Complete response to rivaroxaban in a case of invaginated thrombus thought to have extended through a patent foramen ovale with an accompanying pulmonary embolism.

Occurrence of paradoxical embolisms caused by deep venous thrombosis (DVT) is often encountered in the clinical setting. However, a thrombus that is invaginated from the right atrium into the left atrium (an impending paradoxical embolism) is rare. We report a case of an 80-year-old woman who had the complication of an impending paradoxical embolism and a pulmonary embolism. Because an indication of new anticoagulants was expanded to treatment of venous thromboembolism and oral administration became available, we initially administered edoxaban, which did not cause the thrombus to disappear. Therefore, we switched to rivaroxaban, which resulted in successful elimination of the thrombus. Our findings indicate the differences in effects between each novel oral anticoagulant. <Learning objective: Paradoxical thrombosis is a common clinical occurrence. However, we believe that our case is rare because we were able to collect images confirming that the thrombus had passed through the interatrial septum and was nearly invaginated into the left atrium. Beyond warfarin, current anticoagulant therapy options may involve the factor Xa blockers edoxaban or rivaroxaban for patients with venous thromboembolism. Findings in our case suggested that there are different effects for novel oral anticoagulants in treatment of venous thromboembolism.>.