The role of various methods of kidney function assessment in dosing of oral anticoagulants in atrial fibrillation patients

Aim

To evaluate the frequency and severity of renal function impairment and the potential impact of using the most common estimates of renal function on the dosing of direct oral anticoagulants (DOACs) among patients with atrial fibrillation (AF) and acute coronary syndrome or a planned percutaneous coronary intervention.

Material and methods

The study included 47 patients [age 74 (66; 78) years; 27 (58%) male]. Creatinine clearance (CrCl) was calculated using Cockcroft-Gault equation, glomerular filtration rate (GFR) was estimated by MDRD and CKD-EPI equations. In addition, for the GFR formulas, body surface area (BSA) correction was used. All patients were stratified into categories of GFR and CrCl >50 ml/min, 30-50 ml/min and <30 ml/min. The mismatch between the calculated values of CrCl and GFR was considered as a potential cause of DOAC underdosing (with GFRCrCl).

Results

Chronic kidney disease was diagnosed in 28 (60%) patients, the median serum creatinine was 102.0 (87.8; 117.3) μmol/L. The discrepancy between renal function categories assessed using GFR MDRD and GFR CKD-EPI when compared with CrCl was observed in 23.4% and 27.6% of the cases, respectively. These discrepancies could lead either to underdosing (10.6% and 17.0%, respectively) or overdosing (12.8% and 10.6%, respectively) of DOACs. BSA correction does not resolve the problem of underestimation of kidney 23ОРИГИНАЛЬНЫЕ СТАТЬИ function in 15.4% (GFR MDRD ) and 12.8% (GFR CKD-EPI ) of patients.

Conclusion

Use of GFR estimate of kidney function instead of CrCl equation may lead to prescription of an inadequate dose of DOACs in a significant proportion of patients and, consequently, to an increased risk of thromboembolic or hemorrhagic events.

Key words

Atrial fibrillation, direct oral anticoagulants, chronic kidney disease.