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BackgroundThere has recently been considerable interest in better understanding how blood pressure should be managed after an episode of hospitalized AKI, but there are scant data regarding the associations between blood pressure measured after AKI and subsequent adverse outcomes. We hypothesized that among AKI survivors, higher blood pressure measured three months after hospital discharge would be associated with worse outcomes. We also hypothesized these associations between blood pressure and outcomes would be similar among those who survived non-AKI hospitalizations.MethodsWe quantified how systolic blood pressure (SBP) observed three months after hospital discharge was associated with risks of subsequent hospitalized AKI, loss of kidney function, mortality, and heart failure events among 769 patients in the prospective ASSESS-AKI cohort study who had hospitalized AKI. We repeated this analysis among the 769 matched non-AKI ASSESS-AKI enrollees. We then formally tested for AKI interaction in the full cohort of 1538 patients to determine if these associations differed among those who did and did not experience AKI during the index hospitalization.ResultsAmong 769 patients with AKI, 42 % had subsequent AKI, 13 % had loss of kidney function, 27 % died, and 18 % had heart failure events. SBP 3 months post-hospitalization did not have a stepwise association with the risk of subsequent AKI, loss of kidney function, mortality, or heart failure events. Among the 769 without AKI, there was also no stepwise association with these risks. In formal interaction testing using the full cohort of 1538 patients, hospitalized AKI did not modify the association between post-discharge SBP and subsequent risks of adverse clinical outcomes.ConclusionsContrary to our first hypothesis, we did not observe that higher stepwise blood pressure measured three months after hospital discharge with AKI was associated with worse outcomes. Our data were consistent with our second hypothesis that the association between blood pressure measured three months after hospital discharge and outcomes among AKI survivors is similar to that observed among those who survived non-AKI hospitalizations.

INTRODUCTIONAcute kidney injury and chronic kidney disease (CKD) are common in hospitalized patients. To inform clinical decision making, more accurate information regarding risk of long-term progression to kidney failure is required.METHODSWe enrolled 1538 hospitalized patients in a multicenter, prospective cohort study. Monocyte chemoattractant protein 1 (MCP-1/CCL2), uromodulin (UMOD), and YKL-40 (CHI3L1) were measured in urine samples collected during outpatient follow-up at 3 months. We followed patients for a median of 4.3 years and assessed the relationship between biomarker levels and changes in estimated glomerular filtration rate (eGFR) over time and the development of a composite kidney outcome (CKD incidence, CKD progression, or end-stage renal disease). We paired these clinical studies with investigations in mouse models of renal atrophy and renal repair to further understand the molecular basis of these markers in kidney disease progression.RESULTSHigher MCP-1 and YKL-40 levels were associated with greater eGFR decline and increased incidence of the composite renal outcome, whereas higher UMOD levels were associated with smaller eGFR declines and decreased incidence of the composite kidney outcome. A multimarker score increased prognostic accuracy and reclassification compared with traditional clinical variables alone. The mouse model of renal atrophy showed greater Ccl2 and Chi3l1 mRNA expression in infiltrating macrophages and neutrophils, respectively, and evidence of progressive renal fibrosis compared with the repair model. The repair model showed greater Umod expression in the loop of Henle and correspondingly less fibrosis.CONCLUSIONSBiomarker levels at 3 months after hospitalization identify patients at risk for kidney disease progression.FUNDINGNIH.

