Association of Admission Hemoglobin Levels and Acute Kidney Injury Among Myocardial Infarction Patients Treated With Primary Percutaneous Intervention

Contrast‑associated acute kidney injury in myocardial infarction patients undergoing elective percutaneous coronary intervention: insight from the Iodixanol-AKI Registry

Previous studies have reported a high occurrence of contrast-associated acute kidney injury (CA-AKI) in myocardial infarction (MI) patients undergoing primary percutaneous coronary intervention (PCI). However, the data on CA-AKI in MI patients who underwent elective PCI are limited. To evaluate the incidence of CA-AKI in MI patients undergoing elective PCI. The data were sourced from the Iodixanol-AKI Registry of MI patients scheduled to undergo elective PCI in 8 medical centers from May 2020 to November 2021. The participants were divided into three groups: acute, prior, and multiple MI. The outcomes measured were CA-AKI and the composite endpoint of major adverse renal and cardiovascular events (MARCE). The incidence of CA-AKI was 4.46% (37/830) in the MI patients, 4.40% (7/159) in the acute MI patients, 4.41% (22/499) in the prior MI patients, and 4.65% (8/172) in the multiple MI patients. Of note, 36 patients (97.30%) at AKI stage 1, and only 1 patient at AKI stage 2. There was no difference in the incidence of CA-AKI (P = 0.991) among the three groups. Multivariate regression analysis revealed that the independent risk factors for CA-AKI were diabetes and an estimated glomerular filtration rate (eGFR) < 60 mL/min/1.73 m2. MARCE occurred in 3.4% (28/830) of the total patients and was not associated with either any subgroup of patients with MI or AKI. The incidence of CA-AKI was low and mainly limited to mildly impaired renal function in MI patients undergoing elective PCI.

Development and Validation of Nomogram Based on the Systemic-Immune Inflammation Response Index for Predicting Contrast-Induced Nephropathy in ST-Elevation Myocardial Infarction Patients

Contrast-induced nephropathy (CIN) is a prominent complication of ST-elevation myocardial infarction (STEMI) after primary percutaneous coronary intervention (pPCI). The systemic immune inflammation response index (SIIRI) is a novel inflammatory marker developed by multiplying the monocyte count by the systemic immune inflammation index (SII) and is associated with coronary artery disease severity. We investigated the predictive ability of SIIRI for detecting CIN in STEMI patients (n = 2289) following pPCI and developed a nomogram based on SIIRI for risk stratifying. CIN was diagnosed based on an elevation in baseline creatinine levels >.5 mg/dL or 25% within 72 h after pPCI; 219 CIN (+) and 2070 CIN (-) patients were included. CIN (+) patients had higher SIIRI than CIN (-) patients and SIIRI was an independent predictor of CIN. A nomogram based on SIIRI had good calibration and discrimination abilities for predicting CIN development. SIIRI was superior to SII in discriminating CIN (+) patients. Adding SIIRI to the baseline model, which consists of age, hypertension, hemoglobin, estimated glomerular filtration rate, albumin, ejection fraction, lesion length, and pain-to-balloon time, had a higher discriminative ability and benefit in detecting CIN (+) patients than baseline model as assessed by decision curve analysis.

The predictive value of hematological inflammatory markers for acute kidney injury and mortality in adults with hemophagocytic Lymphohistiocytosis: A retrospective analysis of 585 patients

BACKGROUND

Hemophagocytic lymphohistiocytosis (HLH) is a rare immunological hyperactivation-related disease with a high mortality rate. The purpose of this study was to examine the relationship between complete blood count parameters and the occurrence of acute kidney injury (AKI) and mortality in patients with HLH.

METHODS

We included 585 adult patients with HLH. Logistic regression models for AKI and 28-day mortality were developed.

RESULTS

Multivariate logistic regression models revealed that hemoglobin (HB) ≤ 7.3 g/dl (adjusted OR, 1.651; 95% CI, 1.044-2.612), hemoglobin-to-red blood cell distribution width ratio (HRR) < 0.49 (adjusted OR, 1.692), neutrophil-to-lymphocyte ratio (NLR) ≥ 3.15 (adjusted OR, 1.697), and neutrophil-to-lymphocyte-platelet ratio (NLPR) ≥ 11.0 (adjusted OR, 1.608) were independent risk factors for the development of AKI. Moreover, lower platelet levels (31 × 109/L < platelets < 84 × 109/L, adjusted OR, 2.133; platelets ≤ 31 × 109/L, adjusted OR, 3.545) and higher red blood cell distribution width-to-platelet ratio (RPR) levels (0.20 < RPR < 0.54, adjusted OR, 2.595; RPR ≥ 0.54, adjusted OR, 4.307), lymphocytes ≤ 0.34 × 109/L (adjusted OR, 1.793), NLPR ≥ 11.0 (adjusted OR, 2.898), and the aggregate index of systemic inflammation (AISI) ≤ 7 (adjusted OR,1.778) were also independent risk factors for 28-day mortality. Furthermore, patients with AKI had a worse prognosis than those without AKI (P < 0.05).

