Question 5

a) Define massive pulmonary embolism. (10% marks)

b) Discuss the advantages and disadvantages of thrombolysis, catheter directed clot removal and surgical embolectomy, in the treatment of massive pulmonary embolism. (90% marks)

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College answer

Not available.

Discussion

a) Massive (or "high risk") PE is defined by the AHA guidelines (2011) as:

SBP <90 mmHg for at least 15 minutes;
OR requiring inotropic support,
AND not due to a cause other than PE, pulselessness, or persistent profound bradycardia.

	Advantages	Disadvantages
Thrombolysis	Widely available Use is supported by major society guidelines (AHA 2011, ESC 2019) Reduces the risk of death by as much as 55% Minimally invasive (requires a PIVC) Does not require sedation or anaesthesia	Substantial risk of lifethreatening bleeding, including ICH Risk of bleeding is probably underestimated by clinical trial data May not work in patients who present following a substantial delay (as the clot has started to organise)
Catheter-directed clot removal	Excellent published success rate (~87%), i.e. achieved improvement of hypoxia, haemodynamic stability, and survival Lower risk as compared to systemic thrombolysis May be performed in patients in whom thrombolysis was not completely effective or is contraindicated Can be offered concurrently with antigoagulation Minimally invasive, as compared to surgical embolectomy Can be repeated several times, or thrombolysis can be administered continuously for a sustained period	Data regarding efficacy is mainly derived from registries and pooled results from case series Concern re. publication bias and industry sponsorship Requires interventional radiology, which may not be widely available Invasive Substantial radiation and IV contrast exposure May require sedation or an anaesthetic, which could be dangerous in the haemodynamically unstable patient Still may not work in patients who present following a substantial delay (as the clot has started to organise, and would be less friable)
Surgical embolectomy	Highly effective even for clots which have become organised Can be offered concurrently with antigoagulation May be an option for patients in whom thrombolysis is contraindicated Outcomes are at least as good as thrombolysis, and rates of rethrombosis or intervention are reduced (mortality rate only 12%)	Cannot be offered to patients who have recently received thrombolysis Maximally invasive and requires anaesthetic plus cardiopulmonary bypass Recovery is prolonged in comparison to other methods Rarely performed, which means staff may be deskilled Only available at centres where cardiothoracic surgery is routinely performed

References

Kucher, Nils, et al. "Massive pulmonary embolism." Circulation 113.4 (2006): 577-582.

Kucher, Nils, and Samuel Z. Goldhaber. "Management of massive pulmonary embolism." Circulation 112.2 (2005): e28-e32.

Jaff, Michael R., et al. "Management of massive and submassive pulmonary embolism, iliofemoral deep vein thrombosis, and chronic thromboembolic pulmonary hypertension: a scientific statement from the American Heart Association." Circulation 123.16 (2011): 1788-1830.

Konstantinides, Stavros V., et al. "2019 ESC Guidelines for the diagnosis and management of acute pulmonary embolism developed in collaboration with the European Respiratory Society (ERS) The Task Force for the diagnosis and management of acute pulmonary embolism of the European Society of Cardiology (ESC)." European heart journal 41.4 (2020): 543-603.

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