Association Between ABO Blood Group, COVID-19 Status, and Early Respiratory Outcomes in Acute Pulmonary Embolism: An Interaction Analysis

The influence of COVID-19 infection on the association between ABO blood groups and early outcomes in patients with acute pulmonary embolism (PE) remains uncertain. We conducted a retrospective, single-center cohort study including adult patients admitted with a first episode of acute pulmonary embolism (PE). The interaction between ABO blood group (non-O vs. O) and COVID-19 status was evaluated using multivariable logistic regression models adjusted for PE severity assessed by the Pulmonary Embolism Severity Index (PESI). A total of 211 patients were included, of whom 95 (45.0%) were COVID-19-positive. Among COVID-19-positive patients, non-O blood groups were associated with significantly higher odds of invasive mechanical ventilation (IMV) compared with group O (adjusted odds ratio [aOR] 12.87, 95% CI 4.17–39.75), whereas no association was observed among COVID-19–negative patients (aOR 1.20, 95% CI 0.45–3.23). No interaction was identified for 24 h mortality (p = 0.721) or systemic thrombolysis (p = 0.306). Higher PESI class was independently associated with an increased risk of adverse outcomes. ABO blood group modified the association between COVID-19 infection and early respiratory outcomes in acute PE. These findings suggest a potential role of ABO-related differences in coagulation and endothelial biology in the clinical expression of COVID-associated PE and should be interpreted as hypothesis-generating.