Incidence of stroke attributable to atrial fibrillation increases from 1.5% at age 50–59 years to 23.5% at age 80–89 years. The use of oral anticoagulants to reduce the risk of stroke is well established, but all the available agents can cause bleeds if used in excess dose, in high-risk patients or in patients with reduced kidney function.
This article highlights the need to assess kidney function as stated in the newly published European Heart Rhythm Association (EHRA) of the European Society of Cardiology (ESC) practical guide on the use of the new oral anticoagulants (NOACs).1 The EHRA guide has a section on NOACs for patients with chronic kidney disease (CKD) where it is stated that “a careful follow-up of renal function is required in CKD patients, since all (NOACs) are cleared more or less by the kidney”. It continues “in the context of NOAC treatment, creatinine clearance is best assessed by the Cockcroft method, as this was used in most NOAC trials”.
The authors discuss the issues and present a simple guide on why and how to use the Cockcroft Gault equation for kidney function estimation. They also note that for drug and dosing decisions, reduced kidney function, for whatever reason (not just where a patient has been assessed as having CKD), needs to be assessed to reduce the risk of harm.