Acute kidney injury (AKI) has been reported to be associated with excess risks of death, kidney disease progression and cardiovascular events although previous studies have important limitations. To further examine this, we prospectively studied adults from four clinical centers surviving three months and more after hospitalization with or without AKI who were matched on center, pre-admission CKD status, and an integrated priority score based on age, prior cardiovascular disease or diabetes mellitus, preadmission estimated glomerular filtration rate (eGFR) and treatment in the intensive care unit during the index hospitalization between December 2009-February 2015, with follow-up through November 2018. All participants had assessments of kidney function before (eGFR) and at three months and annually (eGFR and proteinuria) after the index hospitalization. Associations of AKI with outcomes were examined after accounting for pre-admission and three-month post-discharge factors. Among 769 AKI (73% Stage 1, 14% Stage 2, 13% Stage 3) and 769 matched non-AKI adults, AKI was associated with higher adjusted rates of incident CKD (adjusted hazard ratio 3.98, 95% confidence interval 2.51-6.31), CKD progression (2.37,1.28-4.39), heart failure events (1.68, 1.22-2.31) and all-cause death (1.78, 1.24-2.56). AKI was not associated with major atherosclerotic cardiovascular events in multivariable analysis (0.95, 0.70-1.28). After accounting for degree of kidney function recovery and proteinuria at three months after discharge, the associations of AKI with heart failure (1.13, 0.80-1.61) and death (1.29, 0.84-1.98) were attenuated and no longer significant. Thus, assessing kidney function recovery and proteinuria status three months after AKI provides important prognostic information for long-term clinical outcomes.

We examined a novel database linking national donor registry identifiers to records from a US pharmaceutical claims warehouse (2007-2015) to describe opioid and NSAID prescription patterns among LKDs during the first year postdonation, divided into three periods: 0-14 days, 15-182 days, and 183-365 days. Associations of opioid and NSAID prescription fills with baseline factors were examined by logistic regression (adjusted odds ratio, LCL aORUCL ). Among 23,565 donors, opioid prescriptions were highest during days 0-14 (36.6%), but 12.6% of donors filled opioids during days 183-365. NSAID prescriptions rose from 0.5% during days 0-14 to 3.3% during days 183-365. Women filled opioids more commonly than men, and black donors filled both opioids and NSAIDs more commonly than white donors. After covariate adjustment, significant correlates of opioid prescription fills during days 183-365 included obesity (aOR,1.24 1.381.53 ), less than college education (aOR,1.19 1.311.43 ), smoking (aOR,1.33 1.451.58 ), and nephrectomy complications (aOR,1.11 1.291.49 ). NSAID prescription fills in year 1 were not associated with differences in estimated glomerular filtration rate, incidence of proteinuria or new-onset hypertension at the first and second year postdonation. Prescription fills for opioids and NSAIDs for LKDs varied with demographic and clinic traits. Future work should examine longer-term outcome implications to help inform safe analgesic regimen choices after donation.

Background: Many patients with end-stage kidney disease (ESKD) have valvular heart disease requiring surgery. The optimal prosthetic valve is not established in this population. We performed a systematic review and meta-analysis to assess outcomes of patients with dialysis-dependent ESKD who received mechanical or bioprosthetic valves. Methods: We searched Cochrane Central, Medline and Embase from inception to January 2020. We performed screening, full-text assessment, risk of bias and data collection, independently and in duplicate. Data were pooled using a random-effects model. Results: We identified 28 observational studies (n = 9857 patients, including 6680 with mechanical valves and 3717 with bioprosthetic valves) with a median follow-up of 3.45 years. Twenty-two studies were at high risk of bias and 1 was at critical risk of bias from confounding. Certainty in evidence was very low for all outcomes except bleeding. Mechanical valves were associated with reduced mortality at 30 days (relative risk [RR] 0.79, 95% confidence interval [CI] 0.65-0.97, [I.sup.2] = 0, absolute effect 27 fewer deaths per 1000) and at 6 or more years (mean 9.7 yr, RR 0.83, 95% CI 0.72-0.96, [I.sup.2] = 79%, absolute effect 145 fewer deaths per 1000), but increased bleeding (incidence rate ratio [IRR] 2.46, 95% CI 1.41-4.27, [I.sup.2] = 59%, absolute effect 91 more events per 1000) and stroke (IRR 