CONCLUSION

In patients with HLH, hematological parameters are of great value for the early identification of patients at high risk of AKI and 28-day mortality.

Risk factors associated with contrast-associated acute kidney injury in ST-segment elevation myocardial infarction patients: a systematic review and meta-analysis

OBJECTIVE

The objective of this systematic review and meta-analysis was to evaluate the risk factors for contrast-associated acute kidney injury (CA-AKI) in ST-elevation myocardial infarction patients treated with primary percutaneous coronary intervention.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

We searched the databases of PubMed, Embase and Ovid, up to February 2022, for observational studies that investigated the association between risk factors and CA-AKI.

RESULTS

A total of 21 studies were included in the meta-analysis. Of the total 22 015 participants, 2728 developed CA-AKI. Pooled incidence was 11.91% (95% CI 9.69%, 14.14%). Patients with CA-AKI were more likely to be older, female, also had comorbidities (hypertension, diabetes, previous heart failure). Smoking (OR: 0.60; 95% CI 0.52, 0.69) and family history of CAD (coronary artery disease) (OR: 0.76; 95% CI 0.60, 0.95) were associated with lower risk of CA-AKI. Left anterior descending (LAD) artery occlusion (OR: 1.39; 95% CI 1.21, 1.59), left main disease (OR: 4.62; 95% CI 2.24, 9.53) and multivessel coronary disease (OR: 1.33; 95% CI 1.11, 1.60) were risk factors for CA-AKI. Contrast volume (weighted mean difference: 20.40; 95% CI 11.02, 29.79) was associated with increased risk in patients receiving iso-osmolar or low-osmolar non-ionic contrast.

CONCLUSIONS

In addition to the known risk factors, LAD artery infarction, left main disease and multivessel disease are risk factors for CA-AKI. The unexpected favourable association between smoking, as well as family history of CAD, and CA-AKI requires further investigation.

PROSPERO REGISTRATION NUMBER

CRD42021289868.

H2FPEF Score and Contrast-Induced Nephropathy in Patients With Acute Coronary Syndrome Undergoing Percutaneous Coronary Intervention

Contrast-induced nephropathy (CIN) is one of the most common complications associated with coronary angiography and percutaneous coronary intervention (PCI). This study evaluated the relationship between the H₂FPEF (obesity (H), hypertension(H), atrial fibrillation (F), pulmonary hypertension (P), an age >60 years (E), and E/e' > 9 (F)) score which is used to diagnose heart failure with preserved ejection fraction and CIN. Patients (n = 1346) who underwent PCI for acute coronary syndrome (ACS) between December 2018 and January 2021 were retrospectively included. Contrast-induced nephropathy patients had significantly higher H₂FPEF scores (4.10 ± 1.92 vs 2.28 ± 1.56, P < .001). In addition, the H₂FPEF score was found to be an independent risk factor for the development of CIN (Odd Ratio 1.633 95% CI (1.473-1.811), P < .001) together with age, diabetes mellitus, systolic pulmonary arterial pressure, and left anterior descending as an infarct-related artery. According to point biserial correlation analysis, CIN and H₂FPEF score have a strong correlation (r_pb = .376, P < .001). The receiver operating characteristic curve showed the optimal cutoff value of the H₂FPEF score to predict the development of CIN was 2.5, with 79.8% sensitivity and 64.1% specificity. In conclusion, the H₂FPEF score may predict the development of CIN in patients presenting with ACS and undergoing PCI.

What Promotes Acute Kidney Injury in Patients with Myocardial Infarction and Multivessel Coronary Artery Disease-Contrast Media, Hydration Status or Something Else?

Multivessel coronary artery disease (MVCAD) is found in approximately 50% of patients with acute myocardial infarction (AMI) undergoing percutaneous coronary intervention (PCI). Although we have data showing the benefits of revascularization of significant non-culprit coronary lesions in patients with AMI, the optimal timing of angioplasty remains unclear. The most common reason for postponing subsequent percutaneous treatment is the fear of contrast-induced acute kidney injury (CI-AKI). Acute kidney injury (AKI) is common in patients with AMI undergoing PCI, and its etiology appears to be complex and incompletely understood. In this review, we discuss the definition, pathophysiology and risk factors of AKI in patients with AMI undergoing PCI. We present the impact of AKI on the course of hospitalization and distant prognosis of patients with AMI. Special attention was paid to the phenomenon of AKI in patients undergoing multivessel revascularization. We analyze the correlation between increased exposure to contrast medium (CM) and the risk of AKI in patients with AMI to provide information useful in the decision-making process about the optimal timing of revascularization of non-culprit lesions. In addition, we present diagnostic tools in the form of new biomarkers of AKI and discuss ways to prevent and mitigate the course of AKI.

