Various previous observational studies have explored the association of COVID-19 infection with thromboembolism. The majority of these studies have identified the risk during hospitalization, particularly for critical COVID-19 patients who need organ support or ICU stay.
This study from Spain further adds to the understanding of COVID-19 and thromboembolism risk in several ways.
During the first COVID-19 breakout between March 1 and April 30, 2020, Spanish researchers conducted a retrospective, case-controlled analysis of all COVID-19 patients who presented to 62 Spanish Eds. The patients were divided into two groups: those with covid and pulmonary embolism (PE) and those patients having pulmonary embolism (PE) without COVID-19. Across various demographic and clinical variables, cases were matched 1:1 with one of each control group patient. The necessity for intensive care unit (ICU) admission, hospital stays longer than 7 days, and all-cause in-hospital mortality were all evaluated outcomes.
A total of 74,814 COVID-19 patients were assessed in this study, of which 368 (4.92%) developed PE. PE was shown to be substantially more common in COVID-19 patients (310/100,000 person-years) than in non-COVID-19 patients (35/100,000 person-years; odds ratio [OR], 8.95; 95 % confidence interval [CI], 8.51-9.41).
Elevated D-dimer >1000 ng/ml, chest discomfort, and chronic heart failure were all independent predictors of PE (inverse association). Patients with PE with COVID-19 were more likely to have a history of a thromboembolic event, low use of chronic estrogen medication, and be restricted to segmental or subsegmental pulmonary arteries than those without COVID-19. There was a similar in-hospital mortality rate between COVID-19 patients with PE and COVID-19 patients without PE (16.0% for cases vs. 16.6% for COVID-19 controls; OR, 0.96; 95% CI, 0.65-1.42). Compared to PE patients who did not have COVID-19, in-hospital mortality rate was higher among patients with PE and COVID-19 (16.0% vs. 6.5%; OR, 2.74; 95% CI, 1.66-4.51).
This study found PE to be an uncommon finding among COVID-19 patients who are brought to the emergency department. However, the incidence of PE is roughly nine times higher in the general population. In addition, in-hospital mortality was equal in COVID-19 patients with and without PE but was greater in PE patients with COVID-19 than those without.