Independent Predictors Of Acute Kidney Injury Research Articles

Prognostic value of renal function in patients with aortic stenosis treated with transcatheter aortic valve replacement.

The objectives of the present study were to analyze the variation of renal function after transcatheter aortic valve replacement (TAVR) focused on acute kidney injury (AKI) and its impact on short- and mid-term mortality. Changes on renal function after TAVR and their impact on clinical outcomes are incompletely understood until now. At two tertiary centers 221 consecutive patients were submitted to TAVR. Kidney injury was defined according to VARC-2 criteria. Patients were classified according to the presence (group 1) or absence (group 2) of AKI. Creatinine values were collected daily until seventh day after procedure, 1 month, 6 months, and then 1 year after TAVR. At baseline, groups were similar, except for EuroSCORE II (8.66% vs. 7.34%, P = 0.02) and glomerular filtration rate (GFR) (39.59 vs. 48.49 mL/min.1.73 m2 , P = 0.002). Overall 30 day-mortality and 1-year mortality were 6.3% and 14.0%, respectively. Both 30-day mortality (23.1% vs. 1.2%, P < 0.001) and 1-year mortality (44.2% vs. 4.7%, P < 0.001) were higher in group 1. After multivariable-adjusted models, the only independent predictor for AKI after TAVR was baseline GFR (HR: 1.37, 95% CI: 1.08-1.77, P = 0.01). The independent risk factors for 1-year mortality were AKI (HR: 15.66, 95% CI: 6.07-44.63, P < 0.001), COPD (HR: 3.14, 95% CI: 1.05-9.40, P = 0.04) and aortic regurgitation grade postprocedure ≥ 2 (P = 0.05) also after multivariate analysis. In this TAVR cohort, baseline GFR was the only independent predictor of AKI, which negatively impacted on 30-day and 1-year mortality. © 2016 Wiley Periodicals, Inc.

Identification of Risk Factors Associated With Postoperative Acute Kidney Injury After Esophagectomy for Esophageal Cancer

To identify risks factors associated with acute kidney injury (AKI) after esophageal cancer surgery. This was a retrospective study. Single academic center. Subjects with non-metastatic esophageal cancer. Patients were excluded if they were younger than 18 years and had missing data. Primary outcome of the study was AKI according to AKI Network criteria. Demographic and perioperative variables were compared in patients with and without AKI. A multivariate Cox proportional model was used to assess the association between perioperative variables and AKI; p<0.05 was considered statistically significant. AKI was found in 107 (11.9%) of the 898 patients included in the study. The multivariate analysis also showed that BMI (odds ratio [OR] 1.07, 95% confidence interval [CI] 1.03-1.11), number of comorbidities (OR 1.52, 95% CI 1.20-1.93, p = 0.001), and preoperative creatinine concentrations (OR 2.37, 95% CI 1.14-4.92, p = 0.02) were independent predictors for AKI. The use of dexamethasone was associated with a reduced risk for AKI. In support of previous reports in the literature, the authors found that AKI was not an uncommon complication after esophageal surgery. Obesity, cardiovascular comorbidities, and high preoperative concentrations were predictors of AKI. Dexamethasone administration during surgery appeared to have a protective effect. This finding opens an opportunity to further study in a randomized controlled trial the efficacy of dexamethasone in the prevention of AKI.

Invited Commentary

Invited Commentary

Impact of post-procedural hyperglycemia on acute kidney injury after transcatheter aortic valve implantation

