From the Guidelines
Pulmonary embolism (PE) findings include dyspnea, chest pain, tachypnea, and tachycardia as the most common clinical presentations, with CT pulmonary angiography being the gold standard imaging test, as recommended by the most recent guidelines 1. The clinical presentation of PE can vary depending on the size and location of the embolism, with massive PE potentially causing hemodynamic instability and requiring immediate intervention. Some key findings in PE include:
- Dyspnea
- Chest pain
- Tachypnea
- Tachycardia
- Hemoptysis
- Syncope
- Hypoxemia
- Signs of right heart strain in severe cases On diagnostic testing, the following may be observed:
- Elevated D-dimer, though not specific to PE
- Filling defects in pulmonary arteries on CT pulmonary angiography
- Sinus tachycardia, S1Q3T3 pattern, right bundle branch block, or T-wave inversions in anterior precordial leads on ECG
- Atelectasis, pleural effusion, or Hampton's hump (wedge-shaped opacity) on chest X-rays
- Hypoxemia with respiratory alkalosis on arterial blood gases
- Right ventricular dilation and dysfunction, interventricular septal flattening, and pulmonary hypertension on echocardiography in severe PE, as noted in previous studies 1. However, the most recent update on suspected pulmonary embolism recommends the use of multidetector CT pulmonary angiography as the major diagnostic modality currently used 1.
From the FDA Drug Label
In the EINSTEIN DVT and EINSTEIN PE studies, XARELTO was demonstrated to be non-inferior to enoxaparin/VKA for the primary composite endpoint of time to first occurrence of recurrent DVT or non-fatal or fatal PE [EINSTEIN DVT HR (95% CI): 0.68 (0.44,1.04); EINSTEIN PE HR (95% CI): 1.12 (0.75,1. 68)]. Table 20 displays the overall results for the primary composite endpoint and its components for EINSTEIN DVT and EINSTEIN PE studies. In the EINSTEIN PE Study, the primary composite endpoint occurred in 50 (2.1%) XARELTO-treated patients and 44 (1.8%) enoxaparin/VKA-treated patients. Death (PE) occurred in 3 (0.1%) XARELTO-treated patients and 1 (<0.1%) enoxaparin/VKA-treated patient. Symptomatic recurrent PE only occurred in 23 (1.0%) XARELTO-treated patients and 20 (0.8%) enoxaparin/VKA-treated patients.
The findings for pulmonary embolism in the provided drug labels are as follows:
- Symptomatic non-fatal PE occurred in 10 (0.3%) XARELTO-treated patients and 14 (0.5%) enoxaparin/VKA-treated patients in the EINSTEIN PE study 2.
- Death (PE) occurred in 3 (0.1%) XARELTO-treated patients and 1 (<0.1%) enoxaparin/VKA-treated patient in the EINSTEIN PE study 2.
- Symptomatic recurrent PE only occurred in 23 (1.0%) XARELTO-treated patients and 20 (0.8%) enoxaparin/VKA-treated patients in the EINSTEIN PE study 2.
- In the MAGELLAN study, symptomatic non-fatal PE occurred in 10 (0.3%) XARELTO-treated patients and 14 (0.5%) enoxaparin-treated patients 2.
- In the MAGELLAN study, symptomatic non-fatal PE occurred in 7 (0.3%) XARELTO-treated patients and 10 (0.4%) enoxaparin-treated patients in the subgroup of patients not at a high risk of bleeding 2.
From the Research
Pulmonary Embolism Findings
- Pulmonary embolism (PE) is characterized by occlusion of blood flow in a pulmonary artery, typically due to a thrombus that travels from a vein in a lower limb 3
- The incidence of PE is approximately 60 to 120 per 100 000 people per year, with approximately 60 000 to 100 000 patients dying from PE each year in the US 3
- PE should be considered in patients presenting with acute chest pain, shortness of breath, or syncope 3
- The diagnosis is determined by chest imaging, and the clinical probability of PE can be assessed using a structured score or using clinical gestalt 3
Treatment Options
- Anticoagulation is performed with unfractionated heparin (UFH) in hemodynamically unstable patients and with low molecular weight heparins (LMWH) or fondaparinux in normotensive patients 4
- Direct oral anticoagulants such as apixaban, edoxaban, rivaroxaban, or dabigatran are noninferior for treating PE and have a 0.6% lower rate of bleeding compared to heparin combined with a vitamin K antagonist such as warfarin followed by warfarin alone 3
- Systemic thrombolysis is recommended for patients with PE and systolic blood pressure lower than 90 mm Hg, and is associated with an 1.6% absolute reduction of mortality 3
- Catheter-based or systemic fibrinolytic therapy may be considered in sub-massive pulmonary embolism cases where patients demonstrate high-risk features such as severe RV strain on echo or CT, and worsening over time trends in pulse, SBP, and oxygenation despite anticoagulation 5
Risk Stratification and Management
- The decision on the duration of anticoagulation should consider both the individual risk of PE recurrence and the individual risk of bleeding 4
- Patients with a strong transient risk factor have a low risk of recurrence and anticoagulation can be discontinued after three months, while patients with strong persistent risk factor (such as active cancer) have a high risk of recurrence and thus should receive anticoagulant treatment of indefinite duration 4
- Extended oral anticoagulation of indefinite duration should be considered for all patients with intermediate risk of recurrence, given the favourable safety profile of non-vitamin K antagonist oral anticoagulants (NOACs) 4