg). The effects of t-BHQ treatment on CIN rats were elucidated by assessing renal function, HE staining, immunohistochemistry, and western blotting. We also studied the activity of oxidative stress-related markers, such as intracellular ROS level, MDA level, SOD2 activity, and GSH/GSSG ratio. We validated our results by siRNA-mediated silencing of Nrf2 in HK-2 cells exposed to the radiocontrast agent. Treatment with t-BHQ significantly ameliorated the renal function and the histopathological lesions in CIN rats. Further, pretreatment with t-BHQ significantly increased the SOD2 activity and GSH/GSSG ratio and decreased the levels of ROS and MDA in animals subjected to ioversol exposure. In addition, t-BHQ treatment increased the expression of Nrf2, Sirt3, and SOD2 and concomitantly decreased the expression of acetylated-SOD2. When Nrf2-silenced HK-2 cells were exposed to radiocontrast agent, they suffered severe cell oxidative stress, exhibited lower expression of Sirt3 and SOD2, and expressed higher levels of acetylated-SOD2; however, t-BHQ treatment did not affect the protein expression of these indicators in si-Nrf2 HK-2 cells. Our findings suggested that Nrf2 plays an important role in the regulation of the Sirt3/SOD2 antioxidative pathway, and t-BHQ may be a potential agent to ameliorate radiocontrast-induced nephropathy via activating the Nrf2/Sirt3/SOD2 signaling pathway in vitro and in vivo.

Risk factors and safe contrast volume thresholds for postcontrast acute kidney injury after peripheral vascular interventions

OBJECTIVE

Postcontrast acute kidney injury (PC-AKI) is a dreaded complication of peripheral vascular interventions (PVIs) that depends on the volume of contrast administered as well as a patient's baseline kidney function. However, there is currently no guidance on the volume of contrast that is considered safe especially for patients with advanced chronic kidney disease (CKD). This study aims to characterize the incidence, risk factors for, and outcomes after PC-AKI and define thresholds of safety for contrast volume.

METHODS

The Vascular Quality Initiative files for PVI (2010-2018) were reviewed. Patients on dialysis, with renal transplants, or who developed a bleeding complication were excluded. Only records with complete data on baseline creatinine, contrast volume, and PC-AKI (creatinine increase of ≥0.5 mg/dL, or new dialysis requirement) were included. The cumulative incidence of PC-AKI with contrast volume at each stage of CKD was derived. A safe threshold for contrast volume was defined as the volume at which the cumulative incidence of PC-AKI is 0.5% or less. Multivariable logistic regression was used to define risk factors for PC-AKI, and survival analysis was performed using Kaplan-Meier and multivariable Cox proportional hazards regression.

RESULTS

A total of 53,780 procedures were included. There were 16,062 patients (29%) with normal kidney function or CKD1, 21,769 (39%) with CKD2, 14,234 (25%) with CKD3, 1471 (3%) with CKD4, and 199 (<1%) with CKD5. The incidence of PC-AKI was 0.9% and increased with each stage of CKD (CKD1, 0.39%; CKD2, 0.45%; CKD3, 1.5%; CKD4, 4.3%; and CKD5, 7.5%). The safe thresholds for contrast volume for advanced CKD were 50, 20, and 9 mL for CKD3, CKD4, and CKD5, respectively. Regression analysis demonstrated that white race (odds ratio [OR], 0.67; 95% confidence interval [CI], 0.54-0.82) and elective surgery (OR, 0.77; 95% CI, 0.62-0.95) were associated with decreased risk of PC-AKI, whereas inpatient status (OR, 14.5; 95% CI, 9.97-21.2), diabetes (OR, 1.27; 95% CI, 1.02-1.58), advanced CKD (CKD3: OR, 3.65; 95% CI, 2.68-4.98; CKD4: OR, 6.98; 95% CI, 4.72-10.3; CKD5: OR, 8.94; 95% CI, 4.53-17.6), critical limb ischemia (OR, 1.51; 95% CI, 1.14-2.00), acute limb ischemia (OR, 2.47; 95% CI, 1.70-3.59), and contrast-to-eGFR ratio (CGR) (2 ≤ CGR < 3: OR, 1.33; 95% CI, 1.02-1.74; 3 ≤ CGR < 4: OR, 1.90; 95% CI, 1.32-2.75; CGR ≥ 4: OR, 1.79; 95% CI, 1.18-2.70) were significantly associated with increased risk for PC-AKI. Patients who developed PC-AKI had worse in-hospital (16.1% vs 0.45%; P < .01) mortality and long-term survival (log-rank P < .01) compared with those without PC-AKI.

