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.