• atrial fibrillation
• acute coronary syndromes
• acute myocardial infarction

Patients with concomitant atrial fibrillation (AF) account for 5%–10% of those receiving percutaneous coronary intervention (PCI); this prevalence is likely to increase in the future due to the advancing age of the population and attendant comorbidities. Given the great number of possible therapeutic combinations, observational data on patients with AF suffering from acute myocardial infarction (MI) and/or receiving PCI have indicated a large variability of antithrombotic strategies among different countries and centres. Furthermore, available evidence often derives from single-centre registries or small case-controlled series, and refers to patient populations with different characteristics and risk profiles.

Triple antithrombotic therapy for a long time has been empirically considered the ‘ideal’ treatment in this setting of patients, as it may provide protection from both AF-related thromboembolic complications and ischaemic cardiac events, that is, oral anticoagulant therapy to prevent stroke or systemic embolism and dual antiplatelet therapy with aspirin plus clopidogrel to reduce MI and stent thrombosis. However, a close correlation between bleeding events and number or doses of antithrombotic agents has been clearly documented. In particular, studies have shown a greater than threefold elevation in the risk of major bleeding with use of triple versus dual antithrombotic therapy; notably, the occurrence of haemorrhagic complications may negatively affect the prognosis during follow-up. Thus, three randomised trials have recently evaluated whether in patients with AF undergoing PCI a dual antithrombotic treatment (an oral anticoagulant drug plus a P2Y12 inhibitor, usually clopidogrel, withdrawing aspirin) reduces the rates of bleeding events without increase in ischaemic events compared with triple therapy.1–3 Those investigations showed a safety benefit with …