Impact of continuous deterioration of kidney function 6 to 8 months after percutaneous coronary intervention for acute coronary syndrome

Contrast-Associated Acute Kidney Injury: Definitions, Epidemiology, Pathophysiology, and Implications

Acute kidney injury (AKI) is a common occurrence after contrast media administration. Hemodynamic changes, direct tubular injury, and reactive oxygen species are the proposed mechanisms involved in AKI. However, in most scenarios, it is not possible to establish causality despite extensive clinical evaluation, therefore, contrast-associated AKI (CA-AKI) has become a widely accepted term to define AKI postcontrast. CA-AKI is associated with worse clinical outcomes including cardiovascular events and mortality; however, discussions are ongoing whether CA-AKI is a marker of an increased risk of adverse outcomes or a mediator of such outcomes.

Acute kidney injury in diabetes mellitus: Epidemiology, diagnostic, and therapeutic concepts

Acute kidney injury (AKI) and diabetes mellitus (DM) are public health problems that cause a high socioeconomic burden worldwide. In recent years, the landscape of AKI etiology has shifted: Emerging evidence has demonstrated that DM is an independent risk factor for the onset of AKI, while an alternative perspective considers AKI as a bona fide complication of DM. Therefore, it is necessary to systematically characterize the features of AKI in DM. In this review, we summarized the epidemiology of AKI in DM. While focusing on circulation- and tissue-specific microenvironment changes after DM, we described the active cellular and molecular mechanisms of increased kidney susceptibility to AKI under DM stress. We also reviewed the current diagnostic and therapeutic strategies for AKI in DM recommended in the clinic. Updated recognition of the epidemiology, pathophysiology, diagnosis, and medications of AKI in DM is believed to reveal a path to mitigate the frequency of AKI and DM comorbidity that will ultimately improve the quality of life in DM patients.

Predictive Value of N-Terminal Pro B-Type Natriuretic Peptide for Contrast-Induced Nephropathy Non-Recovery and Poor Outcomes Among Patients Undergoing Percutaneous Coronary Intervention

BACKGROUND

Contrast-induced nephropathy (CIN) is a frequent complication in patients undergoing percutaneous coronary intervention (PCI). The degree of recovery of renal function from CIN may affect long-term prognosis. N-terminal pro B-type natriuretic peptide (NT-proBNP) is a simple but useful biomarker for predicting CIN. However, the predictive value of preprocedural NT-proBNP for CIN non-recovery and long-term outcomes in patients undergoing PCI remains unclear.Methods and Results: This study prospectively enrolled 550 patients with CIN after PCI between January 2012 and December 2018. CIN non-recovery was defined as persistent serum creatinine >25% or 0.5 mg/dL over baseline from 1 week to 12 months after PCI in patients who developed CIN. CIN non-recovery was observed in 40 (7.3%) patients. Receiver operating characteristic analysis indicated that the best NT-proBNP cut-off value for detecting CIN non-recovery was 876.1 pg/mL (area under the curve 0.768; 95% confidence interval [CI] 0.731-0.803). After adjusting for potential confounders, multivariable analysis indicated that NT-proBNP >876.1 pg/mL was an independent predictor of CIN non-recovery (odds ratio 1.94; 95% CI 1.03-3.75; P=0.0042). Kaplan-Meier curves showed higher rates of long-term mortality among patients with CIN non-recovery than those with CIN recovery (Chi-squared=14.183, log-rank P=0.0002).

CONCLUSIONS

Preprocedural NT-proBNP was associated with CIN non-recovery among patients undergoing PCI. The optimal cut-off value for NT-proBNP to predict CIN non-recovery was 876.1 pg/mL.

Serum Albumin to Creatinine Ratio and Short-Term Clinical Outcomes in Patients With ST-Elevation Myocardial Infarction

