ABSTRACT
Background : Patients with COVID-19 have a hypercoagulable state with increased risk of thrombotic venous events (VTE). These thrombotic complications could be responsible for a significant part of the morbidity and mortality seen in COVID-19 patients. The high incidence of VTE is seen even despite the use of apparently adequate thrombosis prophylaxis. Therefore, it is suggested that in COVID-19 patients increased intensity thromboprophylaxis or therapeutic anticoagulation should be considered. Aims : We investigated whether the use of therapeutic anticoagulation prior to infection has a beneficial effect on morbidity and mortality in hospitalized COVID-19 patients. Methods : In this multicenter retrospective cohort study, all ≥18 years old COVID-19 patients admitted to 6 hospitals in the Netherlands between March and May 2020 were included. We applied 1:3 propensity score matching to evaluate the association between prior therapeutic anticoagulation use and clinical outcome, with in hospital mortality as primary endpoint. Relevant secondary outcomes included admission to the intensive care unit (ICU), need for invasive mechanical ventilation, pulmonary embolism and length of hospital stay Results : A total of 1154 patients were included, of whom 190 (16%) patients used therapeutic anticoagulation prior to admission. In the propensity score matched analyses, we observed no association between prior use of therapeutic anticoagulation and in hospital mortality compared to no prior use of anticoagulation (RR 1.02 (95% CI;0.80-1.30). We also found no significant differences in secondary outcomes apart from a lower risk of pulmonary embolism in patients using therapeutic anticoagulation prior to infection (RR 0.19 (95% CI;0.05-0.80). Conclusions : Although prior therapeutic anticoagulation use is associated with reduced PE occurrence, it is not associated with better outcome parameters in hospitalized COVID-19 patients in terms of all-cause mortality, ICU admittance, need for mechanical ventilation, and length of hospital stay.
ABSTRACT
BACKGROUND: The global push for the use of hydroxychloroquine (HCQ) and chloroquine (CQ) against COVID-19 has resulted in an ongoing discussion about the effectivity and toxicity of these drugs. Recent studies report no effect of (H)CQ on 28-day mortality. We investigated the effect of HCQ and CQ in hospitalized patients on the non-ICU COVID-ward. METHODS: A nationwide, observational cohort study was performed in The Netherlands. Hospitals were given the opportunity to decide independently on the use of three different COVID-19 treatment strategies: HCQ, CQ, or no treatment. We compared the outcomes between these groups. The primary outcomes were 1) death on the COVID-19 ward, and 2) transfer to the intensive care unit (ICU). RESULTS: The analysis included 1064 patients from 14 hospitals: 566 patients received treatment with either HCQ (n = 189) or CQ (n = 377), and 498 patients received no treatment. In a multivariate propensity-matched weighted competing regression analysis, there was no significant effect of (H)CQ on mortality on the COVID ward. However, HCQ was associated with a significantly decreased risk of transfer to the ICU (hazard ratio (HR) = 0.47, 95% CI = 0.27-0.82, p = 0.008) when compared with controls. This effect was not found in the CQ group (HR = 0.80, 95% CI = 0.55-1.15, p = 0.207), and remained significant after competing risk analysis. CONCLUSION: The results of this observational study demonstrate a lack of effect of (H)CQ on non-ICU mortality. However, we show that the use of HCQ - but not CQ - is associated with a 53% reduction in risk of transfer of COVID-19 patients from the regular ward to the ICU. Recent prospective studies have reported on 28-day, all-cause mortality only; therefore, additional prospective data on the early effects of HCQ in preventing transfer to the ICU are still needed.