Anticoagulants alone are associated with a high rate of resolution of pulmonary embolism (PE) in patients with acute PE and COVID-19 infection. This was the main concluding finding of a study published in the Journal of Vascular Surgery: Venous and Lymphatic Disorders.
The COVID-19 pandemic has led to many associated medical events, such as PEs, Young Erben and Charles Ritchie (Mayo Clinic, Jacksonville, USA) write. They add that the history of PE resolution with anticoagulants is unknown in a COVID-19 infected population. In light of this, the team set to assess the radiographic resolution of PE in patients hospitalised for COVID-19 and acute PE, using contrast-enhanced chest computed tomography (CECT).
To carry out this multicentre, retrospective cohort study, Erben and Ritchie identified patients with acute PE per CECT, and at least one follow-up CECT from 11 March 2020 to 27 May 2021. The authors note that patients were identified using a prospective registry of hospitalised patients with COVID-19, who were receiving care within a multicentre health system in Arizona, Florida, Minnesota, and Wisconsin. COVID-19 infected patients were diagnosed with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) by polymerase chain reaction testing or serology.
The author’s relay that initial and follow-up CECT examinations were reviewed on an independent basis by two radiologists who were evaluating for the resolution of PE. It is noted that the Modified Miller Score was used to assess the thrombus burden at both diagnosis and follow-up.
Of the patients identified with PE and follow-up imaging, 63.8% were male and the average age was 63±16 years. Using patient data, the authors report that 57.4% and 19.1% of patients had hypertension and coronary artery disease, respectively, with 14.9% having a history of cancer. The author’s relay that 42.6% of these patients required intensive care unit care, with an average stay in the department of 7±14 days. Additionally, the average length of overall hospitalisation was 14±19 days.
A total of 6,070 patients identified with infection of COVID-19, 5.7% (n=348) were diagnosed with acute PE, and 13.5% (n=47) had a follow-up CECT examination. Of the 47 patients with diagnosed acute PE, 72.3% had radiographic resolution of PE, with an average follow-up length of 48±43 days (range 6–239 days). The authors relay that the average follow-up imaging time was 44±48 days ( range 3–161 days).
All patients in the cohort received anticoagulation therapy for an average of 149±95 days, including apixaban (63.8%), warfarin (12.8%), and/or rivaroxaban (8.5%). Furthermore, the average Modified Miller Score at PE diagnosis and follow-up was 4.8±3.2 and 1.4±3.3, respectively. A total of nine patients (19%) died at a mean of 13±8 days follow-up CECT (range 1–27 days) and at a mean of 28±16 days after admission (range 11–68 days) and these deaths were associated with the progression of COVID-19 pneumonia.
In conclusion, the authors note that patients hospitalised with COVID-19 had a 5.7% rate of developing PE, with 72.3% of patients having radiographic thrombus resolution at an average of 44 days, while on anticoagulation. Lastly, the authors note that looking forward, prospective studies of the natural history of PEs with COVID-19 that include systematic follow-up imaging are needed to help guide recommendations of anticoagulants.