Risk Factors For Contrast-induced Nephropathy Research Articles

Abstract P131: Effect of uncontrolled systolic blood pressure in hypertensive patients as a risk factor for CIN after coronary angiography with preventative management of CIN : single center prospective study

Background: Contrast induced nephropathy(CIN) is associated with poor outcomes like dialysis and prolonged hospitalization and risk of death. Clinical factor for CIN include advanced age, diabetes (DM), female, heart failure(HF) and hypertension(HTN). Many prophylaxis strategies for CIN(normal saline hydration, N-acetylcysteine, NAHCO3) had been studied and their preventive effects had been known to be no difference. Purpose: We tried to evaluate the effects of uncontrolled systolic blood pressure(defined as SBP>160mmHg) in hypertensive patients as a risk factor for CIN after coronary angiography(CAG) with various preventative management of CIN (normal saline hydration, N-acetylcysteine, NAHCO3). Methods: This study included 41patients who performed CAG combined with various preventative management of CIN in single center. All patients were evaluated with serum creatinine(SCr), creatinine clearance(CrCl) before and after coronary angiography at day0, day1, day2 and day30. Definition of CIN include; SCr increase of ≥0.5 mg/dL, a SCr increase ≥25%, an CrCl decrease of ≥25%, or the composite, occurring 48 to 72 hours after contrast exposure. We also analyzed preexisting renal insufficiency(GFR<60ml/min), DM and HTN, age, sex, anemia, contrast volume and HF which are known risk factors for CIN. Results: 11 of 41 patients developed CIN. There was no statistical differences between the two groups in the aspect of baseline Cr, age, sex, body weight, contrast volume and the prevalence of known risk factor for CIN (DM, HTN, HF and preexisting renal failure). Mean baseline SBP in the CIN group was higher than non-CIN group(166.3±31.9 vs142.4±25.7, P-value=0.018). Among 23 patients with HTN, 11 patients (47.8%) had uncontrolled SBP. The multivariable logistic regression analysis showed that an uncontrolled SBP (odds ratio [OR] 12.63, 95% confidence interval [CI] 1.83-87.07) was the independent risk factor for CIN. Conclusions: CIN associate with variety of short-term and long-term complication after CAG. Hypertension is well known as one of the risk factors for CIN. Even if appropriate preventative management of CIN are taken before and after CAG, uncontrolled SBP in hypertensive patients could increase the risk of CIN.

Risk Factors of Contrast-Induced Nephropathy after Percutaneous Coronary Interventions: An Observational Study

Risk Factors of Contrast-Induced Nephropathy after Percutaneous Coronary Interventions: An Observational Study

Evaluation of contrast induced nephropathy related risk factors and long-term results.

We aimed to evaluate the frequency of contrast induced nephropathy (CIN), its relationship with accepted risk factors and long-term renal outcomes in patients who underwent coronary angiography (CAG). All patients who underwent CAG between April 2020 and April 2021 were retrospectively evaluated. CIN was defined as characteristic increase in serum creatinine after CAG. CIN developed in 50 (5.4%) of 934 patients. The CIN rate was found to be statistically significantly higher in patients with diabetes, hypertension, heart failure and those using diuretics. Pre-procedural hemoglobin, albumin and GFR were found to be independent risk factors for CIN. After discharge, the urea and creatinine values of the patients who developed CIN were significantly higher than those who did not. We concluded that in order to reduce the development of CIN, hemoglobin and albumin levels should be evaluated with renal functions before the procedure and they should be kept within normal limits.

Incidence of acute kidney injury in patients with acute ischaemic stroke undergoing CT angiography (CTA) and CT perfusion (CTP): a systematic review and meta-analysis

Background and purposeWe conducted a systematic review and meta-analysis to assess the incidence of acute kidney injury (AKI) in patients undergoing CT angiography (CTA) and CT perfusion (CTP) for acute...

Exploring the correlation between radial artery access and decreased occurrence of contrast-induced nephropathy.