Serum Uric Acid to Albumin Ratio Can Predict Contrast-Induced Nephropathy in ST-Elevation Myocardial Infarction Patients Undergoing Primary Percutaneous Coronary Intervention

Contrast-induced nephropathy (CIN) is one of the common complication of ST-elevation myocardial infarction (STEMI) following primary percutaneous coronary intervention (pPCI). Serum uric acid to albumin ratio (UAR) is a novel marker, which is associated with acute kidney injury in intensive care unit patients. We investigated the predictive value of UAR for the development of CIN in STEMI patients (n = 1379) after pPCI. The diagnosis of CIN was made based on an increase of basal creatinine levels >.5 mg/dL or 25% within 72 h after pPCI; 128 patients were in the CIN (+) group and 1251 patients were in the CIN (-) group. CIN (+) patients had higher serum uric acid (SUA), UAR, and lower albumin levels than CIN (-) patients. Age, diabetes, hypertension, hemoglobin, glucose at admission, basal creatinine, peak troponin I, total bilirubin, contrast volume/glomerular filtration rate, and UAR were independent predictors of CIN. A cutoff value of 1.62 for UAR detected CIN development with a sensitivity of 54% and specificity of 87.4%, and the discrimination ability of UAR was better than that of SUA or albumin. In conclusion, UAR was an independent predictor of the development of CIN.

Anemia is associated with increased risk of contrast‑induced acute kidney injury: A Systematic Review and Meta-analysis

Previous studies have identified numerous risk factors of contrast-induced acute kidney injury (CI-AKI) in patients undergoing coronary angiography. However, the association between anemia and CI-AKI remains conflicting. Thus, we conducted a meta-analysis to further clarify the relationship between anemia and CI-AKI. PubMed, EMBASE and Web of Science were systematically searched from inception to June 2020 to identify eligible studies. The pooled odds ratios (ORs) with 95% confidence intervals (CIs) were used to estimate the correlation between anemia and CI-AKI. The potential publication bias was estimated using funnel plot and Begg's test. A total of 13 studies (five case-control studies and eight cohort studies) comprising 27,135 patients were included. The pooled results showed that anemia was a significant risk factor of CI-AKI (OR, 1.82; 95% CI, 1.27-2.61). Moreover, the results of subgroup analyses and sensitivity analyses were basically consistent with the overall pooled result. Funnel plot and Begg's test indicated that there existed potential publication bias, but the result of trim and filled analysis showed that the pooled results kept stable after adding 'missing' studies. This meta-analysis suggested that anemia may be correlated with an increased incidence of CI-AKI in patients undergoing coronary angiography. However, our conclusions should be interpreted with caution due to some limitations. Therefore, further high-quality trials should be conducted to confirm our findings.

Association between admission hemoglobin level and prognosis in patients with type 2 diabetes mellitus

BACKGROUND

Anaemia is common in patients with chronic kidney disease (CKD) and is a major risk factor that contributes to mortality in such patients. Type 2 diabetes mellitus (T2DM) is one of the leading causes of CKD. The association between admission hemoglobin levels and renal damage in patients with T2DM remains unclear.

AIM

To evaluate the relationship between admission hemoglobin levels and prognosis in patients with T2DM.

METHODS

We performed a retrospective analysis of 265 consecutive patients presenting with T2DM between 2011 and 2015. The composite endpoint was end-stage renal disease or a 50% reduction in the estimated glomerular filtration rate.

RESULTS

In multivariable-adjusted Cox proportional hazards models (adjusting for demographic factors, traditional risk factors, lipids), the adjusted hazard ratios (HRs) for the highest and middle tertiles compared to the lowest tertile of hemoglobin were 0.82 (95%CI: 0.11-6.26, P = 0.8457) and 0.28 (95%CI: 0.09-0.85, P = 0.0246), respectively. However, after further adjustment for glycaemia control, hemoglobin was positively related to the risk of the composite endpoint (HR: 1.05, 95%CI: 0.14-8.09, P = 0.9602) when the highest tertile was compared to the lowest tertile of hemoglobin. We found a U-shaped relationship between hemoglobin levels and the composite endpoint. The curve tended to reach the lowest level at an optimal hemoglobin level.

CONCLUSION

Among patients with T2DM, a U-shaped relationship was observed between hemoglobin levels and renal damage. A lower admission hemoglobin level (hemoglobin < 13.3 g/dL) is an independent predictor of renal damage.

