Association between End-Stage Renal Disease and Major Adverse Limb Events after Peripheral Vascular Intervention.

PURPOSE: To examine the effect of end-stage renal disease (ESRD) on the likelihood of major adverse limb events (MALEs) in patients with Rutherford Category 4-6 critical limb ischemia (CLI) who underwent percutaneous vascular intervention (PVI). MATERIALS AND METHODS: Two contemporaneous cohorts of patients who underwent PVI for symptomatic CLI from 2012 to 2022, differing in ESRD status, were matched using propensity score methods. This database identified 628 patients who underwent 1,297 lower extremity revascularization procedures; propensity score matching yielded 147 patients (180 limbs, 90 limbs in each group). Kaplan-Meier and Cox proportional hazard analyses were used to assess the effect of ESRD status on MALEs, stratified into major amputation (further stratified into above-knee amputation and below-knee amputation [BKA]) and reintervention (PVI or bypass). RESULTS: After PVI, 31.3% of patients in the matched cohorts experienced a MALE (45.7% ESRD vs 18.2% non-ESRD), and 15.6% experienced a major amputation (27.1% ESRD vs 5.2% non-ESRD). Cox proportional hazards analysis revealed that ESRD was an independent predictor of MALE (hazard ratio [HR], 3.15; 95% CI, 1.58-6.29; P = .001), major amputation (HR, 7.00; 95% CI, 2.06-23.79; P = .002), and BKA (HR, 7.56; 95% CI, 1.71-33.50; P = .008). CONCLUSIONS: ESRD is strongly predictive of MALE and major amputation risk, specifically BKA, in patients undergoing PVI for Rutherford Category 4-6 CLI. These patients warrant closer follow-up, and new methods may become necessary to predict and further reduce their amputation risk.

Percutaneous Management of Dialysis Access Steal Syndrome: Interventions and Outcomes from a Single Institution's 20-Year Experience.

PURPOSE: To determine safety and effectiveness of percutaneous interventions performed by interventional radiologists at a single institution over 2 decades in patients with dialysis access steal syndrome (DASS). MATERIALS AND METHODS: A retrospective review of fistulograms from 2001 to 2021 (N = 11,658) was performed. In total, 286 fistulograms in 212 patients with surgically created dialysis accesses met inclusion criterion of fistulography for suspected DASS. Chart review collected data regarding patient demographics, comorbidities, access characteristics, fistulography findings, intervention(s) performed, and outcomes. Procedures with and without DASS intervention were compared. Odds ratios (ORs), adjusted for age, sex, comorbidities, access characteristics, and multiple within-patient events, were calculated using logistic regression to determine associations between steal intervention status and outcome variables: (a) major adverse events, (b) access preservation, and (c) follow-up surgery. A percutaneously treatable cause of DASS was present in 128 cases (45%). Treatment of DASS lesions was performed in 118 cases. Fifteen embolizations were also performed in patients without DASS lesions. RESULTS: Technical success of DASS interventions, defined by the Society of Interventional Radiology (SIR) reporting standards, was 94%; 54% of interventions resulted in DASS symptom improvement at a median follow-up of 15 days. Patients with steal intervention had 60% lower odds of follow-up surgery (OR, 0.4; P = .007). There was no difference in major adverse events (P = .98) or access preservation (P = .13) between groups. CONCLUSIONS: In this retrospective cohort study, approximately half of DASS fistulograms revealed a percutaneously treatable cause of steal. Over half of DASS interventions resulted in symptomatic relief. Percutaneous intervention was associated with lower odds of follow-up surgery without compromising access preservation.

Frequent vascular access thrombosis in a patient with end stage kidney disease on hemodialysis.

Vascular access thrombosis (VAT) is common among patients receiving hemodialysis and leads to missed dialysis treatments, hospitalizations, catheter placement, and graft/fistula abandonment. This article reviews the association between hypercoagulability and VAT and the high prevalence of hypercoagulable states in end-stage kidney disease (ESKD). This article reviews the role of antithrombotic and anticoagulant medications in preventing VAT. The article concludes by reviewing the unique challenges of using vitamin K antagonists in patients with ESKD.

An Orchestration Platform that Puts Radiologists in the Driver's Seat of AI Innovation: a Methodological Approach.