Objective: To Investigate the Impact of Radial Artery Access on Contrast-Induced Nephropathy (CIN) Incidence. Study Design: Retrospective study. Setting: Department of Cardiology, Hayatabad Medical Complex in Peshawar. Period: January 2021 to June 2022. Material & Methods: Patients aged ≥ 30 who have undergone cardiac catheterization procedures, with a focus on those who have undergone the procedure using radial artery access. Those patients who had pre-existing renal impairments or kidney diseases, with a history of contrast allergies, were included in the study. However, those patients who were under the age of < 30, had undergone cardiac catheterization procedures using femoral artery access, and with incomplete medical records were excluded. All the data were analyzed in SPSS version 26. Results: In our study involving 164 participants. Individuals who experienced CIN exhibited a considerably greater average age of 69.89 years when contrasted with the 66.86 years of those in the non-CIN category (p=0.03). Furthermore, a higher percentage of patients in the CIN group were aged 65 or older (35.1% vs. 11%, p<0.001), highlighting the increased vulnerability of older individuals to CIN. The timing of reperfusion therapy, indicated by the time-to-reperfusion, was significantly longer in the CIN group (6.2 ± 3.3 hours) compared to the non-CIN group (4.9 ± 3.7 hours, p=0.001), suggesting that delayed reperfusion may be a risk factor for CIN. Conclusion: Patients with anterior infarction, delayed reperfusion, lower left ventricular ejection fraction (LVEF), and higher serum creatinine levels were also more likely to develop CIN.

Рrevention of contrast-induced nephropathy during interventional treatment of acute coronary syndrome

The aim of the work was to determine the risk factors of contrast-induced nephropathy in patients with acute coronary syndrome and to evaluate the effectiveness of methods of its prevention. There were examined 62 patients admitted to the interventional cardiology department during 9 months of routine practice with a diagnosis of acute coronary syndrome and concomitant chronic kidney disease. Among them, 56.45% have diabetic nephropathy, 21% – hypertensive nephro­pathy, 19.35% – chronic pyelonephritis, 3.2% – gouty nephropathy. According to the stages of chronic kidney disease: I stage – 8.1%, II stage – 46.8%, III A stage – 30.6%, III B stage – 14.5% of patients. The control group consisted of 32 patients with acute coronary syndrome without kidney pathology. All patients underwent urgent percutaneous coronary intervention using a water-soluble low-osmolarity radiocontrast medium. The risk of contrast-induced nephropathy was determined according to the Mehran scale. Contrast-induced nephropathy was diagnosed by an increase in serum creatinine over 24-48 hours by >25%. Prevention of contrast-induced nephropathy according to existing recommendations was carried out by prescribing early statin therapy and diuresis-controlled combined hydration in 22 patients with concomitant chronic kidney disease. Mathematical processing was performed using Statistica 8.0 software (StatSoft Inc, USA). Patients with chronic kidney disease had a high and very high risk of contrast-induced nephropathy in 19.4% and 3.2% of cases, among them in 91.6% of high and in 100% very high-risk contrast-induced nephropathy developed. Patients in the control group had a low to moderate risk, none of them developed contrast-induced nephropathy. It has been shown that the risk of contrast-induced nephropathy depends on the stage of chronic kidney disease and is associated with a decrease in the ejection fraction of the left ventricle (≤40%), acute left ventricle failure of the III and IV classes according to Killip, a decrease in diuresis in the first 12-24 hours after urgent percutaneous coronary intervention up to ≤0.6 ml/h/kg; in patients with diabetic nephropathy taking metformin 6-12 hours before the administration of the X-ray contrast medium and the glomerular filtration rate ≤45 ml/min./1.73 m2. In patients who underwent prevention of contrast-induced nephropathy in its entirety, its development was not registered.

Administration of N-acetylcysteine for contrast-induced acute kidney injury; an updated mini-review

Contrast-induced acute kidney injury (CI-AKI) is a potential complication of medical imaging procedures that use contrast media. It is important to identify and manage risk factors for contrast-induced nephropathy and to monitor patients for signs of renal damage after contrast administration. N-acetylcysteine (NAC) can prevent CI-AKI through multiple mechanisms of action, including reducing oxidative stress, improving renal hemodynamics, reducing inflammation, reducing apoptosis and fibrosis, reducing oxidative stress-induced DNA damage, reducing tubular cell injury, and reducing renal tubular cell apoptosis. However, the exact mechanisms of action may vary based on the specific study or context. Further research is needed to fully elucidate the molecular mechanisms of NAC in preventing CI-AKI.