Comparative analysis of four established risk scores for predicting contrast induced acute kidney injury after primary percutaneous coronary interventions

Objectives

 This study aimed to compare Mehran Risk Score (MRS) with three well -known scoring systems namely CHA₂DS₂-VASc score, Canada Acute Coronary Syndrome Risk Score (C-ACS), and Thrombolysis in Myocardial Infarction risk index (TRI) to predict the contrast-induced acute kidney injury (CI-AKI) after primary percutaneous coronary intervention (PCI).

Background

CI-AKI is a common complication after primary PCI associated with an adverse prognosis.

Methods

In this study consecutive patients of primary PCI were included. Patients with chronic kidney diseases, exposure to the contrast medium within the past 7 days, and Killip class IV at presentation were excluded. MRS along with three risk scores namely CHA₂DS₂-VASc, C-ACS, and TRI were calculated for all patients and CI-AKI was defined as either 0.5 mg/dL or 25% relative increase in post-procedure serum creatinine. The area under the curve (AUC) curve was reported.

Results

Post primary PCI CI-AKI was observed in 63 (9.1%) patients out of 691 patients. The AUC was 0.745 [0.679-0.810] for MRS, 0.725 [0.662-0.788] for CHA₂DS₂-VASc, 0.671 [0.593-0.749] for C-ACS, and 0.734 [0.674-0.795] for TRI. Sensitivity and specificity were 61.9% [48.8-73.8%] and 76.0% [72.4-79.3%] for MRS ≥ 6.5, 66.7% [53.7-78.0%] and 66.7% [62.9-70.4%] for CHA₂DS₂-VASc ≥ 2, 52.4% [39.4-65.1%] and 79.9% [76.6-83.0%] for C-ACS ≥ 1, and 87.3% [76.5-94.4%] and 49.2% [45.2-53.2%] for TRI ≥ 16 respectively.

Conclusions

The MRS has shown higher discriminating power than CHA₂DS₂-VASc, C-ACS, and TRI. However, the TRI can be of good value in clinical practice due to its simplicity and high sensitivity in detecting patients at higher risk of CI-AKI after primary PCI.

Evidence-to-Practice Gap for Preventing Procedure-Related Acute Kidney Injury in Patients Undergoing Percutaneous Coronary Intervention

Background

Acute kidney injury (AKI) is a common complication of percutaneous coronary intervention. This risk can be minimized with reduction of contrast volume via preprocedural risk assessment. We aimed to identify quality gaps for implementing the available risk scores introduced to facilitate more judicious use of contrast volume.

Methods and Results

We grouped 14 702 patients who underwent percutaneous coronary intervention according to the calculated NCDR (National Cardiovascular Data Registry) AKI risk score quartiles (Q1 [lowest]–Q4 [highest]). We compared the used contrast volume by the baseline renal function and NCDR AKI risk score quartiles. Factors associated with increased contrast volume usage were determined using multivariable linear regression analysis. The overall incidence of AKI was 8.9%. The used contrast volume decreased in relation to the stages of chronic kidney disease (168 mL [SD, 73.8 mL], 161 mL [SD, 75.0 mL], 140 mL [SD, 70.0 mL], and 120 mL [SD, 73.7 mL] for no, mild, moderate, and severe chronic kidney disease, respectively; P<0.001), albeit no significant correlation was observed with the calculated NCDR AKI risk quartiles. Of the variables included in the NCDR AKI risk score, anemia (7.31 mL [1.76–12.9 mL], P=0.01), heart failure on admission (10.2 mL [6.05–14.3 mL], P<0.001), acute coronary syndrome presentation (10.3 mL [7.87–12.7 mL], P<0.001), and use of an intra‐aortic balloon pump (17.7 mL [3.9–31.5 mL], P=0.012) were associated with increased contrast volume.

Conclusions

The contrast volume was largely determined according to the baseline renal function, not the patients' overall AKI risk. These findings highlight the importance of comprehensive risk assessment to minimize the contrast volume used in susceptible patients.

Low hemoglobin levels are independently associated with neonatal acute kidney injury: a report from the AWAKEN Study Group

BACKGROUND

Studies in adults showed a relationship between low hemoglobin (Hb) and acute kidney injury (AKI). We performed this study to evaluate this association in newborns.

METHODS

We evaluated 1891 newborns from the Assessment of Worldwide AKI Epidemiology in Neonates (AWAKEN) database. We evaluated the associations for the entire cohort and 3 gestational age (GA) groups: <29, 29-<36, and ≥36 weeks' GA.

RESULTS

Minimum Hb in the first postnatal week was significantly lower in neonates with AKI after the first postnatal week (late AKI). After controlling for multiple potential confounders, compared to neonates with a minimum Hb ≥17.0 g/dL, both those with minimum Hb ≤12.6 and 12.7-14.8 g/dL had an adjusted increased odds of late AKI (aOR 3.16, 95% CI 1.44-6.96, p = 0.04) and (aOR 2.03, 95% CI 1.05-3.93; p = 0.04), respectively. This association was no longer evident after controlling for fluid balance. The ability of minimum Hb to predict late AKI was moderate (c-statistic 0.68, 95% CI 0.64-0.72) with a sensitivity of 65.9%, a specificity of 69.7%, and a PPV of 20.8%.

