Paradoxical Embolism Treatment & Management

Updated: Aug 11, 2020
  • Author: Igor A Laskowski, MD; Chief Editor: Vincent Lopez Rowe, MD  more...
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Approach Considerations

Treatment of paradoxical embolism (PDE) involves medical intervention, surgical intervention, or both. The presence of PDE in association with pulmonary embolism (PE) or atrial clots increases mortality. No difference in survival exists between patients treated medically and those treated surgically. [14]

The initial treatment is anticoagulation to prevent propagation of an intracardiac clot. Drugs used to treat PDE include the following:

  • Anticoagulants (eg, heparin, warfarin, enoxaparin, and tinzaparin)
  • Antiplatelet agents (eg, dipyridamole-aspirin, clopidogrel, and ticlopidine)
  • Thrombolytics (eg, alteplase, streptokinase, and reteplase)

Embolectomy and closure of an intracardiac communication (eg, a patent foramen ovale [PFO] or an atrial septal defect [ASD]) are the surgical treatments of choice and are widely used in patients with presumed PDE. [15, 4]

In the presence of hemodynamic compromise, patients with PDE may be transferred to medical or surgical intensive care units (ICUs). Transfer to a subacute rehabilitation facility may be beneficial in patients with significant neurologic deficits and no further risk of embolism.

Special concerns

PDE is rare in pregnancy but may occur as a consequence of the increased risk of deep vein thrombosis (DVT). Noninvasive modalities should be chosen over an invasive workup, and the treatment is mainly conservative in nature. Heparin is the anticoagulant of choice; the other anticoagulants and thrombolytics are contraindicated. The eventual treatment of choice depends on the trimester of the pregnancy and the assessment of risks versus benefits of treatment.

PDE in elderly patients is significant because of the associated morbidity and mortality in this age group. Noninvasive and less invasive procedures may be preferable. The risk of falls in elderly persons may make inferior vena cava (IVC) interruption a better choice than warfarin for long-term anticoagulation when DVT and PE are present in PDE.


Pharmacologic Therapy

Anticoagulation can be accomplished by giving heparin, a low-molecular-weight heparin (LMWH) such as enoxaparin or tinzaparin, or a direct thrombin inhibitor such as hirudin in the presence of heparin-induced thrombocytopenia (HIT). The main goal is to prevent the progression of embolic phenomena while awaiting emergency intracardiac embolectomy with PFO closure.

Thrombolysis is an alternative therapy that may be useful when acute cor pulmonale or hemodynamic instability is present because of acute PE. Anticoagulants and thrombolytics can be administered either in conjunction or separately, depending on the absence of contraindications, and they may be used as an alternative to surgical intervention if the patient refuses surgery. Available thrombolytics include alteplase (tissue plasminogen activator [tPA]), reteplase, tenecteplase, and streptokinase.

Contraindications include intracranial disease, recent surgery, and trauma. The use of tPA is associated with a roughly 1% risk of intracranial hemorrhage (ICH). 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 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 PDE can be treated with long-term anticoagulation in the form of warfarin when surgical intervention is not an option. IVC interruption with a caval filter (eg, a Greenfield filter) can be used; however, this approach is not protective against emboli smaller than 3 mm.

If anticoagulation is contraindicated, antiplatelet therapy may be beneficial. Options include dipyridamole-aspirin, clopidogrel, dipyridamole, and ticlopidine. These agents are also beneficial in the treatment of transient ischemic attacks (TIAs), which can be a presentation of PDE.

Oxygen therapy is indicated for hypoxia.


Embolectomy and Closure of Intracardiac Communication

Surgical embolectomy with closure of a PFO or ASD appears to be the best treatment option for patients with impending PDE, except for those with fixed pulmonary hypertension, in whom indefinite anticoagulation is an acceptable option. Transcatheter closure of the intracardiac communication is an alternative to surgical closure. [16, 17, 18] It can be accomplished with the ClamShell (C. R. Bard, Murray Hill, NJ) septal occluder device, the buttoned device, or the CardioSEAL (Nitinol Medical Technologies, Boston, MA) septal occluder device.

Both surgical closure and long-term anticoagulation are associated with significant morbidity and mortality, making transcatheter closure of a PFO or an 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.

Complications of nonsurgical closure of a PFO or ASD for PDE include the intermediate-term risks of recurrent neurologic events due to suboptimal device performance resulting from malalignment, with significant residual shunting and the development of a displaced fractured device-arm friction lesion. The annual rate of recurrent stroke or a transient neurologic event after device placement is 3.2%.

Monitoring of patients is achieved with postclosure transesophageal echocardiography (TEE) or transthoracic echocardiography (TTE) using Doppler color mapping or an 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.