BackgroundPost-operative hyperglycemia, in individuals with and without diabetes, has been identified as a predictor of acute kidney injury (AKI) in patients following cardiac surgery. Whether or not this is also true for patients undergoing transcatheter aortic valve implantation (TAVI) is unknown. ObjectivesTo evaluate whether post-procedural glucose levels are associated with AKI after TAVI. Methods and resultsA total of 422 consecutive patients undergoing transfemoral TAVI were included in the analysis. For each patient, plasma glucose levels were assessed at hospital admission, 4h after the procedure and daily during hospitalization. Post-procedural hyperglycemia was defined as 2 consecutive blood glucose readings ≥150mg/dL in the 72-hour period following TAVI. AKI was defined according to the VARC consensus report regarding standardized endpoint definitions. Overall, 137 (32.5%) patients developed post-procedural hyperglycemia and 138 (33%) patients developed AKI. Hyperglycemia was associated with a 2-fold higher incidence of AKI than in patients without hyperglycemia (48% vs. 25%, p<0.001). In-hospital mortality was higher in patients with hyperglycemia than in those without hyperglycemia (9.6% vs. 1.8%, p<0.001). In-hospital mortality rate was also higher in patients who developed AKI (12.7% vs. 2.7%, p<0.001). Patients with acute hyperglycemia that developed AKI had the highest in-hospital and long-term mortality rate (15% and 38%). Post-procedural hyperglycemia was an independent predictor of AKI. ConclusionsPost-procedural hyperglycemia is associated with a higher incidence of AKI and mortality after TAVI. Randomized controlled trials are needed to determine whether meticulous post-procedural glycemic control following TAVI impacts upon clinical outcomes.

A clinical score to predict acute kidney injury after cardiac surgery in a Southeast-Asian population.

Acute kidney injury (AKI) post-cardiac surgery is associated with significant in-hospital and long-term morbidity. This study aimed to develop a risk score for postoperative AKI in a Southeast-Asian population. A total of 2508 patients underwent cardiac surgery at the two main heart centres in Singapore between July 2008 and November 2011, of which 2385 met the inclusion criteria. The primary outcome was AKI, defined using the Acute Kidney Injury Network (AKIN) criteria. The scoring model was developed on the test cohort of 2385 and validated with another 500 prospectively recruited patients. Logistic regression analysis was used to identify independent predictors of AKI. The risk factors in this model are age ≥65 years, hypertension, estimate glomerular filtration rate (eGFR) ≤60 ml/min, use of intra-aortic balloon pump and cardiopulmonary bypass (CPB) time ≥120 min, which were similar to previous AKI risk models. Other risk factors in our model include preoperative anaemia, intraoperative red blood cell transfusion and lowest haematocrit during CPB, which have not been described previously. The clinical score ranged from 0 to 14 points with three major risk categories. The AKI frequencies are as follows: 0-4 points (18%), 5-8 points (39%) and 9-14 points (64%). The area under the receiver operating curve (ROC) for the test cohort was 0.70 (95% CI 0.68-0.72), similar to the validation cohort (0.75; 95% CI 0.70-0.80). In conclusion, the risk model is valid in predicting AKI post-cardiac surgery and can be used for the early diagnosis and treatment of AKI.

The Impact of Deep Versus Moderate Hypothermia on Postoperative Kidney Function After Elective Aortic Hemiarch Repair

There remains concern that moderate hypothermic circulatory arrest (MHCA) with antegrade cerebral perfusion (ACP) may provide suboptimal distal organ protection compared with deep hypothermic circulatory arrest (DHCA) with retrograde cerebral perfusion (RCP). We compared postoperative acute kidney injury (AKI) in in patients who underwent elective hemiarch repair with either DHCA/RCP or MHCA/ACP. This was a retrospective review of all patients undergoing elective aortic hemiarch reconstruction for aneurysmal disease between 2009 and 2014. Patients were stratified according to the use of DHCA/RCP versus MHCA/ACP. The primary outcome was the occurrence of AKI at 48 hours, as defined by the Risk, Injury, Failure, Loss, End-Stage (RIFLE ) criteria. A multivariable logistic regression identified risk factors for AKI. One hundred eighteen patients who underwent ACP and 471 patients who underwent RCP were included. The mean lowest temperature was 26.4°C in patients who underwent MHCA/ACP and 17.5°C in patients who underwent DHCA/RCP. Baseline demographics were similar except that patients who underwent DHCA/RCP were more likely to have peripheral arterial disease or bicuspid aortic valves. Cardiopulmonary bypass and aortic cross-clamp times were shorter in the MHCA/ACP group. AKI occurred in 19 (16.2%) patients who underwent MHCA/ACP and 67 (14.3%) patients who underwent DHCA/RCP. Four(0.8%) patients who underwent DHCA/RCP required postoperative dialysis. In-hospital mortality tended to increase with increasing RIFLE classification (RIFLE class-0 (No AKI) = 0.41%; Risk = 1.35%, and Injury = 10.0%; p= 0.09). On multivariable analysis, the lowest temperature and cerebral perfusion strategy were not significant predictors of AKI. Lower baseline glomerular filtration rate (GFR), lower preoperative ejection fraction, and longer cardiopulmonary bypass (CPB) time were independently associated with higher AKI. We applied the sensitive RIFLE criteria to examine AKI in patients undergoing elective aortic hemiarch replacement for aneurysmal disease. Baseline renal dysfunction, lower ejection fraction, and longer CPB time are independent predictors of AKI. Compared with DHCA/RCP, our data suggest that an MHCA/ACP cerebral protection strategy does not appear to be associated with worse postoperative renal outcomes.