CONCLUSIONS

Lower Hb in the first postnatal week was associated with late AKI, though the association no longer remained after fluid balance was included.

IMPACT

The current study suggests a possible novel association between low serum hemoglobin (Hb) and neonatal acute kidney injury (AKI). The study shows that low serum Hb levels in the first postnatal week are associated with increased risk of AKI after the first postnatal week. This study is the first to show this relationship in neonates. Because this study is retrospective, our observations cannot be considered proof of a causative role but do raise important questions and deserve further investigation. Whether the correction of low Hb levels might confer short- and/or long-term renal benefits in neonates was beyond the scope of this study.

Addition of routine blood biomarkers to TIMI risk score improves predictive performance of 1-year mortality in patients with ST-segment elevation myocardial infarction

Background

Several biomarkers have been proposed as independent predictors of poor outcomes in ST-segment elevation myocardial infarction (STEMI). We investigated whether adding information obtained from routine blood tests including hypoxic liver injury (HLI), dysglycemia, anemia, and high neutrophil to lymphocyte ratio (NLR) could improve the prognostic performance of the TIMI risk score for the prediction of 1-year mortality.

Methods

A total of 1057 patients with STEMI undergoing primary percutaneous coronary intervention (PCI) between 2007 and 2014 were retrospectively enrolled from 4-regional hospitals. HLI and dysglycemia were defined as serum transaminase > twice the normal upper limit and glucose < 90 or > 250 mg/dL, respectively. The effect of adding biomarkers to the TIMI risk score on its discriminative ability was assessed using c-statistic, net reclassification improvement (NRI), and integrated discrimination improvement (IDI).

Results

The 1-year mortality rate was 7.1%. The best cutoff value of NLR for the prediction of 1-year mortality was 4.3 (sensitivity, 67%; specificity, 65%). HLI (HR 2.019; 95% CI 1.104–3.695), dysglycemia (HR 2.535; 95% CI 1.324–3.923), anemia (HR 2.071; 95% CI 1.093–3.923), and high NLR (HR 3.651; 95% CI 1.927–6.918) were independent predictors of 1-year mortality. When these 4 parameters were added to the TIMI risk score, the c-statistic significantly improved from 0.841 to 0.876 (p < 0.001), and the NRI and IDI were estimated at 0.203 (95% CI 0.130–0.275; p < 0.001) and 0.089 (95% CI 0.060–0.119; p < 0.001), respectively.

Conclusions

The addition of HLI, dysglycemia, anemia, and high NLR to the TIMI risk score may be useful for very early risk stratification in patients with STEMI receiving primary PCI.

Acute cardiorenal anemia syndrome among ST-elevation myocardial infarction patients treated by primary percutaneous intervention

BACKGROUND

Acute kidney injury (AKI) and anemia have been extensively studied in ST-elevation myocardial infarction (STEMI), yet the precise nature of their reciprocal relationship has not been elucidated in STEMI patients.

METHODS

We performed a retrospective analysis of 2096 consecutive patients admitted for STEMI between January 2008 and December 2018 and treated with primary coronary intervention. Patients were stratified into four groups according to the presence of baseline anemia and occurrence of AKI: without anemia or AKI, baseline anemia without AKI, AKI without baseline anemia and acute cardiorenal anemia syndrome (CRAS), defined as the occurrence of AKI in patients with baseline anemia. Patients' medical records were reviewed for in-hospital complications, 30-day and long-term mortality.

RESULTS

The mean age was 61 ± 13 years and 1682 patients (80%) were men. Ten percent of patients had baseline anemia without AKI, 7% had AKI without baseline anemia and 3% were classified as CRAS. We found increments between the four groups for occurrence of new onset atrial fibrillation and heart failure rates, presence of a critical state, and both 30-day and long-term mortality (P < 0.001 for all). Logistic regression models demonstrated that as compared to AKI alone, CRAS was associated with a higher risk for long-term mortality (HR 10.49; 95% CI 6.5-17.1) as compared to anemia (HR 3.32, 95% CI 2.1-5.2) and AKI (HR 7.71, 95% CI 5.1-11.7) alone (P < 0.001 for all).

CONCLUSIONS

Among STEMI patients, the interaction between anemia and AKI is associated with worse short and long-term outcomes and reflects the reciprocity of cardiac and renal exacerbations.

Acute renal impairment in older adults treated with percutaneous coronary intervention for ST-segment elevation myocardial infarction

BACKGROUND

Elderly individuals ( ≥ 75 years) constitute an increasing proportion of patients presenting with myocardial infarction treated with primary percutaneous coronary intervention (PCI), but only limited data are available regarding the incidence and prognostic implications of acute kidney injury (AKI) in this group of patients.

