The effect of renin-angiotensin-aldosterone system blockade on contrast-induced acute kidney injury: a propensity-matched study

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 association between sodium-glucose cotransporter 2 inhibitors and contrast-associated acute kidney injury in patients with type 2 diabetes undergoing angiography: a propensity-matched study

BACKGROUND

Sodium-glucose cotransporter-2 inhibitors (SGLT2i) have been proven to prevent decline in kidney function and failure. Whether SGLT2i affect the risk of contrast-associated acute kidney injury (CA-AKI) remains uncertain.

METHODS

Use of SGLT2i was assessed in consecutive diabetics undergoing coronary angiography (CA) or percutaneous coronary intervention (PCI) from January 2020 to May 2023 at a tertiary hospital in Chongqing, China. Propensity-matched analysis was used to adjust for baseline variables. CA-AKI was defined by the Acute Kidney Injury Network (AKIN) as creatinine increase ≥ 0.3 mg/dl (26.4 μmol/l), or a percentage increase in the serum creatinine level of ≥ 50%.

RESULTS

A total of 604 new users of SGLT2i, and 298 chronic users of SGLT2i were matched with non-users. New use of SGLT2i was not associated with an increased incidence of AKIN-defined CA-AKI (OR 1.60; 95% CI 0.97-2.63; p = 0.065), in-hospital new-onset dialysis (OR 0.50; 95% CI 0.09-2.73; p = 0.422), or death (OR 0.55; 95% CI 0.18-1.66; p = 0.289). However, it was associated with a minor (> 25%) creatinine elevation (OR 1.55; 95% CI 1.04-2.30; p = 0.030), a 0.3 mg/dl increase in creatinine (OR 1.66; 95% CI 1.01-2.75; p = 0.048), and CMSC-defined CA-AKI (OR 1.51; 95% CI 1.02-2.24; p = 0.039). By 90 days, there was no evidence creatinine elevation differed between the two groups (p = 0.590). Chronic use of SGLT2i was not associated with AKIN-defined CA-AKI (OR, 0.92; 95% CI 0.41-2.05; p = 0.838).

CONCLUSIONS

New use of SGLT2i during CA or PCI was not associated with an AKIN-defined CA-AKI, and it did not translate into new-onset dialysis or death during hospital stay. Chronic usage of SGLT2i did not affect creatinine. Further randomized clinical trials are warranted to confirm this finding.

Renal outcomes after contrast exposure in patients with diabetes who use sodium-glucose cotransporter 2 inhibitors

BACKGROUND

Contrast-induced nephropathy has become increasingly prevalent as the age and prevalence of comorbidities in the general population have increased. Most cases of contrast-induced nephropathy are reversible; however, some may progress to acute kidney disease, and subsequently, to chronic kidney disease. Sodium-glucose cotransporter 2 inhibitors (SGLT2i) are known for their renoprotective effects. However, whether the use of these inhibitors affects the risk of contrast-induced kidney injury remains unclear.

METHODS

Data were collected from the Taipei Medical University Clinical Research Database. We included patients with diabetes who had contrast exposure between 2016 and 2020 because of computed tomography or coronary angiography. The primary outcome was the risk of a major adverse kidney event (MAKE), which encompassed acute kidney disease, chronic kidney disease progression, and the need for renal replacement therapy. Overlap weighting was performed to reduce the effects of potential confounders.

RESULTS

This study included 12 421 patients, who were divided into two groups: SGLT2i users (n = 920) and nonusers (n = 11 501). The follow-up period after contrast exposure was 6 months. The risk of a MAKE was lower in SGLT2i users than in nonusers (incidence, 36.9 vs. 49.9 per 1000 person-months, respectively; P = .0011). Furthermore, the incidence of acute kidney disease or chronic kidney disease progression was significantly lower in the SGLT2i users than in nonusers. However, no significant between-group difference was noted in the incidence of other MAKEs.

CONCLUSIONS

SGLT2i may be safely used in diabetic patients needing contrast exposure. The risk of a MAKE may be lower in SGLT2i users than in nonusers.

Renal resistance index independently predicts worsening of renal function after coronary angiography

The renal resistance index (RRI) has been demonstrated to be a useful parameter that can detect patients at a high risk of worsening of renal function (WRF). This study was designed to evaluate the role of the RRI in predicting WRF mediated by the intravascular administration of contrast media. We enrolled patients who were referred for coronary angiography. Renal arterial echo-color Doppler was performed to calculate the RRI. WRF was defined as an increase of > 0.3 mg/dL and at least 25% of the baseline value in creatinine concentration 24-48 h after coronary angiography. Among the 148 patients enrolled in this study, 18 (12%) had WRF. In the multivariate logistic analysis, the RRI was independently associated with WRF (odds ratio [OR]: 1.22; 95% confidence interval [CI]: 1.09-1.36; p = 0.001). After angiography, the RRI significantly increased in both patients with and without WRF. In the receiver operating characteristic curve analyses for WRF, the RRI at baseline and after angiography showed similar accuracy, and the best cutoff value for predicting WRF was 70%. In patients undergoing coronary angiography, the RRI is independently associated with WRF, probably because it provides more accurate information about cardiorenal pathophysiological factors and reflects kidney hemodynamic status and flow reserve.

Renal Safety and Renin-Angiotensin-Aldosterone System Inhibitors in Patients With Contrast Media Exposure: A Multicenter Randomized Controlled Study

ABSTRACT

There is no clear consensus on the safety of renin-angiotensin-aldosterone system inhibitors in patients with contrast media exposure. We aimed to assess the safety of renin-angiotensin-aldosterone system inhibitors in patients exposed to contrast media at 1-year follow-up. Patients treated with angiotensin-converting enzyme inhibitor/angiotensin receptor blocker (ACEI/ARB) were recruited and randomly divided into 2 groups (1:1 ratio): with ACEI/ARB group (ACEI/ARB continued throughout the study period) and without ACEI/ARB group (ACEI/ARB stopped 24 hours before and continued 48 hours after the procedure). The primary endpoint was contrast-induced acute kidney injury (CI-AKI) and secondary endpoints were major adverse cardiovascular events (MACEs), and the need for renal replacement therapy during hospitalization and at 1-year follow-up. The occurrence rates of CI-AKI were not comparable in the ACEI/ARB group and the without ACEI/ARB group (2.92% and 2.62%, respectively; P = 0.866). No significant between-group differences were found with respect to the frequency of MACEs or renal replacement therapy during hospitalization and at 1-year follow-up. On subgroup analysis, among patients with estimated glomerular filtration rate (eGFR) &lt; 45 mL/min, the incidence of CI-AKI was significantly higher in the ACEI/ARB group [17.95% (14/78) vs. 6.02% (5/83), P = 0.029]. Among patients with eGFR ≥ 45 mL/min, the incidence of CI-AKI was comparable in the 2 groups [0.87% (5/572) vs. 2.12% (12/567), P = 0.094]. The incidence of MACEs and renal replacement therapy was not comparable in the 2 groups, during hospitalization and at 1-year follow-up. ACEI or ARB treatment can safely be continued after exposure to contrast media, but not in patients with eGFR &lt; 45 mL/min.

[The atorvastatin effects on the prevention of contrast-induced acute kidney injury during computed tomography with contrast media]

AIM

To assess the role of atorvastatin to the frequency of contrast-induced acute kidney injury (CI-AKI) in patients with cardiovascular diseases (CVD) undergoing computed tomography (CT) with intravenous contrast media.