Current AI-driven research in radiology requires resources and expertise that are often inaccessible to small and resource-limited labs. The clinicians who are able to participate in AI research are frequently well-funded, well-staffed, and either have significant experience with AI and computing, or have access to colleagues or facilities that do. Current imaging data is clinician-oriented and is not easily amenable to machine learning initiatives, resulting in inefficient, time consuming, and costly efforts that rely upon a crew of data engineers and machine learning scientists, and all too often preclude radiologists from driving AI research and innovation. We present the system and methodology we have developed to address infrastructure and platform needs, while reducing the staffing and resource barriers to entry. We emphasize a data-first and modular approach that streamlines the AI development and deployment process while providing efficient and familiar interfaces for radiologists, such that they can be the drivers of new AI innovations.

The Controversy of Contrast-Induced Nephropathy With Intravenous Contrast: What Is the Risk?

Contrast-induced nephropathy (CIN) has long been observed in both experimental and clinical studies. However, recent observational studies have questioned the prevalence and severity of CIN following intravenous contrast exposure. Initial studies of acute kidney injury following intravenous contrast were limited by the absence of control groups or contained control groups that did not adjust for additional acute kidney injury risk factors, including prevalent chronic kidney disease, as well as accepted prophylactic strategies. More contemporary use of propensity score-adjusted models have attempted to minimize the risk for selection bias, although bias cannot be completely eliminated without a prospective randomized trial. Based on existing data, we recommend the following CIN risk classification: patients with estimated glomerular filtration rates (eGFRs) ≥ 45mL/min/1.73m2 are at negligible risk for CIN, while patients with eGFRs<30mL/min/1.73m2 are at high risk for CIN. Patients with eGFRs between 30 and 44mL/min/1.73m2 are at an intermediate risk for CIN unless diabetes mellitus is present, which would further increase the risk. In all patients at any increased risk for CIN, the risk for CIN needs to be balanced by the risk of not performing an intravenous contrast-enhanced study.

Diagnosis and Treatment of Nonmaturing Fistulae for Hemodialysis Access via Transradial Approach: A Case-Control Study.

PURPOSE: To compare outcomes of transradial access for endovascular treatment of nonmaturing hemodialysis fistulae compared to brachial arteriography followed by unidirectional or bidirectional fistula access for intervention. MATERIALS AND METHODS: In this institutional review board-approved, retrospective, case-control study, 56 consecutive patients with nonmaturing arteriovenous fistulae underwent percutaneous intervention between 2015 and 2018. The transradial group (n = 28) underwent radial artery access for diagnostic fistulography and intervention. The control group (n = 28) underwent retrograde brachial artery access for fistulography followed by unidirectional/bidirectional fistula access for intervention. Both groups had similar demographics, fistula characteristics, and stenosis locations. RESULTS: Fewer punctures were required in the transradial group compared to controls (1.2 vs 2.4, P < .0001), and procedure time was shorter (64.9 vs 91.3 minutes, P = .0016). Anatomic, technical, and clinical success rates trended higher in the transradial group compared to controls (93% vs 86%, 96% vs 89%, and 82% vs 64%, respectively). Nonmaturation resulting in fistula abandonment was lower in the transradial group (3.7% vs 25%, P = .025). Primary unassisted patency at 3, 6, and 12 months was 77.1% ± 8.2%, 73.1% ± 8.7%, and 53.3% ± 10.6% in the transradial group, respectively, and 63.0% ± 9.3%, 55.6% ± 9.6%, and 48.1% ± 9.6% in the control group, respectively (P = .76). Primary assisted patency at 12 months was 92.3% ± 5.3% in the transradial group compared to 61.8% ± 9.6% at 12 months in the control group (P = .021). No major complications occurred. Minor complications were lower in the transradial group than in the control group (14% vs 39%, P = .068). CONCLUSIONS: Treatment of nonmaturing fistulae via a transradial approach was safe, improved midterm patency, and was associated with lower rates of fistula abandonment.

Comparison of Clinical Performance of VectorFlow and Palindrome Symmetric-Tip Dialysis Catheters: A Multicenter, Randomized Trial.

