Kidney Failure Risk Equation in vascular access planning: a population-based study supporting value in decision making.

Background: The Kidney Failure Risk Equation (KFRE) can play a better role in vascular access (VA) planning in patients with chronic kidney disease (CKD) requiring hemodialysis (HD). We described the VA creation and utilization pattern under existing estimated glomerular filtration rate (eGFR)-based referral, and investigated the utility of KFRE score as an adjunct variable in VA planning. Methods: Patients with CKD aged ≥18 years with eGFR <20 mL/min/1.73 m2 who chose HD as dialysis modality from January 2010 to August 2020 were included from a population-based database in British Columbia, Canada. Modality selection date was the index date. Exposures were categorized as (i) current eGFR-based referral, (ii) eGFR-based referral plus KRFE 2-year risk score on index date (KFRE-2) >40% and (iii) eGFR-based referral plus KFRE-2 ≤40%. We estimated the proportion of patients who started HD on arteriovenous fistula/graft (AVF/G) within 2 years, indicating timely pre-emptive creation, and the proportion of patients in whom AVF/G was created but did not start HD within 2 years, indicating too-early creation. Results: Study included 2581 patients, median age 71 years, 60% male. Overall, 1562(61%) started HD and 276 (11%) experienced death before HD initiation within 2 years. Compared with current referral, the proportion of patients who started HD on AVF/G was significantly higher when KFRE-2 was considered in addition to current referral (49% vs 58%, P-value <.001). Adjunct KFRE-2 significantly reduced too-early creation (31% vs 18%, P-value <.001). Conclusions: KFRE in addition to existing eGFR-based referral for VA creation has the potential to improve VA resource utilization by ensuring more patients start HD on AVF/G and may minimize too-early/unnecessary creation. Prospective research is necessary to validate these findings.

A Provincial Survey of the Contemporary Management of Autosomal Dominant Polycystic Kidney Disease.

BACKGROUND: Recent years have witnessed an encouraging expansion of knowledge and management tools in the care of patients with autosomal dominant polycystic kidney disease (ADPKD), including measurement of total kidney volume as a biomarker of disease progression, stringent blood pressure targets to slow cyst growth, and targeted treatments such as tolvaptan. OBJECTIVES: We sought to evaluate clinicians' familiarity with, and usage of, novel evidence-based management tools for ADPKD. DESIGN: On-line survey. SETTING: British Columbia, Canada. PARTICIPANTS: Nephrologists in academic and community practice (excluding clinicians who practice exclusively in transplantation). MEASUREMENTS: Participants answered multiple-choice questions in 6 domains: sources of information, self-identified needs for optimal care delivery, prognostication, imaging tests, blood pressure targets, and use of tolvaptan. METHODS: An online survey was developed and disseminated via email to 65 nephrologists engaged in current clinical practice in British Columbia. RESULTS: A total of 29 nephrologists (45%) completed the questionnaire. The most popular source of information was the primary literature (83% of respondents). While 86% of respondents reported assessing the risk of disease progression before the onset of kidney function decline, most were using traditional metrics such as blood pressure and proteinuria rather than validated prediction tools such as the Mayo Classification. Although 90% of respondents obtained additional imaging after diagnosis in some or all of their ADPKD patients, only 1 in 5 reported being confident in their ability to interpret kidney size. The recommended blood pressure (BP) target of <110/75 mmHg was sought by 17% of respondents. All respondents reported being familiar with the literature regarding tolvaptan; however, only half were confident in their ability to identify suitable patients for treatment. The top 3 needs identified by clinicians were better access to medications (69%), clear management protocols (66%), and easier access to imaging tests (59%). LIMITATIONS: Funding mechanisms for tolvaptan can vary; therefore, clinicians' experience with the drug may not be generalizable. Although the response rate was acceptable, the survey is nonetheless subject to responder bias. CONCLUSION: This survey indicates that there is substantial variability in the usage of, and familiarity with, evidence-based ADPKD management tools among contemporary nephrologists, contributing to incomplete translation of evidence into clinical practice. Providing greater access to tolvaptan or imaging tests is unlikely to improve patient care without enhancing knowledge translation and education. TRIAL REGISTRATION: Not applicable as this was a survey.

