P2RY12 and atrial fibrillation: In antithrombotic therapy for patients with CCS and AF, in addition to chronic oral anticoagulation, it is vital to add the antiplatelet (clopidogrel in most cases to avoid a high bleeding risk) or even double antiplatelet (both acetylsalicylic acid and a P2Y12 inhibitor) for patients treated by percutaneous coronary intervention to reduce stent thrombosis and the risk of cardiovascular death.