Evaluation of the Association between COVID-19 Vaccines and Pulmonary Embolism

Introduction: This study investigated the clinical and radiological characteristics and demographics of patients who developed pulmonary embolism (PE) after Coronavirus disease-2019 (COVID-19) vaccination. Methods: The cases of PE were analyzed retrospectively. Data on clinical, demographic, and radiologic characteristics, laboratory findings, Pulmonary Embolism Severity Index (PESI) scores, early mortality scores, PE severity classes, and risk categories for early mortality (low-risk, intermediate-high-risk, intermediate-low-risk and high-risk) were collected from patient files as defined in the European Society of Cardiology guidelines. Patients were divided into two groups: those who had received a COVID-19 vaccine (group 1) and those who had not (group 2). Patients who developed PE within 1 month after vaccination were analyzed separately. Results: A total of 97 patients were included in the study, of whom 61 (62.9%) patients were female. Seventy-five (77.3%) study patients with PE had a history of COVID-19 vaccination (group 1), and 22 (22.7%) had never been vaccinated (group 2). Five (6.6%) patients had received a vaccine within 1 month before PE developed. No significant differences were found between groups 1 and 2 regarding demographics, clinical and radiologic characteristics, laboratory findings, PESI scores, early mortality scores, and PE severity classes (p>0.05), except for mean pulmonary artery pressures. The mean age of patients who developed PE within 1 month after vaccination was 74.6 years, and 80% of these patients were female. The average time to PE after vaccination was 22.2 days, and the mean PESI score was 86.6. Two patients (40%) were in the low-risk category for early mortality and one patient (20%) was in the intermediate/high-risk category. Conclusion: Overall, the characteristics of patients who developed PE after COVID-19 vaccination were comparable to those of patients who had not received a vaccine injection. No statistically significant increases in the incidence of PE were observed within the first month after being vaccinated.