1.63, 95% CI 1.21-2.20, [I.sup.2] = 0%, absolute effect 25 more events per 1000). Conclusion: Mechanical valves were associated with reduced mortality, but increased rate of bleeding and stroke. Given very low certainty for evidence of mortality and stroke outcomes, patients and clinicians may choose prosthetic valves based on factors such as bleeding risk and valve longevity. Study registration: PROSPERO no. CRD42017081863 Contexte : De nombreux patients souffrant d'insuffisance renale terminale (IRT) presentent une valvulopathie necessitant une intervention chirurgicale. On ignore quelle est la valve prothetique optimale chez cette population. Nous avons effectue un examen systematique et une meta-analyse pour evaluer les resultats des patients atteints d'IRT dialyses ayant recu une valvule mecanique ou une bioprothese valvulaire. Methodes : Nous avons interroge les bases de donnees Cochrane Central, Medline et Embase, de leur date de creation jusqu'a janvier 2020. Nous avons procede a la selection, a l'evaluation des textes integraux, a l'evaluation des risques de biais et a la collecte de donnees, independamment et en double. Les donnees ont ete regroupees a l'aide d'un modele a effets aleatoires. Resultats : Nous avons cible 28 etudes d'observation (n = 9857 patients, dont 6680 avec une valvule mecanique et 3717 avec une bioprothese valvulaire), avec un suivi d'une duree mediane de 3,45 ans. Vingt-deux etudes presentaient un risque eleve de biais et 1 etude presentait un risque critique de biais resultant de variables de confusion. La certitude des donnees etait tres faible pour tous les resultats, a l'exception des hemorragies. Les valvules mecaniques ont ete associees a une reduction de la mortalite a 30 jours (risque relatif [RR] de 0,79, intervalle de confiance [IC] de 95 % 0,65-0,97, [I.sup.2] = 0, effet absolu de 27 deces de moins pour 1000 patients) et a 6 ans ou plus (moyenne de 9,7 ans, RR de 0,83, IC de 95 % 0,72-0,96, [I.sup.2] = 79 %, effet absolu de 145 deces de moins pour 1000 patients), mais egalement a une augmentation des hemorragies (rapport des taux d'incidence [RTI] de 2,46, IC de 95 % 1,41-4,27, [I.sup.2] = 59 %, effet absolu de 91 evenements supplementaires pour 1000 patients) et des AVC (IRR de 1,63, IC de 95 % 1,21-2,20, [I.sup.2] = 0 %, effet absolu de 25 evenements supplementaires pour 1000 patients). Conclusion : Les valvules mecaniques ont ete associees a une reduction de la mortalite, mais a une augmentation du taux d'evenements hemorragiques et d'AVC. Compte tenu du tres faible degre de certitude des donnees sur la mortalite et les AVC, les patients et les cliniciens peuvent choisir les bioprotheses valvulaires selon des facteurs comme le risque d'hemorragie et la durabilite de la prothese. Numero d'enregistrement de la recherche : PROSPERO no CRD42017081863, In 2010, more than 2.6 million people worldwide were receiving dialysis for end-stage kidney disease (ESKD), a prevalence that is likely to increase to more than 5.4 million people by [...]

BackgroundLimited data are available regarding clinical implications of lower renal function after living kidney donation. We examined a novel integrated database to study associations between postdonation estimated glomerular filtration rate (eGFR) and use of antihypertensive medication (AHM) treatment after living kidney donation.MethodsStudy data were assembled by linking national U.S. transplant registry identifiers, serum creatinine (SCr) values from electronic medical records, and pharmacy fill records for 3222 living donors (1989-2016) without predonation hypertension. Estimated GFR (mL/min per 1.73 m2) was computed from SCr values by the CKD-EPI equation. Repeated measures multivariable mixed effects modeling examined the associations (adjusted odds ratio, 95%LCLaOR95% UCL) between AHM use and postdonation eGFR levels (random effect) with fixed effects for baseline donor factors.ResultsThe linked database identified an average of 3 postdonation SCr values per donor (range: 1-38). Lower postdonation eGFR (vs ≥75) bore graded associations with higher odds of AHM use (eGFR 30-44: aOR 0.951.472.26; 30 kg/m2 (aOR 1.011.452.09), first-degree donor-recipient relationship (aOR 1.071.381.79), "prehypertension" at donation (systolic blood pressure 120-139: aOR 1.101.461.94; diastolic blood pressure 80-89: aOR 1.061.451.99).ConclusionsThis novel linkage illustrates the ability to identify postdonation kidney function and associate it with clinically meaningful outcomes; lower eGFR after living kidney donation is a correlate of AHM treatment requirements. Further work should define relationships of postdonation renal function, hypertension, and other morbidity measures.