CONCLUSIONS

PVI are associated with low risk of PC-AKI that significantly increases when patients with advanced CKD undergo high acuity cases. Given the strong association with short-term and long-term mortality, risk of PC-AKI should be minimized by using safe thresholds of contrast volume.

Implementation of patient-tailored contrast volumes based on body surface area and heart rate harmonizes contrast enhancement and reduces contrast load in small patients in portal venous phase abdominal CT

PURPOSE

The aim of this study was to evaluate the impact of a patient-tailored contrast volume protocol on portal venous phase abdominal CT-images compared to a fixed volume protocol in daily radiological practice.

METHOD

Data of 77 patients who underwent two contrast-enhanced CT-examinations were collected. The first examination was performed with a fixed contrast volume (95 ml), the follow-up examination was performed with a patient-tailored contrast volume based on patient's BSA and heart rate. The patient-tailored volume was calculated by a software application integrated in the interface of the injection pump. Two independent radiologists assessed subjective and objective image quality. Differences in enhancement and contrast volumes between both protocols were analysed.

RESULTS

Despite a significant contrast volume reduction in women and in patients with low to normal BMI, enhancement was more consistent over different BMI-categories in the patient-tailored contrast volume protocol and there was no significant difference in subjective image quality between both injection protocols.

CONCLUSIONS

A patient-tailored contrast volume protocol based on BSA and heart rate can be considered in daily radiological practice to decrease contrast volumes in women and in low to normal BMI patients and to achieve more consistent contrast enhancement across different BMI-categories in venous phase abdominal CT.

Adenosine antagonists for prevention of contrast-induced nephropathy: A meta-analysis of randomized controlled trials with trial sequential analysis

Contrast-induced nephropathy (CIN) is caused by intravascular administration of contrast agent. The efficacy of adenosine antagonists (AAs) in preventing CIN remains controversial, and its elucidation was the objective of the present meta-analysis. A trial sequential analysis (TSA) to assess the reliability of the pooled results was also performed. The Medline, Embase, Web of Science and Cochrane databases were searched to retrieve all published randomized controlled trials (RCTs) comparing AAs with controls in preventing CIN. Heterogeneity, publication bias and quality of studies were assessed. Sensitivity, cumulative and subgroup analyses were also performed. The risk of random errors was evaluated by TSA. A total of 17 trials with 1,483 subjects were included. Pooled results indicated that AAs significantly reduced the incidence of CIN [risk ratio, 0.53; 95% confidence interval (CI), 0.29-0.95; P=0.034] and the serum creatinine (SCr) level after contrast media (CM) administration (standardized mean difference, -0.24; 95% CI, -0.44 to -0.04; P=0.019). Meta-regression did not identify any significant source of heterogeneity. In the subgroup analyses, AAs tended to exhibit a greater prevention efficacy in trials with sample sizes of ≥70, baseline SCr of <1.5 mg/dl and low study quality. TSA on the incidence of CIN indicated that the required information size determined as n=1,778 was not reached, and that the cumulative Z-curve did not cross the TSA boundary. In conclusion, the present meta-analysis of data from current RCTs suggested that AAs reduce the incidence of CIN and the SCr levels after CM administration. However, TSA showed that the risk of having a false-positive result was greater than 5% in the meta-analysis of the incidence of CIN, indicating that more evidence is required to ensure the benefit of AAs in preventing CIN.

Long-term outcome of biopsy-proven cholesterol crystal embolism

BACKGROUND

Cholesterol crystal embolism (CCE) causes renal damage, and there is an extremely high risk of end-stage renal disease. However, the time course of CCE-related renal deterioration varies and little is known about the subsequent risk of dialysis among patients with biopsy-proven CCE.