There is a lack of evidence regarding the short-term predictive value of serum albumin to creatinine ratio (sACR) in patients with ST-segment elevation myocardial infarction (STEMI). This study aims to investigate the relationship between sACR and short-term outcomes in these patients. We retrospectively enrolled 3057 patients with STEMI who underwent primary percutaneous coronary interventions (PCI) (median age was 58 years, and 74.3% were male). In-hospital mortality occurred in 114 (3.7%) patients. Contrast-induced nephropathy (CIN) was reported in 381 (12.4%) patients. During a 30-day follow-up, stent thrombosis (ST) occurred in 28 (.9%) patients and 30-day death in 147 (4.8%) patients. Multivariable logistic regression analysis reported that sACR was inversely associated with 30-day mortality (adjusted odds ratio (aOR): .51, 95% confidence interval (CI) .31-.82, P < .001). The sACR was also inversely associated with in-hospital mortality (aOR: .71, 95% CI .56-.90, P = .009), CIN (aOR: .60, 95% CI .52-.68, P < .001), congestive heart failure (CHF) (aOR: .64, 95% CI .47-.87, P = .007), and ST (aOR .61, 95% CI .41-.92, P = .001) at 30 days. Our findings suggest that sACR is inversely associated with short-term clinical outcomes in patients with STEMI after PCI.

Contrast-Associated Acute Kidney Injury

Contrast-associated acute kidney injury (CA-AKI) is an impairment of renal function, which occurs within days of intravascular administration of iodinated contrast media. Taking into account that minimally invasive cardiac interventions are becoming increasingly popular, compared to traditional surgery, given their impact on prognosis and costs, CA-AKI remains a subject of increasing interest for patients and physicians. This review summarizes the epidemiology and risk stratification, diagnostic criteria, pathophysiology and clinical implications of CA-AKI, providing evidence for the most studied preventive strategies.

A critical review of chronic kidney disease as a risk factor for coronary artery disease

Chronic kidney disease (CKD) is a significant risk factor for cardiovascular disease (CVD). In addition to common CVD risk factors, the presence of CKD is independently associated with an elevated cardiovascular (CV) risk. We examined the association between CKD and CVD, focusing on coronary artery disease (CAD) in both primary and secondary CVD. A total of 94 articles were included for this review using search strategies on Pubmed and Google scholar. The main findings of our review included that besides sharing common risk factors, CKD induces several physiological microscopic changes leading to increased CV risk. These microscopic changes manifest macroscopically with evidence of the development of primary CAD in CKD patients, in addition to accelerating CAD in those with pre-established CV pathology, with CKD consequently being a risk factor for both primary and secondary CAD progression. Current CV guideline recommendations do not discriminate between those patients with and without CKD. Future research is needed in this area, examining if there may be a role for tighter modifiable risk factor targets in this high-risk population.

Predictive value of preprocedural albuminuria for contrast-induced nephropathy non-recovery in patients undergoing percutaneous coronary intervention

Objective

The present study investigated the predictive value of albuminuria for contrast-induced nephropathy (CIN) non-recovery in patients undergoing percutaneous coronary intervention (PCI).

Methods

We retrospectively enrolled 550 consecutive patients inflicted with CIN after PCI and reassessing kidney function among 1 week–12 months between January 2012 and December 2018. Patients were stratified into three groups according to urine albumin: negative group (urine dipstick negative), trace group (urine dipstick trace) and positive group (urine dipstick ≥ 1 +). The primary outcomes were CIN non-recovery (a decrease of serum creatinine which remains ≥ 25% or 0.5 mg/dL over baseline at 1 week–12 months after PCI in patients inflicted with CIN). The odds ratio (OR) of CIN non-recovery was analyzed by logistic regression using the negative urine dipstick group as the reference group.

Results

Overall, 88 (16.0%) patients had trace urinary albumin, 74 (13.5%) patients had positive urinary albumin and 40 (7.3%) patients developed CIN non-recovery. Patients with positive urinary albumin had significantly higher incidence of CIN non-recovery [negative (3.4%), trace (11.4%) and positive (23.0%), respectively; P < 0.0001]. Multivariate analysis showed that trace and positive urinary albumin were associated with an increased risk of CIN non-recovery (trace vs negative: OR 2.88, P = 0.022; positive vs negative: OR 2.99, P = 0.021). These associations were consistent in subgroups of patients stratified by CIN non-recovery risk predictors. And CIN non-recovery was associated with an increased risk of long-term mortality during a mean follow-up period of 703 days (P < 0.001).

Conclusion

Preprocedural albuminuria was associated with CIN non-recovery in patients undergoing PCI.

Impact of worsening renal function on peak oxygen uptake in patients with acute myocardial infarction

AIM

Worsening renal function (WRF) induced by acute myocardial infarction (AMI) is a strong predictor of cardiovascular events and mortality. Peak oxygen uptake may contribute to prognosis in AMI patients with WRF, however, the impact of WRF on peak oxygen uptake is unclear.