Rationale & objectiveThe process of angiogenesis after kidney injury may determine recovery and long-term outcomes. We evaluated the association of angiogenesis markers with acute kidney injury (AKI) and mortality after cardiac surgery.Study designProspective cohort.Setting & participants1,444 adults undergoing cardiac surgery in the TRIBE-AKI (Translational Research Investigating Biomarker Endpoints for Acute Kidney Injury) cohort.ExposuresPlasma concentrations of 2 proangiogenic markers (vascular endothelial growth factor A [VEGF] and placental growth factor [PGF]) and 1 antiangiogenic marker (soluble VEGF receptor 1 [VEGFR1]), measured pre- and postoperatively within 6 hours after surgery.OutcomesAKI, long AKI duration (≥7 days), and 1-year all-cause mortality.Analytical approachMultivariable logistic regression.ResultsFollowing cardiac surgery, plasma VEGF concentrations decreased 2-fold, and PGF and VEGFR1 concentrations increased 1.5- and 8-fold, respectively. There were no meaningful associations of preoperative concentrations of angiogenic markers with outcomes of AKI and mortality. Higher postoperative VEGF and PGF concentrations were independently associated with lower odds of AKI (adjusted ORs of 0.89 [95% CI, 0.82-0.98] and 0.69 [95% CI, 0.55-0.87], respectively), long AKI duration (0.65 [95% CI, 0.49-0.87] and 0.48 [95% CI, 0.28-0.82], respectively), and mortality (0.74 [95% CI, 0.62-0.89] and 0.46 [95% CI, 0.31-0.68], respectively). In contrast, higher postoperative VEGFR1 concentrations were independently associated with higher odds of AKI (1.56; 95% CI, 1.31-1.87), long AKI duration (1.75; 95% CI, 1.09-2.82), and mortality (2.28; 95% CI, 1.61-3.22).LimitationsAngiogenesis markers were not measured after hospital discharge, so we were unable to determine long-term trajectories of angiogenesis marker levels during recovery and follow-up.ConclusionsHigher levels of postoperative proangiogenic markers, VEGF and PGF, were associated with lower AKI and mortality risk, whereas higher postoperative antiangiogenic VEGFR1 levels were associated with higher risk for AKI and mortality.

Hemodialysis is a life-sustaining treatment for persons with kidney failure. However, those on hemodialysis still face a poor quality of life and a short life expectancy. High-quality research evidence from large randomized controlled trials is needed to identify interventions that improve the experiences, outcomes, and health care of persons receiving hemodialysis. With the support of the Canadian Institutes of Health Research and its Strategy for Patient-Oriented Research, the Innovative Clinical Trials in Hemodialysis Centers initiative brought together Canadian and international kidney researchers, patients, health care providers, and health administrators to participate in a workshop held in Toronto, Canada, on June 2 and 3, 2018. The workshop served to increase knowledge and awareness about the conduct of innovative, pragmatic, cluster-randomized registry trials embedded into routine hemodialysis care and provided an opportunity to discuss and build support for new trial ideas. The workshop content included structured presentations, facilitated group discussions, and expert panel feedback. Partnerships and promising trial ideas borne out of the workshop will continue to be developed to support the implementation of future large-scale trials.

