Patients with an irregular heart beat could benefit from a drug that is easier to administer than the current standard treatment.
The condition, which is more common with older age and affects about 800,000 people in the UK, can lead to blood clots forming and significantly increases the risk of stroke.
A global study, led by the University of Edinburgh and the Duke University in North Carolina, America, compared the effects of warfarin, the standard treatment to prevent clotting for irregular heartbeats, with the drug rivaroxaban.
Rivaroxaban was found to be as effective as warfarin in reducing the risk of stroke, which can be four to six times higher in patients with irregular heart beats.
Both drugs work by reducing the clotting of the blood but, as a result, this can increase the risk of bleeding. The impact of warfarin can be affected by other medications and diet, and so patients taking it must be closely monitored to ensure they are receiving the correct dose.
Rivaroxaban does not need to be so closely monitored, nor the dose adjusted.
Researchers studied 14,000 patients with irregular heat beats and at risk of stroke - a condition known as atrial fibrillation - who were given either warfarin or rivaroxaban.
The study also found that the incidence of bleeding was similar for both drugs. The risk of fatal bleeding on the brain was halved (from 5 per thousand to approx 2 per thousand) among patients taking rivaroxaban.
Atrial fibrillation can affect adults of any age, but is more common as people get older affecting about 10 per cent of over-65s.
Professor Keith Fox, a British Heat Foundation-supported Professor at the University of Edinburgh, said: "We know that about a third of patients eligible for warfarin are not currently receiving it. This may be because they are too frail and may not be able to manage taking the drug appropriately, with the need for blood tests and dosage levels to be monitored closely. This study shows that an alternative drug for patients with irregular heart beats is just as effective while also easier to prescribe and take."
The study is published by the New England Journal of Medicine.
Manesh R. Patel, MD assistant Professor of Medicine at Duke University School of Medicine, said: "Warfarin has been a standard treatment for decades, but requires a rigorous monitoring schedule to ensure therapeutic dosing levels, and is subject to the potential of food and drug interactions that present treatment obstacles for patients and doctors alike. The results of this large global trial have convincingly shown rivaroxaban to be an alternative to warfarin in treating patients with atrial fibrillation and, importantly, with no increase in bleeding."