METHODS

Among 154 patients with AMI who underwent emergency percutaneous coronary intervention and participated in phase II cardiac rehabilitation, those who underwent cardiopulmonary exercise testing were consecutively enrolled. WRF was defined as a ≥20% decrease in estimated glomerular filtration rate (eGFR [ml/min/1.73 m² ]) from admission to that at cardiopulmonary exercise testing. The association of WRF with peak oxygen uptake was evaluated by multivariate regression analysis. The non-WRF group was divided into two subgroups according to eGFR <60/≥60 at cardiopulmonary exercise testing, and eGFR at cardiopulmonary exercise testing and peak oxygen uptake of all three groups were compared.

RESULTS

Ninety-four patients were enrolled in the final analysis. Multiple linear regression analysis showed that WRF was associated with peak oxygen uptake (p = .003). Comparing the non-WRF group with eGFR at cardiopulmonary exercise testing <60 and the WRF group, although eGFR at cardiopulmonary exercise testing was similar (p = 1.000), peak oxygen uptake in the WRF group was significantly lower (p = .026).

CONCLUSION

WRF, not eGFR at cardiopulmonary exercise testing was significantly associated with peak oxygen uptake in patients with AMI. This result suggests that when considering the relationship between renal function and peak oxygen uptake, WRF must be taken into account.

Imaging and surgical predictive factors for postoperative hemorrhage after partial nephrectomy and clinical results of trans-arterial embolization

Partial nephrectomy (PN) has been established as the standard treatment for T1 renal tumors, and postoperative hemorrhage due to vascular complications is a rare but potentially life-threatening complication reported after PN. Thus, this study evaluated the imaging and surgical factors associated with postoperative hemorrhage after PN and the clinical results of trans-arterial embolization. A retrospective review of the institutional PN database was performed from May 2012 to January 2019, revealing that we performed 810 PN procedures at our institution. In total, 12 patients were referred to the interventional radiology department for vascular complications after the procedure. Patients with and without transarterial embolization (TAE) were age- and sex-matched with 56 patients. Preoperative imaging characteristics and operative details were considered. Univariable and multivariable analyses were used to test their eventual association with the occurrence of hemorrhage. Furthermore, renal functions at diagnosis, after operation or embolization for TAE cases, and at the last follow-up were recorded. A diagnosis of hemorrhage was made at a median of 4 (range, 0-25) days after surgery. The majority of patients (50%) presented with gross hematuria. T test revealed higher renal tumor-parenchyma contact area (TPA) (P = .0407), Length-A (P = .0136), Length-P (P = .0267), operation time (P = .0214) and estimated blood loss (P = .0043) in patients with hemorrhage than in controls. Binary logistic regression analysis identified TPA (P = .048) and estimated blood loss (P = .042) as independent predictors for postoperative hemorrhage with an area under the ROC curve of 0.705 (64% sensitivity and 79% specificity). In conclusion, the occurrence of hemorrhage after PN was associated with a larger TPA and more estimated blood loss during the procedure. In patients who underwent selective TAE, renal function remained comparable with that of controls.

A comparison between two different definitions of contrast-associated acute kidney injury for long-term mortality in patients with diabetes undergoing coronary angiography: a prospective cohort study

Background

The definitions of contrast-associated acute kidney injury (CA-AKI) are diverse and have different predictive effects for prognosis, which are adverse for clinical practice. Few articles have discussed the relationship between these definitions and long-term prognosis in patients with diabetes.

Methods

A total of 1154 diabetic patients who were undergoing coronary angiography (CAG) were included in this study. Two definitions of CA-AKI were used: CA-AKI_A was defined as an increase ≥ 0.3 mg/dl or > 50% in serum creatinine (SCr) from baseline within 72 h after CAG, and CA-AKI_B was defined as an increase ≥ 0.5 mg/dl or > 25% in SCr from baseline within 72 h after CAG. We used Cox regression to evaluate the association of these two CA-AKI definitions with long-term mortality and calculate the population attributable risks (PARs) of different definitions for long-term prognosis.

