PO0009 - Prediction of reccurent thrombotic events in survivors after COVID-19

Background: There is an increased risk of thrombotic events in patients with COVID-19, while thrombosis in patients who recovered from COVID-19 is less investigated.

Aims: To investigate thrombotic events in patients who recovered from COVID-19; to establish risk factors for thrombosis development.

Methods: We reviewed 32 patients who recovered from COVID-19 (M/F:13/19, median age: 57 (49-67) years). Group 1 included 16 patients who had had a thrombotic event, whereas 16 patients from group 2 had not. Statistical analysis was performed by non-parametric methods (median (Me), 95% confidence interval (95% CI), Mann-Whitney U test). We used odds ratio and relative risk to measure the association between risk factors and outcome.

Results: 15 patients from group 1 had pulmonary embolism, 1 patient had ischemic stroke. The median term of thrombotic events was 45 (32–60) days. 2 patients had thrombophilia, 2 were hospitalized when the outcome occurred. 5 patients had BMI 30 or more, 7 did not have any risk factors.
There was no statistically significant difference between two groups regarding age, weight, hospitalization duration, respiratory failure degree and its duration. Comorbidity, hospitalization requirement or oxigenotherapy during COVID-19 did not affect the outcome.
The only one association found was increased risk of thrombosis in patients who had not received anticoagulation (RR 2.829 (95% CI 1,279; 6,255); OR 9.533 (95% CI 1.847; 49.206). Risk was also significantly elevated in case of antiplatelet agent use (RR – 2.250 (95% CI 0.898; 5.636); OR – 4.333 (95% CI 0.742; 25.295).

Conclusion(s): Anticoagulant therapy was the only intervention decreased thrombosis probability in survivors after COVID-19. Absence of anticoagulation treatment increases the risk of thrombosis during post-covid period in 9 times.