Use of oral anticoagulants in complex clinical situations with atrial fibrillation.

The present article provides an update on anticoagulant treatment in patients with atrial fibrillation in distinct clinical scenarios requiring particular considerations, such as ischaemic heart disease, electrical cardioversion, pulmonary vein ablation, the presence of valvular disease with or without prosthetic valves, and renal insufficiency, as well as old age and frailty. In patients with non-valvular atrial fibrillation, the presence of renal insufficiency increases both thrombotic and haemorrhagic risk. In mild and moderate stages, direct-acting anticoagulants confer a greater benefit than warfarin, although they usually require dose adjustment. In renal failure/dialysis, there is no solid evidence that warfarin is beneficial and the use of direct-acting anticoagulants is not recommended. Because of its pathophysiology, oral anticoagulation could have a beneficial effect in patients with heart disease. However, vitamin K antagonists have not shown a satisfactory risk-benefit ratio. In contrast, direct-acting anticoagulants, at reduced doses, could have a beneficial effect in this scenario in association with antiplatelet agents. The use of direct-acting anticoagulants prior to electrical cardioversion in patients with non-valvular atrial fibrillation seems to be associated with a risk of cardioembolic events that is at least comparable to that of vitamin K antagonists. Their use avoids delay in the application of electrical cardioversion in patients without adequate INR levels. In the context of their use before and after atrial fibrillation ablation, dabiga-tran and rivaroxaban have demonstrated at least non-inferiority with vitamin K antagonists in terms of safety. In patients with any type or grade of valvular disease and atrial fibrillation, the indication of antithrombo-tic treatment must be evaluated in the same way as in patients with atrial fibrillation and no valvular di-sease. Whenever anticoagulation is required, direct-acting anticoagulants are the treatment of choice in nearly all situations, except in patients with mechanical valves or who have significant rheumatic mitral disease, who should be treated with vitamin K antagonists. The choice of appropriate antithrombotic stra-tegy in frail elderly patients is complex and involves multiple factors beyond assessment of embolic and haemorrhagic risk. Comprehensive geriatric assessment is essential for an individualised final decision. Moreover, any such decision should be consensus-based and periodically reviewed. Direct-acting anticoa-gulants could be the most beneficial alternative in most elderly patients with non-valvular atrial fibrillation.