The effect of chronic DOAC treatment on clinical outcomes of hospitalized patients with COVID-19

Anticoagulant use before COVID-19 diagnosis prevent COVID-19 associated acute venous thromboembolism or not: A systematic review and meta-analysis

BACKGROUND

Coagulopathy and thromboembolic events are associated with poor outcomes in coronavirus disease 2019 (COVID-19) patients. There is conflicting evidence on the effects of chronic anticoagulation on mortality and severity of COVID-19 disease.

AIM

To summarize the body of evidence on the effects of pre-hospital anticoagulation on outcomes in COVID-19 patients.

METHODS

A Literature search was performed on LitCovid PubMed, WHO, and Scopus databases from inception (December 2019) till June 2023 for original studies reporting an association between prior use of anticoagulants and patient outcomes in adults with COVID-19. The primary outcome was the risk of thromboembolic events in COVID-19 patients taking anticoagulants. Secondary outcomes included COVID-19 disease severity, in terms of intensive care unit admission or invasive mechanical ventilation/intubation requirement in patients hospitalized with COVID-19 infection, and mortality. The random effects models were used to calculate crude and adjusted odds ratios (aORs) with 95% confidence intervals (95%CIs).

RESULTS

Forty-six observational studies met our inclusion criteria. The unadjusted analysis found no association between prior anticoagulation and thromboembolic event risk [n = 43851, 9 studies, odds ratio (OR)= 0.67 (0.22, 2.07); P = 0.49; I 2 = 95%]. The association between prior anticoagulation and disease severity was non-significant [n = 186782; 22 studies, OR = 1.08 (0.78, 1.49); P = 0.64; I 2 = 89%]. However, pre-hospital anticoagulation significantly increased all-cause mortality risk [n = 207292; 35 studies, OR = 1.72 (1.37, 2.17); P < 0.00001; I 2 = 93%]. Pooling adjusted estimates revealed a statistically non-significant association between pre-hospital anticoagulation and thromboembolic event risk [aOR = 0.87 (0.42, 1.80); P = 0.71], mortality [aOR = 0.94 (0.84, 1.05); P = 0.31], and disease severity [aOR = 0.96 (0.72, 1.26); P = 0.76].

CONCLUSION

Prehospital anticoagulation was not significantly associated with reduced risk of thromboembolic events, improved survival, and lower disease severity in COVID-19 patients.

COVID-19 and Pulmonary Angiogenesis: The Possible Role of Hypoxia and Hyperinflammation in the Overexpression of Proteins Involved in Alveolar Vascular Dysfunction

COVID-19 has been considered a vascular disease, and inflammation, intravascular coagulation, and consequent thrombosis may be associated with endothelial dysfunction. These changes, in addition to hypoxia, may be responsible for pathological angiogenesis. This research investigated the impact of COVID-19 on vascular function by analyzing post-mortem lung samples from 24 COVID-19 patients, 10 H1N1pdm09 patients, and 11 controls. We evaluated, through the immunohistochemistry technique, the tissue immunoexpressions of biomarkers involved in endothelial dysfunction, microthrombosis, and angiogenesis (ICAM-1, ANGPT-2, and IL-6, IL-1β, vWF, PAI-1, CTNNB-1, GJA-1, VEGF, VEGFR-1, NF-kB, TNF-α and HIF-1α), along with the histopathological presence of microthrombosis, endothelial activation, and vascular layer hypertrophy. Clinical data from patients were also observed. The results showed that COVID-19 was associated with increased immunoexpression of biomarkers involved in endothelial dysfunction, microthrombosis, and angiogenesis compared to the H1N1 and CONTROL groups. Microthrombosis and vascular layer hypertrophy were found to be more prevalent in COVID-19 patients. This study concluded that immunothrombosis and angiogenesis might play a key role in COVID-19 progression and outcome, particularly in patients who die from the disease.

The effect of previous oral anticoagulant use on clinical outcomes in COVID-19: A systematic review and meta-analysis