Results

During the median follow-up period of 7.4 (6.2–8.2) years, the overall long-term mortality was 18.84%, and the long-term mortality in patients with CA-AKI according to both CA-AKI_A and CA-AKI_B criteria were 36.73% and 28.86%, respectively. We found that CA-AKI_A (HR: 2.349, 95% CI 1.570–3.517, p = 0.001) and CA-AKI_B (HR: 1.608, 95% CI 1.106–2.339, p = 0.013) were associated with long-term mortality. The PARs were the highest for CA-AKI_A (31.14%), followed by CA-AKI_B (14.93%).

Conclusions

CA-AKI is a common complication in diabetic patients receiving CAG. The two CA-AKI definitions are significantly associated with a poor long-term prognosis, and CA-AKI_A, with the highest PAR, needs more clinical attention.

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.

Increased Heart Rate during Walk Test Predicts Chronic-Phase Worsening of Renal Function in Patients with Acute Myocardial Infarction and Normal Kidney Function

Chronic-phase worsening renal function (WRF) in patients with acute myocardial infarction (AMI) has been associated with poor prognosis. However, there is no consensus on either the method of prevention or the cause. The aim of this study was to determine factors predictive of chronic-phase WRF from the viewpoint of circulatory dynamics response to exercise during hospitalization of AMI patients without renal dysfunction on admission. We studied 186 consecutively AMI patients who underwent the 200-m walk test. Chronic-phase WRF was defined as a 20% decrease in estimated glomerular filtration rate (eGFR) from baseline to 8–10 months after AMI onset. Heart rate (HR) and systolic blood pressure recorded during the 200-m walk test were evaluated as circulatory dynamics responses. In total, 94 patients were enrolled. Multiple linear regression analysis showed that ΔHR (peak-rest) associated significantly with ΔeGFR (β = 0.427, p = 0.018). The receiver operating characteristic curve of ΔHR to predict chronic-phase WRF showed an area under the curve of 0.77, with a cut-off value of 22.0 bpm having a 95% sensitivity and 55% specificity. Among circulatory dynamics responses during exercise in the acute phase after AMI, ΔHR was an independent predictor of chronic-phase WRF.

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.

A risk scoring model to predict renal progression associated with postcontrast acute kidney injury in chronic kidney disease patients

Postcontrast acute kidney injury (AKI) occurs more frequently in patients with lower estimated glomerular filtration rate. We hypothesized that postcontrast AKI in chronic kidney disease (CKD) patients with distinct risk factors might be associated with accelerated renal progression.We undertook this retrospective cohort study to develop and validate a risk scoring model for predicting renal progression. In a development dataset, 18,278 contrast-enhanced CT scans were performed in 9097 patients with CKD (estimated glomerular filtration rate [eGFR] < 60 mL/min/1.73 m) who were not undergoing dialysis. Postcontrast AKI was observed in 5.8% (1051/18,278) of all contrast-enhanced CTs with 7.6% (689/9097) of the total CKD patients. We investigated the 1-year renal outcome in 224 eligible patients. A risk scoring model was developed with multivariate regression analysis and was assessed in external validation (independent 154 patients).Among 224 patients, 70 (31.3%) patients had progression of renal dysfunction at 1 year (defined as reduction in estimated GFR ≥25% at 1 year). A risk score of 4, 4, 6, 6, 7, or 6 was assigned to diabetes, baseline estimated GFR < 45 mL/min/1.73 m, hypertension, repeated contrast exposure, congestive heart failure, and persistent renal injury (defined as an elevation of serum creatinine ≥25% at 3 months), respectively. An increasing risk score was associated with renal progression. Of note, persistent renal injury was more prevalent in the progression group than in the non-progression group. The AUROC of the model in the development population was 0.765. In the validation dataset, however, the discriminative power decreased (AUROC = 0.653).Our suggested model provided the risk of renal progression, aiding in predicting prognosis, counseling, and improving outcomes in CKD patients complicated by postcontrast AKI.

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.

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.