MATERIALS AND METHODS

One hundred patients with CVD undergoing CT with with intravenous contrast media administration were included in prospective observational study (ClinicalTrials.gov ID NCT04666389). Patients were divided into 3 groups 16 (15.8%) patients receiving atorvastatin at a dose of 80 mg 24 hours and 40 mg before the CT and 40 mg after; 33 (32.7%) patients 40 mg before the CT and 40 mg after; 52 (51.5%) people not receiving statin therapy. The primary endpoint was CI-AKI according to KDIGO criteria: the 25% rise (or 0.5 mg/dl) of serum creatinine from baseline assessed 4872 hours after administration of contrast media. There were 51% of men. The average age was 59.7714.4. The most frequent cardiovascular disease was hypertension 86%.

RESULTS

CI-AKI was diagnosed in 4 (3.96%) patients. At the same time, it was not possible to establish statistically significant relationships (p0.05) between risk factors and the development of CI-AKI. Statins can be a successful way to prevent this complication.

CONCLUSION

Cardiovascular diseases may increase the risk of CI-AKI after computed tomography with intravenous contrast media administration. Therefore, it is recommended to evaluate the serum creatinine concentration in such patients.

Effects of RAAS blocker use on AKI in elderly hypertensive STEMI patients with propensity score weighed method

Studies reported conflicting results on the effect of renin-angiotensin-aldosterone system (RAAS) blocker use on acute kidney injury (AKI) in patients undergoing elective coronary angiography but association in elderly patients with ST-elevation myocardial infarction (STEMI) is not known. Also, there are limited data on the effect of inflammatory markers on AKI. We aimed to investigate the effects of RAAS blocker pretreatment and inflammatory markers on AKI in this population. A total of 471 patients were compared according to presence of RAAS blocker pretreatment at admission. Conventional and inverse probability weighed conditional logistic regression were used to determine independent predictors of AKI. Mean age of the study group was 75.4 ± 7.1 years and 29.1% of the patients were female. AKI was observed in 17.2% of the study population. Weighted conditional multivariable logistic regression analysis revealed that AKI was associated with baseline creatinine levels and C-reactive protein/albumin ratio (CAR) (OR 2.08, 95% CI = 1.13-3.82, p = .02 and OR 1.19, 95% CI = 1.01-1.41, p = .04, respectively). No significant association was found between RAAS blocker pretreatment and AKI. CAR and elevated baseline creatinine levels were independent predictors of AKI in this patient group.

Low-Osmolar vs. Iso-Osmolar Contrast Media on the Risk of Contrast-Induced Acute Kidney Injury: A Propensity Score Matched Study

Objective:

Among the various risk factors associated with contrast-induced acute kidney injury (CI-AKI), the importance of osmolality and viscosity is emerging among the characteristics of contrast media (CM) itself. High osmolality CM (HOCM) is deprecated and low osmotic pressure (LOCM) and iso-osmotic pressure (IOCM) are mainly used in clinical situations where the results of studies on their effect on the development of CI-AKI are contradictory. We evaluated the association between the type of CM and the risk of CI-AKI.

Materials and Methods

A retrospective observational cohort study to analyze the effect of the type of CM on the development of CI-AKI. Using propensity score (PS) matching, 2,263 LOCM and IOCM groups were paired for analysis from 5,267 patients and fulfilled the inclusion criteria among 12,742 patients who underwent CAG between 1 January 2007, and 31 December 2016. LOCM included iopromide and iopamidol, IOCM was iodixanol. CI-AKI, which was the primary endpoint, was defined based on the Kidney Disease Improving Global Outcomes criteria within 48 h after exposure to the CM. A multivariable logistic regression analysis was used in the unmatched and matched cohorts, respectively. In addition, a stratified model on clinically important variables, including a high Mehran score (≥ 6), was also used in the matched cohort.

Results

LOCM users showed an increased incidence of CI-AKI (11.7% vs. 9.3%; p = 0.006), but it lost statistical significance after PS matching (9.9% vs. 9.5%, p = 0.725). In multivariable analyses, the adjusted odds ratio for CI-AKI in the LOCM group were 1.059 [95% confidence interval (CI) = 0.875–1.282; p = 0.555] in unmatched cohort and 0.987 (95% CI = 0.803–1.214; p = 0.901) in matched cohort. These results were also consistent with the high-risk (high Mehran score) group.

Conclusions

Although the role of CM types in the development of CI-AKI has been debated, our observation shows that the selection between LOCM and IOCM during CAG has no influence on the incidence of CI-AKI.

Impact of contrast-induced acute kidney injury on long-term major adverse cardiovascular events and kidney function after percutaneous coronary intervention: insights from a territory-wide cohort study in Hong Kong

BACKGROUND

The impact of contrast-induced acute kidney injury (CI-AKI) on long-term major adverse cardiovascular events (MACE) remains controversial.

METHOD

This was a retrospective cohort study from 14 hospitals under the Hospital Authority of Hong Kong between 2004 and 2017. Severe CI-AKI was defined as an increase in serum creatinine of >50% from the baseline value, an absolute increase of >1 mg/dL (88 μmol/L) or requiring dialysis after percutaneous coronary intervention (PCI). Mild CI-AKI was defined as an increase in serum creatinine of >25% from the baseline value or an absolute increase of >0.5 mg/dL (44 μmol/L) after PCI but not fulfilling the criteria for severe CI-AKI. The primary endpoint was MACE, defined as a composite outcome of all-cause mortality, non-fatal myocardial infarction after hospital discharge, stroke or any unplanned coronary revascularization, in a time-to-first-event analysis up to 5 years after PCI. The secondary endpoints were individual components of MACE and cardiovascular mortality.

RESULTS

A total of 34 576 patients were analysed. After adjustment for cardiovascular risk factors, procedural characteristics and medication use, the risk of MACE at 5 years was significantly higher with mild CI-AKI {hazard ratio [HR], 1.18 [95% confidence interval (CI) 1.12-1.26); P < 0.001} and severe CI-AKI [HR 1.92 (95% CI 1.78-2.07); P < 0.001]. Severe CI-AKI was associated with higher adjusted risks of each secondary end point and the risks monotonically accrued over time.

CONCLUSIONS

Among patients undergoing a first-ever PCI, CI-AKI of any severity was associated with a higher adjusted risk of MACE at 5 years. Severe CI-AKI has a stronger association with MACE and its individual components, with an excess of early and late events.

Mechanistic insights into the role of serum-glucocorticoid kinase 1 in diabetic nephropathy: A systematic review

Aberrant expression of serum-glucocorticoid kinase 1 (SGK1) contributes to the pathogenesis of multiple disorders, including diabetes, hypertension, obesity, fibrosis, and metabolic syndrome. SGK1 variant is expressed in the presence of insulin and several growth factors, eventually modulating various ion channels, carrier proteins, and transcription factors. SGK1 also regulates the enzymatic activity of Na⁺ K⁺ ATPase, glycogen synthase kinase-3, ubiquitin ligase Nedd4-2, and phosphomannose mutase impacting cell cycle regulation, neuroexcitation, and apoptosis. Ample evidence supports the crucial role of aberrant SGK1 expression in hyperglycemia-mediated secondary organ damage. Diabetic nephropathy (DN), a dreadful microvascular complication of diabetes, is the leading cause of end-stage renal failures with high morbidity and mortality rate. The complex pathogenesis of DN encompasses several influencing factors, including transcriptional factors, inflammatory markers, cytokines, epigenetic modulators, and abnormal enzymatic activities. SGK1 plays a pivotal role by controlling various physiological functions associated with the occurrence and progression of DN; therefore, targeting SGK1 may favorably influence the clinical outcome in patients with DN. This review aimed to provide mechanistic insights into SGK1 regulated DN pathogenesis and summarize the evidence supporting the therapeutic potential of SGK1 inhibition and its consequences on human health.