OBJECTIVE

To evaluate the incidence and prognostic implications of AKI in older adults ( ≥ 75 years) with ST-segment elevation myocardial infarction (STEMI) treated with primary PCI.

PATIENTS AND METHODS

A retrospective cohort, observational, single-center study of consecutive 416 older patients with STEMI (≥ 75 years) treated with primary PCI between January 2008 and August 2017 was conducted. AKI was defined as an increase of at least 0.3 mg/dl in serum creatinine within 48 h following admission.

RESULTS

A total of 96/416 (23%) patients developed AKI. The occurrence of AKI was associated with adverse in-hospital outcomes, higher 30 days (25 vs. 6%; P < 0.001), and long-term mortality (46 vs. 17%; hazard ratio: 3.2; 95% confidence interval: 2.1-4.7; P < 0.001). Among patients with AKI, 46/96 (48%) demonstrated recovery of renal function at hospital discharge. Lack of renal function recovery at discharge (50/96 patients; 52%) was associated with the occurrence of new or progression of baseline chronic kidney disease.

CONCLUSION

Among older patients with STEMI undergoing primary PCI, AKI is a frequent complication associated with adverse renal short-term and long-term outcomes.

Acute kidney injury in hospitalized patients who underwent percutaneous kidney biopsy for histological diagnosis of their renal disease

BACKGROUND

Performing a kidney biopsy is necessary to accurately diagnose diseases such as glomerulonephritis and tubulointerstitial nephritis, among other such conditions. These conditions predispose patients to chronic kidney disease, as well as acute kidney injury (AKI). Notably, most epidemiological studies describing AKI have not investigated this patient population.

METHODS

Included patients admitted to the nephrology ward of a tertiary hospital who underwent percutaneous kidney biopsy. AKI was diagnosed based on the Kidney Disease: Improving Global Outcomes criteria.

RESULTS

Of the 223 patients investigated, 140 (62.8%) showed AKI. Of these, 91 (65%), 19 (13.6%), and 30 (21.4%) presented with AKI classified as stages 1, 2, and 3, respectively. The primary indication for performing biopsy was nephrotic syndrome or nephrotic proteinuria (73 [52.1%] in the AKI vs. 51 [61.4%] in the non-AKI group, p = 0.048). Focal segmental glomerulosclerosis was the most prevalent primary disease (24 [17.1%] in the AKI vs. 15 [18.0%] in the non-AKI group, p = 0.150). Multivariate analysis of risk factors associated with AKI showed hemoglobin levels (odds ratio [OR] 0.805, 95% confidence interval [CI] 0.681-0.951, p = 0.011), serum high-density lipoprotein cholesterol levels (HDL-c, OR 0.970, 95% CI 0.949-0.992, p = 0.008), and baseline serum creatinine levels (OR 2.703, 95% CI 1.471-4.968, p = 0.001) were significantly associated with AKI.

CONCLUSIONS

We observed a high prevalence of AKI in hospitalized patients who underwent kidney biopsy to investigate their renal disease, particularly glomerulonephritis. Higher levels of hemoglobin and serum HDL-c were associated with a lower risk of AKI.

Complete blood count in acute kidney injury prediction: a narrative review

Acute kidney injury (AKI) is a complex syndrome defined by a decrease in renal function. The incidence of AKI has raised in the past decades, and it is associated with negative impact in patient outcomes in the short and long term. Considering the impact of AKI on patient prognosis, research has focused on methods to assess patients at risk for developing AKI, diagnose subclinical AKI, and on prevention and treatment strategies, for which it is crucial an understanding of pathophysiology the of AKI. In this review, we discuss the use of easily available parameters found in a complete blood count to detect patients at risk for developing AKI, to provide an early diagnosis of AKI, and to predict associated patient outcomes.

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.

The patient with anemia

PURPOSE OF REVIEW

Anemia remains a global health issue. This review addresses the recent findings on anemia in surgical patients and its significance in perioperative setting.

RECENT FINDINGS

The prevalence of anemia in surgical populations is high, ranging from one-third of population to nearly 100%. Anemia is an independent, modifiable risk factor for a growing list of unfavorable events, complications and diminished functional outcomes (lasting for months following discharge), as well as a major predisposing factor for allogeneic blood transfusions. Therefore, timely screening and diagnosis of anemia prior to elective surgeries is of great importance. Nonetheless, studies suggest that many opportunities to properly manage anemia in perioperative setting are lost. Patient blood management provides a framework of evidence-based strategies to effectively reduce the risk of occurrence of anemia and treat it with the ultimate goal of improving patient outcomes. Studies on the clinical impact of patient blood management strategies are emerging.

SUMMARY

Active screening for anemia and proper management of it in perioperative setting is essential. Several strategies to prevent anemia - including elimination of unnecessary diagnostic blood draws - are effective and reasonable approaches.

