A new study suggests almost 40,000 patients with an irregular heartbeat are being treated with anti-coagulants, even though they are at risk of adverse effects.
GPs are recommended to prescribe anticoagulants, such as warfarin, to patients with arrhythmia to reduce their risk of stroke.
However, anticoagulants also increase the risk of bleeding and safety advice recommends against their use in patients who are at risk of complications, for example if they have an ulcer, are pregnant or have previously had a stroke due to bleeding.
To test whether these recommendations are being put into practice, researchers from the University of Birmingham investigated whether contraindications influence anticoagulant prescribing in the UK.
The study, published in the BJGP today, reviewed patient records from 645 GP surgeries over 12 years (2004–2015). The researchers found that patients with atrial fibrillation and contraindications to anticoagulants were just as likely to be prescribed the drugs as those without any risk factors.
Author of the study Professor Tom Marshall said the situation did not change over time: ‘Safety advice seems not to influence prescribing of anticoagulants. Patients considered a safety risk were just as likely to be prescribed the drugs. It was the same in every year from 2004 to 2015.’
He added GPs have been encouraged to prescribe anticoagulants to prevent strokes, but there needs to be more awareness of the risks.
Professor Marshall said: ‘The sting in the tail is that more people who perhaps shouldn’t be on anticoagulants are also taking them: about 38,000 nationally. We need to understand the reasons for this and whether patients might be come to any harm.’
NICE guidance on the management of atrial fibrillation clearly states that anticoagulants should only be used in the absence of contraindications.
The authors say more research is needed to understand why GPs prescribe anticoagulants to at-risk patients, and whether some patients with contraindications might still benefit from anticoagulant treatment.
Conversely, a study from the University of Birmingham published last year urged GPs to prescribe more preventive drugs. The study found that approximately one-third of stroke and mini-stroke (TIA) patients could be missing out on preventive drugs.