Contrast-induced acute kidney injury after computed tomography with contrast media in patients with cardiovascular diseases

Aim. To assess the frequency of contrast-induced acute kidney injury (CI-AKI) in patients with cardiovascular diseases (CVD) undergoing computed tomography (CT) with intravenous contrast media. Materials and methods. In prospective observational study (ClinicalTrials.gov ID NCT04666389) were included 51 patients with CVD undergoing CT with intravenous contrast media administration. The primary endpoint was CI-AKI according to KDIGO criteria [the 25% rise (or 0.5 mg/dl) of serum creatinine from baseline assessed 4872 hours after administration of contrast media]. There were 51% of women included in the study. The average age was 61.741.5. The most frequent cardiovascular disease was hypertension in both men and women 52 and 39% respectively. Results. CI-AKI was diagnosed in 2 (3.92%) patients. At the same time, it was not possible to establish statistically significant relationship (p0.05) between risk factors and the development of CI-AKI. Conclusion. Cardiovascular diseases may increase the risk of CI-AKI after CT with intravenous contrast media administration. Therefore, it is recommended to evaluate the serum creatinine concentration in such patients.

Angiotensin-Converting Enzyme Inhibitors and Contrast-Associated Acute Kidney Injury After Coronary Angiography and Intervention

Contrast-associated acute kidney injury has multiple definitions, but is generally described as worsening renal function after administration of iodinated contrast media. It is associated with high in-hospital mortality and poor long-term survival. Furthermore, patients undergoing coronary angiography commonly have comorbidities such as hypertension or congestive heart failure, which are often treated with renin-angiotensin-aldosterone system-blocking agents such as angiotensin-converting enzyme inhibitors and angiotensin receptor blockers. Trials assessing the effects of these renin-angiotensin-aldosterone system-blocking agents on the subsequent development of contrast-associated acute kidney injury have shown conflicting data, suggesting both beneficial and harmful effects. Therefore, there are no clear guidelines on whether clinicians should discontinue renin-angiotensin-aldosterone system-blocking agents peri-procedurally. In this article, we review the data from trials assessing the effects of peri-procedural renin-angiotensin system-blocking agent use in patients undergoing coronary and peripheral angiography and intervention. Future studies will likely focus on the extent of damage or potential benefit of these agents on renal function, cardiac function, as well as morbidity and mortality. Currently, there is insufficient evidence to recommend discontinuation of angiotensin-converting enzyme inhibitors prior to coronary angiography.

Evidence-Based Practices in the Cardiac Catheterization Laboratory: A Scientific Statement From the American Heart Association

Cardiac catheterization procedures have rapidly evolved and expanded in scope and techniques over the past few decades. However, although some practices have emerged based on evidence, many traditions have persisted based on beliefs and theoretical concerns. The aim of this review is to highlight common preprocedure, intraprocedure, and postprocedure catheterization laboratory practices where evidence has accumulated over the past few decades to support or discount traditionally held practices.

Association between Diabetes Mellitus and Contrast-Associated Acute Kidney Injury: A Systematic Review and Meta-Analysis of 1.1 Million Contrast Exposure Patients

BACKGROUND

Although diabetes mellitus (DM) has been a common risk factor of contrast-associated acute kidney injury (CA-AKI) for a long time, several current studies showed that DM is not an independent risk factor. Due to this diverse finding, we aim to conduct a systematic review assessing the effect of DM on CA-AKI.

METHODS

We searched Ovid Medline, Embase, and Cochrane Database of Systematic Reviews (to June 1, 2020) for studies assessing the association between DM and CA-AKI. Random meta-analysis was performed to derive the pooled estimates of the adjusted odds ratio (OR) and corresponding 95% confidence intervals (CIs).

RESULTS

A total of 84 studies involving 1,136,827 participants were included in this meta-analysis. The presence of DM was associated with an higher risk of CA-AKI (pooled OR: 1.58, 95% CI: 1.48-1.70, I2 = 64%). Furthermore, the predictive effect of elevated CA-AKI for was stronger in the subgroup of DM patients with chronic kidney disease (CKD) (OR: 2.33, 95% CI: 1.21-4.51), while the relationship between DM and CA-AKI was not significant in subgroup patients without CKD (OR: 1.12, 95% CI: 0.73-1.72).

CONCLUSION

This is the first meta-analysis to prove that DM is an independent risk factor of CA-AKI in patients. While the predictive value of DM for CA-AKI in patients with normal kidney function was weakened, more protective treatments are needed in diabetic patients with kidney dysfunction to avoid the occurrence of CA-AKI.

Predictive Value of Hypoalbuminemia for Contrast-Associated Acute Kidney Injury: A Systematic Review and Meta-Analysis

Contrast-associated acute kidney injury (CA-AKI) is a major adverse complication of intravascular administration of contrast medium. Current studies have shown that hypoalbuminemia might be a novel risk factor of CA-AKI. This systematic review and meta-analysis was performed to evaluate the predictive value of hypoalbuminemia for CA-AKI. Relevant studies were identified in Ovid-Medline, PubMed, Embase, and Cochrane Library up to December 31, 2019. Two authors independently screened studies, consulting with a third author when necessary to resolve discrepancies. The pooled odds ratio (OR) was calculated to assess the association between hypoalbuminemia and CA-AKI using a random-effects model or fixed-effects model. Eight relevant studies involving a total of 18 687 patients met our inclusion criteria. The presence of hypoalbuminemia was associated with an increased risk of CA-AKI development (pooled OR: 2.59, 95% CI: 1.80-3.73). Hypoalbuminemia is independently associated with the occurrence of CA-AKI and may be a potentially modifiable factor for clinical intervention. This systematic review and meta-analysis was registered in PROSPERO (CRD42020168104).

Iodinated contrast medium: Is there a re(n)al problem? A clinical vignette-based review

As we were taught, for decades, that iodinated contrast-induced acute kidney injury should be dreaded, considerable efforts were made to find out effective measures in mitigating the renal risk of iodinated contrast media. Imaging procedures were frequently either downgraded (unenhanced imaging) or deferred as clinicians felt that the renal risk pertaining to contrast administration outweighed the benefits of an enhanced imaging. However, could we have missed the point? Among the abundant literature about iodinated contrast-associated acute kidney injury, recent meaningful advances may help sort out facts from false beliefs. Hence, there is increasing evidence that the nephrotoxicity directly attributable to modern iodinated CM has been exaggerated. Failure to demonstrate a clear benefit from most of the tested prophylactic measures might be an indirect consequence. However, the toxic potential of iodinated contrast media is well established experimentally and should not be overlooked completely when making clinical decisions. We herein review these advances in disease and pathophysiologic understanding and the associated clinical crossroads through a typical case vignette in the critical care setting.