METHODS

We performed a retrospective cohort study of 38 Japanese patients in whom a histological diagnosis of CCE was made from September 1992 to July 2005. Competing risk regression analysis was used to investigate the association between declining renal function ( ≥ 1.5 elevation of serum creatinine within 26 weeks after CCE) or its subtypes (acute [ < 1 week after CCE], subacute [1 to < 6 weeks], and chronic [6 to < 26 weeks]) and the risk of dialysis, with adjustment for age, baseline serum creatinine, and the precipitating event (iatrogenic or spontaneous).

RESULTS

During a median follow-up period of 25.9 weeks, 14 patients (35.9%) started dialysis. Multivariable analysis showed that patients with declining renal function had a higher risk of commencing dialysis than those without declining function (subdistribution hazard ratio [SHR] 9.47; 95% confidence interval [CI] 1.34-66.8). Patients with different renal presentations had a similarly increased risk of commencing dialysis, with the risk being significantly higher for the subacute and chronic patterns of declining renal function (adjusted SHR [95% CI] for acute, subacute, and chronic declining renal function[vs. no decline]: 7.36 [0.85-63.6], 11.9 [1.36-101], and 10.7 [1.49-77.0], respectively).

CONCLUSION

Declining renal function after CCE, even later than 6 weeks, was significantly associated with the subsequent risk of dialysis.

Allopurinol Administration for the Prevention of Contrast-Induced Nephropathy: A Network Meta-analysis With Trial Sequential Analysis

Contrast-induced nephropathy represents a major source of morbidity in patients undergoing coronary angiography. Various preventive measures have been proposed, although the optimal one remains still unknown. The aim of the present meta-analysis is to accumulate current literature knowledge and evaluate the renoprotective effects of allopurinol administration before contrast medium exposure. To achieve this, MEDLINE, Scopus, Cochrane Central Register of Controlled Trials, Clinicaltrials.gov, and Google Scholar databases were searched from inception to November 8, 2018. Statistical meta-analysis was conducted with Review Manager 5.3, TSA 0.9.5.5 and R-3.4.3. Six studies were included with a total of 918 patients. Quantitative synthesis revealed that allopurinol leads to significantly reduced incidence of contrast-induced nephropathy compared with hydration alone [odds ratio: 0.29, 95% confidence interval: (0.09-0.90)]. Trial sequential analysis suggested that Z-curve crossed the O'Brien-Fleming significance boundaries, although required information size was not reached. Network meta-analysis indicated that allopurinol had the highest probability (81.2%) to rank as the most effective intervention compared with hydration and N-acetyl cysteine; however, significant overlap with the rest treatments was noted. In conclusion, the present meta-analysis suggests that allopurinol may represent a promising measure for the prevention of acute kidney injury after coronary angiography. Future large-scale randomized controlled trials should verify this finding, while combinations of allopurinol with other novel interventions should be evaluated to define the most effective strategy to be implemented in the clinical setting.

Alpha-tocopherol and contrast-induced nephropathy: A meta-analysis of randomized controlled trials

Background: Contrast-induced nephropathy (CIN) is a relevant cause of acute renal dysfunction and is associated with an increased morbidity and mortality. Purpose: Verify the effect of α-tocopherol pre-treatment on CIN prevention in subjects with chronic kidney disease. Methods: A Medline/Embase and clinicaltrials.gov were searched up to May 1st, 2017. Randomized controlled trials recruiting patients undergoing diagnostic or therapeutic radiocontrast infusion comparing the effect of either oral or i.v. multiple administration of pharmacological dose of α-tocopherol in preventing CIN versus placebo were included. A random-effects model, calculating Mantel-Haenszel odds ratio with 95% confidence interval, was applied to study the effect of α-tocopherol on CIN occurrence. Funnel plot analysis was used to assess publication bias, while agreement within studies was measured by the I² index and tested with the Q-Cochran test. Results: Out of 242 studies, 4 trials were selected. CIN incidence resulted significantly lower in α-tocopherol compared to placebo group (5.8% vs. 15.4%, MH-OR [95% C.I.] 0.34 [0.19 - 0.59]). Alpha-tocopherol treatment was associated with both a tendential higher eGFR (mean difference 2.19 [95% C.I. -0.41; 4.79] mL/min) and lower creatinine level (mean difference -0.06 [95% C.I. -0.21; 0.09] mg/dl) compared to placebo. No relevant publication bias (p = 0.48) and heterogeneity (I² = 0%; χ² = 1.01, df = 3 [p = 0.80], I² = 0%) were evident. Conclusions: Alpha-tocopherol pre-treatment is associated with reduction of incidence of CIN. Its administration deserves to be further explored as a simple and inexpensive tool for CIN prevention.

