Unstable Patients with Suspected or Confirmed PE

Decision making around thrombolysis is complicated and should be approached in a multidisciplinary fashion by senior clinicians with relevant expertise. Many guidelines including the European Society of Cardiology guidelines22 suggest the use of a PERT model (pulmonary embolus response team model) to assess each individual patients risk factors for mortality from PE vs their risk from thrombolytic therapy.

Thrombolysis is indicated for patients with haemodynamic instability, i.e.: a systolic blood pressure <90mmHg or a drop in systolic of >40mmHg for >15 minutes not caused by another cause.

The decision to administer thrombolytics may be made by senior clinicians prior to confirmatory testing in patients who are peri-arrest and in whom the clinical suspicion for pulmonary embolism is sufficiently high and where emergency CTPA is not possible. In such cases point of care ultrasound may aid decision making.

For patients with sub-massive PE decision making surrounding the need for fibrinolytic therapy is more complex and should be made on a case-by-case basis. NICE14 states that thrombolytics should not be offered to haemodynamically stable patients with or without RV dysfunction.

Some clinicians advocate that intermediate-high risk patients with without haemodynamic instability may be considered for thrombolytic therapy. The PEITHO23 trial published in 2014 demonstrated reduced haemodynamic decompensation in intermediate risk patients but an increased risk of major haemorrhage or stroke. The HI-PEITHO24 trial is currently ongoing looking at the use of endovascular therapy vs anticoagulation alone in this patient group. Decision making around treatment approach in this patient cohort is discussed in detail in the ESC 2019 guideline for the diagnosis and management of acute PE22.