Application of systemic inflammation score for the assessment of contrast-induced acute kidney injury; a review

Contrast-related acute renal failure is a multifactorial condition that involves oxidative stress, inflammation, and direct tubular toxicity. Risk factors for contrast-induced nephropathy comprise pre-existing kidney dysfunction, diabetes mellitus, advanced age, congestive heart failure, hypotension, anemia, and volume depletion. Preventive measures include identifying high-risk patients and implementing preventive measures such as adequate hydration, minimizing contrast use, and avoiding using contrast media in patients with pre-existing renal dysfunction. The systemic inflammation score is a promising tool for predicting contrast-associated acute kidney injury (CA-AKI) in patients undergoing contrast-enhanced imaging procedures. Further studies are needed to validate the use of SIS in clinical practice and to better understand the underlying mechanisms of inflammation in (CA-AKI).

Incidence and risk factors of contrast-induced nephropathy in acute stroke patients undergoing computed tomography angiography: A single-center study.

To investigate the prevalence and risk factors linked to contrast-induced nephropathy in this specific patient population, aiming to ensure the highest quality of clinical care. In a retrospective analysis, all patients who presented with an acute stroke to King Fahad Hospital, Jeddah, Emergency Department from March until November 2022 and underwent Computed Tomography Angiography (CTA) brain, Inclusion criteria were as follows: a baseline creatinine results and CTA examination performed within 24 hours of symptom onset and an available early (<5 days after CTA) follow-up creatinine result. Among 246 stroke patients in the emergency, 182 underwent brain CTA and 8.24% had Contrast-Induced Nephropathy (CIN). intracerebral hemorrhage (ICH) increased CIN risk 7-fold (OR=6.7; 95% CI: 1.23-33.3). Abnormal baseline raised CIN risk 8-fold (OR=7.8; 95% CI: 1.74-35.1). hypertension doubled the risk for CIN (OR=2.1; 95% CI: 1.26-6.98) CONCLUSION: The incidence of CIN was 8.2%, particularly elevated in patients with ICH, hypertension, tissue plasminogen administration, and abnormal baseline, necessitating vigilance in managing acute stroke cases.

Different hydration methods for the prevention of contrast-induced nephropathy in patients with elective percutaneous coronary intervention: a retrospective study

BackgroundHydration is currently the main measure to prevent contrast-induced nephropathy (CIN). We aimed to compare the preventive effect of preprocedure and postprocedure hydration on CIN in patients with coronary heart disease undergoing elective percutaneous coronary intervention (PCI).MethodsA retrospective study included 198 cases of postprocedure hydration and 396 cases of preprocedure hydration using propensity score matching. The incidence of CIN 48 h after PCI and adverse events within 30 days after contrast media exposure were compared between the two groups. Logistic regression analysis was used to analyse the risk factors for CIN.ResultsThe incidence of CIN in the postprocedure hydration group was 3.54%, while that in the preprocedure hydration group was 4.8%. There was no significant difference between the two groups (p = 0.478). Multivariate logistic regression analysis showed that diabetes mellitus, baseline BNP and cystatin C levels, and contrast agent dosage were independent risk factors for CIN. There was no significant difference in the incidence of major adverse events between the two groups (3.03% vs. 2.02%, p = 0.830).ConclusionsPostprocedure hydration is equally effective compared to preoperative hydration in the prevention of CIN in patients with coronary heart disease undergoing elective PCI.

Examine the Risk Factors for Contrast-Induced Nephropathy in Patients Undergoing Percutaneous Coronary Intervention (PCI) and the Prevalence of this Complication

Objective: The purpose of this study was to determine the incidence of contrast-induced nephropathy and risk variables among patients undergoing multi-vessel percutaneous coronary intervention (PCI). Study Design: Prospective / Observational study Place and Duration: Department of Interventional Cardiology, Peshawar Institute of Cardiology Peshawar in the duration from November 2022 to April, 2023. Methods: There were 168 patients of both genders with ages 20-70 years were presented in this study. Data on enrolled patients' age, gender, BMI, marital status and education level were collected after receiving written permission from each patient. This research included people who had undergone a percutaneous coronary intervention. Serum creatinine &gt;0.5mg/dl from the baseline value was classified as contrast induced nephropathy. CIN-related risk factors were studied. Data was analyzed using SPSS 22.0. Results: Patients mean age was 49.8±19.44 years and with mean body mass index 24.1±7.37 kg/m2. 90 patients were males. CIN was found in 42 (25%) cases. Contrast volume, hypertension, diabetes mellitus, and age &gt;60 were the most common risk factors for CIN. Conclusion: Contrast-induced nephropathy is a serious danger for patients undergoing PCI. Anemia (age &gt;60), diabetes mellitus (contrast volume &gt;150 ml), and heart failure were found to increase the likelihood of developing CIN. Keywords: Contrast Induced Nephropathy, Percutaneous Coronary Intervention, Risk Factors

