What are the findings of a pulmonary embolism (PE)?

From the Guidelines

Pulmonary embolism (PE) findings include dyspnea, pleuritic chest pain, tachypnea, tachycardia, hypoxemia, and hemoptysis, and the most recent and highest quality study recommends CT pulmonary angiography as the major diagnostic modality 1. The diagnosis of PE is often difficult to obtain and is frequently missed, with mortality in untreated PE approximately 30%, but with adequate treatment, this can be reduced to 2–8% 1.

Key Findings

• Patients may present with sudden onset shortness of breath, anxiety, and a sense of impending doom
• Physical examination may reveal decreased breath sounds, crackles, increased pulmonary component of S2, and signs of deep vein thrombosis like calf swelling or tenderness
• Diagnostic tests include D-dimer (elevated in PE), CT pulmonary angiography (gold standard showing filling defects in pulmonary arteries), ventilation-perfusion scan (showing mismatched perfusion defects), and ECG (may show S1Q3T3 pattern, right heart strain, or sinus tachycardia) 1
• Echocardiography can demonstrate right ventricular dysfunction in severe cases
• Arterial blood gases typically show hypoxemia, hypocapnia, and respiratory alkalosis
• Risk stratification tools like the Wells score or PERC rule help determine pre-test probability

Diagnostic Approach

• The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel 1
• CT pulmonary angiography is the major diagnostic modality currently used, with ventilation and perfusion scans remaining largely accurate and useful in certain settings 1
• MR angiography can be useful in some clinical scenarios and lower-extremity ultrasound can substitute by demonstrating deep vein thrombosis 1

From the FDA Drug Label

In the EINSTEIN PE study, 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 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. EINSTEIN PE StudyN=2419 n (%) N=2413 n (%) Primary Composite Endpoint50 (2.1)44 (1.8)1.12 (0.75,1.68) Death (PE)3 (0.1)1 (<0.1) Death (PE cannot be excluded)8 (0.3)6 (0.2) Symptomatic PE and DVT02 (<0. 1) Symptomatic recurrent PE only23 (1.0)20 (0.8) Symptomatic recurrent DVT only18 (0.7)17 (0. 7)

The findings for pulmonary embolism (PE) in the EINSTEIN PE study include:

• Symptomatic recurrent PE only: 23 (1.0%) in the XARELTO group and 20 (0.8%) in the enoxaparin/VKA group
• Death (PE): 3 (0.1%) in the XARELTO group and 1 (<0.1%) in the enoxaparin/VKA group
• Death (PE cannot be excluded): 8 (0.3%) in the XARELTO group and 6 (0.2%) in the enoxaparin/VKA group 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, and diagnosis is determined by chest imaging 3

Diagnosis and Treatment

• The clinical probability of PE can be assessed using a structured score or using clinical gestalt, and D-dimer testing can be used to exclude PE in patients with low or intermediate clinical probability 3
• 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 lower rate of bleeding compared to heparin combined with a vitamin K antagonist such as warfarin 3
• Systemic thrombolysis is recommended for patients with PE and systolic blood pressure lower than 90 mm Hg, and is associated with a reduction in mortality 3

Anticoagulant Therapy

• Warfarin, unfractionated heparin (UFH), and low-molecular-weight heparins are anticoagulants that have been used for treatment of pulmonary embolism 5
• Currently approved drugs for treatment of venous thromboembolism include UFH, enoxaparin, dalteparin, fondaparinux, warfarin, and rivaroxaban 5
• The advent of newer oral anticoagulants such as rivaroxaban, dabigatran, and apixaban has provided alternative therapeutic options for long-term anticoagulation 5
• Enoxaparin monotherapy without oral anticoagulation is a feasible treatment option for symptomatic pulmonary embolism, with a shorter hospital length of stay compared to standard therapy 6