Anemia: A significant cardiovascular mortality risk after ST-segment elevation myocardial infarction complicated by the comorbidities of hypertension and kidney disease

Background

The effect of anemia on patients with ST-segment elevation myocardial infarction (STEMI) remains a controversial issue. The aim of this study was to explore the effect of anemia on STEMI patients.

Methods and results

From January 2005 to December 2014, 1751 patients experienced STEMI checked serum hemoglobin initially before any administration of fluids or IV medications. 1751 patients then received primary percutaneous intervention immediately. A total of 1388 patients were enrolled in the non-anemia group because their serum hemoglobin level was more than 13 g/L in males, and 12 g/L in females. A total of 363 patients were enrolled in the anemia group because their serum hemoglobin level was less than 13 g/L in males, and 12 g/L in females. Higher incidences of major adverse cerebral cardiac events (22.9% vs. 33.8%; p<0.001) were also noted in the anemia group, and these were related to higher incidence of cardiovascular mortality (6.5% vs. 20.4%; p<0.001). A higher incidence of all-cause mortality (8.6% vs. 27.7%; p<0.001) was also noted in the anemia group. A Kaplan-Meier curve of one-year cardiovascular mortality showed significant differences between the non-anemia and anemia group in all patients (P<0.001), and the patients with hypertension (P<0.001), and chronic kidney disease (CKD) (P = 0.011).

Conclusion

Anemia is a marker of an increased risk in one-year cardiovascular mortality in patients with STEMI. If the patients have comorbidities such as hypertension, or CKD, the effect of anemia is very significant.

Acute Kidney Injury Risk Assessment: Differences and Similarities Between Resource-Limited and Resource-Rich Countries

The incidence of acute kidney injury (AKI) among acutely ill patients is reportedly very high and has vexing consequences on patient outcomes and health care systems. The risks and impact of AKI differ between developed and developing countries. Among developing countries, AKI occurs in young individuals with no or limited comorbidities, and is usually due to environmental causes, including infectious diseases. Although several risk factors have been identified for AKI in different settings, there is limited information on how risk assessment can be used at population and patient levels to improve care in patients with AKI, particularly in developing countries where significant health disparities may exist. The Acute Disease Quality Initiative consensus conference work group addressed the issue of identifying risk factors for AKI and provided recommendations for developing individualized risk stratification strategies to improve care. We proposed a 5-dimension, evidence-based categorization of AKI risk that allows clinicians and investigators to study, define, and implement individualized risk assessment tools for the region or country where they practice. These dimensions include environmental, socioeconomic and cultural factors, processes of care, exposures, and the inherent risks of AKI. We provide examples of these risks and describe approaches for risk assessments in the developing world. We anticipate that these recommendations will be useful for health care providers to plan and execute interventions to limit the impact of AKI on society and each individual patient. Using a modified Delphi process, this group reached consensus regarding several aspects of AKI risk stratification.

Anesthesia for Patients with Anemia

Anemia is a common and often ignored condition in surgical patients. Anemia is usually multifactorial and iron deficiency and inflammation are commonly involved. An exacerbating factor in surgical patients is iatrogenic blood loss. Anemia has been repeatedly shown to be an independent predictor of worse outcomes. Patient blood management (PBM) provides a multimodality framework for prevention and management of anemia and related risk factors. The key strategies in PBM include support of hematopoiesis and improving hemoglobin level, optimizing coagulation and hemostasis, use of interdisciplinary blood conservation modalities, and patient-centered decision making throughout the course of care.

Anaemia is not a risk factor for progression of acute kidney injury: a retrospective analysis

Background

In hospitalised patients, anaemia increases the risk of developing acute kidney injury (AKI). Our aim was to determine whether anaemia also has an impact on the risk of progression from early AKI to more severe AKI in critically ill patients.

Methods

We retrospectively analysed the data of patients admitted to the adult intensive care unit between 2007 and 2009 who had AKI I as per the AKI Network classification, and who had undergone haemodynamic monitoring within 12 h of AKI I. We collected baseline characteristics, severity of illness, haemoglobin (Hb), and haemodynamic parameters in the first 12 h of AKI I and differentiated between patients who progressed to AKI III and those who did not. Univariate and multivariate logistic regression analyses were used to identify risk factors for progression. Associations between Hb, arterial oxygen saturation and cardiac index were explored by receiver operating characteristic curve analysis.