Low free triiodothyronine is associated with contrast-induced acute kidney injury and long-term outcome in elderly patients who underwent percutaneous coronary intervention

Objective:

Low free triiodothyronine (fT₃) is common in elderly patients with cardiovascular disease. The purpose of this study was to evaluate the relationship between low fT₃ and contrast-induced acute kidney injury (CI-AKI), including the long-term outcomes, in elderly patients after a percutaneous coronary intervention (PCI).

Methods:

A total of 350 patients aged ≥75 years who underwent PCI between January 2012 and December 2015 were consecutively enrolled. The perioperative thyroid function, including fT₃, was measured before PCI. A low fT₃ was defined as fT₃ <3.1 pmol/L with normal thyrotropin and free thyroxine. CI-AKI was defined as an absolute serum creatinine (SCr) increase ≥0.30 mg/dL or a relative increase in SCr ≥50% from the baseline value within 48 hours after contrast media exposure. A multivariate logistic regression analysis was applied to analyze whether low fT₃ was an independent risk factor for CI-AKI. The Cox regression analysis was used to evaluate the relationship between low fT₃ and long-term prognosis.

Results:

A total of 46 (13.1%) patients developed CI-AKI. The incidence of CI-AKI was significantly higher in the low fT₃ group than in the normal group (26.5% vs. 9.9%, p<0.01). A multivariable logistic analysis demonstrated that a low fT₃ level was significantly related to CI-AKI [odds ratio (OR)=2.41; 95% confidence interval (CI), 1.11–5.27; p=0.027]. The Cox regression analysis showed that a low fT₃ was associated with long-term mortality [adjusted hazard ratio (HR)=2.00; 95% CI, 1.04–3.83; p=0.037] during the follow-up of mean 1.67 years.

Conclusion:

A low fT₃ concentration was independently associated with CI-AKI and poor prognosis in elderly patients who had undergone PCI.

Periprocedural Concerns in the Patient with Renal Disease

Treating patients with kidney disease can be both a difficult and a complex process. Understanding how to care for patients who have kidney disease is essential for lowering perioperative as well as periprocedural morbidity and mortality. The primary aim in renal evaluation and care is to control and mitigate factors that may result in acute kidney injury (AKI) and/or cause further decline in renal function. It is essential for the foot and ankle specialist to recognize patients who are predisposed to developing or already have impairment of renal function.

Shortening Hospital Stay Is Feasible and Safe in Patients With Chronic Thromboembolic Pulmonary Hypertension Treated With Balloon Pulmonary Angioplasty

BACKGROUND

There is no consensus on the length of hospital stay (LOHS) and post-interventional management after balloon pulmonary angioplasty (BPA) in patients with chronic thromboembolic pulmonary hypertension (CTEPH). We examined temporal trends with respect to LOHS and requirement for intensive care for BPA and their relationship with the incidence of BPA-related complications.

METHODS

From November 2012 to September 2017, a total of 123 consecutive patients with CTEPH who underwent BPA were enrolled (age: 66.0 [54.0 to 74.0], World Health Organization [WHO] functional class II/III/IV; 27/88/8). Patients were divided for analysis into 3 groups according to the date of their first BPA: early-, middle-, and late-phase groups.

RESULTS

Mean pulmonary arterial pressure decreased from 36.0 (29.0 to 45.0) to 20.0 (16.0 to 22.0) mm Hg after BPA (P < 0.001). The LOHS was 41.0 (31.0 to 54.0) days in total including all sessions and 6.6 (6.0 to 7.9) days/session. Despite no significant differences in age, baseline hemodynamics, and laboratory data among the 3 groups, there was a significant reduction in LOHS (7.9 [7.0 to 9.5], 6.5 [6.1 to 7.3], 6.0 [5.3 to 6.5] days/session, P < 0.001) and use of intensive/high care unit (100%, 93%, 46%, P < 0.001). The reduction in LOHS and intensive/high care unit use did not affect the occurrence of BPA-related complications.