Acute Kidney Injury After Abdominal Surgery: Incidence, Risk Factors, and Outcome.

Acute kidney injury (AKI) is a serious complication after major surgical procedures. We examined the incidence, risk factors, and mortality of patients who sustained AKI after abdominal surgery in a large population-based cohort. All patients who underwent open and laparoscopic abdominal surgery (excluding genitourinary and abdominal vascular procedures), between 2007 and 2014 at the University Hospital in Reykjavik were identified and their perioperative serum creatinine (SCr) measurements used to identify AKI after surgery employing the Kidney Disease: Improving Global Outcome (KDIGO) criteria. Risk factors were evaluated using multivariate logistic regression analysis and 30-day mortality compared with a propensity score-matched control group. During the 8-year period, a total of 11,552 abdominal surgeries were performed on 10,022 patients. Both pre- and postoperative SCr measurements were available for 3902 (33.8%) of the surgical cases. Of these, 264 (6.8%) were complicated by AKI; 172 (4.4%), 49 (1.3%), and 43 (1.1%) were classified as KDIGO stages 1, 2 and 3, respectively. The overall incidence of AKI for patients with available SCr values was 67.7 (99% confidence interval [CI], 57.7-78.6) per 1000 surgeries. In logistic regression analysis, independent risk factors for AKI were female sex (odds ratio [OR] = 0.68; 99% CI, 0.47-0.98), hypertension (OR = 1.75; 99% CI, 1.10-2.74), preoperative chronic kidney disease (OR= 1.68; 99% CI, 1.12-2.50), ASA physical status classification of IV (OR = 9.48; 99% CI, 3.66-29.2) or V (OR = 21.4; 99% CI, 5.28-93.6), and reoperation (OR = 4.30; 99% CI, 2.36-7.70). Patients with AKI had greater 30-day mortality (18.2% vs 5.3%; P < 0.001) compared with propensity score-matched controls. AKI is an important complication of abdominal surgery. In addition to sex, hypertension, and chronic kidney disease, ASA physical status classification is an independent predictor of AKI. Individuals who develop AKI have substantially worse short-term outcomes, including higher 30-day mortality, even after correcting for multiple patient- and procedure-related risk factors.

Acute Kidney Injury After Transcatheter Aortic Valve Replacement.

Acute kidney injury (AKI) during transcatheter aortic valve replacement (TAVR) increases morbidity and mortality. In this study, we investigated the incidence and risk factors for AKI in patients undergoing TAVR. Two hundred ninety consecutive patients underwent TAVR. Valve Academic Research Consortium (VARC)-I criteria for AKI diagnosis at 72 hours, and VARC-II criteria at seven days were employed. Overall AKI incidence was 24.62% (65/264): 50 patients at 72 hours and 15 patients at seven days. Multivariate logistic regression determined transapical (TA) approach (OR: 4.46 [1.37-7.63]), preprocedural glomerular filtration rate less than 45 mL/min (OR: 3.47 [1.35-14.70]), and blood transfusion (OR: 3.34 [1.58-11.09]) as independent predictors for AKI at 72 hours; and prior coronary artery bypass grafting (OR: 3.02 [1.007-9.09]) and peripheral artery disease (PAD) (OR: 3.53 [1.06-11.62]) for AKI at seven days. In-hospital and 30-day mortality was higher in AKI patients. Non-AKI patients' survival was 93% at six months, 89% at 12 months, and 86% at 24 months, whereas survival in AKI at 72 hours was 66% at 6, 12, and 24 months (HR AKI vs. non-AKI: 3.9 [CI: 2.0-7.6]), and survival in AKI at seven days was 64% at 6, 12, and 24 months, HR: 3.13 (CI: 1.42-6.92). For the 12 dialysis patients survival was 82% at 6, 12, and 24 months. AKI after TAVR is associated with worse outcomes. Blood transfusion should be administered restrictively in TAVR. Patients with CKD, PAD, prior CABG, and TA approach require close surveillance as they are at risk for AKI through seven days after TAVR. doi: 10.1111/jocs.12768 (J Card Surg 2016;31:416-422).

