Introduction: SARS-CoV-2 infection causes severe endothelial damage, an essential step for cardiovascular complications including coagulopathies and thromboembolisms. Endothelial progenitor cells (EPCs) could act as a biomarker of vascular damage but its role in SARS-CoV-2 is unknown.

Objectives: The study aims to quantify the number of EPCs at 3 and 6 months after SARS-CoV-2 infection and to assess whether the number of EPCs differs from COVID-19 patients who suffered an acute pulmonary embolism (PE) than those that did not. Moreover, it will be evaluated if this increase correlates with any of the clinical parameters studied.

Materials and Methods: A total of 22 patients were recruited in the study at different time points after overcoming COVID-19 (3 and 6 months) and 26 healthy controls. All subjects were matched for age, gender, BMI and clinical comorbidities. Of these 22 COVID-19 patients, 9 had suffered PE. EPCs were obtained from peripheral blood and cultured with specific medium and conditions. The appearance, number of colonies and days of appearance were quantified.

Results: The results show an abnormal increase in the number of EPCs at 3 and 6 months post-infection compared to controls. There was no difference in EPCs production in post-COVID-19 patients who presented an acute PE compared to those that did not. Non-PE patients with higher levels of D dimer showed significant higher troponin levels at 6 months compared to PE patients. No correlation was found between troponin levels and the number or appearance of EPCs colonies or with any other clinical parameter studied.

Conclusion: The results confirm the presence of vascular sequelae in post-COVID-19 patients that is maintained for up to 6 months.