CONCLUSIONS

Increasing experience with BPA was associated with a reduction in LOHS and the use of intensive/high care unit, but no change was noted in the rate of BPA-related complications. These findings suggest that the reduction in both LOHS and use of the intensive care unit for BPA is feasible and does not jeopardize the safety of the procedure.

Influence of symptomatic pseudoaneurysms on postoperative renal function after partial nephrectomy: results of a matched pair analysis

PURPOSE

A symptomatic pseudoaneurysm (SPA) is a rare but severe complication after partial nephrectomy (PN). Selective trans-arterial embolization (TAE) is the treatment of choice with high success rates. However, the influence of this intervention on postsurgical renal function has not been studied.

METHODS

Between 2005 and 2016 we performed 1047 PNs at our institution. Postsurgical SPA occurred in 40 patients (3.8%). Patients with and without SPA were matched in a 1:2 ratio concerning tumor complexity (RENAL) and pre-operative renal function (CKD stage). Any CKD upstage and a relevant CKD progression (CKD ≥ III) were defined as endpoints. Furthermore, the influence of the amount of contrast agent applied during TAE was assessed.

RESULTS

All patients with SPA were treated successfully with TAE. No significant difference could be detected concerning clinical, functional and surgical aspects. Median follow-up time accounted for 12.5 (6.75-27.5) months. Kaplan-Meier analyses detected an increased rate of any CKD upstage (p = 0.066) and relevant CKD progression (p = 0.01) in patients with SPA. Multivariate analysis identified post-operative SPA to be an independent predictor for a relevant CKD progression (HR 4.15, p = 0.01). The amount of contrast agents used did not have an impact on the development of a relevant CKD progression (p = 0.72).

CONCLUSION

Patients treated with TAE after PN show an additional risk for an impairment of renal function over time. Hence, those patients should explicitly be informed about possible consequences and closely monitored by nephrologists.

Involvement of organic cation transporter 2 in the metformin-associated increased lactate levels caused by contrast-induced nephropathy

The application of iodinated contrast medium has become a risk factor for metformin-associated lactic acidosis (MALA), which leads to the accumulation of metformin in vivo is one of the principal reasons for MALA. However, the molecular mechanism of the adverse event is not yet clear. In this study, iohexol injection was used as a model drug. The contrast agent acute kidney injury rat model, in vivo rat pharmacokinetic study, kidney slices and HK-2 cells were performed to elucidate the pharmacokinetic molecular mechanism of accumulation of metformin caused by contrast-induced nephropathy (CIN). Plasma exposure of metformin was increased significantly in the CIN group compared with that in the normal and control groups. The AUC of metformin was from 2791 ± 382 μg min mL-1 to 4784 ± 767 μg min mL-1. The cumulative urinary excretion of metformin was also reduced in the CIN group. The uptake of metformin decreased in kidney slices in the CIN group. Compared with the normal and control groups, the blood lactate concentration was increased after intravenous administration of metformin in the CIN group followed a similar trend to the plasma concentrations of metformin. After treatment with contrast medium, the expression of OCT2 was reduced in rat kidney and HK-2 cells. These findings highlight that OCT2 deficiency was associated with increased lactate levels during metformin treatment caused by CIN.

Safety Lapses Prior to Initiation of Hemodialysis for Acute Kidney Injury in Hospitalized Patients: A Patient Safety Initiative

Background: Safety lapses in hospitalized patients with acute kidney injury (AKI) may lead to hemodialysis (HD) being required before renal recovery might have otherwise occurred. We sought to identify safety lapses that, if prevented, could reduce the need for unnecessary HD after AKI; Methods: We conducted a retrospective observational study that included consecutive patients treated with HD for AKI at a large, tertiary academic center between 1 September 2015 and 31 August 2016. Exposures of interest were pre-specified iatrogenic processes that could contribute to the need for HD after AKI, such as nephrotoxic medication or potassium supplement administration. Other outcomes included time from AKI diagnosis to initial management steps, including Nephrology referral; Results: After screening 344 charts, 80 patients were included for full chart review, and 264 were excluded because they required HD within 72 h of admission, were deemed to have progression to end-stage kidney disease (ESKD), or required other renal replacement therapy (RRT) modalities in critical care settings such as continuous renal replacement therapy (CRRT) or sustained low efficiency dialysis (SLED). Multiple safety lapses were identified. Sixteen patients (20%) received an angiotensin converting enzyme inhibitor or angiotensin receptor blocker after AKI onset. Of 35 patients with an eventual diagnosis of pre-renal AKI due to hypovolemia, only 29 (83%) received a fluid bolus within 24 h. For 28 patients with hyperkalemia as an indication for starting HD, six (21%) had received a medication associated with hyperkalemia and 13 (46%) did not have a low potassium diet ordered. Nephrology consultation occurred after a median (IQR) time after AKI onset of 3.0 (1.0⁻5.7) days; Conclusions: Although the majority of patients had multiple indications for the initiation of HD for AKI, we identified many safety lapses related to the diagnosis and management of patients with AKI. We cannot conclude that HD initiation was avoidable, but, improving safety lapses may delay the need for HD initiation, thereby allowing more time for renal recovery. Thus, development of automated processes not only to identify AKI at an early stage but also to guide appropriate AKI management may improve renal recovery rates.