There has been debate regarding how best to manage patients with PFO after a cryptogenic stroke. A meta-analysis by Abdelaziz et al aimed at assessing long-term outcomes of transcatheter PFO closure versus medical therapy alone found that the former reduced the recurrence of stroke as compared with the latter and that no significant safety concerns arose. [19]  

A review of eight randomized controlled trials (RCTs) by Fortuni et al found that patients treated with PFO closure were less likely to experience recurrence of cerebrovascular events than those treated medically; however, PFO closure was associated with a higher incidence of new-onset atrial fibrillation or flutter. [20]

A meta-analysis of five RCTs by Darmoch et al, comparing PFO closure with medical therapy in patients with cryptogenic stroke, found that PFO closure was a safe and effective intervention for prevention of stroke recurrence. [21]




Appropriate treatment can lead to morbidity and mortality. Thrombolytic treatment can lead to ICH with extensive neurologic deficits. Transcatheter closure of PFO may lead to residual shunting as a result of malalignment of the occluder device; this can cause recurrent strokes.

Surgical intervention (in the form of embolectomy and PFO closure) in the presence of intracardiac embolus and PFO has a survival rate of 75% and a mortality close to 25%. In view of all the complications of treatment, the benefits must be carefully weighed against the risks. To avoid medicolegal pitfalls, patients and their families should be provided with a thorough explanation of the outcome of the intervention.



The diet depends on whether the patient has any significant comorbid conditions (eg, hypertension or diabetes mellitus) and whether he or she is stable enough to tolerate oral feeding or assisted feeding. Nasogastric or nasoenteral feeding is appropriate when patients cannot protect the airway.



Patients with PDE should remain in bed until the threat of dislodgment of the thrombus is minimal. Elderly patients who have an 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 and are not at risk for falls or further embolism.



Prevention has been controversial. Whether prophylaxis benefits persons with a recognized predisposition for PDE and whether routine screening for PFO or ASD with contrast echocardiography is advisable for patients with hypercoagulable states are yet to be determined.



Radiologic interventionists can help in the diagnostic evaluation of patients with PDE (which may include angiographic or arteriographic studies); they can also help in the treatment of these patients with transcatheter device placement for PFO closure.

For removal of an intracardiac thrombus to correct impending PDE, a cardiothoracic surgeon should be consulted. Open-heart surgery is an alternative for closing the intracardiac communication.

For peripheral embolectomy, a vascular surgeon should be consulted. All emboli removed from the peripheral arterial system should be sent to the pathology laboratory for histologic examination; cardiac myxoma is an important differential diagnosis of PDE, and the clinical manifestations (peripheral, visceral, and cerebral embolism) are identical.

For patients with PDE and PE with hemodynamic compromise, consultation with a pulmonologist or an intensivist may be useful with respect to positive-pressure ventilation and intensive care monitoring.

Early (ie, ≤ 1 hour) evaluation by a neurologist is very important when thrombolysis is to be performed in the setting of acute stroke.


Long-Term Monitoring

Inpatient care for people with PDE depends on their hemodynamic stability and on the any associated presenting clinical manifestations (eg, PE, TIA, acute arterial embolism, or debilitating neurologic deficits) that may warrant intensive care or regular monitoring. Safety precautions and fall prevention measures must be initiated as indicated, especially in elderly patients.

Aspiration prophylaxis is paramount in patients who are bedridden and have minimal or no cough reflex. A neurologic watch is necessary to monitor any further neurologic deficit, so that intervention can take place before further deterioration. Intensive care monitoring is needed when hypotension is present when the patient needs vasopressors, intubation, and mechanical ventilation.

Pain management is needed in patients with acute arterial limb occlusion that commonly presents with severe pain and pain associated with DVT. Gastrointestinal prophylaxis is needed to prevent stress ulcers in the presence of cerebral insult. Skin care may involve frequent turning and protective skin devices to prevent skin breakdown and eventual decubitus ulcer.

Outpatient care for PDE is based on evidence of idiopathic venous thrombosis, hypercoagulable states, PE, risk-determined DVT, and the sequelae of the clinical manifestation.

Long-term anticoagulation with warfarin may be used for 6 months in patients with DVT or PE or as lifelong therapy with monitoring of the international normalized ratio (INR) in patients with hypercoagulable states. Long-term antithrombotic therapy with antiplatelet drugs is needed for patients with a history of TIA.

Physical therapy is needed for patients who will benefit from physical rehabilitation. A visiting nurse may be highly beneficial for monitoring INR at home and helping patients in the administration of subcutaneous injection of LMWH used for long-term anticoagulation, with the goal of eventual self-administration.