Therapeutic uncertainties: first finding of atrial fibrillation in acute coronary syndrome.

Atrial fibrillation (AF) and coronary artery disease share several risk factors and their simultaneous presentation in the same patient, sometimes in the course of acute coronary syndrome (ACS), is not a rare occurrence. Patients with AF and ACS represent an important clinical challenge in terms of diagnosis, prognosis and therapy. From a diagnostic point of view, AF may be new onset as a complication of ACS, or a pre-existing asymptomatic AF that is occasionally diagnosed during ACS. Regarding the prognosis, AF, whether new onset or already known, has been shown to exert a negative prognostic impact during ACS. Finally, the main therapeutic dilemma concerns the selection of the optimal antithrombotic therapy, which, at least in the first period following ACS, would require the combination of anticoagulant and antiplatelet drugs, with a consequent increase in the risk of bleeding complications. Several randomized studies have evaluated the therapeutic options in patients with AF and coronary artery disease, overall showing the advantage of a dual therapy with an antiplatelet and an anticoagulant compared with a long-term triple therapy with dual antiplatelet and anticoagulant therapy; the analyses of the ACS subgroups of these randomized studies confirmed such results also in the acute setting.