Potential Effect of Substituting Estimated Glomerular Filtration Rate for Estimated Creatinine Clearance for Dosing of Direct Oral Anticoagulants

Abstract Background In the clinical trials with direct oral anticoagulants (DOAC) estimates of creatinine clearance (CrCl) with Cockcroft-Gault equation were used to assess renal functions. Recently, most laboratories report renal function estimated with the Modification of Diet in Renal Disease (MDRD) or Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equations, which may lead to impaired dosing of DOACs by physicians. Purpose To compare estimated glomerular filtration rate and estimated creatinine clearance in a large group of patients with atrial fibrillation and chronic kidney disease. Methods Physicians from 423 institutions in the Czech Republic were asked to enroll 5 consecutive outpatients with atrial fibrillation (AF) treated by a DOAC with stage 3 chronic kidney disease and glomerular filtration rate (eGFR) 30–59 ml/min estimated by MDRD or CKD EPI equations into the registry. Besides eGFR, serum creatinine values were recorded and CrCl calculated by the Cockroft-Gault formula. Results of CrCl and eGFR obtained in individual patients were compared and statistically analyzed using two-sample t-test. Results A total of 2115 patients were enrolled. Mean CrCl was 47.43 ml/min, mean eGFR calculated by MDRD and CKD-EPI was lower 43.88 and 43.53 ml/min (P for difference <0.001 for both). Mean difference between CrCl and eGFR in individual patients calculated by MDRD and CKD-EPI was 8.8 and 9.41 ml/min. A difference beween CrCl and eGFR >10 ml/min was found in 31.5% and 34.8% patients when using MDRD and CKD-EPI formulas. The respective differences between CrCl and eGFR between 4.1 and 10 ml/min were found in 28.5% (MDRD) and 30.8% (CKD-EPI). At CrCl above or below 50 ml/min, 24.0% and 24.2% were misclassified when using eGFR calculated by MDRD and CKD-EPI. At CrCl above or below 30 ml/min, 9.8% (MDRD) and 10.0% (CKD-EPI) patients were misclassified (please see Figures). Conclusions When eGFR estimated by MDRD or CKD-EPI is used to assess renal function and guide DOAC dosing instead of CrCl calculated by the Cockroft-Gault formula in patients with AF and stage 3 CKD, more than a third of patients is misclassified and wrong DOAC dose can be recommended. FUNDunding Acknowledgement Type of funding sources: Private company. Main funding source(s): Boehringer-Ingelheim Differences between CrCl and CKD-EPI Differences between CrCl and MDRD

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Comparative Effectiveness and Safety of Oral Anticoagulants Across Kidney Function in Patients With Atrial Fibrillation

Circulation Cardiovascular Quality and Outcomes ◽

10.1161/circoutcomes.120.006515 ◽

2020 ◽

Vol 13 (10) ◽

Author(s):

Xiaoxi Yao ◽

Jonathan W. Inselman ◽

Joseph S. Ross ◽

Rima Izem ◽

David J. Graham ◽

...

Keyword(s):

Atrial Fibrillation ◽

Glomerular Filtration Rate ◽

Glomerular Filtration ◽

Kidney Function ◽

Major Bleeding ◽

Comparative Effectiveness ◽

Lower Risk ◽

Filtration Rate ◽

Estimated Glomerular Filtration Rate ◽

Oral Anticoagulants

Background: Patients with atrial fibrillation and severely decreased kidney function were excluded from the pivotal non–vitamin K antagonist oral anticoagulants (NOAC) trials, thereby raising questions about comparative safety and effectiveness in patients with reduced kidney function. The study aimed to compare oral anticoagulants across the range of kidney function in patients with atrial fibrillation. Methods and Results: Using a US administrative claims database with linked laboratory data, 34 569 new users of oral anticoagulants with atrial fibrillation and estimated glomerular filtration rate ≥15 mL/(min·1.73 m 2 ) were identified between October 1, 2010 to November 29, 2017. The proportion of patients using NOACs declined with decreasing kidney function—73.5%, 69.6%, 65.4%, 59.5%, and 45.0% of the patients were prescribed a NOAC in estimated glomerular filtration rate ≥90, 60 to 90, 45 to 60, 30 to 45, 15 to 30 mL/min per 1.73 m 2 groups, respectively. Stabilized inverse probability of treatment weighting was used to balance 4 treatment groups (apixaban, dabigatran, rivaroxaban, and warfarin) on 66 baseline characteristics. In comparison to warfarin, apixaban was associated with a lower risk of stroke (hazard ratio [HR], 0.57 [0.43–0.75]; P <0.001), major bleeding (HR, 0.51 [0.44–0.61]; P <0.001), and mortality (HR, 0.68 [0.56–0.83]; P <0.001); dabigatran was associated with a similar risk of stroke but a lower risk of major bleeding (HR, 0.57 [0.43–0.75]; P <0.001) and mortality (HR, 0.68 [0.48-0.98]; P =0.04); rivaroxaban was associated with a lower risk of stroke (HR, 0.69 [0.51–0.94]; P =0.02), major bleeding (HR, 0.84 [0.72–0.99]; P =0.04), and mortality (HR, 0.73 [0.58–0.91]; P =0.006). There was no significant interaction between treatment and estimated glomerular filtration rate categories for any outcome. When comparing one NOAC to another NOAC, there was no significant difference in mortality, but some differences existed for stroke or major bleeding. No relationship between treatments and falsification end points was found, suggesting no evidence for substantial residual confounding. Conclusions: Relative to warfarin, NOACs are used less frequently as kidney function declines. However, NOACs appears to have similar or better comparative effectiveness and safety across the range of kidney function.

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