Risk factors and outcomes of acute renal infarction

BackgroundRenal infarction (RI) is an uncommon disease that is difficult to diagnose. As little is known about clinical characteristics of this disease, we investigated its underlying risk factors and outcomes. MethodsWe performed a retrospective single-center study of 89 patients newly diagnosed with acute RI between January 2002 and March 2015 using imaging modalities. Clinical features, possible etiologies, and long-term renal outcome data were reviewed. ResultsThe patients' mean age was 63.5 ± 15.42 years; 23.6% had diabetes and 56.2% had hypertension. Unilateral and bilateral involvements were shown in 80.9% and 19.1% of patients, respectively; proteinuria and hematuria were reported in 40.4% and 41.6%, respectively. Cardiovascular disease was the most common underlying disease, followed by renal vascular injury and hypercoagulability disorder. Fourteen patients had no specific underlying disease. At the time of diagnosis, acute kidney injury (AKI) was found in 34.8% of patients. Univariate analysis revealed diabetes mellitus (DM), leukocytosis, and high C-reactive protein (CRP) as significant risk factors for the development of AKI. On multivariate analysis, DM and high CRP levels were independent predictors for AKI. During follow-up, chronic kidney disease developed in 27.4% of patients. Univariate and multivariate Cox regression analyses showed old age to be an independent risk factor for this disease, whereas AKI history was a negative risk factor. ConclusionDM patients or those with high CRP levels should be observed for renal function deterioration. Clinicians should also monitor for RI in elderly patients.

Urine Output During Cardiopulmonary Bypass Predicts Acute Kidney Injury After Cardiac Surgery: A Single-Center Retrospective Analysis.

Urine output is closely associated with renal function and has been used as a diagnostic criterion for acute kidney injury (AKI). However, urine output during cardiopulmonary bypass (CPB) has never been identified as a predictor of postoperative AKI. Considering altered renal homeostasis during CPB, we made a comprehensible approach to CPB urine output and evaluated its predictability for AKI.Patients undergoing cardiovascular surgery with the use of CPB, between January 2009 and December 2011, were retrospectively reviewed. AKI was defined as an increase in serum creatinine ≥0.3 mg/dL in the first postoperative 48 hours. We extrapolated a possible optimal amount of urine output from the plot of probability of AKI development according to CPB urine output. After separating patients by the predicted optimal value, we performed stepwise logistic regression analyses to find potential predictors of AKI in both subgroups.A total of 696 patients were analyzed. The amount of CPB urine output had a biphasic association with the incidence of AKI using 4 mL/kg/h as a boundary value. In a multivariate logistic regression to find predictors for AKI in entire patients, CPB urine output did not show statistical significance. After separating patients into subgroups with CPB urine output below and over 4 mL/kg/h, it was identified as an independent predictor for AKI with the odds ratio of 0.43 (confidence interval 0.30–0.61) and 1.11 (confidence interval 1.02–1.20), respectively.The amount of urine output during CPB with careful analysis may serve as a simple and feasible method to predict the development of AKI after cardiac surgery at an early time point.

