Discrepancias entre el empleo de las ecuaciones MDRD-4 IDMS y CKD-EPI en vez de la de Cockcroft-Gault en la determinación de la posología de los anticoagulantes orales directos en pacientes con fibrilación auricular no valvular

Different Renal Function Equations and Dosing of Direct Oral Anticoagulants in Atrial Fibrillation

Background

Randomized trials of direct oral anticoagulants (DOACs) adopted the Cockcroft-Gault (CG) formula to calculate estimated glomerular filtration rate (eGFR) to determine the dosages of DOACs.

Objectives

The authors aimed to investigate the agreements/disagreements of eGFRs calculated using different equations (CG, Modified Diet in Renal Disease [MDRD], and Chronic Kidney Disease Epidemiology Collaboration [CKD-EPI] formulas), and their impacts on the dosages of DOACs and clinical outcomes.

Methods

Medical data from a multicenter health care provider in Taiwan including 39,239 patients with atrial fibrillation were used. Among these patients, there were 11,185 and 2,323 patients treated with DOACs and warfarin, respectively.

Results

At the cutoff values of eGFR of <15, 15-50, and >50 mL/min, the agreements were 78% between MDRD and CG and 81% between CKD-EPI and CG. The disagreements among the different equations were largely due to overestimations, especially for patients aged >75 years and with a body weight of <50 kg (58.8% for MDRD and 50.9% for CKD-EPI). Among patients receiving DOACs whose dosages were defined as “on label” based on MDRD or CKD-EPI, only those whose dosages were “truly on label” based on CG were associated with a lower risk of major bleeding (adjusted HR: 0.34; 95% CI: 0.26-0.45) compared to warfarin.

Conclusions

The adoptions of MDRD or CKD-EPI rather than CG would result in inappropriate dosing of DOACs (mainly overdosing), which would attenuate the advantages of DOACs compared to warfarin. The CG equation should be used as the gold standard to calculate eGFRs and guide the DOAC dosages.

The Impact of Multiple Renal Estimates on Pharmacist Dosing Recommendations: A Randomized Trial

Background:

Numerous equations are used for estimation of renal function, and many electronic medical records report multiple clearance estimates to assist with drug dosing. It is unknown whether the presence of multiple clearance estimates affects clinical decision-making.

Objective:

To determine whether the presence of multiple renal clearance estimates affects pharmacist drug dosing decisions.

Methods:

A randomized trial in the form of an electronic survey including 4 clinical vignettes was delivered to hospital pharmacists. Vignettes consisted of a patient presenting with an acute pulmonary embolism requiring enoxaparin therapy. Pharmacists were randomized to receive a single estimate of renal function or multiple estimates for all vignettes. The primary outcome was deviation from approved recommendations on at least 1 vignette. The χ2 test was used to detect differences in deviation rates between groups. Logistic regression was performed to adjust for the effects of potentially confounding variables.

Results:

A total of 154 studies were completed (73 in the multiple-estimate group and 81 in the single-estimate group). Pharmacists presented with multiple renal estimates were significantly more likely to deviate from recommended dosing regimens than pharmacists presented with a single estimate (54.7% vs 38.2%; P = 0.04). The results were driven primarily by the 2 vignettes that included discordance among Cockcroft-Gault equation creatinine clearance estimates. Logistic regression identified multiple estimates as the only independent predictor of deviation ( P = 0.04).

Conclusion and Relevance:

Pharmacists provided with a single renal clearance estimate were more likely to adhere to approved dosing recommendations than pharmacists provided with multiple estimates.

Clearance Confusion: An Exploratory Analysis of Inpatient Dosing Discordances Between Renal Estimating Equations

Background:

Numerous equations exist for estimating renal clearance for drug dosing, and discordance rates may be as high as 40% in certain populations. However, the populations and types of equations used in these studies may not be generalizable to broader pharmacy practice.

Objectives:

To determine the dosing discordance rate between Cockcroft-Gault (C-G), Chronic Kidney Disease Epidemiology (CKD-EPI), and Modification of Diet in Renal Disease (MDRD) equations in a community hospital population.

Methods:

This was a cross-sectional analysis of inpatients who had documented renal function assessment over a 6-month period. Renal estimation was calculated using 5 equations (MDRD, CKD-EPI, and 3 C-G variants). Differences between equations were assessed using mean bias, dosing discordance, and agreement (κ statistic). Patients with acute kidney injury and those requiring renal replacement therapy were excluded.