Anemia (Hemoglobin ≤ 13 g/dL) as a Risk Factor for Contrast-Induced Acute Kidney Injury Following Coronary Angiography

Contrast-induced acute kidney injury (CI-AKI) following coronary angiography is associated with increased mortality. The association between severity of anemia and CI-AKI following coronary angiography is not well-established. In this retrospective study, we aimed at assessing the association of anemia of various severity with the risk of CI-AKI in patients who underwent coronary angiography. We included all patients who underwent coronary angiography with or without percutaneous coronary intervention from January 2012 to December 2016 at a single tertiary care hospital. CI-AKI was defined as ≥0.3 mg/dL increase in creatinine from baseline and anemia was defined as baseline hemoglobin ≤13 g/dL. Patients were stratified into three subgroups-mild (11.1 to 13.0 g/dL), moderate (9.1 to 11.0 g/dL) and severe anemia (7.0 to 9.0 g/dL). Crude and adjusted odds ratios (AOR) were calculated using univariate multiple logistic regression analysis. Of 2,055 patients (females = 30.7%, mean age 58.0 ± 12.5 years) who underwent coronary angiography, 293 (14.3%) developed CI-AKI. Presence of anemia was associated with increased risk of developing CI-AKI (AOR = 5.3, 95% confidence interval [CI] = 3.8 to 7.3, p < 0.001). Risk of CI-AKI was increasingly higher with increasing severity of the anemia; mild (AOR = 3.4, 95% CI = 2.5 to 4.7, p < 0.001), moderate (AOR = 9.8, 95% CI = 6.9 to 14.2, p < 0.001) and severe (AOR = 13.7, 95% CI = 8.2 to 23.1, p < 0.001). In conclusion, severity of anemia is a strong predictor of CI-AKI following coronary angiography.

Acute Kidney Injury in Diabetic Patients With Acute Myocardial Infarction: Role of Acute and Chronic Glycemia

Background

In acute myocardial infarction, acute hyperglycemia is a predictor of acute kidney injury (AKI), particularly in patients without diabetes mellitus. This emphasizes the importance of an acute glycemic rise rather than glycemia level at admission. We investigated whether, in diabetic patients with acute myocardial infarction, the combined evaluation of acute and chronic glycemic levels may have better prognostic value for AKI than admission glycemia.

Methods and Results

At admission, we prospectively measured glycemia and estimated average chronic glucose levels (mg/dL) using glycosylated hemoglobin (HbA_1c), according to the following formula: 28.7×HbA_1c (%)−46.7. We evaluated the association with AKI of the acute/chronic glycemic ratio and of the difference between acute and chronic glycemia (Δ_A−C). We enrolled 474 diabetic patients with acute myocardial infarction. Of them, 77 (16%) experienced AKI. The incidence of AKI increased in parallel with the acute/chronic glycemic ratio (12%, 14%, 22%; P=0.02 for trend) and Δ_A−C (13%, 13%, 23%; P=0.01) but not with admission glycemic tertiles (P=0.22). At receiver operating characteristic analysis, the acute/chronic glycemic ratio (area under the curve: 0.62 [95% confidence interval, 0.55–0.69]; P=0.001) and Δ_A−C (area under the curve: 0.62 [95% confidence interval, 0.54–0.69]; P=0.002) accurately predicted AKI, without difference in the area under the curve between them (P=0.53). At reclassification analysis, the addition of the acute/chronic glycemic ratio and Δ_A−C to acute glycemia allowed proper AKI risk prediction in 16% of patients.

Conclusions

In diabetic patients with acute myocardial infarction, AKI is better predicted by the combined evaluation of acute and chronic glycemic values than by assessment of admission glycemia alone.

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.

Remote ischemic preconditioning for prevention of contrast induced nephropathy-Insights from an Indian study

Objectives

To study if four cycles of remote ischemic preconditioning (RIPC) could offer protection against contrast induced nephropathy (CIN) and post procedural renal dysfunction in high risk patients undergoing percutaneous coronary intervention (PCI).

Methods

This was a prospective single blind randomized sham controlled trial where patients undergoing coronary angioplasty with stage III chronic kidney disease were randomized into sham preconditioning and remote ischemic preconditioning. The primary outcome was the reduction in the incidence of CIN. The secondary outcomes were the maximum improvement in eGFR, maximum reduction in serum creatinine and composite of requirement of hemodialysis, death and rehospitalization for heart failure up to 6 weeks after PCI.