Determinants of Insufficient Optimal Medical Therapy after Acute Myocardial Infarction

Objective Although the importance of evidence-based optimal medical therapy (OMT) after acute myocardial infarction (AMI) has been recognized, the prescription rate of OMT is not sufficiently high in real-word clinical settings. The purpose of this study was to identify the clinical characteristics of AMI patients who did not receive OMT. Methods The present study was a retrospective study. OMT was defined as the combination of antiplatelet therapy, angiotensin-converting enzyme (ACE) inhibitors/angiotensin II receptor blockers (ARBs), beta-blockers, and statins at the time of hospital discharge. Non-OMT was defined as the lack of either antiplatelet therapy, ACE inhibitors/ARBs, beta-blockers, or statins. Results A total of 457 AMI patients were included as the final study population, and 98 patients (22.4%) lacked at least 1 OMT medication. The prescription rates of antiplatelet therapy, ACE inhibitors/ARBs, beta-blockers, and statins were 98.7%, 87.5%, 90.4%, and 96.7%, respectively. In the multivariate logistic regression analysis, age [per 1-year increase: odds ratio (OR) 1.033, 95% confidence interval (CI) 1.007-1.059, p=0.014], hemodialysis (vs. no hemodialysis: OR 2.707, 95% CI 1.082-6.774, p=0.033), estimated glomerular filtration rate <30 mL/min/1.73 m² without hemodialysis (OR 4.585, 95% CI 1.975-10.644, p<0.001), AMI caused by vasospastic angina (VSA) (vs. no VSA: OR 13.198, 95% CI 1.809-96.260, p=0.011), and asthma (vs. no asthma: OR 7.241, 95% CI 1.716-30.559, p=0.007) were significantly associated with non-OMT, whereas heart rate on admission (per 1-bpm increase: 0.987, 95% CI 0.975-0.999, p=0.033), any PCI (vs. no PCI: OR 0.156, 95% CI 0.066-0.373, p<0.001), and ST-elevation myocardial infarction (STEMI) (vs. NSTEMI: OR 0.384, 95% CI 0.218-0.675, p=0.001) were inversely associated with non-OMT. Conclusion An advanced age, VSA, bradycardia, asthma, impaired renal function, non-PCI revascularization, and non-ST-elevation myocardial infarction were significantly associated with non-OMT.

Meta-analysis of effect of renin-angiotensin-aldosterone system blockers on contrast-induced nephropathy

Background:

The purpose of this study was to systematically evaluate the effect of renin–angiotensin–aldosterone system blockers on the incidence of contrast-induced nephropathy in patients undergoing coronary angiography or percutaneous coronary intervention.

Methods:

A systematic literature search of several databases was conducted to identify studies that met the inclusion criteria. A total of 12 studies with 14 trials that performed studies on a total of 4864 patients (2484 treated with renin–angiotensin–aldosterone system blockers and 2380 in the control group) were included. The primary endpoint was the overall incidence of contrast-induced nephropathy. Analyses were performed with STATA version 12.0.

Results:

The overall contrast-induced nephropathy incidence in renin–angiotensin–aldosterone system blocker and control groups was 10.43% and 6.81%, respectively. The pooled relative risk of contrast-induced nephropathy incidence was 1.22 (95% confidence interval: 0.81–1.84) in the renin–angiotensin–aldosterone system blocker group. An increased risk of developing contrast-induced nephropathy in the renin–angiotensin–aldosterone system blocker group was observed among older people, non-Asians, chronic users, and studies with larger sample size, and the pooled RRs and 95% confidence intervals were 2.02 (1.21–3.36), 2.30 (1.41–3.76), 1.69 (1.10–2.59) and 1.83 (1.28–2.63), respectively.

Conclusions:

Intervention with renin–angiotensin–aldosterone system blockers was associated with an increased risk of contrast-induced nephropathy among non-Asians, chronic users, older people, and studies with larger sample size. Large clinical trials with strict inclusion criteria are needed to confirm our results and to evaluate the effect further.

Renin-angiotensin-aldosterone system blockade is associated with higher risk of contrast-induced acute kidney injury in patients with diabetes

As the incidence of diabetes and cardiovascular comorbidities continues to rise, driven by increased prevalence of obesity and an aging population, so does the demand for percutaneous coronary intervention (PCI) to restore cardiac blood flow. Renin-angiotensin-aldosterone system (RAAS) inhibitors are commonly prescribed to hypertensive diabetic patients to prevent diabetic nephropathy. However, evidence suggests that angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs) may increase the risk of contrast-induced acute kidney injury (CIAKI) following coronary angiography (CAG) and PCI. We therefore conducted a retrospective, multicenter study applying the propensity score matching method to evaluate the impact of RAAS inhibition on CIAKI in diabetic patients undergoing CAG/PCI. Among 2240 subjects that met the inclusion criteria, 704 patients in the ACEIs/ARBs group were successfully matched to eligible control patients. The incidence of CIAKI (serum creatinine increase ≥0.5 mg/dl or ≥25% from baseline within 72 h post-CAG/PCI) was significantly higher in the ACEIs/ARBs group than in the control group (26.6% vs. 16.2%, P<0.001). However, control patients showed increased risk of overall adverse cardiovascular events (4.1% vs. 1.8% for ACEIs/ARBs; P=0.016). These data indicate that RAAS inhibition increases the risk of CIAKI in diabetic patients, but confers protection against early cardiovascular events.

Use of Intravenous Iodinated Contrast Media in Patients with Kidney Disease: Consensus Statements from the American College of Radiology and the National Kidney Foundation

Intravenous iodinated contrast media are commonly used with CT to evaluate disease and to determine treatment response. The risk of acute kidney injury (AKI) developing in patients with reduced kidney function following exposure to intravenous iodinated contrast media has been overstated. This is due primarily to historic lack of control groups sufficient to separate contrast-induced AKI (CI-AKI; ie, AKI caused by contrast media administration) from contrast-associated AKI (CA-AKI; ie, AKI coincident to contrast media administration). Although the true risk of CI-AKI remains uncertain for patients with severe kidney disease, prophylaxis with intravenous normal saline is indicated for patients who have AKI or an estimated glomerular filtration rate less than 30 mL/min/1.73 m² who are not undergoing maintenance dialysis. In individual high-risk circumstances, prophylaxis may be considered in patients with an estimated glomerular filtration rate of 30-44 mL/min/1.73 m² at the discretion of the ordering clinician. This article is a simultaneous joint publication in Radiology and Kidney Medicine. The articles are identical except for stylistic changes in keeping with each journal's style. Either version may be used in citing this article.

Use of Intravenous Iodinated Contrast Media in Patients With Kidney Disease: Consensus Statements from the American College of Radiology and the National Kidney Foundation

Intravenous iodinated contrast media are commonly used with CT to evaluate disease and to determine treatment response. The risk of acute kidney injury (AKI) developing in patients with reduced kidney function following exposure to intravenous iodinated contrast media has been overstated. This is due primarily to historic lack of control groups sufficient to separate contrast-induced AKI (CI-AKI; ie, AKI caused by contrast media administration) from contrast-associated AKI (CA-AKI; ie, AKI coincident to contrast media administration). Although the true risk of CI-AKI remains uncertain for patients with severe kidney disease, prophylaxis with intravenous normal saline is indicated for patients who have AKI or an estimated glomerular filtration rate less than 30 mL/min/1.73 m² who are not undergoing maintenance dialysis. In individual high-risk circumstances, prophylaxis may be considered in patients with an estimated glomerular filtration rate of 30-44 mL/min/1.73 m² at the discretion of the ordering clinician.

Radiological iodinated contrast-induced nephropathy

The use of iodinated contrast media can cause renal toxicity. Whether contrast media are exclusively responsible for kidney damage is currently the subject of debate, given that in most cases, other potential causes of the renal failure are present. With current low-osmolar and iso-osmolar contrast media, the incidence rate of contrast-induced nephropathy is estimated to be <1% in the low-risk population but can increase to 37% in patients who are administered contrast by an intra-arterial administration and/or who have renal failure with an estimated glomerular filtration rate (eGFR) <30mL/min/1.73m². To minimize the risk of renal toxicity, the recommendation is to administer the least amount of contrast possible and ensure appropriate volume expansion by infusing 0.9% saline solution.

Maximum allowable contrast dose and prevention of acute kidney injury following cardiovascular procedures

PURPOSE OF REVIEW

Contrast-induced acute kidney injury (CI-AKI) is a serious complication. Although nonmodifiable and modifiable risk factors have been thoroughly characterized, the utility of the maximal allowable contrast dose (MACD) has not received adequate attention. The focus of this review is to provide a critical appraisal of this modifiable risk factor.