Proenkephalin for the early detection of acute kidney injury in hospitalized patients with chronic kidney disease

BACKGROUND

The early detection of acute kidney injury (AKI) in patients with chronic kidney disease (CKD) is an unmet clinical need. Proenkephalin (PENK) might improve the early detection of AKI.

METHODS

One hundred and eleven hospitalized CKD patients undergoing radiographic contrast procedures were enrolled. PENK was measured in a blinded fashion at baseline (before contrast media administration) and on day 1 (after contrast media administration). The potential of PENK levels to predict contrast-induced AKI was the primary endpoint.

RESULTS

Baseline creatinine and baseline PENK were similar in AKI and no-AKI patients. In AKI patients, day 1 PENK (198 pmol/L vs 121 pmol/L, P < 0.01) was significantly higher compared to no-AKI patients. The area under the curve (AUC) for the prediction of AKI by day 1 PENK was 0.79, 95% CI: 0.70-0.87, similar to serum creatinine: 0.78, 95% CI: 0.61-0.95. Delta PENK was significantly higher in AKI compared to no-AKI patients (53 pmol/L vs 1 pmol/L, P < 0.01). The AUC for the prediction of AKI by delta PENK was high (0.92, 95%CI 0.82-1.00) and remained high for creatinine-blind AKI (0.94, 95% CI: 0.87-0.97).

CONCLUSION

Delta PENK levels improve the early detection of contrast-induced AKI in CKD patients over serial creatinine sampling. Delta PENK accelerates the detection of creatinine-blind AKI by 24 hours.

Tailoring protocols for chest CT applications: when and how?

In the medical era of early detection of diseases and tailored therapies, an accurate characterization and staging of the disease is pivotal for treatment planning. The widespread use of computed tomography (CT)-often with the use of contrast material (CM)-probably represents the most important advance in diagnostic radiology. The result is a marked increase in radiation exposure of the population for medical purposes, with its intrinsic carcinogenic potential, and CM affecting kidney function. The radiologists should aim to minimize patient's risk by reducing radiation exposure and CM amount, while maintaining the highest image quality. To achieve this goal, it is necessary to perform "patient-centric imaging". The purpose of this review is to provide radiologists with "tips and tricks" to control radiation dose at CT, summarizing technical artifices in order to reduce image noise and increase image contrast. Also chest CT tailored protocols are supplied, with particular attention to three most common thoracic CT protocols: aortic/cardiac CT angiography (CTA), pulmonary CTA, and routine chest CT.

Contrast-Induced Nephropathy: Update on the Use of Crystalloids and Pharmacological Measures

Contrast-induced nephropathy (CIN) is a frequent and severe complication in subjects receiving iodinated contrast media for diagnostic or therapeutic purposes. Several preventive strategies were evaluated in the past. Recent clinical studies and meta-analyses delivered some new aspects on preventive measures used in the past and present. We will discuss all pharmacological and nonpharmacological procedures. Finally, we will suggest individualized recommendations for CIN prevention.