PURPOSE: To compare clinical performance of 2 widely used symmetric-tip hemodialysis catheters. MATERIALS AND METHODS: Patients with end-stage renal disease initiating or resuming hemodialysis were randomized to receive an Arrow-Clark VectorFlow (n = 50) or Palindrome catheter (n = 50). Primary outcome was 90-d primary unassisted catheter patency. Secondary outcomes were Kt/V ([dialyzer urea clearance × total treatment time]/total volume of urea distribution), urea reduction ratio (URR), and effective blood flow (QB). RESULTS: Primary unassisted patency rates with the VectorFlow catheter at 30, 60, and 90 d were 95.5% ± 3.3, 87.2% ± 7.3, and 80.6% ± 9.8, respectively, compared with 89.1% ± 6.2, 79.4% ± 10.0, and 71.5% ± 12.6 with the Palindrome catheter (P = .20). Patients with VectorFlow catheters had a mean Kt/V of 1.5 at 30-, 60-, and 90-day time points, significantly higher than the mean Kt/V of 1.3 among those with Palindrome catheters (P = .0003). URRs were not significantly different between catheters. Catheter QB rates exceeded National Kidney Foundation-recommended thresholds of 300 mL/min at all time points for both catheters and were similar for both catheters (median, 373 mL/min). Catheter failure, ie, poor flow rate requiring guide-wire exchange or removal, within the 90-day primary outcome occurred in 3 VectorFlow subjects and 5 Palindrome subjects (P = .72). Infection rates were similar, with 0.98 infections per 1,000 catheter days for VectorFlow catheters compared with 2.62 per 1,000 catheter days for Palindrome catheters (P = .44). CONCLUSIONS: The 90-day primary patency rates of Palindrome and VectorFlow catheters were not significantly different, and both achieved sustained high QB through 90 day follow-up. However, dialysis adequacy based on Kt/V was consistently better with the VectorFlow catheter versus the Palindrome.

Increased Fatty Acid Oxidation in Differentiated Proximal Tubular Cells Surviving a Reversible Episode of Acute Kidney Injury.

BACKGROUND/AIMS: Fatty acid oxidation (FAO), the main source of energy produced by tubular epithelial cells in the kidney, was found to be defective in tubulo-interstitial samples dissected out in kidney biopsies from patients with chronic kidney disease (CKD). Experimental data indicated that this decrease was a strong determinant of renal fibrogenesis, hence a focus for therapeutic interventions. Nevertheless, whether persistently differentiated renal tubules, surviving in a pro-fibrotic environment, also suffer from a decrease in FAO, is currently unknown. METHODS: To address this question, we isolated proximal tubules captured ex vivo on the basis of the expression of an intact brush border antigen (Prominin-1) in C57BL6/J mice subjected to a controlled, two-hit model of renal fibrosis (reversible ischemic acute kidney injury (AKI) or sham surgery, followed by angiotensin 2 administration). A transcriptomic high throughput sequencing was performed on total mRNA from these cells, and on whole kidneys. RESULTS: In contrast to mice subjected to sham surgery, mice with a history of AKI displayed histologically more renal fibrosis when exposed to angiotensin 2. High throughput RNA sequencing, principal component analysis and clustering showed marked consistency within experimental groups. As expected, FAO transcripts were decreased in whole fibrotic kidneys. Surprisingly, however, up- rather than down-regulation of metabolic pathways (oxidative phosphorylation, fatty acid metabolism, glycolysis, and PPAR signalling pathway) was a hallmark of the differentiated tubules captured from fibrotic kidneys. Immunofluorescence co-staining analysis confirmed that the expression of FAO enzymes was dependent of tubular trophicity. CONCLUSIONS: These data suggest that in differentiated proximal tubules energetic hyperactivity is promoted concurrently with organ fibrogenesis.

Polarization-independent atomic prism filter for removing amplified spontaneous emission.

We create an optical frequency, polarization-independent, narrow bandpass filter of 1.3 GHz (3 dB bandwidth), using the steep dispersion near the rubidium D1 atomic transitions within a prism-shaped vapor cell. This enables us to clean the amplified spontaneous emission from a laser by more than 3 orders of magnitude. Such a filter could find uses in fields such as quantum information processing and Raman spectroscopy.

TREM-1 Mediates Inflammatory Injury and Cardiac Remodeling Following Myocardial Infarction.

