Teaching Nonradiologists to Identify Right Heart Strain on Computed Tomography Scans of Acute Pulmonary Embolism

Abstract

Acute pulmonary embolism management is centered on the presence of right ventricular (RV) strain. Patients with RV strain have a greater than twofold increase in 30-day mortality (1, 2). RV strain is present in ⩾25% in patients with pulmonary embolism (3). This is associated with adverse outcomes even in patients with low pulmonary embolism severity index (3). RV dilation on computed tomography pulmonary angiography (CTPA) was associated with increased 30-day mortality in patients with acute pulmonary embolism (4). European Society of Cardiology guidelines allow the use of CTPA and/or echocardiography in pulmonary embolism risk stratification (5). Even though echocardiography is invaluable in pulmonary embolism management, it is often delayed (6). RV/left ventricular (LV) ratio on CTPA is a clinical endpoint in clinical trials involving catheter-directed treatments in patients with intermediate-risk pulmonary embolism (7–11). Identifying RV strain on CTPA facilitates treatment decisions. Measurements of the RV/LV ratio on CTPA by trained radiologists tend to be very accurate and reproducible (12). The accuracy and reproducibility of measurements obtained by other medical professionals have not been well described.