Prehospital aspirin use is associated with improved clinical outcomes in pulmonary embolism: A retrospective case-control study.

BACKGROUND: Pulmonary embolism (PE) is a leading cause of cardiovascular mortality. Although anticoagulation is the cornerstone of treatment, aspirin's potential to modulate thromboinflammation and improve outcomes in non-surgical PE patients remains underexplored. AIM: To assess whether prehospital aspirin use is associated with improved outcomes in patients hospitalized with acute PE. METHODS: We conducted a retrospective case-control study of 323 adult patients admitted with computed tomography-confirmed acute PE from January 2020 to December 2023. Patients were stratified according to documented daily aspirin use for ≥ 7 days prior to hospital admission. Primary outcomes included right ventricular strain, intensive care admission, shock, mechanical ventilation, and in-hospital mortality. Univariate logistic regression was used. A P value < 0.05 was considered significant. RESULTS: Total of 323 patients, 90 (27.9%) used aspirin prehospital. Aspirin users were older (74.2 ± 14.3 years vs 66.9 ± 16.7 years, P < 0.001) and had more coronary artery disease. Aspirin use was associated with significantly lower rates of right ventricular strain on computed tomography [22.2% vs 34.8%, odds ratio (OR) = 0.536, 95% confidence interval (CI): 0.305-0.944, P = 0.029], Intensive care admission (16.7% vs 28.8%, OR = 0.496, 95%CI: 0.266-0.924, P = 0.025), shock (2.2% vs 9.9%, OR = 0.208, 95%CI: 0.048-0.899, P = 0.021), and in-hospital mortality (3.3% vs 11.6%, OR = 0.260, 95%CI: 0.080-0.889, P = 0.022). CONCLUSION: Prehospital aspirin use is associated with reduced severity and mortality in acute PE. These findings support a potential protective role for aspirin and warrant validation in prospective, multicenter trials.