Rewarming Temperature During Cardiopulmonary Bypass and Acute Kidney Injury: A Multicenter Analysis

Acute kidney injury (AKI) after cardiopulmonary bypass (CPB) is associated with a requirement for dialysis, a longer stay in the intensive care unit, a longer hospital length of stay, and mortality. An oxygenator arterial outlet temperature greater than 37°C has been reported to be associated with AKI; however, the influence of other rewarming temperatures is unclear. Using multicenter registry data, this study aimed to evaluate the role of CPB rewarming temperatures on AKI. Data from 8,407 adult patients undergoing coronary artery bypass grafting (CABG) or valve repair or replacement, or a combination, were collected using the Perfusion Downunder Collaborative Database. Primary variables of interest were rewarming temperatures, defined as cumulative time the oxygenator arterial outlet temperature was greater than 36°C, greater than 36.5°C, or greater than 37°C. Propensity scores were calculated to determine the predicted probability of hyperthermic perfusion (rewarming temperature >37°C). The influence of temperature on AKI was determined using separate multivariate models adjusting for propensity score in the entire cohort (n= 6,904) and in propensity-matched patients (n= 2,044). Overall, 11.8% of patients acquired AKI. The duration of rewarming temperature greater than 36°C or 36.5°C was not associated with AKI. The duration of rewarming temperature greater than 37°C (hyperthermic perfusion) was independently associated with RIFLE (Risk, Injury, Failure, Loss, End-stage renal disease) risk classification or greater (odds ratio [OR], 1.42; 95% confidence interval [CI], 1.09-1.77; p= 0.012) and injury classification or greater AKI (OR, 1.52; 95% CI, 1.09-1.97; p= 0.016) in the entire cohort, and injury classification or greater AKI (OR, 1.51; 95% CI, 1.15-1.90; p= 0.006) in propensity-matched patients. The duration of hyperthermic perfusion-rewarming temperature greater than 37°C-was an independent predictor of AKI. Avoidance of hyperthermic perfusion may be more beneficial in reducing AKI than avoidance of rewarming.

Relation of Pulmonary Artery Pressure and Renal Impairment in ST Segment Elevation Myocardial Infarction Patients.

Recent reports have demonstrated the adverse effects of venous congestion on renal function in patients having heart failure. None of the above trials, however, included patients with acute ischemia. Echocardiographic correlates of increased right ventricular afterload would be associated with an increased risk of acute kidney injury (AKI) in ST elevation myocardial infarction (STEMI) patients undergoing primary percutaneous coronary intervention (PCI). We conducted a retrospective study of consecutive 930 STEMI patients who underwent primary PCI and had a full echocardiography study performed within 72 hours of hospital admission between June 2011 and December 2014. Echocardiography demonstrated that patients with AKI had significantly lower left ventricular (LV) ejection fraction, higher systolic pulmonary artery pressure (SPAP), and right atrial pressures (P < 0.001 for all). Following the performance of logistic multivariate analysis model, SPAP (HR 1.07, 95% CI 1.04-1.11; P < 0.001) and LV ejection fraction (HR 0.95, 95% CI 0.92-0.99; P = 0.03) emerged as independent predictors of AKI. On receiver operating characteristic (ROC) curve analysis, the optimal cutoff value of SPAP to predict AKI was measured as more than 32 mmHg, with 71% sensitivity and 62% specificity (AUC 0.739, 95% CI 0.671-0.806, P < 0.001). Among STEMI patients undergoing primary PCI, worse LV function and elevated SPAP were associated with increased risk of AKI.

Acute kidney injury in Hemiscorpius lepturus scorpion stung children: Risk factors and clinical features.

Acute kidney injury (AKI) is frequently seen in Hemiscorpius lepturus scorpion stung children. We have previously reported several victims with hemolytic uremic syndrome (HUS) and a disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13 deficiency. Hence, we conducted this study to identify predictive factors and clinical features of AKI in H. lepturus scorpion stung patients. We included all 215 H. lepturus scorpion stung children with no previous renal diseases in two groups (with and without AKI) and compared them based on their clinical and laboratory findings. AKI was found in 27.4% of patients, they were significantly younger and with lower body weight (P = 0.006, P = 0.011, respectively). There was a significant difference between groups with and without AKI in findings such as fever (P = 0.003), hypertension (P <0.001), hemolytic anemia (P <0.001), thrombocytopenia (P <0.001), massive proteinuria (P <0.001), hemoglobinuria (P <0.001), pyuria (P <0.001), and hematuria (P = 0.004). HUS was in 5.5% and disseminated intravascular coagulation in 14.6% which had a significant association with AKI (P <0.001).There were several independent predictors for AKI in a multivariate regression model including thrombocytopenia (P = 0.002), pyuria (P = 0.01), proteinuria (P =0.01), and fever (P = 0.02). Hemodialysis was performed in four patients but kidney function improved in all patients and there was no findings of renal impairment after three months follow-up. We found several predictors for AKI in children following H. lepturus scorpion sting including younger age, delay in receiving medical care, pigmenturia, microangiopathic hemolytic anemia, proteinuria, and pyuria.