RECENT FINDINGS

Several retrospective and prospective cohort studies have demonstrated that the incidence of CI-AKI among patients receiving contrast media in volumes exceeding the MACD is consistently higher compared with those who do not exceed the MACD (an average of 24 vs. 6%). Furthermore, the MACD is independent predictor of CI-AKI and other adverse events. A two-step algorithm incorporating the determination of the MACD and the contrast volume to eGFR ratio prior to a planned cardiovascular procedure is a sound approach to minimize contrast volume and prevent CI-AKI.

SUMMARY

Prevention of CI-AKI must remain a clinical priority. Intraprocedural preventive measures should include a priori calculation of the MACD and contrast volume to eGFR ratio to limit contrast volume. Other measures may include the adoption of the transradial approach, the use of automated contrast injectors and small catheters to limit contrast volume, the use of low-osmolar contrast agents, and if necessary the use of staged procedures. We call for the system-wide implementation of evidence-based care bundles to prevent CI-AKI.

Incidence, Predictors, and Impact on Six-Month Mortality of Three Different Definitions of Contrast-Induced Acute Kidney Injury After Coronary Angiography

We assessed incidence, predictors, and impact on 6-month mortality of contrast-induced acute kidney injury (CI-AKI) after coronary angiography with or without percutaneous coronary intervention in patients with acute coronary syndrome (ACS), according to 3 different CI-AKI definitions. Serum creatinine (sCr) was assessed at baseline and 48 to 72 hours after procedure to classify patients into 3 CI-AKI groups: Group 1: increase in sCR ≥25% over baseline but absolute increase <0.5 mg/dl; Group 2: absolute increase ≥0.5 mg/dl; Group 3: absolute increase ≥0.3 mg/dl or ≥50% over baseline. The association between CI-AKI and all-cause 6-month mortality was assessed using multivariate Cox regression. Among 1,002 patients included, median age was 68 [57 to 79] years. The sample had the following characteristics: 70% men, 25% diabetics, 22% had a history of myocardial infarction, 21% had baseline estimated glomerular filtration rate (as calculated by the Modification of Diet in Renal Disease)  <60 ml/min/1.72 m², 34% had ST-segment elevation myocardial infarction, 61% underwent percutaneous coronary intervention, and 43% had multivessel disease. Based on changes in sCr, 89 patients (8.9%) were classified in Group 1; 69 (6.9%) in Group 2; and 157 (15.7%) in Group 3, whereas sCr did not increase >25% in the remaining 844 (84.2%). CI-AKI was significantly associated with 6-month all-cause mortality using the definitions for Group 2 (hazard ratio 3.1, 95% confidence interval [CI] 1.5 to 6.6, p = 0.002) and Group 3 (hazard ratio 2.03, 95% CI 1.03 to 4.0, p = 0.04), but not Group 1. In conclusion, based on the definition used for CI-AKI, CI-AKI is observed in 6% to 15.7% of patients. An increase of 25% over baseline sCr does not identify high-risk patients. CI-AKI defined as an increase in sCr >0.3 mg/dl identifies 15.7% of the population at 2-fold higher risk of mortality.

Determinants of Acute Kidney Injury and Renal Function Decline After Endovascular Abdominal Aortic Aneurysm Repair

OBJECTIVE/BACKGROUND

Endovascular aneurysm repair (EVAR) may be associated with renal injury and more insight is needed into potential risk factors. The aim was to identify clinical, anatomical, and peri-procedural parameters as potential risk factors for the occurrence of acute kidney injury (AKI) and to evaluate chronic kidney disease (CKD) after EVAR.

METHODS

A cohort of 212 consecutive patients who underwent elective EVAR for abdominal aortic aneurysm from January 2009 to October 2016 was included. A subgroup of 149 patients with 2 years follow-up was compared with a set of 135 non-operated aneurysm patients with smaller aneurysms (similar cardiovascular risk profile) to assess CKD. Primary outcomes were AKI (Acute Kidney Injury Network criteria) and CKD measured by estimated glomerular filtration rate (Kidney Disease Improving Global Outcomes guidelines). For AKI, candidate risk factors were identified by univariate and multivariate logistic regression analysis; for chronic renal function decline, risk factors were identified using Cox regression analysis.

RESULTS

AKI occurred in 30 patients (15%). On multivariate analysis, the use of angiotensin II blocker (odds ratio [OR] 4.08, 95% confidence interval [CI] 1.38-12.07) and peri-operative complications (OR 3.12, 95% CI 1.20-8.10) were independent risk factors for AKI, whereas statin use was a protective factor (OR 0.19, 95% CI 0.07-0.52). EVAR resulted in a significant increase (23.5%) in the occurrence of CKD compared with the control group (6.7%; p <.001). On univariate and multivariate Cox regression the risk factors: aortic neck diameter (per mm increase) (hazard ratio [HR] 1.13, 95% CI 1.02-1.25), renal artery stenosis >50% (HR 2.24, 95% CI 1.05-4.79), and the occurrence of AKI (HR 2.19, 95% CI 0.99-4.85) were significant predictors of CKD.

CONCLUSION

This study identified use of angiotensin II blockers and peri-operative complications as risk factors for AKI. In addition, the problem of renal function decline after EVAR is highlighted, which indicates that prolonged protective measures (e.g., in those patients at high risk) over time are needed to improve patient outcomes.

Longitudinal Risk of Adverse Events in Patients With Acute Kidney Injury After Percutaneous Coronary Intervention: Insights From the National Cardiovascular Data Registry

BACKGROUND

Acute kidney injury (AKI) remains a common complication after percutaneous coronary intervention (PCI) and is associated with adverse in-hospital patient outcomes. The incidence of adverse events after hospital discharge in patients having post-PCI AKI is poorly defined, and the relationship between AKI and outcomes after hospital discharge remains understudied.

METHODS AND RESULTS

Using the National Cardiovascular Data Registry CathPCI registry, we assessed the incidence of AKI among Medicare beneficiaries after PCI from 2004 to 2009 and subsequent post-discharge adverse events at 1 year. AKI was defined using Acute Kidney Injury Network (AKIN) criteria. Adverse events included death, myocardial infarction, bleeding, and recurrent kidney injury. Using Cox methods, we determined the relationship between in-hospital AKI and risk of post-discharge adverse events by AKIN stage. In a cohort of 453 475 elderly patients undergoing PCI, 39 850 developed AKI (8.8% overall; AKIN stage 1, 85.8%; AKIN 2/3, 14.2%). Compared with no AKI, in-hospital AKI was associated with higher post-discharge hazard of death, myocardial infarction, or bleeding (AKIN 1: hazard ratio [HR], 1.53; confidence interval [CI], 1.49-1.56 and AKIN 2/3: HR, 2.13; CI, 2.01-2.26), recurrent AKI (AKIN 1: HR, 1.70; CI, 1.64-1.76; AKIN 2/3: HR, 2.22; CI, 2.04-2.41), and AKI requiring dialysis (AKIN 1: HR, 2.59; CI, 2.29-2.92; AKIN 2/3: HR, 4.73; CI, 3.73-5.99). For each outcome, the highest incidence was within 30 days.

CONCLUSIONS

Post-PCI AKI is associated with increased risk of death, myocardial infarction, bleeding, and recurrent renal injury after discharge. Post-PCI AKI should be recognized as a significant risk factor not only for in-hospital adverse events but also after hospital discharge.