CONTEXTE: On a assisté au cours des dernières années à un élargissement prometteur des connaissances et des outils de gestion dans le domaine des soins prodigués aux patients atteints de maladie polykystique rénale autosomale dominante (MPRAD). On pense notamment à la mesure du volume rénal total comme biomarqueur de l'évolution de la maladie, à des cibles strictes en matière de pression artérielle visant à ralentir la croissance des kystes et à des traitements ciblés comme le tolvaptan. OBJECTIFS: Nous souhaitions évaluer la connaissance des cliniciens à l'égard de ces nouveaux outils fondés sur des données probantes et mesurer leur usage en contexte de MPRAD. TYPE D'ÉTUDE: Sondage en ligne. CADRE: Colombie-Britannique, Canada. PARTICIPANTS: Les néphrologues pratiquant en milieu hospitalier universitaire et communautaire (à l'exception des médecins pratiquant exclusivement en transplantation). MESURES: Les participants ont répondu à un questionnaire à choix multiples touchant six domaines précis: les sources d'information, les besoins autodéclarés pour une prestation de soins optimaux, le pronostic, les tests d'imagerie, les cibles de pression artérielle et l'utilization du tolvaptan. MÉTHODOLOGIE: Un sondage en ligne a été élaboré et distribué par courriel à 65 néphrologues pratiquant actuellement en Colombie-Britannique. RÉSULTATS: En tout, 29 néphrologues (45 %) ont répondu au questionnaire. La principale source d'information était la littérature (83 % des répondants). Bien que 86 % des répondants mentionnaient évaluer le risque de progression de la maladie avant les premières manifestations d'un déclin de la fonction rénale, la plupart recouraient à des indicateurs traditionnels comme la pression artérielle et la protéinurie plutôt qu'à des outils validés comme la classification de la clinique Mayo. Et bien que 90 % des répondants aient pu faire des tests d'imagerie supplémentaires après le diagnostic, chez certains ou chez tous leurs patients atteints de MPRAD, seul un médecin sur cinq s'est déclaré confiant en sa capacité d'interpréter la taille du rein. La cible recommandée de pression artérielle, soit moins de 110/75 mmHg, était recherchée par seulement 17 % des répondants. Tous les médecins ont mentionné être familiers avec la littérature portant sur le tolvaptan, mais la moitié des répondants doutaient de leur capacité à bien cerner les patients pour qui ce traitement est adéquat. Les cliniciens ont nommé trois principaux besoins: un meilleur accès aux médicaments (69 %), des protocoles de prise en charge clairs (66 %) et un accès plus facile aux tests d'imagerie (59 %). LIMITES: Les mécanismes de financement du tolvaptan sont variables et ainsi, l'expérience des cliniciens avec ce médicament pourrait ne pas être généralisable. Bien que le taux de réponse ait été jugé acceptable, le sondage demeure sujet à des biais de la part des répondants. CONCLUSION: Ce sondage indique qu'il existe une variabilité substantielle dans l'usage et la connaissance des outils de gestion de la MPRAD fondés sur les données probantes parmi les néphrologues. Cette situation contribue à l'application incomplète des résultats dans la pratique clinique. Offrir un accès accru au tolvaptan ou aux tests d'imagerie est peu susceptible d'améliorer les soins si l'application des connaissances et l'éducation ne sont pas améliorées. ENREGISTREMENT DE L'ESSAI: Sans objet puisqu'il s'agit d'une étude sous forme de sondage.

CT of Kidney Volume in Autosomal Dominant Polycystic Kidney Disease: Accuracy, Reproducibility, and Radiation Dose.

Background Total kidney volume (TKV) assessment is valuable in autosomal dominant polycystic kidney disease (ADPKD) but the reference standard method of MRI planimetry requires access to MRI and time-consuming interpretation. Purpose To determine whether accurate TKV measurements comparable to the resource-intensive reference standard of MRI planimetry can be obtained by using alternate methods including dose-reducing CT protocols and time-saving measurement equations. Materials and Methods In this prospective study conducted September 2016 to June 2017, adult participants with ADPKD underwent one MRI and two CT examinations. Low-dose (LD) and ultra-low-dose (ULD) CT examinations were performed with radiation doses 1.4 and 2.6 times lower, respectively, than the authors' institution's standard abdomen and pelvis CT. ULD CT examinations were reconstructed via model-based iterative reconstruction. Three TKV measurement equations were applied to all image sets, and MRI manual planimetry was the reference standard. Spearman correlation with the reference standard, simple linear regression, and root mean square error (RMSE) calculation analyzed accuracy of these methods; intraclass correlation coefficient examined reproducibility. Results Thirty participants (mean age, 41 years; age range, 24-67 years) had a mean TKV of 1368.9 mL ± 1146.13 (standard deviation). The ULD and LD CT protocols had median dose-length product of 58.8 and 115.5 mGy ∙ cm, respectively (P = .01), and CT dose index of 1.2 and 3.9 mGy, respectively (P < .001). All imaging modalities and measurement equations had excellent correlation with the reference standard (r2 > 0.98). RMSE ranged from 80.5 to 157.3 mL (5.9%-11.5% of mean TKV). Intraclass correlation coefficients were greater than 0.98 for all methods. Mean measurement times for the ellipsoid method ranged from 4.6 to 5.2 minutes compared with a mean of 27.7 minutes (range, 14-60 minutes) for manual planimetry. Conclusion Accurate and reproducible total kidney volume measurements comparable to the reference standard of MRI planimetry can be obtained by using a dose-minimizing ultra-low-dose CT protocol and volume measurement based on discrete linear measurements. © RSNA, 2019 Online supplemental material is available for this article.