Diagnostic performance of pulmonary embolism imaging in patients with history of asthma.

Lazarus, Matthew; Kim, Yoel; Mathai, Bertin; Levsky, Jeffrey M; Freeman, Leonard M; Haramati, Linda B; Moadel, Renee M

Asthma and pulmonary embolism (PE) can present with overlapping symptoms, and distinguishing between these two conditions can be challenging. Asthma may limit imaging for PE due to either worsened ventilation defects on ventilation/perfusion scan (VQ) or increased motion artifact on CT pulmonary angiography (CTPA). Methods: We identified adults evaluated for PE with VQ or CTPA from 2012-2016. Patients with chronic lung disease (other than asthma) were excluded. Studies were classified as negative, positive, or non-diagnostic. Follow-up of negative cases were reviewed to determine rate of repeat exam (within one week) and false-negative rate (defined as diagnosis of venous thromboembolism within 90 days). Results: We reviewed 19,412 adults (age 52 ±18 years, 70% women) evaluated for PE (60% with VQ, 40% with CTPA); 23% had history of asthma. Non-diagnostic results were comparable for those with and without asthma for both VQ (asthma 3.3%; non-asthma 3.8%; P = 0.223) and CTPA (asthma 1.6%; non-asthma 1.5%; P = 0.891). History of asthma was not associated with higher repeat exam after negative imaging for VQ (asthma 1.9%; non-asthma 2.1%; P = 0.547) or CTPA (asthma 0.6%; non-asthma 0.6%; P = 0.796), nor was history of asthma associated with higher false negative rate for VQ (asthma 0.4%; non-asthma 0.9%; P = 0.015) or CTPA (asthma 1.9%; non-asthma 1.5%; P = 0.347). Conclusion: History of asthma in the preceding ten years was not associated with impaired diagnostic performance of PE imaging for either VQ or CTPA.