Background: Incidence of thrombotic events associated to Coronavirus disease-2019 (COVID-19) is difficult to assess and reported rates differ significantly . Optimal thromboprophylaxis is unclear .
Objectives: We aimed to analyze the characteristics of patients with a confirmed thrombotic event including inflammatory and hemostatic parameters, compare patients affected by arterial vs venous events and examine differences between survivors and non-survivors . We reviewed compliance with thromboprophylaxis and explored how the implementation of a severity-adjusted protocol could have influenced outcome .
Methods: Single-cohort retrospective study of COVID-19 patients admitted, from March 3 to May 3, to the Infanta Leonor University Hospital in Madrid, epicenter of the Spanish outbreak .
Results: Among 1,127 patients , 80 thrombotic events were diagnosed in 69 patients (6.1% of the entire cohort). 43 patients (62 %) suffered venous thromboembolism, 18 (26 %) arterial events and 6 (9 %) concurrent venous and arterial thrombosis . Most patients (90 %) with a confirmed thrombotic event where under low-molecular-weight heparin treatment . Overt disseminated intravascular coagulation (DIC) was rare . Initial ISTH DIC score and pre-event CRP were significantly higher among non-survivors . In multivariate analysis, arterial localization was an independent predictor of mortality (OR=18 , 95% CI : 2.4-142, p <.05).
Conclusions: Despite quasi-universal thromboprophylaxis, COVID-19 lead to a myriad of arterial and venous thrombotic events . Considering the subgroup of patients with thrombotic episodes, arterial events conferred very poor prognosis and an ISTH DIC score ≥3 at presentation was identified as a potential predictor of mortality . Severity-adjusted thromboprophylaxis seemed to decrease the number of events and could have influenced mortality . Randomized controlled trials are eagerly awaited.