Diagnostic Approach to Pulmonary Embolism

Initial Risk Stratification

The European Society of Cardiology recommends determining if a patient has hemodynamic instability, with shock or hypotension and systolic blood pressure <90 mmHg, to guide the diagnostic approach for pulmonary embolism in patients with high clinical probability 1, 2
The European Heart Journal suggests that if the patient is hemodynamically unstable and CT is not immediately available, bedside echocardiography should be performed to assess for right ventricular overload, with a Class I recommendation for PE-specific treatment if RV overload is present 2

The European Society of Cardiology recommends assessing clinical probability using either a three-level scheme (low, intermediate, or high probability) or a two-level scheme (PE unlikely or PE likely), with a Class I recommendation for further testing based on clinical probability 1, 2
The European Heart Journal suggests measuring D-dimer only in patients with low or intermediate clinical probability, or those classified as "PE unlikely", with a Class III recommendation against measuring D-dimer in patients with high clinical probability 1, 2
The European Society of Cardiology recommends that if D-dimer is negative in low/intermediate probability patients, the diagnosis of PE should be rejected without further testing, with a Class I recommendation and a 3-month thromboembolic risk below 1% 1, 2

The European Heart Journal recommends CTPA as the imaging test of first choice, which should be performed in patients with elevated D-dimer levels or high clinical probability, with a Class I recommendation for accepting the diagnosis of PE if CTPA shows a segmental or more proximal filling defect 1, 2
The European Society of Cardiology suggests that V/Q scintigraphy is a valid option when CTPA is contraindicated, with a Class I recommendation for rejecting the diagnosis of PE without further testing if the perfusion lung scan is normal 1, 3
The European Heart Journal recommends against performing CT venography as an adjunct to CTPA, with a Class III recommendation, and against using MR angiography to rule out PE, with a Class III recommendation 1

The European Society of Cardiology recommends that treatment should not be delayed to obtain imaging in unstable patients, with a Class I recommendation for bedside echocardiography showing RV overload as sufficient to justify treatment 2