3 ︱ DISCUSSION
In this report, we present an unusual case of bi-atrial thrombus after device-based closure of ASD with acute cerebral infarction and pulmonary embolism. Bafflingly, there are no definitive guidelines for cardiac thrombus management in patients with acute cerebral infarction and pulmonary embolism. A recent paper reported a case of intracardiac thrombus that crossed the patent foramen ovale (PFO) and caused ischemic stroke, and was treated with intravenous unfractionated heparin under close neurological monitoring 2. The patient in our case was decided to undergo surgical resection and atrial septal repair by a multidisciplinary team, including cardiology, neurology, respirology and hematology specialists. During the surgery, rivaroxaban antithrombotic therapy was switched to low-molecular heparin anticoagulation and aspirin antiplatelet treatment. Postoperative ultrasound found that there were no thrombi in the heart and limbs, except a few floating in the right internal jugular vein and subclavian artery.
Pulmonary embolism occurred 6 months after aspirin antiplatelet therapy in this patient, which may be related to incomplete endothelialization of the device, causing right atrial thrombus formation and detachment into the right pulmonary artery. Followed by rivaroxaban antithrombotic therapy for 6 months, acute cerebral infarction still occurred, which may be due to the patient’s lack of strict compliance during medication, resulting in multiple systemic thrombosis and vital organ infarction. As noted above, these complications are most likely due to the non-adherence to antiplatelet and antithrombotic therapy.
Although TTE and CT has been widely used to detect intracardiac thrombus, 3D-TEE is considered to be more superior than both, thanks to its advantages, including real-time, clarity and vividness3. Compared with TTE, TEE can closely observe cardiovascular system via esophagus, which overcomes the interference of edema, emphysema, obesity, dressings, and mechanical ventilation. Meanwhile, TEE is more suitable for intraoperative guidance and timely evaluation as compared with CT. In addition, real-time 3D-TEE provides patients with a virtual reality heart model with high temporal and spatial resolution, allowing cardiac surgeons to identify structure changes and valvular lesions.
Notably, this case needs to be differentiated from paradoxical embolization and atrial myxoma. As far as we know, acute cerebral infarction and pulmonary embolism can also be present in patients with paradoxical embolism and atrial myxoma. One distinguished feature of paradoxical embolism is the significant increase of right atrial pressure in patients with ASD or PFO, resulting in right-to-left shunt at the atrial level 4. Moreover, the most common site of atrial myxomas is on the atrial septum, of which 75–80% located in the left atrium 5. The usual complications of left atrial myxoma are mitral valve obstruction and left heart failure, but acute stroke is relatively rare. Pathological examination plays a key role in differentiating atrial myxoma from thrombus. Specifically, myxomas are composed of ovoid, spindle, or stellate mononuclear myxoma cells, whereas thrombi are predominantly composed of blood cells.