Diastolic dysfunction predicts the risk of contrast-induced nephropathy and outcome post-emergency percutaneous coronary intervention in AMI patients with preserved ejection fraction

Patients with acute myocardial infarction (AMI) and reduced left ventricular ejection fraction (LVEF) are at high risk of contrast-induced nephropathy (CIN). However, the risk factors of CIN in AMI patients with preserved LVEF remain largely unknown now. The present study explored the relationship between LV diastolic function and CIN in this patient cohort. The present prospective cohort study enrolled 379 AMI patients with preserved LVEF (≥ 50%) who underwent emergency percutaneous coronary interventions (PCI). Transthoracic echocardiography was performed before PCI using a portable echocardiography system. Diastolic function was graded as normal, indeterminate and diastolic dysfunction according to the current recommendation of the American Society of Echocardiography and the European Association of Cardiovascular Imaging. A total of 88 patients (23.2%) developed CIN. Multivariate logistic regression analysis showed that both diastolic dysfunction (DD) and the mitral E velocity to mitral annular tissue Doppler E' velocity ratio (E/E') were independent predictors of CIN (P < 0.001). Other independent risk factors of CIN included increased Mehran score, ST-segment-elevation myocardial infarction, higher HbA1c and left anterior descending lesion, as well as the use of diuretics. Multivariate Cox regression analysis found that CIN, DD, higher N-terminal pro-B-type natriuretic peptide and HbA1c were independent predictors of MACE 2 years after AMI. Diastolic dysfunction determined before emergency PCI is linked with increased risk of CIN in AMI patients with preserved LVEF. CIN and diastolic dysfunction are independent predictors of MACE at 2 years in this patient cohort.

Transcatheter Arterial Embolization Therapy for Huge Renal Cysts: Two Case Reports

We encountered 2 patients with symptomatic huge simple renal cysts. In case 1, 4,000 mL of cyst fluid was drained via a catheter, but intracystic bleeding occurred immediately afterwards. Transcatheter arterial embolization (TAE) was performed, after which the bleeding stopped, and cyst drainage was repeated successfully. After 2 years, the total cyst volume was reduced from 11,775 mL to 75.4 mL. In case 2, TAE was performed prophylactically before drainage. Subsequently, 9,400 mL of fluid was removed from multiple cysts. After 1 year, the total cyst volume was reduced from 9,215 mL to 633 mL without bleeding. Based on these 2 cases, prophylactic TAE before drainage may be useful in patients with huge renal cysts.

Tolvaptan rescue contrast-induced acute kidney injury: A case report

RATIONALE

Contrast-induced acute kidney injury is one of the most serious adverse effects of contrast media and is related to three distinct but interacting mechanisms: medullary ischemia, formation of reactive oxygen species and direct tubular cell toxicity, especially in the patients with chronic kidney disease. The strategies of treatment, including stabilization of hemodynamic parameters and maintenance of normal fluid and electrolyte balance, were similar to the management of other types of acute kidney injury.

PATIENT CONCERNS

A 58-year-old woman experienced acute oligouria after complex percutaneous coronary intervention for multiple vessel coronary artery disease.

DIAGNOSES

Chest radiography showed pulmonary congestion and hyponatremia was noted after fluid hydration for suspicious contrast-induced nephropathy.

INTERVENTIONS

Oral tolvaptan, at 15mg per day, was used for three days.

OUTCOMES

Urine output increased gradually and symptoms relieved one day later after using tolvaptan. Serum creatinine also improved to baseline level one week later after this event.

LESSONS

Here, we reported an interesting case about contrast-induced acute kidney injury and hypervolemic hyponatremia, where tolvaptan was used to rescue the oliguric phase. Tolvaptan could be considered to use for contrast-induced acute kidney injury and had possibility of prevention from hemodialysis. Larger studies are still needed to investigate the role of tolvaptan in rescuing the oliguric phase in contrast-induced acute kidney injury.

Cardiac Computed Tomography for Left Atrial Appendage Occlusion: Acquisition, Analysis, Advantages, and Limitations

Transcatheter left atrial appendage occlusion is increasingly used for stroke prevention in atrial fibrillation. The technique has proven effective and safe in randomized trials and multiple observational studies. The procedure is challenging due to the complex anatomy of the left atrial appendage; accurate cardiac imaging is essential for procedural guidance. Transesophageal echocardiography is the gold standard, but cardiac computed tomography (CT) has gained increasing interest within recent years. Cardiac CT offers high-resolution imaging allowing for preprocedural anatomic evaluation and device sizing, but may also be useful for exclusion of left atrial appendage thrombus, and follow-up assessment of residual peri-device leaks.