Serum Uric Acid Levels and Renal Impairment among ST-Segment Elevation Myocardial Infarction Patients Undergoing Primary Percutaneous Intervention

Background: Elevated serum uric acid (UA) levels are associated with adverse outcomes in ST-segment elevation myocardial infarction (STEMI) patients undergoing primary percutaneous coronary intervention (PCI). However, the relation between UA and acute kidney injury (AKI) in this population is unclear. We evaluated the effect of elevated UA levels on the risk to develop AKI among consecutive STEMI patients treated with primary PCI. Methods: We performed a retrospective analysis of 1,372 consecutive patients admitted with the diagnosis of STEMI between January 2008 and February 2015. Patients were stratified into quartiles according to UA levels as follows: quartile 1, <4.7 mg/dl; quartile 2, 4.8 to <5.6 mg/dl; quartile 3, 5.7 to <6.6 mg/dl, and quartile 4, >6.7 mg/dl. Results: STEMI patients with elevated UA levels had a higher frequency of AKI (4 vs. 6% vs. 10 vs. 24%; p < 0.001). In a subgroup analysis of patients with reduced baseline estimated glomerular filtration rate (≤60 ml/min/1.73 m²), an elevated UA level was associated with a significant risk to develop AKI, with 46% of patients developing AKI in the highest UA quartile. In a multivariate logistic regression model, for every 1-mg/dl increase in the UA concentration, the adjusted risk for AKI increased by 46% (OR = 1.46, 95% CI 1.18-1.66; p < 0.001). Conclusions: Among STEMI patients undergoing primary PCI, elevated UA levels are an independent predictor of AKI.

Sleep apnoea is a risk factor for acute kidney injury after coronary artery bypass grafting.

Acute kidney injury (AKI) is a common complication in patients who undergo coronary artery bypass grafting (CABG). Sleep apnoea is associated with sympathetic activation, inflammatory reaction and plaque burden. The possible status of sleep apnoea as a risk factor for AKI after CABG has not been studied. We recruited 169 patients for an overnight sleep study using a Food and Drug Administration-approved portable device before they underwent elective CABG. AKI after CABG was defined as a relative increase of greater than 25% or an absolute increase of greater than 0.5 mg/dl in the serum creatinine level from baseline within 5 days after CABG. A generalized structural equation model (gSEM) was then applied to ascertain whether sleep apnoea, defined as an Apnoea-Hypopnoea index (AHI) of 15 or higher, was associated with AKI after CABG after adjusting for the effects of confounding variables. Of the 150 patients (88.8%) who completed the study, the incidence of AKI after CABG was 22.7%. The mean AHI was higher in the AKI group (27.4 ± 19.8) than that in the non-AKI group (18.3 ± 16.5; P < 0.01). The prevalence of sleep apnoea was higher in the AKI group (64.7%) than that in the non-AKI group (45.7%; P = 0.05). The patients in the AKI group were older (P < 0.01) and shorter (P = 0.03) and had higher systolic blood pressures (P = 0.01), greater waist circumferences (P = 0.04) and larger left atrial diameters (P < 0.01) than those in the non-AKI group. The patients in the AKI group had higher serum haemoglobin levels (P = 0.04) and lower glucose levels (P < 0.01) than those in the non-AKI group. A gSEM based on binomial distributions showed that sleep apnoea was an independent predictor of AKI after CABG (adjusted odds ratio, 2.89; confidence interval, 1.09-7.09; P = 0.03) after adjustment for the effects of haemoglobin, glucose levels, the left atrial diameter and systolic blood pressure. Sleep apnoea is prevalent and is associated with AKI after CABG. The data presented here provide the first insights into the potential of treating sleep apnoea to attenuate the risk of AKI after CABG.

