Two-Thirds of Patients with Low-Risk Pulmonary Embolism are Admitted to Hospital Unnecessarily

Adopting Newer Clinical Guidelines Could Result In Substantial Cost Savings, Relieve ED Crowding

BOSTON – An acute pulmonary embolism (PE) is a blockage of a lung artery—most often a blood clot that forms in another part of the body and travels to the lungs. A pulmonary embolism can occur suddenly and can be life-threatening (with survival rates as low as 65 percent), but if caught and treated in time, they are rarely fatal (with survival rates above 90 percent).

Based on new evidence, clinical practice guidelines were recently changed to prioritize outpatient management of patients with low-risk PE over hospitalization. However, a new analysis by investigators at the Richard A. and Susan F. Smith Center for Outcomes Research in Cardiology at Beth Israel Deaconess Medical Center (BIDMC) showed that discharge rates of patients with acute PE from U.S. emergency departments (ED) have remained low and unchanged over time despite those changes. The findings, published in Annals of Internal Medicine, suggest that many patients with low-risk PE are needlessly admitted to the hospital for inpatient management.

“We speculate that outpatient management for low-risk acute PE is still largely underutilized in the United States,” said corresponding author, Eric A. Secemsky, MD, MSc, Section Head of Interventional Cardiology and Vascular Research at the Smith Center and Director of Vascular Intervention in the CardioVascular Institute at BIDMC. “Previous studies have established the safety of outpatient management among select patients, resulting in changes in international clinical societies’ guidelines. Widespread adoption of these guidelines can improve patient care, decrease unnecessary time in the hospital and substantially reduce overall healthcare spending by limiting costly inpatient admissions.”

Using data from U.S. EDs participating in the National Hospital Ambulatory Medical Care Survey, Secemsky and colleagues evaluated national trends in the proportion of discharges for ED visits for acute PE between 2012 and 2020, as well as the patient characteristics and other factors that might be associated with ED discharge.

Looking at the demographics, co-morbidities, hospital characteristics and medications prescribed for the more than 1.6 million patients who visited U.S. EDs for acute PE between 2012 and 2020, the team found that, overall, approximately one-third of low-risk patients were discharged over the nine-year study period. This discharge rate remained constant over time as well, showing no statistically significant increase from 2012-2014 to 2018-2020, despite ongoing recommendations among leading societies supporting the role of outpatient management for low-risk PE patients.

No clinical variable such as a patient’s age, sex or race, or hospital characteristic such as urban versus rural location were predictive of the rates of outpatient management. While the reasons underlying the low rates of outpatient management of patients with low-risk PE are unclear, the investigators speculate the lack of infrastructure in place for short-term follow-up and management of these patients may make physicians and other providers uncomfortable sending them home.

“Further research to investigate these reasons more precisely is certainly warranted,” said first author Nathan W. Watson, a research fellow at the Smith Center and fourth-year medical student at Harvard Medical School. “Our findings are particularly important as U.S. healthcare costs continue to surge and overcrowding within EDs remains a critical issue. We hypothesize that additional resources will be needed for patients to get timely follow-up visits and clinical oversight over newly prescribed anticoagulants to manage PE. However, the costs of maturing these outpatient pathways will most likely offset the costs incurred from a hospital admission and be overall more desirable to the patient.”

Co-authors included Brett J. Carroll, MD, Anna Krawisz, MD, and Alec Schmaier, MD, PhD, of BIDMC.

This research was funded by the National Institutes of Health/ National Heart, Lung and Blood Institute (grant K23H L 150290). Carroll is a member of the Scientific Advisory Board for Koya Medical and reports institutional research support from Bristol-Myers Squibb. Secemsky reports grant funding from the National Institutes of Health/ National Heart, Lung and Blood Institute, the Food and Drug Administration, BD, Boston Scientific, Cook, CSI, Laminate Medical, Medtronic and Phillips, and reports consulting and speaking fees from Abbott, Bayer, BD, Boston Scientific, Cook, Cordis, CSI, Inari, Medtronic, Philips Shockwave, and VentureMed.