Would a pulmonary embolism (PE) causing cor pulmonale be classified as a massive or submassive PE?

Classification of Pulmonary Embolism with Cor Pulmonale

A pulmonary embolism causing cor pulmonale should be classified as submassive PE, not massive PE, according to established guidelines. 1

Understanding PE Classification

Pulmonary embolism is classified into three main categories based on hemodynamic status and evidence of right ventricular dysfunction:

• Massive PE: Defined as acute PE with sustained hypotension (systolic blood pressure <90 mmHg for at least 15 minutes or requiring inotropic support), pulselessness, or persistent profound bradycardia (heart rate <40 bpm with signs of shock) 1

• Submassive PE: Defined as acute PE without systemic hypotension but with evidence of right ventricular dysfunction (including cor pulmonale) 1

• Non-massive PE: Acute PE without hypotension or evidence of right ventricular dysfunction 1

Cor Pulmonale in PE Classification

• Cor pulmonale (right ventricular enlargement and dysfunction due to pulmonary hypertension) in the setting of PE without hypotension is specifically classified as submassive PE 1

• The European Society of Cardiology guidelines explicitly state that "evidence of acute cor pulmonale coinciding with a high clinical suspicion in patients without major previous cardiac or respiratory disease" is sufficient for diagnosis of submassive PE 1

• The presence of right ventricular hypokinesis or dysfunction (which occurs in cor pulmonale) is the defining feature of submassive PE 1

Clinical Implications of Classification

• Submassive PE with cor pulmonale carries significant prognostic implications, with worse outcomes compared to non-massive PE without right ventricular dysfunction 1

• Early and late mortality is significantly higher in patients with moderate to severe right ventricular dysfunction assessed by echocardiography in confirmed PE 1

• The classification impacts treatment decisions, particularly regarding thrombolytic therapy 1

Treatment Considerations Based on Classification

• For massive PE: Thrombolytic therapy is indicated unless absolutely contraindicated 1

• For submassive PE with cor pulmonale: Thrombolytic therapy may be considered in the absence of contraindications, though this remains somewhat controversial 1

• Recent research suggests catheter-directed thrombolysis may reduce mortality in submassive PE with acute cor pulmonale compared to anticoagulation alone 2

• The use of thrombolytic therapy in patients with submassive PE (RV dysfunction/cor pulmonale) remains debated, with some studies showing benefit and others showing increased bleeding risk without mortality benefit 3, 4

Diagnostic Approach

• Echocardiography is particularly useful for identifying right ventricular dysfunction and cor pulmonale in suspected PE 1

• Decreased collapsibility of the inferior vena cava (less than 40% inspiratory change) is reported in 82% of patients with clinically important PE and is a sign that improves with treatment 1

• CT measurements of right ventricular dilation (RV/LV ratio >0.9) can also help identify submassive PE 1