The molecular mechanism of contrast-induced nephropathy (CIN) and its link to in vitro studies on iodinated contrast media (CM)

Iodinated contrast media (iodinated CM) have increased ability to absorb x-rays and to visualize structures that normally are impossible to observe in a radiological examination. The use of iodinated CM may destory renal function, commonly known as contrast-induced nephropathy (CIN), which can result in acute renal failure (ARF). This review article mainly focuses on the following areas: (1) classifications of iodinated CM: ionic or non-ionic, high-osmolarity contrast media (HOCM), low-osmolarity contrast media (LOCM) and iso-osmolarity contrast media (IOCM); (2) an introduction to the physical and chemical properties of the non-ionic iodinated CM; (3) the management of anaphylactic reaction by iodinated CM; (4) a suggested single injection of adult doses and maximum dose for non-ionic iodinated CM; (5) the molecular mechanism of contrast-induced nephropathy (CIN); (6) In vitro studies on iodinated CM. Based on above information, this review article provide an insight for understanding the drug safety of iodinated CM.

Renoprotective effect of nicorandil in patients undergoing percutaneous coronary intervention: a meta-analysis of 4 randomized controlled trials

Many studies have evaluated the renoprotective effect of nicorandil in patients undergoing percutaneous coronary intervention (PCI), but the results are inconsistent. We therefore conducted this meta-analysis to evaluate the protective effect of nicorandil against contrast-induced nephropathy (CIN). We searched PubMed, Embase, the Cochrane Library, Web of Science, and clinical trials database. Studies compared the nicorandil (plus hydration) with hydration alone in patients receiving PCI were eligible. The primary outcome was the incidence of CIN. Four randomized controlled trials (RCTs) with 730 patients were included. All enrolled patients were with renal dysfunction or with moderate risk for CIN. Meta-analysis showed that nicorandil was associated with a decrease of CIN (odds ratio 0.33, 95% confidence interval [CI], 0.19~0.58, p < 0.001), without heterogeneity across the studies (I² = 33.7%, p = 0.210). Moreover, nicorandil treatment could significantly reduce the level of serum creatinine, estimated glomerular filtration rate and cystatin C at 48 hours after procedures (standardized mean difference [SMD] -0.17, 95%CI -0.33~-0.01; SMD 0.29, 95% CI 0.11~0.48; SMD -0.17, 95%CI -0.33~-0.01, respectively). Nicorandil can reduce the incidence of CIN and result in favorable changes in renal function in patients undergoing PCI. More RCTs with large sample size and high quality are needed to confirm our results.

Impact of continuation of metformin prior to elective coronary angiography on acute contrast nephropathy in patients with normal or mildly impaired renal functions

Objective:

Discontinuation of metformin treatment in patients scheduled for elective coronary angiography (CAG) is controversial because of post-procedural risks including acute contrast-induced nephropathy (CIN) and lactic acidosis (LA). This study aims to discuss the safety of continuing metformin treatment in patients undergoing elective CAG with normal or mildly impaired renal functions.

Methods:

Our study was designed as a single-centered, randomized, and observational study including 268 patients undergoing elective CAG with an estimated glomerular filtration rate of >60 mL/min/1.73 m². Of these patients, 134 continued metformin treatment during angiography, whereas 134 discontinued it 24 h before the procedure. CIN was defined as either a 25% relative increase in serum creatinine levels from the baseline or a 0.5 mg/dL increase in the absolute value that measured 48 h after CAG. Logistic regression analysis was performed to identify independent predictors of CIN and LA after CAG.

Results:

Both groups were comparable in terms of demographics and laboratory values. CIN at 48 h was 8% (11/134) in the metformin continued group and 6% (8/134) in the metformin discontinued group (p=0.265). Patients in neither of the groups developed metformin-induced LA. Based on multiple regression analysis, the ejection fraction [p=0.029, OR: 0.760; 95% CI (0.590–0.970)] and contrast volume [p=0.016, OR: 0.022 95% CI (0.010–0.490)] were independent predictors of CIN.

Conclusion:

Patients scheduled for elective CAG with normal or mildly impaired renal functions and preserved left ventricular ejection fraction (>40%) may safely continue metformin treatment.