Abstract 15440: The Incidence and Outcomes of Acute Kidney Injury After TAVR

Introduction: Acute kidney injury (AKI) is a known complication after cardiovascular procedures and is associated with increased all-cause-mortality. Hypothesis: We aimed to assess the incidence, predictors, and long-term outcomes of AKI after TAVR. Methods: We evaluated inoperable patients with severe aortic stenosis who received TAVR in an academic institution from 04/2008 to 06/2015. AKI was defined according to the consensus report of the Valve Academic Research Consortium. Predictors of AKI were evaluated using multivariable logistic regression modeling. Results: Among 457 patients who underwent TAVR, 78 (17%) developed AKI. There were no differences in age, gender, BMI, hypertension, dyslipidemia, smoking status, or medications use among patients with and without AKI. However, patients with AKI were more likely to have diabetes mellitus (DM), chronic kidney disease (CKD) and prior history of stroke than patients without AKI (Figure). Patients with AKI had also lower baseline hemoglobin (AKI: 11 g/dL vs. No AKI: 12, p=0.004) and higher baseline creatinine (1.45 vs. 1.1, p=&lt;0.001). Procedural characteristics that were associated with AKI included: hypotension, IABP/LV assist device use, bleeding, and vascular complications. Patients with AKI had higher all-cause-mortality (14% vs. 2%, p &lt;0.001), higher median hospital length of stay (12 vs. 7 days, p &lt;0.001) and a higher incidence of new dialysis requirement (12% vs. 1%, p &lt;0.001), and dialysis at one month (8% vs. 1%, p =0.001). Multivariate logistsic regression analysis identified DM, CKD, and IABP or LV assist device use as independent predictors of AKI. Conclusion: Our results suggest that AKI is relatively common post TAVR and it is associated with increased mortality, length of stay, and dialysis requirement. Patients with underlying CKD and DM who require IABP or LV assist devices for hemodynamic support are at the highest risk of AKI.

Predictors of Perioperative Acute Kidney Injury in Obese Patients Undergoing Laparoscopic Bariatric Surgery: a Single-Centre Retrospective Cohort Study.

Obesity has been associated with increased risk of perioperative acute kidney injury (AKI). We aim to establish the incidence of AKI among patients undergoing laparoscopic bariatric surgery and identify potential risk factors. Records of 1230 patients who underwent laparoscopic bariatric surgery in a tertiary centre from 1 December 2009 to 31 January 2014 were retrospectively studied. AKI diagnosis was made by comparing the baseline and post-operative serum creatinine to determine the presence of predefined significant change based on the Kidney Disease: Improving Global Outcomes (KDIGO) definition. Univariate analyses were performed to determine significant clinical factors, and multiple logistic regression analysis was subsequently done to determine independent predictors of AKI. Thirty-five (2.9%) patients developed AKI during the first 72h post-surgery. Multivariate logistic regression analysis revealed impaired renal function (OR 10.429, 95% CI 3.560 to 30.552), use of angiotensin-converting enzyme inhibitors and angiotensin II receptor blockers (OR 3.038, 95% CI 1.352 to 6.824), and body mass index (OR 1.048, 95% CI 1.005 to 1.093) as independent predictors of perioperative acute kidney injury in the obese patients who underwent laparoscopic bariatric surgery. We found that the incidence of perioperative AKI among patients who underwent laparoscopic bariatric surgery is at 2.9%. Impaired renal function, use of angiotensin-converting enzyme inhibitors and angiotensin II receptor blockers and raised body mass index were found to be independent predictors of AKI. Patients with these risk factors could be considered at risk for developing perioperative AKI, and extra perioperative vigilance should be undertaken.

Colistin-associated Acute Kidney Injury in Severely Ill Patients: A Step Toward a Better Renal Care? A Prospective Cohort Study.