The Chronic Kidney Disease (CKD) Prognosis Consortium is a collaborative author of the above-mentioned article. The CKD Prognosis Consortium investigators/collaborators are as follows: • African American Study of Kidney Disease and Hypertension (AASK): Brad Astor, Lawrence J. Appel; Canadian Study of Prediction of Death, Dialysis and Interim Cardiovascular Events (CanPREDDICT): Adeera Levin, Mila Tang, Ognjenka Djurdjev; Cleveland Clinic CKD Registry Study (CCF): Sankar D. Navaneethan, Stacey E. Jolly, Jesse D. Schold, Joseph V. Nally Jr.; Chronic Renal Impairment in Birmingham (CRIB): David C. Wheeler, Jonathan Emberson, John Townend, Martin Landray; Chronic Renal Insufficiency Cohort Study (CRIC): Harold I. Feldman, Chi-yuan Hsu, James P. Lash, Lawrence J. Appel; Chronic Renal Insufficiency Standards Implementation Study (CRISIS): Philip A. Kalra, James P. Ritchie, Raman Maharajan, Rachel J. Middleton, Donal J. O'Donoghue; German Chronic Kidney Disease Study (GCKD): Kai-Uwe Eckardt, Markus P. Schneider, Anna Köttgen, Florian Kronenberg, Barbara Bärthlein; Geisinger Health System: Alex R. Chang, Jamie A. Green, H. Lester Kirchner, Kevin Ho; Grampian Laboratory Outcomes, Morbidity and Mortality Studies – 2 (GLOMMS2): Angharad Marks, Corri Black, Gordon J. Prescott, Nick Fluck; Gonryo Study: Masaaki Nakayama, Mariko Miyazaki, Tae Yamamoto, Gen Yamada; Hong Kong CKD Studies: Angela Yee-Moon Wang, Sharon Cheung, Sharon Wong, Jessie Chu, Henry Wu; Ontario Institute for Clinical Evaluative Sciences, Provincial Kidney, Dialysis and Transplantation program (ICES KDT): Amit X. Garg, Eric McArthur, Danielle M. Nash; Maccabi Health System: Varda Shalev, Gabriel Chodick; Multifactorial Approach and Superior Treatment Efficacy in Renal Patients with the Aid of a Nurse Practitioner (MASTERPLAN): Peter J. Blankestijn, Jack F.M. Wetzels, Arjan D. van Zuilen, Jan A. van den Brand; Modification of Diet in Renal Disease Study (MDRD): Andrew S. Levey, Lesley A. Inker, Mark J. Sarnak, Hocine Tighiouart; Nanjing CKD Network Cohort Study (Nanjing CKD): Haitao Zhang; NephroTest Study (NephroTest): Benedicte Stengel, Marie Metzger, Martin Flamant, Pascal Houillier, Jean-Philippe Haymann; National Renal Healthcare Program – Uruguay (NRHP-URU): Pablo G. Rios, Nelson Mazzuchi, Liliana Gadola, Verónica Lamadrid, Laura Sola; New Zealand Diabetes Cohort Study (NZDCS): John F. Collins, C. Raina Elley, Timothy Kenealy; Parcours de Soins des Personnes Agées (PSPA): Olivier Moranne, Cecile Couchoud, Cecile Vigneau; Primary-Secondary Care Partnership to Prevent Adverse Outcomes in Chronic Kidney Disease (PSP CKD): Nigel J. Brunskill, Rupert W. Major, David Shepherd, James F. Medcalf; Racial and Cardiovascular Risk Anomalies in CKD Cohort (RCAV): Csaba P. Kovesdy, Kamyar Kalantar-Zadeh, Miklos Z. Molnar, Keiichi Sumida, Praveen K. Potukuchi; Reduction of Endpoints in Non-insulin Dependent Diabetes Mellitus with the Angiotensin II Antagonist Losartan (RENAAL): Hiddo J.L. Heerspink, Dick de Zeeuw, Barry Brenner; Stockholm CREAtinine Measurements Cohort (SCREAM): Juan Jesus Carrero, Alessandro Gasparini, Abdul Rashid Qureshi, Carl-Gustaf Elinder; Second Manifestations of ARTerial Disease Study (SMART): Frank L.J. Visseren, Yolanda van der Graaf; Swedish Renal Registry CKD Cohort (SRR CKD): Marie Evans, Maria Stendahl, Staffan Schön, Mårten Segelmark, Karl-Göran Prütz; Sunnybrook Cohort: David M. Naimark, Navdeep Tangri; West of Scotland CKD Study: Patrick B. Mark, Jamie P. Traynor, Colin C. Geddes, Peter C. Thomson.• CKD Prognosis Consortium Steering Committee: Alex R. Chang, Josef Coresh (Chair), Ron T. Gansevoort, Morgan E. Grams, Anna Köttgen, Andrew S. Levey, Kunihiro Matsushita, Mark Woodward, Luxia Zhang.