Warfarin is best suited, in areas of slowly-running blood, such as in veins and the pooled blood behind artificial and natural valves, and pooled in dysfunctional cardiac atria. So common clinical indications for
warfarin use are
atrial fibrillation, the presence of artificial heart valves, deep venous thrombosis (clots), and pulmonary embolism (where the embolized clots first form in veins).