RATIONALE: Optimal outcome after myocardial infarction (MI) depends on a coordinated healing response in which both debris removal and repair of the myocardial extracellular matrix play a major role. However, adverse remodeling and excessive inflammation can promote heart failure, positioning leucocytes as central protagonists and potential therapeutic targets in tissue repair and wound healing after MI. OBJECTIVE: In this study, we examined the role of triggering receptor expressed on myeloid cells-1(TREM-1) in orchestrating the inflammatory response that follows MI. TREM-1, expressed by neutrophils and mature monocytes, is an amplifier of the innate immune response. METHODS AND RESULTS: After infarction, TREM-1 expression is upregulated in ischemic myocardium in mice and humans. Trem-1 genetic invalidation or pharmacological inhibition using a synthetic peptide (LR12) dampens myocardial inflammation, limits neutrophils recruitment and monocyte chemoattractant protein-1 production, thus reducing classical monocytes mobilization to the heart. It also improves left ventricular function and survival in mice (n=20-22 per group). During both permanent and transient myocardial ischemia, Trem-1 blockade also ameliorates cardiac function and limits ventricular remodeling as assessed by fluorodeoxyglucose-positron emission tomographic imaging and conductance catheter studies (n=9-18 per group). The soluble form of TREM-1 (sTREM-1), a marker of TREM-1 activation, is detectable in the plasma of patients having an acute MI (n=1015), and its concentration is an independent predictor of death. CONCLUSIONS: These data suggest that TREM-1 could constitute a new therapeutic target during acute MI.

Initial Clinical Experience: Symmetric-Tip Dialysis Catheter with Helical Flow Characteristics Improves Patient Outcomes.

PURPOSE: To report preliminary clinical experience with a new symmetric-tip dialysis catheter compared with a conventional split-tip catheter. MATERIALS AND METHODS: Over a 5-month period, patients requiring a tunneled catheter for hemodialysis or undergoing exchange of a dysfunctional dialysis catheter at a tertiary academic medical center were retrospectively analyzed. Patients underwent placement of a VectorFlow or Ash Split Cath catheter at the discretion of the inserting interventional radiologist. Patient demographics, catheter patency, mean blood flow rate, and arterial and venous pressures were compared according to catheter type. Catheter failure was analyzed based on clinical and anatomic variables by using a multivariate Cox proportional-hazards model. RESULTS: A total of 33 VectorFlow and 46 Ash Split Cath catheters were placed. Patients in the VectorFlow group had significantly higher body mass index (P = .013) and Charlson Comorbidity Index (P = .049), as well as more non-internal jugular vein placements. At 120 days, 89% of VectorFlow catheters remained functional, compared with 45% of Ash Split Cath catheters (P = .046). The VectorFlow catheter was associated with 16% lower arterial pressures during dialysis (P = .009); mean blood flow rate was equivalent. On multivariate analysis, the risk of catheter failure was 13.3 times higher in the Ash Split Cath group compared with the VectorFlow group (P = .004). Left-sided catheters were also predictive of catheter failure (relative risk = 5.5; P = .02). CONCLUSIONS: The VectorFlow catheter was associated with a significant increase in intervention-free catheter patency compared with the Ash Split Cath catheter, with equivalent flow at lower arterial pressures during dialysis.

Brillouin optical correlation domain analysis with 4 millimeter resolution based on amplified spontaneous emission.

A new technique for Brillouin scattering-based, distributed fiber-optic measurements of temperature and strain is proposed, analyzed, simulated, and demonstrated. Broadband Brillouin pump and signal waves are drawn from the filtered amplified spontaneous emission of an erbium-doped fiber amplifier, providing high spatial resolution. The reconstruction of the position-dependent Brillouin gain spectra along 5 cm of a silica single-mode fiber under test, with a spatial resolution of 4 mm, is experimentally demonstrated using a 25 GHz-wide amplified spontaneous emission source. A 4 mm-long localized hot spot is identified by the measurements. The uncertainty in the reconstruction of the local Brillouin frequency shift is ± 1.5 MHz. The single correlation peak between the pump and signal is scanned along a fiber under test using a mechanical variable delay line. The analysis of the expected spatial resolution and the measurement signal-to-noise ratio is provided. The measurement principle is supported by numerical simulations of the stimulated acoustic field as a function of position and time. Unlike most other Brillouin optical correlation domain analysis configurations, the proposed scheme is not restricted by the bandwidth of available electro-optic modulators, microwave synthesizers, or pattern generators. Resolution is scalable to less than one millimeter in highly nonlinear media.