Results

Eleven out of fifty patients in the study group developed CIN (22%) compared to eighteen out of the fifty control patients (36%) (p = 0.123). There was a statistically significant improvement in the post procedure creatinine values at 24 h (p = 0.013), 48 h (p = 0.015), 2 weeks (p = 0.003), 6 weeks (p = 0.003) and post procedure glomerular filtration rate (eGFR) values at 24 h (p = 0.026), 48 h (p = 0.044), 2 weeks (p = 0.015) and 6 weeks (p = 0.011) in study group compared to control group. The secondary outcome composite of requirement of hemodialysis, death and rehospitalization for heart failure was not statistically significant (p: 0.646).

Conclusion

RIPC does not result in significant reduction of CIN. However RIPC helps in the prevention of post procedural worsening in eGFR and serum creatinine even up to 6 weeks.

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.

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.

Contrast-Induced Acute Kidney Injury: An Update

Contrast-induced acute kidney injury (CI-AKI) is defined as an abrupt deterioration in renal function associated with the administration of iodinated contrast media. This type of acute kidney injury is frequently encountered as a complication of percutaneous coronary intervention (PCI) and is associated with adverse short- and long-term outcomes including mainly mortality, cardiovascular morbidity and prolongation of hospitalization. The incidence of CI-AKI after PCI ranges from 2 to 20 % according to baseline kidney function. It may also range according to the clinical setting, being higher after emergency PCI. The primary manifestation is a small decline in kidney function, occurring 1 to 3 days after the procedure. Kidney function usually returns to preexisting levels within 7 days. Incidence of acute renal failure requiring dialysis following PCI is rare (<1 %). The present article aims to review up-to-date published data concerning diagnosis, definition, epidemiology and prognosis of this novel in-hospital epidemic.

Bilirubin Levels are Associated With Contrast-Induced Nephropathy in Peripheral Artery Disease

The relationship between contrast-induced nephropathy (CIN) and oxidative mechanisms is well documented. Our aim was to demonstrate the possible relationship between CIN and serum bilirubin as an antioxidant molecule. This retrospective study included 359 patients with peripheral artery disease (PAD) who underwent peripheral diagnostic angiography; 179 developed CIN after the intervention and another 180 were the control group, matched for age, gender, and cardiovascular risk factors. Baseline, 48- to 72-hour, and 30-day laboratory values, major adverse cardiovascular events, and dialysis requirements were recorded. Patients with CIN had significantly higher levels of uric acid, red cell distribution width, and neutrophil-to-lymphocyte ratio (NLR) but lower total bilirubin compared to the control patients ( P < .05). Multivariate logistic regression analysis showed that diabetes mellitus, left ventricular ejection fraction, uric acid, NLR, and total bilirubin levels were independent predictors of CIN development ( P = .01, P = .001, P = .001, P = .01, and P = .001, respectively). This study demonstrated that decreased total bilirubin was associated with CIN development after the administration of radiocontrast agents in patients with PAD.

Long-Term Adverse Effects of Low-Osmolar Compared With Iso-Osmolar Contrast Media After Coronary Angiography

The relative incidence of long-term adverse effects between low-osmolar contrast media (LOCM) and iso-osmolar contrast media (IOCM) after coronary angiography is still unclear. We analyzed cardiology patients undergoing coronary angiography from January 2006 to July 2013 using either LOCM (iohexol, iopromide) or IOCM (iodixanol) at a single institution. For each contrast medium, primary (all-cause mortality, n = 6,992) and secondary outcomes (long-term renal injury and cardiovascular events beyond 90 days, n = 2,792) were recorded. Inverse probability weighing (IPW) was applied to minimize the selection bias between groups. Unadjusted all-cause mortality was significantly lower for LOCM versus IOCM (hazard ratio [HR] 0.28, 95% CI 0.23 to 0.34). After multivariate Cox regression or IPW, all-cause mortality became comparable and lost statistical significance. Chronic kidney disease subgroup had higher mortality risk when receiving LOCM compared with IOCM (regression adjusted HR 1.80, 95% CI 0.95 to 3.42; IPW-adjusted HR 1.57, 95% CI 0.99 to 2.48). In conclusion, after coronary angiography, patients receiving LOCM had comparable overall long-term mortality compared with IOCM after adjustment. LOCM tended to induce higher long-term mortality than IOCM in chronic kidney disease cohorts.

Prognostic significance of serum creatinine and its change patterns in patients with acute coronary syndromes

BACKGROUND

In acute coronary syndromes (ACS), serum creatinine (sCr) levels have short- and long-term prognostic value. However, it is possible that repeated evaluations of sCr during hospitalization, rather than measuring sCr value at admission only, might improve risk assessment. We investigated the relationship between sCr baseline value, its changes, and in-hospital mortality in patients hospitalized with ACS.

