From the Guidelines
Pulmonary embolism (PE) can be classified into two main types: massive and non-massive, with a subgroup of non-massive PE referred to as submassive, based on the presence of right ventricular hypokinesis. The classification of PE is crucial for determining the appropriate treatment approach and predicting patient outcomes. According to the guidelines on diagnosis and management of acute pulmonary embolism by the European Society of Cardiology 1, massive PE is characterized by shock and/or hypotension, defined as a systolic blood pressure <90 mmHg or a pressure drop of 40 mmHg for >15 min.
Some key characteristics of each type include:
- Massive PE: significant hemodynamic instability, often requiring aggressive treatment such as thrombolytic therapy
- Submassive PE: right ventricular dysfunction but normal blood pressure, potentially requiring close monitoring and consideration of thrombolysis
- Non-massive PE: minimal hemodynamic effects, typically treated with anticoagulation alone
The distinction between these types is essential for guiding treatment decisions and improving patient outcomes, as the mortality rate for untreated PE can be as high as 30%, but can be reduced to 2–8% with adequate anticoagulant treatment 1.
From the Research
Types of Pulmonary Embolism (PE)
- High-risk pulmonary embolism or massive pulmonary embolism: defined by the patient's response, including circulatory shock and sustained hypotension 2
- Nonmassive or normotensive pulmonary embolism: can be further stratified into low-risk, intermediate-risk, and submassive pulmonary embolism 2, 3
- Low-risk pulmonary embolism: can potentially be treated as outpatients, evaluated by clinical models such as the Pulmonary Embolism Severity Index (PESI) 2
- Intermediate-risk pulmonary embolism: can be further stratified into less-severe and more-severe intermediate risk, may benefit from intensive clinical surveillance 2
- Hemodynamically unstable PE (massive PE): characterized by circulatory shock and sustained hypotension 4
- Hemodynamically stable PE (submassive PE and low-risk PE): characterized by the absence of circulatory shock and sustained hypotension 4
- Submassive PE: a type of hemodynamically stable PE, may require thrombolytic therapy 4
- Low-risk PE: a type of hemodynamically stable PE, can potentially be treated as outpatients 3