• CKD Prognosis Consortium Data Coordinating Center: Shoshana H. Ballew (Assistant Project Director), Jingsha Chen (Programmer), Josef Coresh (Principal Investigator), Morgan E. Grams (Director of Nephrology Initiatives), Lucia Kwak (Programmer), Kunihiro Matsushita (Director), Yingying Sang (Lead Programmer), Aditya Surapaneni (Programmer), Mark Woodward (Senior Statistician).• Kidney Disease Improving Global Outcomes (KDIGO) Controversies Conference on Prognosis and Optimal Management of Patients with Advanced CKD: Kai-Uwe Eckardt (Conference Co-Chair), Brenda R. Hemmelgarn (Conference Co-Chair), David C. Wheeler (KDIGO Co-Chair), Wolfgang C. Winkelmayer (KDIGO Co-Chair), John Davis (CEO), Danielle Green (Managing Director), Michael Cheung (Chief Scientific Officer), Tanya Green (Communications Director), Melissa McMahan (Programs Director).

Background The Coronavirus Disease 2019 (COVID-19) pandemic has exacerbated mental health challenges among physicians and non-physicians. However, it is unclear if the worsening mental health among physicians is due to specific occupational stressors, reflective of general societal stressors during the pandemic, or a combination. We evaluated the difference in mental health and addictions health service use between physicians and non-physicians, before and during the COVID-19 pandemic. Methods and findings We conducted a population-based cohort study in Ontario, Canada between March 11, 2017 and August 11, 2021 using data collected from Ontario's universal health system. Physicians were identified using registrations with the College of Physicians and Surgeons of Ontario between 1990 and 2020. Participants included 41,814 physicians and 12,054,070 non-physicians. We compared the first 18 months of the COVID-19 pandemic (March 11, 2020 to August 11, 2021) to the period before COVID-19 pandemic (March 11, 2017 to February 11, 2020). The primary outcome was mental health and addiction outpatient visits overall and subdivided into virtual versus in-person, psychiatrists versus family medicine and general practice clinicians. We used generalized estimating equations for the analyses. Pre-pandemic, after adjustment for age and sex, physicians had higher rates of psychiatry visits (aIRR 3.91 95% CI 3.55 to 4.30) and lower rates of family medicine visits (aIRR 0.62 95% CI 0.58 to 0.66) compared to non-physicians. During the first 18 months of the COVID-19 pandemic, the rate of outpatient mental health and addiction (MHA) visits increased by 23.2% in physicians (888.4 pre versus 1,094.7 during per 1,000 person-years, aIRR 1.39 95% CI 1.28 to 1.51) and 9.8% in non-physicians (615.5 pre versus 675.9 during per 1,000 person-years, aIRR 1.12 95% CI 1.09 to 1.14). Outpatient MHA and virtual care visits increased more among physicians than non-physicians during the first 18 months of the pandemic. Limitations include residual confounding between physician and non-physicians and challenges differentiating whether observed increases in MHA visits during the pandemic are due to stressors or changes in health care access. Conclusions The first 18 months of the COVID-19 pandemic was associated with a larger increase in outpatient MHA visits in physicians than non-physicians. These findings suggest physicians may have had larger negative mental health during COVID-19 than the general population and highlight the need for increased access to mental health services and system level changes to promote physician wellness., Author(s): Daniel T. Myran 1,2,3,*, Rhiannon Roberts 1, Eric McArthur 4, Nivethika Jeyakumar 4, Jennifer M. Hensel 5, Claire Kendall 1,2,3,6, Caroline Gerin-Lajoie 7,8, Taylor McFadden 7, Christopher Simon 7, [...]

