Paradoxical Embolism Treatment & Management

Paradoxical embolism (PDE) treatment involves medical intervention, surgical intervention, or both. The initial treatment is anticoagulation to prevent propagation of an intracardiac clot. The presence of paradoxical embolism (PDE) with PE or atrial clots increases mortality. No difference in survival exists whether patients are treated medically or surgically.

• Anticoagulation can be in the form of heparin, low molecular-weight heparin (LMWH; eg, enoxaparin, tinzaparin), or the new direct thrombin inhibitors (eg, hirudin) in the presence of heparin-induced thrombocytopenia (HIT). The main goal is to prevent the progression of embolic phenomena while awaiting emergent intracardiac embolectomy with PFO closure.
• Thrombolytics are another alternative available therapy when acute cor pulmonale or hemodynamic instability is present because of acute PE. Anticoagulation and thrombolytics can be used in conjunction or separately, depending on the absence of contraindications and as an alternative to surgical intervention if the patient refuses. Thrombolytics include the recombinant tissue-type plasminogen activator (tPA), reteplase, and TNKase.

  • Contraindications include intracranial disease, recent surgery, or trauma. An approximate 1% risk of intracranial hemorrhage exists with the use of tPA.
  • It has the additional advantage of treating associated PE and acute arterial occlusion of the extremities. This can lead to immediate decrease in pulmonary artery pressure and can reduce the incidence of recurrent paradoxical embolism (PDE).
  • Treatment of the underlying cause of increased right atrial pressure is intended to reverse the right-to-left shunt, restoring the hemodynamic homeostasis.
• DVT and PE in conjunction with paradoxical embolism (PDE) can be treated with long-term anticoagulation in the form of warfarin when surgical intervention is not an option. Inferior vena cava interruption with caval filters, such as a Greenfield filter, can be used. However, they are not protective against emboli smaller than 3 mm.
• Antiplatelet therapy may be beneficial if anticoagulants are contraindicated. Options include dipyridamole/aspirin (Aggrenox), clopidogrel (Plavix), dipyridamole (Persantine), and ticlopidine (Ticlid). They also are beneficial in the treatment of TIA, which can be a presentation of paradoxical embolism (PDE).
• Oxygen therapy is indicated for hypoxia.

Surgical therapies that include embolectomy and intracardiac communication closure (commonly PFO) are the treatments of choice and are used widely in patients with presumed paradoxical embolism (PDE).^[5]

• Surgical embolectomy with closure of a PFO or ASD appears to be the best treatment option for patients with an impending paradoxical embolism (PDE), except in fixed pulmonary hypertension, where indefinite anticoagulation is an acceptable option.
• Transcatheter closure of intracardiac communication is an alternative option to surgical closure.^[6]

  • Both surgical closure and long-term anticoagulation therapy have significant associated morbidity and mortality, making transcatheter closure of PFO or ASD a promising alternative to surgical closure and a promising treatment for patients who are unable to tolerate long-term anticoagulation or who are poor surgical candidates.
  • Transcatheter closure can be employed using a Bard ClamShell septal occluder device, the buttoned device, or the CardioSEAL septal occluder device. These all are available for transcatheter closure.
  • Complications of nonsurgical closure of PFO or ASD for paradoxical embolism (PDE) are intermediate-term risks of recurrent neurologic events due to suboptimal device performance due to malalignment of the device, with significant residual shunting and the development of a displaced fractured device-arm friction lesion. The rate of recurrent stroke or a transient neurological event following the device placement is 3.2% per year.
• Monitoring of patients is achieved with postclosure TEE or TTE using Doppler color mapping or agitated saline solution contrast injection. Residual shunting may eventually lead to surgical closure when recurrent neurologic deficit or stroke complicates transcatheter PFO or ASD closure.

• Radiology interventionists can help in the diagnostic evaluation (which may include angiographic/arteriographic studies) of patients with paradoxical embolism (PDE); they can also help in the treatment of these patients with transcatheter device placement for PFO closure.
• A cardiothoracic surgeon should be consulted to remove an intracardiac thrombus to correct impending paradoxical embolism (PDE). Open-heart surgery is an alternative to close the intracardiac communication.
• A vascular surgeon should be consulted for peripheral embolectomy.
• All emboli removed from the peripheral arterial system should be sent to pathology for histological examination because cardiac myxoma is an important differential diagnosis of paradoxical embolism (PDE), and the clinical manifestations (peripheral, visceral, cerebral embolism) are identical.
• Consultation with a pulmonologist and/or intensivist may be useful for patients with paradoxical embolism (PDE) and PE with hemodynamic compromise for positive-pressure ventilation and intensive care monitoring.
• Early (< 1 h) evaluation by a neurologist is very important for thrombolysis in acute stroke.

• Diet depends on the comorbid state of the patient, such as hypertension or diabetes mellitus, and whether the patient is stable enough to tolerate oral feeding or assisted feeding.
• Nasogastric/nasoenteral feeding is appropriate when patients cannot protect their airway.

• Bedrest: Patients with paradoxical embolism (PDE) should remain in bed until the threat of dislodgement of the thrombus is minimal.
• Restraints: Elderly patients with increased risk of falls or patients who are confused should be protected with restraints or one-on-one monitoring to prevent falls that can lead to bleeding in the presence of anticoagulation.
• Early mobilization is possible in patients who are hemodynamically stable, without risk of falls and without risk of further embolism.