04 Sep 2006

Antithrombotic therapy in atrial fibrillation Symposium

Dr Lip

Topics: Atrial Fibrillation
Session number: 120000
Session title: Antithrombotic therapy in Atrial Fibrillation
Authors: Lip, G.Y.H. Birmingham, United Kingdom

A well-attended session on antithrombotic therapy in atrial fibrillation (AF) was held on Tuesday 4th September, which covered aspects ranging from pathophysiology to clinical practice, ending with presentations on new antithrombotic strategies. D Van Wagoner (Cleveland, USA) started the session with an elegant view on the prothrombotic state in AF, and what ‘drives’ the increased tendency to thrombogenesis in this condition. We learnt of the hypercoagulable state in AF, and the links to remodelling, inflammation, endothelial (dys)function, growth factors, etc.

The coagulation system – rather than platelets - dominates the pathophysiology of thrombogenesis in AF, and some were not surprised with the results from the ACTIVE-W trial, which was stopped early because of clear evidence of the superiority of oral anticoagulation therapy over aspirin-clopidogrel in stroke prevention. S Hohnloser (Frankfurt,DE) presented the results from this study, which was recently published in the Lancet. Of interest, patients on oral anticoagulation therapy at study entry had less vascular events and a lower risk of major bleeding.

R De Caterina (Chieti, IT) discussed the role of the pentasaccharides in AF, especially with idraparinux. The AMADEUS trial would be presented at the AHA meeting in November but the trial was stopped early due to low endpoint rate and bleeding issues.

A G Turpie (Hamilton, CA) finished the session with an overview of the oral factor Xa inhibitors, and the potential application to stroke prophylaxis in AF. Many of these agents are in development, and – like the direct thrombin inhibitors - may prove an alternative to the Vitamin K antagonists. Promising initial data – at least in venous thromboembolism - show that these drugs do not need monitoring, have few food and drug interactions, and a good efficacy/safety profile. Conclusion This was an interesting session dealing with ‘bench to bedside’ aspects of AF thromboprophylaxis. Insights into the prothrombotic state have allowed a greater understanding on how AF fulfils Virchow’s triad for thrombogenesis, and what ‘drives’ the prothrombotic state in AF.

Until new antithrombotic strategies are widely available, we depend on good risk stratification to target which ‘high risk’ patients with AF would benefit most from anticoagulation. Indeed, indices of the prothrombotic state in AF can even help refine clinical risk stratification in AF.

Improving anticoagulation monitoring with ‘point of care’ testing has also helped management of such patients. Nonetheless, new anticoagulant drugs hold great promise and we await them with interest.

The content of this article reflects the personal opinion of the author/s and is not necessarily the official position of the European Society of Cardiology.