pulmonary embolism readministration of TPA

This patient presented with acute hemodynamically unstable pulmonary embolism (also called massive or high-risk pulmonary embolism) and appropriately received IV thrombolytic therapy with alteplase. However some patients, such as this one, deteriorate or fail to improve hemodynamically in response to thrombolytic therapy and are at very high risk for death. In this situation, catheter-assisted mechanical thrombectomy offers the highest likelihood of benefit (choice B is correct). CT angiogram of the chest shows multiple bilateral pulmonary thromboemboli (red arrows in Figures 5-8) and right ventricular enlargement (green arrows in Figures 7-8). Guidelines from the American College of Chest Physicians recommend catheter-assisted mechanical thrombectomy in patients who have failed to improve despite IV thrombolysis, are at high bleeding risk, or continue to manifest shock that is likely to lead to death before systemic thrombolysis can take effect. There remains a paucity of data regarding the initial use of catheter-based therapies in preference to IV thrombolytic therapy in patients with acute hemodynamically unstable pulmonary embolism and normal bleeding risk, and IV thrombolytic therapy remains the therapy of first choice in such patients.

Readministration of thrombolytic agents is best studied in patients with acute ST-elevation myocardial infarction who fail to demonstrate sustained coronary reperfusion after initial thrombolytic therapy; this approach is generally avoided if possible in acute myocardial infarction owing to increased risks of bleeding and limited efficacy versus percutaneous interventions. While data in pulmonary embolism are largely lacking, readministration of a thrombolytic agent in this setting is expected to similarly increase the risk of bleeding, does not have established benefit, and is thus not recommended (choice A is incorrect).

Inferior vena cava filter placement is indicated in acute pulmonary embolism when the patient cannot be safely treated with anticoagulation or has suffered recurrent venous thromboembolism while on sustained therapeutic anticoagulation. Inferior vena cava placement also can be considered in patients with acute pulmonary embolism who are thought to be at high risk of life-threatening deterioration due to recurrent pulmonary embolism shortly after presentation, particularly if there is very limited cardiopulmonary reserve and a large clot burden in the deep veins of the lower extremities. However, inferior vena cava placement would not be expected to reverse this patient's progressive shock and high risk for death; furthermore, the presence of a large lower-extremity clot burden has not been established (choice C is incorrect).

In patients with respiratory failure and circulatory collapse due to pulmonary embolism, stabilization with venoarterial extracorporeal membrane oxygenation may be appropriate. In contrast, venovenous extracorporeal membrane oxygenation treats abnormalities of gas exchange but does not provide hemodynamic support and thus does not have a role in the treatment of acute hemodynamically unstable pulmonary embolism (choice D is incorrect).1

Footnotes

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