Results:

A total of 466 patients were eligible for inclusion. Dosing discordance was evident between C-G variants and both MDRD and CKD-EPI equations in greater than 20% of patients. Agreement was highest between MDRD and CKD-EPI (κ = 0.93) and lowest between MDRD and C-G calculated using ideal body weight (κ = 0.33). The majority of discordant instances led to higher dosing recommendations when using MDRD and CKD-EPI equations compared with C-G variants. Dosing discordance exceeded 18% between the different C-G variants, with the highest discordance (36%) observed between total body weight and ideal body weight variants.

Conclusion and Relevance:

Dosing discordance between renal estimating equations is widespread. Practitioners and institutions should be aware of these differences when dosing medications and implementing renal dosing policies.

Burden of Inappropriate Prescription of Direct Oral Anticoagulants at Hospital Admission and Discharge in the Elderly: A Prospective Observational Multicenter Study

INTRODUCTION

Direct oral anticoagulants (DOACs) were developed to overcome some of the limitations associated with vitamin K antagonists (VKAs), such as interindividual variability or the need for therapeutic drug monitoring. However, the complexity of DOAC dose regimens can still lead to dosing errors and potential bleeding-related or thromboembolic adverse events, especially in the elderly.

OBJECTIVE

Our objective was to evaluate the rate of inappropriate preadmission DOAC prescriptions at hospital and to evaluate the ability of hospitals to correct them.

METHODS

An observational prospective study was conducted in elderly patients (aged ≥ 65 years) hospitalized in six acute units of three Parisian university hospitals between February and July 2018. DOAC prescriptions prior to admission and at discharge were analyzed according to the guidelines in the summaries of product characteristics.

RESULTS

A total of 157 patients were included in the study, with a median age of 84 years (interquartile range [IQR] 77-89). The median glomerular filtration rate, determined with the Cockcroft-Gault equation, was 48 mL/min (IQR 35-61). Apixaban was the most frequently prescribed drug, mainly for atrial fibrillation. Overall, 48 (30.6%) and 34 (22.4%) prescriptions were inappropriate prior to admission and at discharge, respectively, showing a significant decrease (p < 0.001). Hospitals significantly corrected more inappropriate prescriptions (37.5%) than they generated (4.6%) (p < 0.05). The nature of the inappropriate prescribing was underdosing (68.8% and 76.5% prior to admission and at discharge, respectively), followed by overdosing (stable rate at almost 20%) and indication errors. No risk factors for inappropriate use were identified by our analysis.

CONCLUSION

One-third of DOAC preadmission prescriptions for elderly patients were inappropriate, indicating that a need remains to strengthen DOAC prescribing guidelines in ambulatory clinical practice. However, the rate of inappropriate prescriptions decreased at patient discharge. Future studies are needed to test actions to promote the proper use of DOACs.

Choice of Renal Function Estimator Influences Adverse Outcomes with Dabigatran Etexilate in Patients with Atrial Fibrillation

Background  Clinical significance of dosing dabigatran with different estimates of renal function for treatment of atrial fibrillation (AF) is unknown. Renal function is routinely estimated by the chronic kidney disease epidemiology initiative equation (CKD-EPI) and used to guide dosing. The aim of this study was to investigate the risk of adverse outcomes for patients with AF when different estimators of renal function are used.

Material and Methods  AF patient data were extracted from national administrative databases. Renal function was estimated using Cockcroft–Gault, CKD-EPI, and CKD-EPI adjusted for body surface area (CKD-EPI-BSA). Outcomes of cerebrovascular accident (CVA), systemic embolism (SE), and hemorrhage were extracted.

Results  In total, 2,425 patients were identified, of which there were hospitalizations for 138 (5.7%) hemorrhagic events, 45 (1.9%) CVA/SE, and 33 (1.4%) unspecified CVA. The level of agreement between Cockcroft–Gault with CKD-EPI and CKD-EPI-BSA yielded a weighted kappa statistic of 0.47 and 0.71, respectively. CKD-EPI and CKD-EPI-BSA significantly overestimated renal function in elderly patients resulting in higher recommended doses compared with Cockcroft–Gault. The hazard ratio for a hemorrhagic event was 2.32 (95% confidence interval, 1.22–4.42; p  = 0.01) when a high dose was given compared with normal dose, based on Cockcroft–Gault.

Conclusion  Both CKD-EPI and CKD-EPI-BSA equations significantly overestimated renal function in the elderly population compared with the Cockcroft–Gault equation. This may lead to dose selection errors for dabigatran, particularly for those with severe impairment, increasing the risk of adverse outcome. Hence, CKD-EPI and CKD-EPI-BSA equations should not be substituted for the Cockcroft–Gault equation in the elderly for the purpose of renal dosage adjustments.