What is the difference between plavix (clopidogrel) and rivaroxaban? which one is a superior bloodthinner for patient with stent and atrial fibrilation?

Different: The easiest way to think about anticoagulants is to separate them into categories. Plavix (clopidogrel) and Aspirin prevent clotting on the arterial side and are designed for coronary artery disease and stents (plavix (clopidogrel) in particular.) rivaroxaban prevents venous clotting and is good for atrial fibrillation and venous thromboembolic disease. You need Plavix (clopidogrel) for your stent and rivaroxaban for your atrial fib.

Different drugs: Plavix (clopidogrel) is a "blood thinner" that acts on the cells called the platelets. Usually, people take Plavix (clopidogrel) after a stent. Rivaroxaban is a true blood thinner, that makes the blood unable to form a clot. That is taken with atrial fibrillation to prevent strokes. That's the difference.