METHODS

In 2,756 ACS patients, sCr was measured at hospital admission and then daily, until discharge from coronary care unit. Patients were grouped according to the maximum sCr change observed: <0.3 mg/dL change from baseline (stable renal function [SRF] group), ≥0.3 mg/dL decrease (improved renal function [IRF] group), and ≥0.3 mg/dL increase (worsening renal function [WRF] group).

RESULTS

Of the 2,756 patients, 2,163 (78%) had SRF, 292 (11%) had IRF, and 301 (11%) had WRF. In-hospital mortality in the 3 groups was 0.5%, 2%, and 14% (P < .001), respectively. Peak sCr value was a more powerful predictor of mortality (area under the curve 0.86, 95% CI 0.81-0.92) than the initial sCr value (area under the curve 0.69, 95% CI 0.63-0.77; P < .001). When sCr and its change patterns during coronary care unit stay were evaluated together, improved mortality risk stratification was found.

CONCLUSIONS

In ACS patients, daily sCr value and its change pattern are stronger predictors of in-hospital mortality than the initial sCr value only; thus, their combined evaluation provides a more accurate and dynamic stratification of patients' risk. Finally, the intermediate mortality risk of IRF patients possibly reflects acute kidney injury started before hospitalization.

Effect of Contrast-Induced Nephropathy on the Long-Term Outcome of Patients with Non-ST Segment Elevation Myocardial Infarction

BACKGROUND

Contrast-induced nephropathy (CIN) has been traditionally associated with increased mortality and adverse cardiovascular events. We sought to determine whether CIN has a negative impact on the long-term outcome of patients with non-ST segment elevation myocardial infarction (NSTEMI).

METHODS

A total of 312 consecutive patients (mean age 59 years, 76% male) who presented with NSTEMI and had undergone an early invasive procedure were retrospectively included. CIN was defined as either a 25% or 0.5-mg/dl increase in baseline serum creatinine (Cr) 72 h after the procedure. The primary endpoint of the study was mortality in the long-term follow-up (38 months, interquartile range 30-40). The secondary endpoint consisted of mortality and myocardial infarction (MI).

RESULTS

CIN developed in 30 (9.6%) patients. Independent predictors of CIN were the contrast volume-to-Cr clearance ratio, left ventricular ejection fraction and hemoglobin concentration. The primary (20 vs. 8.5%, p = 0.042) and secondary endpoints (33.3 vs. 17%, p = 0.029) were observed more frequently in patients with CIN during long-term follow-up. The unadjusted odds ratio (OR) of CIN was 2.55 [95% confidence intervals (CI) 1.04-6.24, p = 0.040] for mortality and 2.15 (CI 1.09-4.25, p = 0.028) for mortality/MI. However, after adjustment for confounding factors, CIN was not an independent predictor of either mortality (OR 1.62, CI 0.21-12.57, p = 0.646) or mortality/MI (OR 1.12, CI 0.31-4.0, p = 0.860).

CONCLUSION

The effect of CIN on the long-term outcome of patients with NSTEMI was substantially influenced by confounding factors. CIN was a marker, rather than a mediator, of increased cardiovascular risk, and the baseline renal function was more conclusive as a long-term prognosticator.

Contrast-Induced Nephropathy

Contrast-induced nephropathy (CIN) represents an important adverse effect of contrast media (CM) administration. Contrast-induced nephropathy is associated with prolonged hospitalization as well as increased cardiovascular morbidity, renal morbidity, and all-cause mortality. Several risk factors may predict CIN incidence, and various scores and ratios have been proposed to identify high-risk patients. Novel biomarkers may provide an earlier diagnosis of CIN. A multifactorial approach is required for CIN prevention including hydration, administration of low- or iso-osmolar CM, minimizing CM volume, and statin administration. Renal function may deteriorate after CM administration, even in the absence of CIN. Therefore, this deterioration may not be an “all or none” phenomenon; it may well occur in many patients receiving CM, with/without CIN, and may prove to be an underestimated risk factor. Patients should be followed up for longer periods as outpatients after CM exposure to assess kidney function and predict subsequent increased morbidity and mortality.