Atrial fibrillation is the commonest heart rhythm disorder. To provide clinicians and patients with a more tangible picture of the potential impact of novel oral anticoagulants for Europeans, Ron Pisters, MD, PhD, Department of Cardiology, Maastricht University Medical Centre in The Netherlands, and his Dutch, British and Canadian colleagues investigated potential benefits of novel oral anticoagulants apixaban and dabigatran in patients with atrial fibrillation. Their article, highlighting recent findings, has now been published in "Thrombosis and Haemostasis."
Initially, the authors discussed the common underutilization of vitamin-K-antagonists (eg. warfarin) in high-risk atrial fibrillation patients, often due to the need for monitoring. "But we should learn from the lessons of the past on antithrombotic undertreatment of patients with atrial fibrillation and the associated detrimental effects on outcome."
The novel oral anticoagulants are equally potent (or sometimes better) as vitamin K antagonists in reducing the stroke risk. Moreover, the risk of the most feared anticoagulation-related complication, i.e. intracranial hemorrhage (hemorrhagic stroke), is reduced to a historical low in patients with atrial fibrillation who are receiving novel oral anticoagulants compared to those being treated with vitamin K-antagonists. In addition, the new oral anticoagulants are more user-friendly as there is no more need for frequent anticoagulation monitoring using the INR laboratory test.
They investigated the potential benefit of apixaban and dabigatran and the impact on patients with atrial fibrillation and one or more, and two or more risk factors for stroke, assuming these drugs would have been given to all atrial fibrillation patients instead of their current antithrombotic medication. For apixaban, this theoretical regimen could potentially result in the annual saving of an additional 12 people from suffering a stroke, four from major bleeding events and seven from dying per 1,000 treated atrial fibrillation patients. Apixaban was associated with less major bleeding events compared to the vitamin-K-antagonists. Furthermore, the novel oral anticoagulant significantly reduced all-cause mortality and was better tolerated than warfarin, exemplified by significantly lower permanent discontinuation rates. With dabigatran 150 mg twice daily there was also a significant reduction in the risk of hemorrhagic stroke.
Extrapolation of the data to the whole of Europe would translate into the prevention of an additional 64,573 major cardiovascular events and deaths each year among high risk patients with atrial fibrillation, by the use of apixaban, 43,235 with the use of dabigatran 150 mg bid and 27,272 with the use of dabigatran 110 mg bid.
These impressive numbers clearly show how the novel oral anticoagulants would major impact on reducing cardiovascular events and deaths in Europe.
Pisters R, Nieuwlaat R, Lane DA, et al. Potential net clinical benefit of population-wide implementation of apixaban and dabigatran among European patients with atrial fibrillation: A modelling analysis from the Euro Heart Survey. Thromb Haemost 2013; 109: 328-336.
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