Anticoagulants and Antiplatelets

A 55-year-old woman with acute coronary syndrome is started on dual antiplatelet therapy. Which is the most common site of bleeding in patients on chronic aspirin and clopidogrel therapy?

A 58-year-old woman with mechanical mitral valve replacement (on warfarin, INR 2.5) presents with acute coronary syndrome (NSTEMI). Troponin is elevated. Coronary angiography is planned within 6 hours. She has no contraindications to dual antiplatelet therapy. What is the most appropriate immediate next step?

A 62-year-old man with atrial fibrillation (CHA₂DS₂-VASc score = 4) presents to the emergency department with acute ischaemic stroke. CT head shows no haemorrhage. He is on aspirin 75 mg daily but was not on anticoagulation. Thrombolysis with intravenous alteplase is being considered. What is the most appropriate immediate next step regarding anticoagulation?

Which of the following antiplatelet agents irreversibly inhibits platelet aggregation by covalently acetylating cyclooxygenase-1 (COX-1)?

Warfarin exerts its anticoagulant effect by inhibiting which vitamin K-dependent clotting factors?