High-resolution long-range distributed Brillouin analysis using dual-layer phase and amplitude coding.

A new, hybrid time-domain and correlation-domain Brillouin analysis technique is proposed and demonstrated, providing a large number of high-resolution acquisition points. The method is based on dual-layer hierarchal encoding of both amplitude and phase. The pump and signal waves are co-modulated by a relatively short, high-rate binary phase sequence. The phase modulation introduces Brillouin interactions in a large number of discrete and localized correlation peaks along the fiber under test. In addition, the pump wave is also amplitude-modulated by a slower, carefully synthesized, long on-off-keying sequence. Brillouin interactions at the correlation peaks imprint weak replicas of the pump amplitude sequence on the intensity of the output signal wave. The Brillouin amplifications at individual correlation peaks are resolved by radar-like, matched-filter processing of the output signal, following a recently-proposed incoherent compression protocol. The method provides two significant advantages with respect to previous, pulse-gated correlation-domain analysis schemes, which involved a single pump pulse. First, compression of the extended pulse sequence enhances the measurement signal-to-noise ratio, which is equivalent to that of a large number of averages over repeating single-pulse acquisitions. The acquisition times are potentially much reduced, and the number of resolution points that may be practically interrogated increases accordingly. Second, the peak power level of the pump pulses may be lowered. Hence, the onset of phase pattern distortion due to self-phase modulation is deferred, and the measurement range can be increased. Using the proposed method, the acquisition of Brillouin gain spectra over a 2.2 km-long fiber with a spatial resolution of 2 cm is demonstrated experimentally. The entire set of 110,000 resolution points is interrogated using only 499 position scans per choice of frequency offset between pump and signal. A 5 cm-long hot-spot, located towards the output end of the pump wave, is properly recognized in the measurements.

Outcomes of single-stage compared to two-stage basilic vein transposition fistulae.

Basilic vein transposition (BVT) fistulae are increasing in prevalence in the United States. We examined outcomes of BVT fistulae created in a single stage compared to those created in two stages. Prospective QA databases identified a consecutive cohort of 144 patients with BVT fistulae. Of these, 42% were created in one stage and 58% in two stages. Fistula maturation rates, mean time to fistula use and intensity of percutaneous interventions were compared; patency rates were compared from time of first intervention. Maturation rates (including assisted maturation) were 90% among 1-stage and 75% among 2-stage BVT (p = 0.02). Mean time to initiation of fistula use was 142 days (1-stage) and 146 days (2-stage) (p = 0.92). Intensity of percutaneous interventions was 1.84/patient-year of dialysis (PYD) (1-stage) and 2.15/PYD (2-stage) (p = 0.57). Secondary patency at 1, 2, 3, and 4 years for 1-stage BVT was 86%, 75%, 69%, and 57%; secondary patency at 1, 2, 3, and 4 years for 2-stage BVT was 76%, 71%, 49%, and 25%, respectively (p = 0.12). BVT creation in two stages confers only a modest reduction in maturation rates and secondary patency and therefore should be considered over a synthetic graft in patients with basilic veins deemed inadequate for 1-stage BVT.

Preeclampsia Prediction Using Machine Learning and Polygenic Risk Scores From Clinical and Genetic Risk Factors in Early and Late Pregnancies.

BACKGROUND: Preeclampsia, a pregnancy-specific condition associated with new-onset hypertension after 20-weeks gestation, is a leading cause of maternal and neonatal morbidity and mortality. Predictive tools to understand which individuals are most at risk are needed. METHODS: We identified a cohort of N=1125 pregnant individuals who delivered between May 2015 and May 2022 at Mass General Brigham Hospitals with available electronic health record data and linked genetic data. Using clinical electronic health record data and systolic blood pressure polygenic risk scores derived from a large genome-wide association study, we developed machine learning (XGBoost) and logistic regression models to predict preeclampsia risk. RESULTS: Pregnant individuals with a systolic blood pressure polygenic risk score in the top quartile had higher blood pressures throughout pregnancy compared with patients within the lowest quartile systolic blood pressure polygenic risk score. In the first trimester, the most predictive model was XGBoost, with an area under the curve of 0.74. In late pregnancy, with data obtained up to the delivery admission, the best-performing model was XGBoost using clinical variables, which achieved an area under the curve of 0.91. Adding the systolic blood pressure polygenic risk score to the models did not improve the performance significantly based on De Long test comparing the area under the curve of models with and without the polygenic score. CONCLUSIONS: Integrating clinical factors into predictive models can inform personalized preeclampsia risk and achieve higher predictive power than the current practice. In the future, personalized tools can be implemented to identify high-risk patients for preventative therapies and timely intervention to improve adverse maternal and neonatal outcomes.

