Concerning CT findings may be serving as a barrier to treating patients with low-risk pulmonary embolisms in cheaper outpatient settings, according to research published Wednesday in JAMA Network Open [1].

Most patients who visit the emergency department with such blood clots in the lungs end up hospitalized. This occurs despite evidence-based medical society guidelines urging providers to consider discharge in upward of 50% of those with lower risk scores.

Michigan Medicine recently sought to explore this issue, analyzing data from more than 800 patients treated for PE at a single academic medical center between 2016-2019. They found that emergency medicine providers often kept PE patients overnight, despite their cases appearing to be low-risk.

“In summary, ED patients with acute, low-risk PE had similar short-term outcomes irrespective of [PE-protocol computed tomography, or CTPE] results. Nonetheless, specific CTPE findings were associated with increased resource utilization and hospitalization of these patients,” Colin F. Greineder, MD, PhD, with Michigan’s Department of Medicine, and co-authors concluded. “Future implementation studies aimed at maximizing guideline-recommended outpatient management of acute low-risk PE should account for and address EM clinician concerns regarding CTPE imaging.”

Such providers often may perceive certain CT findings as high risk, including right ventricular strain, pulmonary infarction or saddle PE (when the clot “saddles” the main pulmonary artery). However, many of the commonly used risk stratification tools—such as the PE Severity Index, or PESI—do not incorporate such imaging findings, the authors noted.

Greineder et al. divided their data into high- and low-risk cases using a combination of PESI class and biomarker results. The low-risk group was further separated based on CT findings such as pulmonary infarction, right ventricle enlargement, etc. The final sample included 331 low-risk patients (40.5%) and 486 more of the high-risk variety (59.5%).

Clinical outcomes appeared similar across the low-risk group, including zero deaths within 30 days among patients with concerning CT findings and 2.2% among those without them. Low-risk patients with concerning CT results also were discharged from the ED less frequently than those without them (2% vs. 7.8%). And they more frequently received additional services such as echocardiography (57.6% vs. 27.2%) and PE response team activation (22.5% vs. 6.1%).

“Our findings suggest not only that outpatient management may be considered for these patients, but that concerning CTPE findings represent an important barrier to discharge,” the authors noted. “Compelling evidence, including the results of the current study, will likely need to be paired with effective implementation strategies to overcome their perceived risk. Indeed, as clinicians and health systems become more comfortable and facile with other aspects of home treatment, we expect a widening of the gap in discharge of low-risk patients with and without concerning CTPE findings.”

Read much more in JAMA Network Open at the link below.