Data on the prognosis of patients treated with oral anticoagulation (OAC) prior to hospital admission for COVID-19 remains controversial and insufficient. Therefore, we endeavored to perform a systematic review and meta-analysis to evaluate the effect of chronic use of OAC prior to the diagnosis of COVID-19 on intensive care unit (ICU) admission and mortality. An electronic search of the Pubmed, Embase, Cochrane library databases was conducted. Meta-analysis and statistical analyses were completed with using the RevMan 5.3 and Stata 12.0. A total of 13 articles representing data from 1,266,231 participants were included in this study. The meta-analysis of unadjusted results showed no decrease in mortality (OR = 1.31, 95% CI: 0.99 to 1.73, P = 0.059) or ICU admission rate (OR = 0.71, 95% CI: 0.29 to 1.77, P = 0.46) in COVID-19 patients with prior OAC therapy at hospital admission compared to patients without prior use of OAC. Moreover, the meta-analysis of adjusted results showed no lower risk of mortality (OR = 1.08, 95% CI: 0.90 to 1.30, P = 0.415) or ICU admission (OR = 1.50, 95% CI: 0.72 to 3.12, P = 0.284) in patients with prior OAC use compared to patients without previous OAC use. In conclusion, the results of this study revealed that the use of OAC prior to hospital admission appeared to be ineffective in reducing the risk of intensive care need and mortality in COVID-19 patients. Randomized controlled trials are needed to evaluate and optimize the use of OAC in COVID-19 infection.

The Use of Oral Anticoagulation Is Not Associated With a Reduced Risk of Mortality in Patients With COVID-19: A Systematic Review and Meta-Analysis of Cohort Studies

Background: Hypercoagulability and thromboembolic events are associated with poor prognosis in coronavirus disease 2019 (COVID-19) patients. Whether chronic oral anticoagulation (OAC) improve the prognosis is yet controversial. The present study aimed to investigate the association between the chronic OAC and clinical outcomes in COVID-19 patients.

Methods: PubMed, Embase, Web of Science, and the Cochrane Library were comprehensively searched to identify studies that evaluated OAC for COVID-19 until 24 July 2021. Random-effects model meta-analyses were performed to pool the relative risk (RR) and 95% confidence interval (CI) of all-cause mortality and intensive care unit (ICU) admission as primary and secondary outcomes, respectively. According to the type of oral anticoagulants [direct oral anticoagulants (DOACs) or vitamin K antagonists (VKAs)], subgroup and interaction analyses were performed to compare DOACs and VKAs. Meta-regression was performed to explore the potential confounders on all-cause mortality.

Results: A total of 12 studies involving 30,646 patients met the inclusion criteria. The results confirmed that chronic OAC did not reduce the risk of all-cause mortality (RR: 0.92; 95% CI 0.82–1.03; p = 0.165) or ICU admission (RR: 0.65; 95% CI 0.40–1.04; p = 0.073) in patients with COVID-19 compared to those without OAC. The chronic use of DOACs did not reduce the risk of all-cause mortality compared to VKAs (P_interaction = 0.497) in subgroup and interaction analyses. The meta-regression failed to detect any potential confounding on all-cause mortality.

Conclusion: COVID-19 patients with chronic OAC were not associated with a lower risk of all-cause mortality and ICU admission compared to those without OAC, and the results were consistent across DOACs and VKA subgroups.

Systematic Review Registration:clinicaltrials.gov, identifier CRD42021269764.

Vitamin K in COVID-19—Potential Anti-COVID-19 Properties of Fermented Milk Fortified with Bee Honey as a Natural Source of Vitamin K and Probiotics

Vitamin K deficiency is evident in severe and fatal COVID-19 patients. It is associated with the cytokine storm, thrombotic complications, multiple organ damage, and high mortality, suggesting a key role of vitamin K in the pathology of COVID-19. To support this view, we summarized findings reported from machine learning studies, molecular simulation, and human studies on the association between vitamin K and SARS-CoV-2. We also investigated the literature for the association between vitamin K antagonists (VKA) and the prognosis of COVID-19. In addition, we speculated that fermented milk fortified with bee honey as a natural source of vitamin K and probiotics may protect against COVID-19 and its severity. The results reported by several studies emphasize vitamin K deficiency in COVID-19 and related complications. However, the literature on the role of VKA and other oral anticoagulants in COVID-19 is controversial: some studies report reductions in (intensive care unit admission, mechanical ventilation, and mortality), others report no effect on mortality, while some studies report higher mortality among patients on chronic oral anticoagulants, including VKA. Supplementing fermented milk with honey increases milk peptides, bacterial vitamin K production, and compounds that act as potent antioxidants: phenols, sulforaphane, and metabolites of lactobacilli. Lactobacilli are probiotic bacteria that are suggested to interfere with various aspects of COVID-19 infection ranging from receptor binding to metabolic pathways involved in disease prognosis. Thus, fermented milk that contains natural honey may be a dietary manipulation capable of correcting nutritional and immune deficiencies that predispose to and aggravate COVID-19. Empirical studies are warranted to investigate the benefits of these compounds.