From the Guidelines
Thrombophilia screening is generally not recommended for most patients with pulmonary embolism (PE), especially in cases of provoked PE, elderly patients, and those with active cancer. The main contraindications for thrombophilias screening in patients with pulmonary embolism include:
- Patients with provoked PE (such as those with recent surgery, trauma, immobilization, or pregnancy) 1
- Elderly patients
- Those with active cancer
- Patients who have completed their intended anticoagulation therapy duration or those who will receive indefinite anticoagulation regardless of results Testing during an acute thrombotic event or while on anticoagulation therapy can yield unreliable results, as acute phase reactants and anticoagulants can interfere with test accuracy 1. Additionally, screening has limited clinical utility in changing management decisions for most patients, as the presence of a thrombophilia rarely alters the duration or intensity of anticoagulation therapy. The cost-effectiveness of universal screening is poor, with minimal impact on preventing recurrent events 1. Some key points to consider when evaluating patients with suspected acute PE include:
- Using validated clinical prediction rules to estimate pretest probability in patients in whom acute PE is being considered 1
- Not obtaining d-dimer measurements or imaging studies in patients with a low pretest probability of PE and who meet all Pulmonary Embolism Rule-Out Criteria 1
- Obtaining a high-sensitivity d-dimer measurement as the initial diagnostic test in patients who have an intermediate pretest probability of PE or in patients with low pretest probability of PE who do not meet all Pulmonary Embolism Rule-Out Criteria 1 Selective testing may be considered in specific situations such as unprovoked PE in young patients (under 50), those with strong family history of venous thromboembolism, or in unusual thrombosis locations, where results might influence treatment decisions or family counseling 1.
From the Research
Contraindications for Thrombophilias Screening
The decision to screen for thrombophilias in patients with pulmonary embolism should be made judiciously, considering the potential risks and benefits. The following points highlight contraindications and limitations for thrombophilias screening:
- Routine screening for thrombophilias is not recommended for all patients with pulmonary embolism, as it may not significantly impact clinical management or improve outcomes for most patients 2.
- Testing for thrombophilias can be complex, and the results may be unreliable due to the presence of acute thrombosis and antithrombotic therapies 3.
- The presence of antiphospholipid syndrome (APS) may be a contraindication for inferior vena cava (IVC) filter placement, as it may not prevent recurrent pulmonary emboli and can lead to IVC thrombosis 4.
- Screening for thrombophilias in asymptomatic individuals is not recommended, as routine prophylaxis is not advised, and screening may lead to unnecessary anxiety and costs 5.
- The utility of identifying other thrombophilias in symptomatic venous thromboembolism (VTE) is questionable, as the risk of recurrence does not appear to be increased by an appreciable degree with the most common disorders 5.
Specific Clinical Scenarios
In certain clinical scenarios, thrombophilias screening may be considered:
- Following unprovoked venous thromboembolism, testing for thrombophilias may be considered to guide treatment decisions 3.
- In relatives of patients with thrombosis, testing for thrombophilias may be considered to assess their risk for future thrombosis 3.
- In female relatives of patients with thrombosis considering estrogen use or pregnancy, testing for thrombophilias may be considered to guide treatment decisions and assess their risk for future thrombosis 3.