Family history of venous thromboembolism predicts the diagnosis of acute pulmonary embolism in the emergency department.

BACKGROUND: Pulmonary embolism (PE) clinical decision rules do not consider a patient's family history of venous thromboembolism (VTE). We evaluated whether a family history of VTE predicts acute PE in the emergency department (ED).

METHODS: Over a 5.5-year study period, we enrolled a prospective convenience sample of patients presenting to an academic emergency department with chest pain and/or shortness of breath. We defined a family history of VTE as a first-degree relative with previous PE or deep vein thrombosis (DVT). We noted outcomes of testing during the patient's ED stay, including the diagnosis of acute PE by either computed tomography (CT) or ventilation/perfusion (VQ) scan.

RESULTS: Of the 3024 study patients, 19.4% reported a family history of VTE and 1.9% were diagnosed with an acute PE during the ED visit. Patients with a family history of VTE were more likely to be diagnosed with a PE: 3.2% vs. 1.6% (p = 0.009). 82.3% of patients were Pulmonary Embolism Rule-out Criteria (PERC) positive, and among PERC-positive patients, those with a family history of VTE were more likely to be diagnosed with a PE: 3.6% vs. 1.9% (p = 0.016). Of patients who underwent testing for PE (33.7%), patients with a family history of VTE were more likely to be diagnosed with a PE: 9.4% vs. 4.9% (p = 0.032).

CONCLUSION: Patients with a self-reported family history of VTE in a first-degree relative are more likely to be diagnosed with an acute PE in the ED, even among those patients considered to have a higher likelihood of PE.