Critically ill patients with severe sepsis or septic shock may need relatively high colistin daily doses for efficacy against multidrug-resistant and extensively drug-resistant gram-negative rods. However, acute kidney injury (AKI) may represent a major dose-limiting adverse effect of colistin. We sought to determine AKI occurrence and to identify factors influencing AKI risk in severely ill patients receiving colistin according to a recently proposed dosing strategy. A prospective, observational, cohort study involving patients with severe sepsis or septic shock who received colistin was performed. AKI was defined according to Acute Kidney Injury Network criteria. Colistin administration was driven by a modified pharmacokinetics-pharmacodynamics (PK/PD)-based dosing approach. Of 70 patients who received colistin at a median daily dose of 9 million IU (MIU; interquartile range, 5.87-11.1 MIU), 31 (44%) developed AKI. In univariate analysis, age, Acute Physiology and Chronic Health Evaluation (APACHE) II score, Sequential Organ Failure Assessment (SOFA), score and baseline renal impairment were significantly associated with AKI. Moreover, patients with AKI were less frequently treated with adjuvant ascorbic acid (P = .003). In multivariate analysis, independent predictors of AKI were baseline renal impairment (adjusted hazard ratio, 4.15; 95% confidence interval, 1.9-9.2; P < .001) and age (1.03; 1.0-1.05; P = .028), whereas a strong independent renal-protective role emerged for ascorbic acid (0.27; .12-.57; P < .001). In severely ill patients receiving colistin according to a PK/PD-driven dosing approach, baseline renal impairment and older age strongly predict AKI occurrence, but concomitant administration of ascorbic acid markedly reduces AKI risk, allowing safer use of colistin.

Acute Kidney Injury in Patients With Chronic Kidney Disease Undergoing Internal Carotid Artery Stent Implantation

This study sought to investigate acute kidney injury (AKI) following carotid artery stenting (CAS). Few data exist on AKI following CAS. This study evaluated 126 chronic kidney disease (CKD) patients who underwent CAS. The risk for contrast-induced AKI was defined by the Mehran score. Hemodynamic depression (i.e., periprocedural systolic blood pressure <90 mm Hg or heart rate <60 beats/min), AKI (i.e., an increase of ≥0.3 mg/dl in the serum creatinine concentration at 48 h), and 30-day major adverse events (including death, stroke, and acute myocardial infarction) were assessed. AKI occurred in 26 patients (21%). Although baseline kidney function and contrast volume were similar in the AKI group and the non-AKI group, the risk score was higher (10 ± 3 vs. 8 ± 3; p = 0.032), and hemodynamic depression (mostly due to hypotension) (65.5% vs. 35%; p = 0.005) was more common in the AKI group. The threshold of hemodynamic depression duration for AKI development was 2.5 min (sensitivity 54%, specificity 82%). Independent predictors of AKI were hemodynamic depression (odds ratio [OR]: 4.01; 95% confidence interval [CI]: 1.07 to 15.03; p = 0.009), risk score (OR: 1.29; 95% CI: 1.03 to 1.60; p = 0.024), and male sex (OR: 6.07; 95% CI: 1.18 to 31.08; p = 0.021). Independent predictors of 30-day major adverse events that occurred more often in the AKI group (19.5% vs. 7%; p = 0.058) were AKI (HR: 4.83; 95% CI: 1.10 to 21.24; p = 0.037) and hemodynamic depression (HR: 5.58; 95% CI: 1.10 to 28.31; p = 0.038). AKI in CKD patients undergoing CAS is mostly due to hemodynamic depression and is associated with a higher 30-day major adverse events rate.

Risk Factors for Colistin-Associated Acute Kidney Injury: A Multicenter Study from Turkey.

The aim of this study was to investigate the incidence of acute kidney injury (AKI) and risk factors due to colistin use in patients infected with multidrug-resistant pathogens. This multicenter, retrospective, observational study was conducted in Turkey, at 5 different research and university hospitals. Cox regression analyses were performed, to determine independent predictors of AKI. From April 2012 to July 2014, a total of 216 patients aged between 18-94 years, treated with colistimethate sodium (CMS) were included in the study. The mean age of the patients was 60.3 ± 20.1 years. The overall incidence of AKI was 34.3% (74/216) at any time during treatment. Concomitant use of loop diuretics, baseline creatinine level, and CMS dosage were independently associated with AKI. According to our results, patients with higher baseline creatinine levels, or patients who had to use concomitant loop diuretics may need to be monitored more closely, and dose adjustment should be done promptly. More comprehensive studies are, however, still needed to evaluate the efficacy of low-dose colistin since higher doses tend to increase the risk of AKI.