Radiofrequency guidewire-facilitated recanalization of chronic thoracic central venous occlusions in hemodialysis patients.

PURPOSE: To assess the outcome and safety of radiofrequency (RF) wire recanalization in patients with end-stage renal disease (ESRD) and chronic central venous occlusions (CVO). MATERIALS AND METHODS: A retrospective review of ESRD patients who underwent RF-wire recanalization of symptomatic chronic thoracic CVO from January 2017 to August 2022 yielded 20 patients who underwent 21 procedures. All patients had undergone at least one prior unsuccessful attempt at central venous recanalization using conventional catheter-based techniques. Technical success was defined by the ability to cross the CVO using RF-wire recanalization enabling endovascular treatment. Access circuit patency was evaluated based on follow-up imaging and symptomatic improvement. RESULTS: Radiofrequency wire recanalization was successful in 17/21 procedures (81%) with all patients (100%) reporting resolution of arm ± facial swelling. Three major complications occurred (14%): two hemothoraces and one hemopericardium. Medial stent diameter was 13 mm (range, 9-14 mm). Mean duration of hospital stay was 2 days ± 3 days. Mean procedure time was 158 ± 46 min with a mean fluoroscopy time of 31.7 ± 16.3 min. Primary unassisted patency at 6 and 12 months was 94 ± 6% and 85 ± 10%, respectively. Additional interventions resulted in significantly increased stent graft patency (P = 0.006). CONCLUSION: Radiofrequency wire-enabled recanalization of CVO in symptomatic dialysis patients has a high rate of technical success with resolution of arm and facial swelling and resumed use of the ipsilateral dialysis access. Although a superior safety profile was seen than with needle-based techniques such as sharp recanalization, major complications were not infrequent indicating that this RF-wire procedure should be performed in centers equipped to manage central venous perforations.

Prevalence of stages 3-5 chronic kidney disease in New Caledonia / Prévalence de la maladie rénale chronique stades 3-5 en Nouvelle-Calédonie.

New Caledonia is a French territory located in the South Pacific Ocean. The prevalence rate of end-stage renal disease is nearly 3,000 per million inhabitants, making it one of the highest prevalence rates in the world. Preventing chronic kidney disease is a major public health issue. This article presents prevalence rates of chronic kidney disease (CKD) stages 3-5 for New Caledonia defined by a glomerular filtration rate estimated below 60 mL/min/1.73 m2. Estimation was assessed from data collected during two "Adult health barometer" surveys carried out in the general adult population. Therefore, our study assessed two prevalence rates: 7.8% [6.1; 10.1] and 5.3% [3.3; 8.5]. Those prevalence rates were two to four times higher than in mainland France which is consistent with the high prevalence rate of end stage renal disease treated in New Caledonia. Hence, CKD prevention is essential for New Caledonia.

La Nouvelle-Calédonie est une collectivité française dans l'océan Pacifique Sud. Le taux de prévalence de l'insuffisance rénale chronique terminale traitée s'élève à près de 3 000 par million d'habitants, soit un des taux de prévalence parmi les plus élevés au monde. Cet article présente pour la première fois les taux de prévalence de la maladie rénale chronique aux stades 3-5 pour la Nouvelle-Calédonie, définie par un débit de filtration glomérulaire estimé inférieur à 60 mL/min/1,73 m2. Ces résultats ont été estimés à partir des deux enquêtes « Baromètre santé adulte ¼ en population générale adulte. Notre étude a estimé des taux de prévalence de 7,8 % [6,1 ; 10,1] et de 5,3 % [3,3 ; 8,5]. Le taux de prévalence de la maladie rénale chronique serait donc deux à quatre fois plus élevé qu'en France métropolitaine. La prévention de la maladie rénale chronique est primordiale pour la Nouvelle-Calédonie.