Contrast-induced nephropathy after recanalization chronic coronary occlusion in patients with renal artery stenosis and normal creatinine levels

Introduction. Contrast-induced nephropathy (CIN) is a complication that occurs after contrast medium (CM) administration. The existing risk scales for possible CIN include chronic kidney disease and do not take into account stenotic changes in the renal artery with normal serum creatinine levels.The Objective was to study the frequency of CIN in patients with acute and chronic coronary occlusion (CCO) after endovascular recanalization in the presence of hemodynamically significant renal artery damage with initially normal creatinine levels.Methods and Materials. The study included 38 patients with acute coronary syndrome (control group) and 67 patients with CCO and hemodynamically significant renal artery stenosis (main group). Stenting of one of the renal arteries was performed in 25 patients out of 67 patients before planned coronary revascularization.Results. The incidences of CIN were significantly higher than the calculated one in patients with CCO and renal artery stenosis. In the group of patients with pre-stenting of the renal arteries, there was a decrease in cases of CIN.Conclusions. Renal artery stenosis with normal creatinine levels is an additional risk factor for CIN.

Risk Factors of Contrast-Induced Nephropathy in Patients Undergoing Coronary Intervention Procedures

Introduction: Coronary intervention (coronary angiography and percutaneous coronary intervention) is a medical procedure that uses significant amounts of contrast, which can lead to an increased incidence of contrast-induced nephropathy (CIN). This study aimed to determine the risk factors for contrast-induced nephropathy in patients undergoing coronary intervention procedures at Dr. M Djamil General Hospital, Padang, Indonesia.&#x0D; Methods: This study is a cross-sectional analytic observational study. A total of 100 research subjects participated in this study. Univariate analysis of the frequency distribution was performed on the variable test. Bivariate analysis was performed to determine the risk factors associated with CIN in patients undergoing coronary intervention procedures, p&lt;0.05.&#x0D; Results: The results of the study showed that contrast volume ≥ 100 ml was associated with the incidence of CIN, p&lt;0.05. In addition, serum creatinine level &gt; 1.5 mg/dL was associated with the incidence of CIN, p&lt;0.05.&#x0D; Conclusion: Contrast volume ≥ 100 ml and serum creatinine level &gt; 1.5 mg/dl increase the risk of contrast-induced nephropathy in patients undergoing coronary intervention procedures at Dr. M Djamil General Hospital, Padang, Indonesia.

The Value of C-reactive Protein/Albumin Ratio in the Prediction of Contrast-Induced Nephropathy in Emergency Department Patients.

Contrast-induced nephropathy (CIN) is the third most common cause of acute renal failure in hospitalized patients and is an important cause of prolonged hospital stay, morbidity, and mortality. We aimed to investigate the effectiveness and sufficiency of the prognostic capacity of the inflammatory biomarkers C-reactive Protein (CRP) and albumin ratio (CAR) in predicting the development of CIN in patients undergoing contrast-enhanced computed tomography (CT) imaging in the emergency department (ED). This study was performed on patients whose laboratory values ​​could be reached within 48 hours after contrast-enhanced CT imaging in the emergency department of our hospital. The patients were divided into two groups as those with and without CIN according to their increased creatinine levels. Its effectiveness in detecting the development of CIN in the early period was evaluated comparatively. One hundred and twenty-five patients were included. CIN developed in 10.4% of the patients. The CAR was 0.19 (IQR: 0.17-0.33) in the group with CIN and 0.02 (IQR: 0.01-0.06) in the group without CIN; and the difference between the two groups was significant (p<0.001). In multivariate logistic regression analysis, it was found that the CAR increased as an independent risk factor for CIN (OR: 2.326; 95% CI: 1.39-3.893; p=0.001). We think that early identification of patients who may develop CIN through the CAR in EDs and early initiation of treatment for CIN may affect the morbidity-mortality rate and reduce the duration of hospitalization and treatment costs.