Update on the renal toxicity of iodinated contrast drugs used in clinical medicine

An important side effect of diagnostic contrast drugs is contrast-induced acute kidney injury (CI-AKI; a sudden decrease in renal function) occurring 48-72 hours after injection of a contrast drug that cannot be attributed to other causes. Its existence has recently been challenged, because of some retrospective studies in which the incidence of AKI was not different between subjects who received a contrast drug and those who did not, even using propensity score matching to prevent selection bias. For some authors, only patients with estimated glomerular filtration rate <30 mL/min/1.73 m2 are at significant risk of CI-AKI. Most agree that when renal function is normal, there is no CI-AKI risk. Many experimental studies, however, are in favor of the existence of CI-AKI. Contrast drugs have been shown to cause the following changes: renal vasoconstriction, resulting in a rise in intrarenal resistance (decrease in renal blood flow and glomerular filtration rate and medullary hypoxia); epithelial vacuolization and dilatation and necrosis of proximal tubules; potentiation of angiotensin II effects, reducing nitric oxide (NO) and causing direct constriction of descending vasa recta, leading to formation of reactive oxygen species in isolated descending vasa recta of rats microperfused with a solution of iodixanol; increasing active sodium reabsorption in the thick ascending limbs of Henle's loop (increasing O2 demand and consequently medullary hypoxia); direct cytotoxic effects on endothelial and tubular epithelial cells (decrease in release of NO in vasa recta); and reducing cell survival, due to decreased activation of Akt and ERK1/2, kinases involved in cell survival/proliferation. Prevention is mainly based on extracellular volume expansion, statins, and N-acetylcysteine; conflicting results have been obtained with nebivolol, furosemide, calcium-channel blockers, theophylline, and hemodialysis.

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

Contrast-induced acute kidney injury (CI-AKI) is one of the most common causes of AKI in clinical practice. CI-AKI has been found to be strongly associated with morbidity and mortality of the patients. Furthermore, CI-AKI may not be always reversible and it may be associated with the development of chronic kidney disease. Pathophysiology of CI-AKI is not exactly understood and there is no consensus on the preventive strategies. CI-AKI is an active research area thus clinicians should be updated periodically about this topic. In this review, we aimed to discuss the indications of contrast-enhanced imaging, types of contrast media and their impact on nephrotoxicity, major pathophysiological mechanisms, risk factors and preventive strategies of CI-AKI and alternative non-contrast-enhanced imaging methods.

Pre-procedural renal resistive index accurately predicts contrast-induced acute kidney injury in patients with preserved renal function submitted to coronary angiography

The study aimed to evaluate the clinical utility of ultrasonographic intra-renal blood flow parameters, together with the wide range of different risk factors, for the prediction of contrast-induced acute kidney injury (CI-AKI) in patients with preserved renal function, referred for coronary angiography or percutaneous coronary interventions (CA/PCI). This prospective study covered 95 consecutive patients (69.5% men; median age 65 years) subject to elective or urgent CA/PCI. Data regarding 128 peri-procedural variables were collected. Ultrasonographic intra-renal blood flow parameters, including renal resistive index (RRI) and pulsatility index (RPI), were acquired directly before the procedure. CI-AKI was defined as ≥50% relative or ≥0.3 mg/dL absolute increase of serum creatinine 48 h after procedure. CI-AKI was confirmed in nine patients (9.5%). Patients with CI-AKI had higher SYNTAX score (p = 0.0002), higher rate of left main disease (p < 0.00001), peripheral artery disease (PAD; p = 0.02), coronary artery anomaly (p = 0.017), more frequently underwent surgical revascularization (p = 0.0003), 'had greater...' intima-(p = 0.004) and extra-medial thickness (p = 0.001), and received higher contrast media dose (p = 0.049), more often overused non-steroidal anti-inflammatory drugs (p = 0.001), and had substantially higher pre-procedural RRI (0.69 vs. 0.62; p = 0.005) and RPI values (1.54 vs. 1.36; p = 0.017). Logistic regression confirmed age, SYNTAX score, presence of PAD, diabetes mellitus, and pre-procedural RRI independently predicted CI-AKI onset (AUC = 0.95; p < 0.0001). Pre-procedural RRI > 0.69 had 78% sensitivity and 81% specificity in CI-AKI prediction. High pre-procedural RRI seems to be a useful novel risk factor for CI-AKI in patients with preserved renal function. Coronary, peripheral and renal vascular pathology contribute to the development of CI-AKI following CA/PCI.

Renin-Angiotensin-Aldosterone System Blockade in Critically Ill Patients Is Associated with Increased Risk for Acute Kidney Injury

Acute kidney injury (AKI) is a major clinical problem and a predictor of outcomes in critically ill patients who frequently required treatments in the intensive care unit (ICU). Renin-angiotensin-aldosterone system (RAAS) blockers are commonly used for treating hypertension but demands caution because of accompanying illnesses including AKI. The aim of this study was to evaluate whether the use of RAAS blockers affected the incidence of AKI in ICU patients. From a total of 26,287 patients who were admitted to the ICU from January 2003 to December 2013 were included in the final analyses. The primary outcome was the incidence of AKI based on the prescription of RAAS blockers. The secondary outcomes were all-cause mortality. RAAS blocker users were more likely to develop AKI (P < 0.001) and remained an independent risk factor for AKI (odds ratio [OR], 1.56; 95% confidence interval [CI], 1.37-1.79; P < 0.001) after adjusting confounding factors. There was no significant difference in the cumulative 90-day survival rate between the RAAS blocker users and non-users (P = 0.381). However, the adjusted mortality risk associated with AKI was 1.38 (95% CI, 1.22 to 1.56; P < 0.001) and increased as the severity of AKI stage increased from 1 to 3: 1.17 (1.02 to 1.36), 1.77 (1.45 to 2.16), and 1.93 (1.55 to 2.41; P < 0.01 for the trend). RAAS blockers may have a harmful influence to increase the incidence of AKI and temporary withholding of these medications may deserve careful consideration in ICU patients.

Contrast Medium Exposure During Computed Tomography and Risk of Development of End-Stage Renal Disease in Patients With Chronic Kidney Disease: A Nationwide Population-Based, Propensity Score-Matched, Longitudinal Follow-Up Study

The aim of the study was to investigate the long-term association between contrast medium exposure during computed tomography (CT) and the subsequent development of end-stage renal disease (ESRD) in patients with chronic kidney disease (CKD). We conducted a population-based cohort study using Taiwan's National Health Insurance Research Database. A total of 7100 patients with nonadvanced CKD who underwent contrast medium-enhanced CT were identified and served as the study cohort. To avoid selection bias, we used the propensity score to match 7100 nonadvanced CKD patients, who underwent noncontrast medium-enhanced CT to serve as the comparison cohort. The age, sex, index year, and frequency of undergoing CTs were also matched between the study and comparison cohorts. Participants were followed until a new diagnosis of ESRD or December 31, 2011. Hazard ratios (HRs) with 95% confidence interval (95% CI) were calculated using the Cox proportional hazards regression. Contrast medium exposure was not identified as a risk factor for developing ESRD in nonadvanced CKD patients after confounders adjustment (adjusted HR = 0.91; 95% CI, 0.66-1.26; P = 0.580). We further divided the patients who underwent CTs with contrast medium use into ≤1 exposure per year on average, >1 and <2 exposure per year on average, and ≥2 exposure per year on average. After adjusting for confounders, we identified a much higher risk for developing ESRD in the 2 groups of >1 and <2 exposure per year on average and ≥2 exposure per year on average (adjusted HR = 8.13; 95% CI, 5.57-11.87 and adjusted HR = 12.08; 95% CI, 7.39-19.75, respectively) compared with the patients who underwent CTs without contrast medium use. This long-term follow-up study demonstrated that contrast medium exposure was not associated with an increased risk of ESRD development in nonadvanced CKD patients.