Prevalence of stage 3-5 chronic kidney disease in New Caledonia / Prévalence de la maladie rénale chronique stades 3-5 en Nouvelle-Calédonie.

New Caledonia is a French territory located in the South Pacific Ocean. The prevalence rate of end-stage renal disease is nearly 3,000 per million inhabitants, making it one of the highest prevalence rates in the world. Preventing chronic kidney disease is a major public health issue. This article presents prevalence rates of chronic kidney disease (CKD) stages 3-5 for New Caledonia defined by a glomerular filtration rate estimated below 60 mL/min/1.73 m2. Estimation was assessed from data collected during two "Adult health barometer" surveys carried out in the general adult population. Therefore, our study assessed two prevalence rates: 7.8% [6.1; 10.1] and 5.3% [3.3; 8.5]. Those prevalence rates were two to four times higher than in mainland France which is consistent with the high prevalence rate of end stage renal disease treated in New Caledonia. Hence, CKD prevention is essential for New Caledonia.

La Nouvelle-Calédonie est une collectivité française dans l'océan Pacifique Sud. Le taux de prévalence de l'insuffisance rénale chronique terminale traitée s'élève à près de 3 000 par million d'habitants, soit un des taux de prévalence parmi les plus élevés au monde. Cet article présente pour la première fois les taux de prévalence de la maladie rénale chronique aux stades 3-5 pour la Nouvelle-Calédonie, définie par un débit de filtration glomérulaire estimé inférieur à 60 mL/min/1,73 m2. Ces résultats ont été estimés à partir des deux enquêtes « Baromètre santé adulte ¼ en population générale adulte. Notre étude a estimé des taux de prévalence de 7,8 % [6,1 ; 10,1] et de 5,3 % [3,3 ; 8,5]. Le taux de prévalence de la maladie rénale chronique serait donc deux à quatre fois plus élevé qu'en France métropolitaine. La prévention de la maladie rénale chronique est primordiale pour la Nouvelle-Calédonie.

Redundancy in electronic health record corpora: analysis, impact on text mining performance and mitigation strategies.

BACKGROUND: The increasing availability of Electronic Health Record (EHR) data and specifically free-text patient notes presents opportunities for phenotype extraction. Text-mining methods in particular can help disease modeling by mapping named-entities mentions to terminologies and clustering semantically related terms. EHR corpora, however, exhibit specific statistical and linguistic characteristics when compared with corpora in the biomedical literature domain. We focus on copy-and-paste redundancy: clinicians typically copy and paste information from previous notes when documenting a current patient encounter. Thus, within a longitudinal patient record, one expects to observe heavy redundancy. In this paper, we ask three research questions: (i) How can redundancy be quantified in large-scale text corpora? (ii) Conventional wisdom is that larger corpora yield better results in text mining. But how does the observed EHR redundancy affect text mining? Does such redundancy introduce a bias that distorts learned models? Or does the redundancy introduce benefits by highlighting stable and important subsets of the corpus? (iii) How can one mitigate the impact of redundancy on text mining? RESULTS: We analyze a large-scale EHR corpus and quantify redundancy both in terms of word and semantic concept repetition. We observe redundancy levels of about 30% and non-standard distribution of both words and concepts. We measure the impact of redundancy on two standard text-mining applications: collocation identification and topic modeling. We compare the results of these methods on synthetic data with controlled levels of redundancy and observe significant performance variation. Finally, we compare two mitigation strategies to avoid redundancy-induced bias: (i) a baseline strategy, keeping only the last note for each patient in the corpus; (ii) removing redundant notes with an efficient fingerprinting-based algorithm. (a)For text mining, preprocessing the EHR corpus with fingerprinting yields significantly better results. CONCLUSIONS: Before applying text-mining techniques, one must pay careful attention to the structure of the analyzed corpora. While the importance of data cleaning has been known for low-level text characteristics (e.g., encoding and spelling), high-level and difficult-to-quantify corpus characteristics, such as naturally occurring redundancy, can also hurt text mining. Fingerprinting enables text-mining techniques to leverage available data in the EHR corpus, while avoiding the bias introduced by redundancy.