Effect of Vigileo/FloTrac System-Guided Aggressive Hydration in Acute Myocardial Infarction Patients to Prevent Contrast-Induced Nephropathy After Urgent Percutaneous Coronary Intervention

Tailored hydration strategies appear to provide an effective solution for preventing contrast-induced nephropathy (CIN) after percutaneous coronary intervention (PCI). The Vigileo/FloTrac system could predict the patients' fluid responsiveness and tolerance to hydration. This prospective multicenter, randomized controlled, open-label study evaluated the efficacy of aggressive hydration guided by the Vigileo/FloTrac system for CIN prevention in patients with acute myocardial infarction (AMI). This trial enrolled patients with AMI undergoing urgent PCI, and these patients were randomized (1:1) to receive either aggressive hydration guided by Vigileo/FloTrac system (intervention group) or general hydration (control group). Patients with AMI in the intervention group received a loading dose of saline, and the hydration speed was adjusted according to the change of Vigileo/FloTrac index. The primary end point is CIN, which was defined as a >25% or >0.5mg/100ml increase in serum creatinine compared with baseline during the first 72hours after urgent PCI. This trial was registered in ClinicalTrials.gov (NCT04382313). A total of 344 patients with AMI were enrolled and randomized in our trial, and the baseline characteristics, including risk factors of CIN, of the Vigileo/FloTrac-guided hydration group (n=173) and control group (n=171) were well balanced (all p >0.05). The total hydration volume in Vigileo/FloTrac-guided hydration group was significantly much more than control group (1,910 ± 600 vs 440 ± 90ml, p <0.001). The incidence of CIN in the Vigileo/FloTrac-guided hydration group was significantly decreased than that in the control group (12.1% [21/173] vs 22.2% [38/171], p=0.013). There was not significantly different in the incidence of acute heart failure after PCI (9.2% [16/173] vs 7.6% [13/171], p=0.583). The incidence of main adverse cardiovascular events in the Vigileo/FloTrac-guided hydration group was lower than that in the control group but without statistically difference (30 events [17.3%] vs 38 events [22.2%], p=0.256). In conclusion, Vigileo/FloTrac system-guided aggressive hydration could effectivelydecrease the risk of CIN for patients with AMI undergoing urgent PCI and avoid attack of acute heart failure at the same time.

Contrast Induce Nephropathy in Patients Undergoing Percutaneous Coronary Intervention for Acute Coronary Syndrome: Differences in STEMI and NSTEMI

Contrast-induced nephropathy (CIN) is a common complication of percutaneous coronary intervention (PCI) in patients with acute coronary syndrome. The incidence and risk factors for CIN in patients with ST-segment elevation myocardial infarction (STEMI) and non-ST-segment elevation myocardial infarction (NSTEMI) undergoing PCI are not well understood. In this prospective observational study, we enrolled 314 patients who underwent PCI for acute coronary syndrome at the cardiology department of KGMC MTI-HMC, Peshawar from June 1, 2022 to December 31, 2022. The incidence of CIN was higher in patients with STEMI compared to those with NSTEMI (18.5% vs. 8.7%, p=0.036). Hypertension was found to be a significant risk factor for CIN (OR 3.36, 95% CI 1.49-7.57, p=0.003), but it did not fully explain the differential risk between the two groups. Our findings suggest that the underlying pathophysiology of STEMI and NSTEMI may play a role in the development of CIN. Further studies are needed to identify the contributing factors and potential interventions to reduce the risk of CIN in patients undergoing PCI for acute coronary syndrome.

The triglyceride-glucose index and contrast-induced nephropathy in non-ST elevation myocardial infarction patients undergoing percutaneous coronary intervention.

