What is PT INR Test? Cardiology Basics

INR is short for International Normalized Ratio of Prothrombin Time. It is also called PT-INR. INR monitoring is used to monitor the dosage of vitamin K antagonists like warfarin. Vitamin K antagonists are used for stroke prevention in atrial fibrillation as well as for deep vein thrombosis and pulmonary embolism. Non vitamin K oral anticoagulants (NOACs), also known as direct oral anticoagulants (DOACs) like dabigatran, rivaroxaban and apixaban do not need INR monitoring. Warfarin is routinely used when there is a mechanical prosthetic valve, to prevent valve thrombosis and thromboembolism. As of now, DOACs are not ideal for mechanical prosthetic valves as they have a higher thrombogenicity.