Results

Two hundred and ten patients (median age 70 years, 68 % male) underwent haemodynamic monitoring within 12 h of AKI I; 85 (41.5 %) progressed to AKI III. The proportion of patients with underlying cardiac disease was significantly higher among progressors versus non-progressors (58 % vs 34 %, respectively; p = 0.001). On the first day of AKI I, progressors had a significantly higher Sequential Organ Failure Assessment score (9 vs 8; p < 0.001), lower cardiac index (median 2.6 vs 3.3 L/min/m²; p < 0.001), higher arterial lactate (2 vs 1.6 mmol/L; p < 0.001), higher central venous pressure (16 vs 13; p = 0.02), lower mean arterial blood pressure (median 71 vs 74 mmHg; p = 0.01) and significantly higher requirement for cardiovascular and respiratory support, but there was no difference in Hb concentration (median 96 g/L in both groups). Multivariable regression analysis showed that heart disease, need for mechanical ventilation, arterial lactate, Sequential Organ Failure Assessment score, central venous pressure and cardiac index on first day of AKI I were independently associated with progression to AKI III. There was no significant difference in the risk of progression between patients with Hb ≤ or >80 g/L, and ≤ or >100 g/L on day of AKI I.

Conclusions

In critically ill patients with AKI stage 1, anaemia was not associated with an increased risk of progression to more severe AKI.

Acute kidney injury among ST elevation myocardial infarction patients treated by primary percutaneous coronary intervention: a multifactorial entity

Acute kidney injury is a frequent complication among ST segment elevation myocardial infarction (STEMI) patients undergoing primary percutaneous coronary intervention (PCI), and is associated with adverse outcomes. While contrast nephropathy is considered the most important reason for worsening of renal function, recent data have suggested the role of other important factors among this specific patient population. In the present review, we examine the various factors leading to renal impairment in STEMI patients and place the findings in the context of this specific patient population in the era of primary PCI. These factors include contrast nephropathy, time to coronary reperfusion, cardiac pump function and hemodynamics as well as various inflammatory and metabolic markers.

Prognostic Implications of Acute Renal Impairment among ST Elevation Myocardial Infarction Patients with Preserved Left Ventricular Function

BACKGROUND

Only limited data is present regarding the incidence and prognostic implications of acute kidney injury (AKI) in ST elevation myocardial infarction (STEMI) patients with preserved left ventricular (LV) function in the primary percutaneous coronary intervention (PCI) era.

METHODS

We conducted a retrospective study of 842 consecutive STEMI patients with preserved LV function (ejection fraction ≥50%, assessed by echocardiography) who underwent primary PCI between January 2008 and January 2015. AKI was defined as an increase of ≥0.3 mg/dl in serum creatinine within 48 h following admission. Patients were assessed for all-cause mortality up to 5 years.

RESULTS

Fifty-two patients (6.2%) developed AKI. Patients with AKI were older, had impaired baseline renal function, and presented more often with heart failure throughout their hospitalization. Patients with AKI had a higher 5-year all-cause mortality (13.4 vs. 2.4%, p < 0.001). Compared to patients with no AKI, the adjusted hazard ratio for all-cause mortality was 2.64 (95% CI 1.25-5.56, p = 0.01).

CONCLUSIONS

Among STEMI patients with preserved LV function undergoing primary PCI, AKI is associated with a higher long-term mortality.

Effect of intravenous iron on outcomes of acute kidney injury

BACKGROUND

Little is known about benefit versus risk in treating iron deficiency anemia with intravenous (IV) iron in patients with acute kidney injury (AKI). Concerns about adverse outcomes may dissuade use and could contribute to greater use of red blood cell (RBC) transfusion.

STUDY DESIGN AND METHODS

We performed a retrospective case-control study of patients with AKI who received IV iron (cases) compared to those with AKI without IV iron (controls).

RESULTS

We identified 67 cases and 67 controls matched for age, stage of chronic kidney disease, and severity of anemia (hemoglobin [Hb], 7.7 ± 0.1 mg/dL vs. 7.5 ± 0.1 mg/dL; p = 0.47). Cases tended to be sicker with longer length of stay (27 + 4 days vs. 15 + 1.3 days; p = 0.003) and more intensive care unit days (13 + 2 days vs. 5 + 1 days; p = 0.003), more often with diagnosis of sepsis and greater number of antibiotics used (2.7 ± 0.3 vs. 1.8 ± 0.2; p = 0.02). Sepsis and AKI preceded use of IV iron. Despite greater illness severity, there was no difference in dialysis (38.8% vs. 34.3%; p = 0.59), mortality (24% vs. 21%; p = 0.679), or severity and/or recovery of AKI. Discharge Hb was similar (9.0 ± 0.1 mg/dL vs. 9.1 ± 0.1 mg/dL; p = 0.47). IV iron was used later in the stay and hence the cases also had more RBC transfusions.

CONCLUSIONS

We were unable to find any adverse consequences of use of IV iron when used to treat anemia in patients with AKI in regard to recovery of AKI or mortality even in patients with a diagnosis of sepsis. Consideration of preemptive use of IV iron in AKI with severe anemia is warranted to determine if this would reduce RBC transfusion.