AIM:To investigate early postoperative biomarkers for risk discrimination of advanced acute kidney injury (AKI). MATERIALS & METHODS:Postoperative plasma biomarkers including NGAL, h-FABP, CK-MB, hsTNT, NT-proBNP, IL-6, IL-10 and VEGF were analyzed using group-based method among 426 patients with AKI after cardiac surgery. RESULTS:Six patient groups with distinct biomarker patterns were identified. Individual biomarker displayed significant difference across the groups. The groups showed better discrimination for advanced AKI than any single biomarker either with or without adjusting for clinical variables. Average concentration of a single biomarker within each group, mortality and risk of a secondary outcome all demonstrated an approximately U-shaped relationship with proportion of advanced AKI within each group. CONCLUSION:The group-based analysis revealed that the order of the patient groups with an increasing likelihood of advanced AKI had a nonlinear relationship with average concentration of an individual biomarker, mortality and risk of other outcomes.

BackgroundAcute kidney injury is a risk factor for death in cardiac surgical patients. Plasma cystatin C and creatinine have different temporal profiles in the postoperative setting, but the associations of simultaneous changes in both filtration markers compared with change in only one marker with prognosis after hospital discharge are not well described.MethodsThis is a longitudinal study of 1,199 high-risk adult cardiac surgical patients in the TRIBE-AKI (Translational Research Investigating Biomarker Endpoints for Acute Kidney Injury) Consortium who survived hospitalization. We examined in-hospital peak changes of cystatin C and creatinine in the 3 days after cardiac operations. We evaluated associations of these filtration markers with death, adjusting for demographics, operative characteristics, medical comorbidities, preoperative estimated glomerular filtration rate, preoperative urinary albumin-to-creatinine ratio, and site.ResultsDuring the first 3 days of hospitalization, nearly twice as many patients had a 25% or higher rise in creatinine (30%) compared with a 25% or higher peak rise in cystatin C (15%). The risk of death was higher in those with elevations in cystatin C (adjusted hazard ratio [HR], 1.83; 95% confidence interval [CI], 1.4 to 2.37) or creatinine (adjusted HR, 1.90; 95% CI, 1.32 to 2.72) compared with patients who experienced a postoperative decrease in either filtration marker. Patients who had simultaneous elevations of 25% or higher in cystatin C and creatinine were at similar adjusted risk for 3-year mortality (HR, 1.79; 95% CI, 1.03 to 3.1) as those with a 25% or higher increase in cystatin C alone (HR, 2.2; 95% CI, 1.09 to 4.47).ConclusionsElevations in creatinine postoperatively are more common than elevations in cystatin C. However, elevations in cystatin C appeared to be associated with a higher risk of death after hospital discharge.