Exploring Potential Reasons for the Temporal Trend in Dialysis-Requiring AKI in the United States

BACKGROUND AND OBJECTIVES

The population incidence of dialysis-requiring AKI has risen substantially in the last decade in the United States, and factors associated with this temporal trend are not well known.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We conducted a retrospective cohort study using data from the Nationwide Inpatient Sample, a United States nationally representative database of hospitalizations from 2007 to 2009. We used validated International Classification of Diseases, Ninth Revision codes to identify hospitalizations with dialysis-requiring AKI and then, selected the diagnostic and procedure codes most highly associated with dialysis-requiring AKI in 2009. We applied multivariable logistic regression adjusting for demographics and used a backward selection technique to identify a set of diagnoses or a set of procedures that may be a driver for this changing risk in dialysis-requiring AKI.

RESULTS

From 2007 to 2009, the population incidence of dialysis-requiring AKI increased by 11% per year (95% confidence interval, 1.07 to 1.16; P<0.001). Using backward selection, we found that the temporal trend in the six diagnoses, septicemia, hypertension, respiratory failure, coagulation/hemorrhagic disorders, shock, and liver disease, sufficiently and fully accounted for the temporal trend in dialysis-requiring AKI. In contrast, temporal trends in 15 procedures most commonly associated with dialysis-requiring AKI did not account for the increasing dialysis-requiring AKI trend.

CONCLUSIONS

The increasing risk of dialysis-requiring AKI among hospitalized patients in the United States was highly associated with the changing burden of six acute and chronic conditions but not with surgeries and procedures.

Effects of withdrawing vs continuing renin-angiotensin blockers on incidence of acute kidney injury in patients with renal insufficiency undergoing cardiac catheterization: Results from the Angiotensin Converting Enzyme Inhibitor/Angiotensin Receptor Blocker and Contrast Induced Nephropathy in Patients Receiving Cardiac Catheterization (CAPTAIN) trial

BACKGROUND

It is unclear if holding angiotensin-converting enzyme inhibitors (ACEI) or angiotensin receptor blockers (ARB) prior to coronary angiography reduces contrast-induced acute kidney injury (AKI). We undertook a randomized trial to investigate the effect of holding ACEI/ARB therapy prior to coronary angiography on the incidence of AKI.

METHODS

We randomly assigned 208 patients with moderate renal insufficiency (creatinine ≥ 1.7mg/dL within 3 months and/or documented creatinine ≥ 1.5mg/dL within 1 week before cardiac catheterization) to hold ACEI/ARB ≥24 hours preprocedure or continue ACEI/ARB. The primary outcome was the incidence of AKI defined as an absolute rise in serum creatinine of ≥0.5mg/dL from baseline and/or a relative rise in serum creatinine of ≥25% compared with baseline measured at 48 to 96 hours postcardiac catheterization.

RESULTS

All patients were taking an ACEI (72.1%) or ARB (27.9%) prior to randomization. At 48 to 96 hours, the primary outcome occurred in 18.4% of patients who continued ACEI/ARB compared with 10.9% of the patients who held ACEI/ARB (hazard ratio 0.59, 95% CI 0.30-1.19, P = .16). In a prespecified secondary outcome, there was a lower rise in mean serum creatinine after the procedure in patients who held ACEI/ARB (0.3 ± 0.5 vs 0.1 ± 0.3mg/dL, P = .03). The clinical composite of death, myocardial infarction, ischemic stroke, congestive heart failure, rehospitalization for cardiovascular cause, or need for dialysis preprocedure occurred in 3.9% who continued ACEI/ARB compared with 0% who held the ACEI/ARB (hazard ratio 0.11, 95% CI 0.01-2.96, P = .06).

CONCLUSION

In this pilot study of patients with moderate renal insufficiency undergoing cardiac catheterization, with-holding ACEI/ARB resulted in a non-significant reduction in contrast-induced AKI and a significant reduction in post-procedural rise of creatinine. This low cost intervention could be considered when referring a patient for cardiac catheterization.

The Effect of Renin-Angiotensin-Aldosterone System Blockade Medications on Contrast-Induced Nephropathy in Patients Undergoing Coronary Angiography: A Meta-Analysis

BACKGROUND

Contrast-induced nephropathy (CIN) is the main complication of contrast media administration (CM) in patients undergoing coronary angiography (CAG) and percutaneous coronary intervention (PCI). There are inconsistent results in the literature regarding the effect of renin-angiotensin-aldosterone system (RAAS) blockers (angiotensin-converting enzyme inhibitors [ACEIs] and angiotensin receptor blockers [ARBs]) on CIN. We evaluated the association between the administration of ACEI/ARBs and CIN, as well as the effect of ACEI/ARBs on post-procedural changes in renal function index, in patients undergoing CAG.

METHODS

We searched Pubmed, EMBASE, Cochrane Central Register of Controlled Trials and ClinicalTrials.gov for relevant studies. The primary search generated 893 potentially relevant articles. A total of 879 studies were excluded because they did not meet the selection criteria. Finally, 14 studies were eligible for inclusion. There were 7,288 patients that received ACEI/ARBs and 8,159 patients that received placebo or naive to ACEI/ARBs in the study. A random or a fixed effect model was used to calculate the pooled odd ratios (ORs).

RESULTS

The risk of CIN was significantly increased in the ACEI/ARBs group compared to the control group (OR= 1.50, 95%CI: 1.03-2.18, P =0.03). The magnitude of association was significantly reinforced in the observational studies (OR=1.84, 95%CI 1.19-2.85, P=0.006) but not in the randomized controlled trials (OR=0.88, 95%CI 0.41-1.90 P=0.74). The summary adjusted OR of 4 observational studies was 1.56 (95%CI 1.25-1.94, P<0.0001) and was weaker than the unadjusted OR.

CONCLUSIONS

Although there is some evidence to suggest that the administration of RAAS blockers was associated with the increased risk of CIN in patients undergoing CAG, the robustness of our study remains weak. The results are based on small observational studies and need further validation.

Inhibition of RAS in diabetic nephropathy

Diabetic kidney disease (DKD) is a progressive proteinuric renal disorder in patients with type 1 or type 2 diabetes mellitus. It is a common cause of end-stage kidney disease worldwide, particularly in developed countries. Therapeutic targeting of the renin-angiotensin system (RAS) is the most validated clinical strategy for slowing disease progression. DKD is paradoxically a low systematic renin state with an increased intrarenal RAS activity implicated in its pathogenesis. Angiotensin II (AngII), the main peptide of RAS, is not only a vasoactive peptide but functions as a growth factor, activating interstitial fibroblasts and mesangial and tubular cells, while promoting the synthesis of extracellular matrix proteins. AngII also promotes podocyte injury through increased calcium influx and the generation of reactive oxygen species. Blockade of the RAS using either angiotensin converting enzyme inhibitors, or angiotensin receptor blockers can attenuate progressive glomerulosclerosis in animal models, and slows disease progression in humans with DKD. In this review, we summarize the role of intrarenal RAS activation in the pathogenesis and progression of DKD and the rationale for RAS inhibition in this population.

Prevention of contrast-induced nephropathy through a knowledge of its pathogenesis and risk factors

Contrast-induced nephropathy (CIN) is an iatrogenic acute renal failure (ARF) occurring after the intravascular injection of iodinated radiographic contrast media. During the past several years, in many patients undergoing computed tomography, iodinated contrast media have not been used for the fear of ARF, thereby compromising the diagnostic procedure. But recent studies have demonstrated that CIN is rarely occurring in patients with normal renal function and that preexisting chronic renal failure and/or diabetes mellitus represent(s) predisposing condition(s) for its occurrence. After the description of CIN and its epidemiology and pathophysiology, underlying the important role played by dehydration and salt depletion, precautions for prevention of CIN are listed, suggested, and discussed. Maximum priority has to be given to adequate hydration and volume expansion prior to radiographic procedures. Other important precautions include the need for monitoring renal function before, during, and after contrast media injection, discontinuation of potentially nephrotoxic drugs, use of either iodixanol or iopamidol at the lowest dosage possible, and administration of antioxidants. A long list of references is provided that will enable readers a deep evaluation of the topic.

