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Clinical Effectiveness Group

Two thirds of atrial fibrillation patients on dual-antithrombotic therapy are prescribed the medication for too long, increasing the risk of internal bleeding

An observational study of people with the heart condition atrial fibrillation, published by a student of Queen Mary’s Wellcome Trust-funded PhD programme: Health Data in Practice, has found that almost 2 in 3 (65.9%) patients on dual-antithrombotic therapy (DAT) receive the treatment for more than 12 months. This is considered too long and puts the patient at increased risk of bleeding complications.

A woman having her blood pressure taken by a GP

Atrial fibrillation (AF) is a heart condition that causes an irregular and rapid heartbeat. People who have AF in combination with another heart condition, such as coronary heart disease, are typically treated with two blood thinning medications at the same time, known as dual-antithrombotic therapy (DAT). This treatment is usually recommended for a period of 3-6 months to prevent blood clots and reduce the risk of heart attacks. But prolonged treatment with DAT places the patient at increased risk of life-threatening bleeding complications - most commonly bleeding from the internal lining of the stomach. For this reason, treatment with DAT for longer than 12 months is not recommended. 

The risk of bleeding can be reduced further by prescribing medication to reduce acid levels in the stomach. But the study, which analysed 1.2 million anonymised GP records in North East London, also found that 1 in 6 (16%) patients being treated with DAT are not prescribed gastroprotective medication. 

The authors argue that duration of DAT and prescription of gastroprotective therapies require urgent improvement to ensure the best possible outcomes for patients with atrial fibrillation.

Dr Zahra Raisi-Estabragh, NIHR Clinical Lecturer in Cardiology, Queen Mary University of London, said:

“Patients on dual-antithrombotic therapy should be routinely reviewed to make sure they are not exceeding the recommended duration for treatment - DAT is rarely appropriate for longer than 3-6 months and beyond 12 months puts people at undue risk of serious complications.

“Dedicated educational initiatives, audits of clinical practice and automated medication alerts may be useful tools to achieving these aims.”

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