ImportanceIdentifying patients at risk of chronic kidney disease (CKD) progression may facilitate more optimal nephrology care. Kidney failure risk equations, including such factors as age, sex, estimated glomerular filtration rate, and calcium and phosphate concentrations, were previously developed and validated in 2 Canadian cohorts. Validation in other regions and in CKD populations not under the care of a nephrologist is needed.ObjectiveTo evaluate the accuracy of the risk equations across different geographic regions and patient populations through individual participant data meta-analysis.Data sourcesThirty-one cohorts, including 721,357 participants with CKD stages 3 to 5 in more than 30 countries spanning 4 continents, were studied. These cohorts collected data from 1982 through 2014.Study selectionCohorts participating in the CKD Prognosis Consortium with data on end-stage renal disease.Data extraction and synthesisData were obtained and statistical analyses were performed between July 2012 and June 2015. Using the risk factors from the original risk equations, cohort-specific hazard ratios were estimated and combined using random-effects meta-analysis to form new pooled kidney failure risk equations. Original and pooled kidney failure risk equation performance was compared, and the need for regional calibration factors was assessed.Main outcomes and measuresKidney failure (treatment by dialysis or kidney transplant).ResultsDuring a median follow-up of 4 years of 721,357 participants with CKD, 23,829 cases kidney failure were observed. The original risk equations achieved excellent discrimination (ability to differentiate those who developed kidney failure from those who did not) across all cohorts (overall C statistic, 0.90; 95% CI, 0.89-0.92 at 2 years; C statistic at 5 years, 0.88; 95% CI, 0.86-0.90); discrimination in subgroups by age, race, and diabetes status was similar. There was no improvement with the pooled equations. Calibration (the difference between observed and predicted risk) was adequate in North American cohorts, but the original risk equations overestimated risk in some non-North American cohorts. Addition of a calibration factor that lowered the baseline risk by 32.9% at 2 years and 16.5% at 5 years improved the calibration in 12 of 15 and 10 of 13 non-North American cohorts at 2 and 5 years, respectively (P = .04 and P = .02).Conclusions and relevanceKidney failure risk equations developed in a Canadian population showed high discrimination and adequate calibration when validated in 31 multinational cohorts. However, in some regions the addition of a calibration factor may be necessary.

BackgroundThe interaction between baseline kidney function and the performance of biomarkers of acute kidney injury (AKI) on the development of AKI is unclear.Study designPost hoc analysis of prospective cohort study.Setting & participantsThe 1,219 TRIBE-AKI Consortium adult cardiac surgery cohort participants.PredictorUnadjusted postoperative urinary biomarkers of AKI measured within 6 hours of surgery.OutcomeAKI was defined as AKI Network stage 1 (any AKI) or higher, as well as a doubling of serum creatinine level from the preoperative value or the need for post-operative dialysis (severe AKI).MeasurementsStratified analyses by preoperative estimated glomerular filtration rate (eGFR) ≤ 60 versus > 60mL/min/1.73m(2).Results180 (42%) patients with preoperative eGFRs≤60mL/min/1.73m(2) developed clinical AKI compared with 246 (31%) of those with eGFRs>60mL/min/1.73m(2) (P

BackgroundAcute kidney injury (AKI) is a serious complication of cardiac operations for which there remains no specific therapy. Animal data and several observational studies suggest that statins prevent AKI, but the results are not conclusive, and many studies are retrospective in nature.MethodsWe conducted a multicenter prospective cohort study of 625 adult patients undergoing elective cardiac operations. All patients were taking statins and were grouped according to whether statins were continued or held in the 24 hours before operation. The primary outcome was AKI as defined by a doubling of serum creatinine or dialysis. The secondary outcome was the peak level of several kidney injury biomarkers. The results were adjusted for demographic and clinical factors.ResultsContinuing (vs holding) a statin before operation was not associated with a lower risk of AKI, as defined by a doubling of serum creatinine or dialysis (adjusted relative risk [RR] 1.09; 95% confidence interval [CI] 0.44, 2.70). However, continuing a statin was associated with a lower risk of elevation of the following AKI biomarkers: urine interleukin-18, urine neutrophil gelatinase-associated lipocalin, urine kidney injury molecule-1, and plasma neutrophil gelatinase-associated lipocalin (adjusted RR 0.34; 95% CI 0.18, 0.62), (adjusted RR 0.41; 95% CI 0.22, 0.76), (adjusted RR 0.37; 95% CI 0.20, 0.76), (adjusted RR 0.62; 95% CI 0.39, 0.98), respectively.ConclusionsStatins may prevent kidney injury after cardiac operations, as evidenced by lower levels of kidney injury biomarkers.