The impact of renin-angiotensin-aldosterone system blockade on contrast-induced nephropathy: a meta-analysis of 12 studies with 4,493 patients

OBJECTIVES

This meta-analysis investigated the impact of renin-angiotensin-aldosterone system (RAAS) blockade on the occurrence of contrast-induced nephropathy (CIN).

METHODS

Twelve studies comparing the use of RAAS blockade in a total of 4,493 patients undergoing a contrast-using procedure were included. The primary endpoint was the overall postprocedural incidence of CIN.

RESULTS

In the overall pooled analysis, there was no significant difference between the two groups, RAAS blockade 'used' versus 'not-used', in the incidence of postprocedural CIN in the random-effects model (OR 1.27, 95% CI 1.77-2.11, p = 0.351, I(2) = 61.9%). In the stratified analysis, however, for chronic RAAS blockade users, the continuation of the drug was significantly associated with a higher incidence of CIN compared with discontinuation (OR 2.06, 95% CI 1.62-2.61, p < 0.001, I2 = 0.0%). A hazard of continuation was marked in a subgroup of older patients or in patients with chronic kidney disease. For drug-naïve patients, however, administration of RAAS blockade before contrast procedures did not reduce the development of CIN significantly (OR 0.52, 95% CI 0.23-1.16, p = 0.108, I2 = 34.2%).

CONCLUSION

Discontinuation of RAAS blockade in chronic users is associated with a significantly lower incidence of CIN, whereas administration of RAAS blockade as a preventive measure for naïve patients did not show a significant effect on the incidence of CIN.

The Choice of the Iodinated Radiographic Contrast Media to Prevent Contrast-Induced Nephropathy

In patients with preexisting renal impairment, particularly those who are diabetic, the iodinated radiographic contrast media may cause contrast-induced nephropathy (CIN) or contrast-induced acute kidney injury (CI-AKI), that is, an acute renal failure (ARF), usually nonoliguric and asymptomatic, occurring 24 to 72 hours after their intravascular injection in the absence of an alternative aetiology. Radiographic contrast media have different osmolalities and viscosities. They have also a different nephrotoxicity. In order to prevent CIN, the least nephrotoxic contrast media should be chosen, at the lowest dosage possible. Other prevention measures should include discontinuation of potentially nephrotoxic drugs, adequate hydration with i.v. infusion of either normal saline or bicarbonate solution, and eventually use of antioxidants, such as N-acetylcysteine, and statins.

Evaluation of acute kidney injury in the hospital setting

Acute kidney injury (AKI) is becoming more prevalent in the hospital setting and is associated with the worst prognostic outcomes, including increased mortality. Many different factors contribute to the development of AKI in hospitalized patients, including medications, older age, sepsis, and comorbid conditions. Correct evaluation and management of AKI requires investigation and understanding of important causative factors for each of the 3 pathophysiologic categories of renal failure. Preventative efforts rely on prompt recognition of AKI while avoiding iatrogenic insults in the hospital setting.

The growth of acute kidney injury: a rising tide or just closer attention to detail?

Acute kidney injury (AKI), previously termed acute renal failure, is associated with increased mortality, prolonged hospital stay, and accelerated chronic kidney disease (CKD). Over the past 2 decades, dramatic rises in the incidences of AKI have been reported, particularly within the United States. The question arises as to whether these changes reflect actual increases in disease incidence, or are potentially explained by the introduction of consensus definitions that rely on small standardized changes in serum creatinine, changes in coding and reimbursement, or increasingly available and more liberal use of dialysis. In this review, we explore the secular trends in AKI incidence in North America and Western Europe and its potential contributors.

Acute kidney injury by radiographic contrast media: pathogenesis and prevention

It is well known that iodinated radiographic contrast media may cause kidney dysfunction, particularly in patients with preexisting renal impairment associated with diabetes. This dysfunction, when severe, will cause acute renal failure (ARF). We may define contrast-induced Acute Kidney Injury (AKI) as ARF occurring within 24-72 hrs after the intravascular injection of iodinated radiographic contrast media that cannot be attributed to other causes. The mechanisms underlying contrast media nephrotoxicity have not been fully elucidated and may be due to several factors, including renal ischaemia, particularly in the renal medulla, the formation of reactive oxygen species (ROS), reduction of nitric oxide (NO) production, and tubular epithelial and vascular endothelial injury. However, contrast-induced AKI can be prevented, but in order to do so, we need to know the risk factors. We have reviewed the risk factors for contrast-induced AKI and measures for its prevention, providing a long list of references enabling readers to deeply evaluate them both.

Side effects of radiographic contrast media: pathogenesis, risk factors, and prevention

Radiocontrast media (RCM) are medical drugs used to improve the visibility of internal organs and structures in X-ray based imaging techniques. They may have side effects ranging from itching to a life-threatening emergency, known as contrast-induced nephropathy (CIN). We define CIN as acute renal failure occurring within 24-72 hrs of exposure to RCM that cannot be attributed to other causes. It usually occurs in patients with preexisting renal impairment and diabetes. The mechanisms underlying CIN include reduction in medullary blood flow leading to hypoxia and direct tubule cell damage and the formation of reactive oxygen species. Identification of patients at high risk for CIN is important. We have reviewed the risk factors and procedures for prevention, providing a long list of references enabling readers a deep evaluation of them both. The first rule to follow in patients at risk of CIN undergoing radiographic procedure is monitoring renal function by measuring serum creatinine and calculating the eGFR before and once daily for 5 days after the procedure. It is advised to discontinue potentially nephrotoxic medications, to choose radiocontrast media at lowest dosage, and to encourage oral or intravenous hydration. In high-risk patients N-acetylcysteine may also be given.

Effect of renin-angiotensin-system blockers on contrast-medium-induced acute kidney injury after coronary angiography

BACKGROUND/AIMS

With the increasing incidence of cardiovascular disease, angiocardiography using contrast-enhancing media has become an essential diagnostic and therapeutic tool, despite the risk of contrast-medium-induced acute kidney injury (CIAKI). CIAKI may be exacerbated by renin-angiotensin-system (RAS) blockers, which are also used in a variety of cardiovascular disorders. This study evaluated the effects of RAS blockade on CIAKI after coronary angiography.

METHODS

Patients who underwent coronary angiography in our hospital between May 2009 and July 2011 were reviewed. Serum creatinine levels before and after coronary angiography were recorded. CIAKI was diagnosed according to an increase in serum creatinine > 0.5 mg/dL or 25% above baseline.

RESULTS

A total of 1,472 subjects were included in this study. Patients taking RAS blockers were older, had a higher baseline creatinine level, lower estimated glomerular filtration rate (eGFR), and had received a greater volume of contrast medium. After propensity score matching, no difference was observed between the RAS (+) and RAS (.) groups. Multiple logistic regression identified RAS blockade, age, severe heart failure, contrast volume used, hemoglobin level, and eGFR as predictors of CIAKI. Multiple logistic regression after propensity matching showed that RAS blockade was associated with CIAKI (odds ratio, 1.552; p = 0.026).

CONCLUSIONS

This study showed that the incidence of CIAKI was increased in patients treated with RAS blockers.