The triglyceride glucose (TyG) index is an indicator of insulin resistance and associated with increased risk of diabetes mellitus and cardiovascular events. Our study investigates the correlation between TyG index and contrast induced nephropathy (CIN) in non-diabetic patients with non-ST elevation myocardial infarction (NSTEMI) undergoing percutaneous coronary intervention (PCI). 350 non-diabetic NSTEMI patients (183, 52.3% male) undergoing PCI were retrospectively enrolled. The enrolled cohort was divided into 2 groups based on the calculated TyG index, namely values < 8.65 or higher. CIN was defined as an increase in serum creatinine > 25% or 0.5 mg/dL from baseline in the first 48 to 72 hours after PCI. A total of 56 (16%) cases of CIN were diagnosed. In contrast to patients with lower TyG indexes, patients with higher TyG indexes (≥8.65) had a higher frequency of CIN, 9.5%. versus 20.8% respectively (P .004). Patients with CIN also had higher TyG indexes (8.74 ± 0.12 vs 8.67 ± 0.11, P < .001). In addition, TyG index, age, and glomerular filtration rate were identified as independent risk factors for CIN in logistic regression model (OR: 2.5 CI: 1.3-4.6, P .006, OR: 1.0 CI: 1.0-1.1, P < .001, OR: 1.0 KI: 1.03-1.06, P .025). In the ROC analysis, the area under the curve predictive of CIN was 0.666 (P < .001, 95% [CI] 0.58-0.75) with a cutoff value of 8.69 (sensitivity 71,4%, specificity 55.1%) TyG index. Higher TyG indexes are associated with an increased risk of CIN in non-diabetic patients with NSTEMI.

房颤冷冻消融一站式术后对比剂肾病的发生率及危险因素分析

房颤冷冻消融一站式术后对比剂肾病的发生率及危险因素分析

Risk factors of contrast-induced nephropathy in patients with acute coronary syndrome

Patients with acute coronary syndrome (ACS) are at high risk of contrast-induced nephropathy (CIN), which is associated with prolonged hospitalization, higher morbidity and mortality after angiographic procedures. The occurrence of CIN is regarded as a transient and reversible condition. However, the persistence of CIN until hospital discharge in patients with ACS has not been thoroughly analyzed. We aimed to analyze CIN persistent until hospital discharge in contemporary ACS population referred to invasive diagnostics and treatment. A total of 2638 consecutive patients with ACS were included in a prospective registry. The occurrence of CIN was defined as a 25% increase in serum creatinine from baseline or a 0.5 mg/dl (44 μmol/l) increase in the absolute value. Criteria of CIN at hospital discharge were met in 10.7% of patients. Immediate percutaneous coronary intervention (PCI) after angiography (67% of patients) was associated with higher rates of CIN compared to patients referred for other treatment strategies (P < 0.001). The logistic regression model showed that anemia at baseline (8.7% of patients) was an independent predictor of CIN, which occurred in 17.9% of anemic patients and 10% of patients without anemia (P < 0.001). Also, ST-segment elevation myocardial infarction (STEMI) presentation and immediate PCI were independent predictors of CIN. Despite intravenous fluid administration during the hospital stay, CIN persisted until hospital discharge in more than 10% of patients with ACS. Anemia at baseline, STEMI presentation, and immediate PCI strategy were independent predictors of CIN. Thus, preventive actions should be specially aimed at those groups of patients.

Red blood cell distribution width-to-albumin ratio: a new inflammatory biomarker to predict contrast-induced nephropathy after emergency percutaneous coronary intervention.

Contrast-induced nephropathy (CIN) remains a dreaded complication in the cardiac diagnostic and interventional area. We investigated the relationship between red blood cell distribution width-to-albumin ratio (RAR) and CIN in elderly patients with ST-segment elevation myocardial infarction (STEMI) undergoing emergency percutaneous coronary intervention (PCI). A total of 1532 elderly patients were enrolled and divided into the CIN group and the non-CIN group. The risk factors of CIN were evaluated by univariate and multivariate regression analysis. Receiver-operating characteristic (ROC) curve analysis was used to identify the best predictive value. CIN occurred in 129 (8.42%) patients. Patients in the CIN group had significantly higher RAR than those in the non-CIN group (4.69 ± 0.73 vs. 3.18 ± 0.64, P < 0.001). In multivariate regression analysis, RAR was an independent risk factor for the development of CIN (OR: 1.506, 95% CI: 1.227-2.083, P = 0.025), along with age, creatinine, eGFR, hs-CRP and contrast agent dose. The AUC of RAR was 0.755 (95% CI 0.703-0.807), and an optimal cutoff value of 3.64 or higher predicted CIN with a sensitivity of 76.2% and specificity of 65.7%. As a combined inflammatory-related index, RAR was an independent risk factor for the development of CIN in elderly patients with STEMI undergoing emergency PCI. The RAR could be a simple but relatively reliable parameter for identifying high-risk patients.