Illustrating: Advice about choice of oral anticoagulant drugs and risk/benefit ratio

Patient Case

Mrs PJ is an 80 year old woman who has been on warfarin for some years for her atrial fibrillation. She has been well controlled on the warfarin with her regular blood tests showing that her  INR readings demonstrated  a Time in the Therapeutic range (TTR) of 74%. She has stable chronic kidney failure and has been treated for high blood pressure. She takes several other drugs relating to her arthritis and her diabetes. She has come to ask whether she can change to the new oral anticoagulant drugs which her cousin told her about.

How the GP used HeliconHeart to advise the patient

Examining the benefit and risk details together in HeliconHeart – Anticoagulant and Stroke prevention services, the GP can show the patient her risk of bleeding expressed as a HAS-BLED score (see table below). This shows that she is at high risk of bleeding on the anticoagulant drugs and that a component of this risk relates to her kidney failure.

 HAS BLED Risk FactorsScore
HHypertension (systolic BP > 160mmHg)1
AAbnormal renal and liver function (1 point each)
  • Abnormal renal function: chronic dialysis, renal transplantation or serum Cr > 200μmol/L

  • Abnormal liver function: chronic hepatic disease (e.g. cirrhosis) or biochemical evidence of significant hepatic derangement (e.g. bilirubin > 2 x upper limit of normal in association with AST/ALT/ALP > 3x upper limit of normal)

1 or 2
SStroke2
BBleeding (previous bleeding history and/or predisposition to bleeding e.g. bleeding diathesis, anaemia etc)1
LLabile INR’s (unstable/high INR’s or poor time in therapeutic range e.g. < 60%)1
EElderly (e.g. age > 65years)1
DDrugs or alcohol (1 point each) – concomitant use of e.g. antiplatelets, NSAIDs, or alcohol abuse1 or 2
Maximum score9

It is now clear to the patient that the newer oral anticoagulant drugs are contra-indicated in her. Although she is at an increased risk of bleeding with warfarin, it is a safer drug for her to be taking particularly as it is closely monitored with regular blood tests.