Variations in clinical management of non-vitamin K antagonist oral anticoagulants in patients with atrial fibrillation according to different equations for estimating renal function

Prescription of non-vitamin K antagonist oral anticoagulants (NOACs) requires an assessment of renal function (RF) and the Cockcroft–Gault (CG) equation is traditionally recommended. The objective of the study was to evaluate the potential changes in NOACs management using different equations for estimating RF. In a post hoc analysis of a prospective cohort of patients with atrial fibrillation, we considered different equations: (1) CG for creatinine clearance (CrCl), (2) modification of diet in renal disease (MDRD), (3) CKD-EPI, (4) Berlin Initiative Study 1 (BIS-1) and (5) full age spectrum (FAS), for glomerular filtration rate (GFR). RF was classified according to CrCl in three categories: severely depressed (SD-RF) < 30 ml/min; moderately depressed (MD-RF) 30–49 ml/min; preserved/mildly depressed (P-RF) ≥ 50 ml/min. Concordances in the assignments were analyzed. A population of 402 patients (61.2% males, age 72 ± 11) was categorized according to CrCl: 12 patients (2.9%) as SD-RF, 81 (20.1%) as MD-RF, 309 (76.8%) as P-RF. A potential change in NOACs management could occur using GFR equations rather than CrCl in 16.9% of patients using MDRD formula, in 11.7% using BIS-1, in 14.7% using CKD-EPI and in 12.9% using the FAS equation. Important changes in RF estimates were more frequent in patients aged ≥ 75, but also BMI had a meaningful impact. Use of equations estimating GFR instead of the Cockcroft–Gault equation may result in changes in NOACs management in 12–17% of patients. In the elderly ≥ 75, more pronounced changes in RF classification are detectable according to different equations and NOACs dosing should be further investigated.