Prevention of stroke in patients with atrial fibrillation: Current strategies and future directions

The morbidity and mortality associated with atrial fibrillation (AF) are related mainly to ischaemic stroke, and the prevention of thrombo-embolism is an important component of the patient management. The choice of optimum antithrombotic therapy for a given patient depends on the risk of thrombo-embolism, and the assessment of thrombo-embolic risk using validated stratification schemes, such as the CHADS2 score, is a critical step. Improved stratification schemes are needed that take into account the risk of intracerebral haemorrhage, which is the most worrisome complication of anticoagulant therapy. The pattern of AF (paroxysmal, persistent, or permanent) should not influence the selection of antithrombotic treatment. Similarly, successful rhythm control is not a sound basis for withdrawing antithrombotic treatment, and whether this situation differs after successful catheter ablation of AF has not been established. At present, oral vitamin K antagonists alone are recommended for patients with AF at moderate-to-high risk of stroke. A combination of anticoagulant and antiplatelet drugs is necessary in patients with AF undergoing percutaneous coronary intervention and stent implantation, but the optimal therapeutic management of these patients has not been defined. The development of new antithrombotic agents that are easier to use and have a superior benefit-to-risk ratio will extend treatment to a greater proportion of the AF population at risk. The large number of phase III trials currently investigating specific inhibitors of thrombin or factor Xa that do not require laboratory monitoring suggests that this goal is within reach.