Which medication inhibits platelet aggregation and is used in cardiac ischemia?

• A. Aspirin
• B. Heparin
• C. Clopidogrel
• D. Warfarin

Answer: (A)

Aspirin directly targets platelets to prevent clumping, which is crucial in heart ischemia where a new clot can worsen the blockage. It does this by irreversibly inhibiting the enzyme COX-1 in platelets, which reduces the production of thromboxane A2, a chemical that normally promotes platelet activation and aggregation. Because platelets can’t make more COX-1, the antiplatelet effect lasts for the platelet’s lifetime (about a week), providing effective, rapid protection against thrombosis in acute coronary situations.

Other options act differently: heparin and warfarin are anticoagulants that slow clot formation in the blood vessels by interfering with the coagulation cascade, not by stopping platelets from clumping. Clopidogrel also inhibits platelets but through a different pathway (ADP receptor blockade); it’s often used in ACS as part of combination therapy or when aspirin isn’t suitable. The standout choice for a single medication that inhibits platelet aggregation and is widely used in cardiac ischemia is aspirin.