Stability of vitamin K antagonist anticoagulation after COVID-19 diagnosis

Impact of prior oral anticoagulation therapies on post-discharge outcomes after COVID-19: Results from a global federated health network analysis

BACKGROUND

The impact of chronic oral anticoagulant (OACs) use on long-term post-discharge outcomes after coronavirus disease 2019 (COVID-19) hospitalisation remains unclear. Herein, we compared clinical outcomes up to 2-years after COVID-19 hospitalisation between patients on vitamin K antagonists (VKAs), direct-acting OACs (DOACs) and no OAC therapy.

METHODS

Data from TriNetX, a global federated health research network, were used. Adult patients on VKAs, DOACs or no OAC therapy at diagnosis of COVID-19 between 20 January 2020 and 31 December 2021, who were hospitalised for COVID-19, were included. The primary outcomes were all-cause mortality, ischaemic stroke/transient ischaemic attack (TIA)/systemic embolism (SE) and the composite of intracranial haemorrhage (ICH)/gastrointestinal bleeding, at 2 years after COVID-19 hospitalisation.

RESULTS

We included 110,834 patients with COVID-19. Following propensity score matching (PSM), we identified a decreased mortality risk in DOAC-treated patients compared to the no OAC cohort (RR .808, 95% CI .751-.870). A higher risk of ischaemic stroke/TIA/SE was observed in VKA users compared to DOAC users (RR 1.100, 95% CI 1.020-1.220) and in VKA users compared to patients not taking OAC (RR 1.400, 95% CI 1.140-1.720). VKA use was associated with a greater risk of ICH/gastrointestinal bleeding than DOAC users (RR 1.198, 95% CI 1.066-1.347), while DOAC users had a lower risk compared to no OAC-treated patients (RR .840, 95% CI .754-.936).

CONCLUSION

COVID-19 patients taking prior DOACs were associated with lower long-term mortality risk and ICH/gastrointestinal bleeding than patients not taking OAC. Compared to patients on DOACs, VKA users were associated with higher risks of mortality, ischaemic stroke/TIA/SE and ICH/gastrointestinal bleeding.

Good practice statements for antithrombotic therapy in the management of COVID-19: Guidance from the SSC of the ISTH

Despite the emergence of high quality randomized trial data with the use of antithrombotic agents to reduce the risk of thromboembolism, end-organ failure, and possibly mortality in patients with coronavirus disease 2019 (COVID-19), questions still remain as to optimal patient selection for these strategies, the use of antithrombotics in outpatient settings and in-hospital settings (including critical care units), thromboprophylaxis in special patient populations, and the management of acute thrombosis in hospitalized COVID-19 patients. In October 2021, the International Society on Thrombosis and Haemostasis (ISTH) formed a multidisciplinary and international panel of content experts, two patient representatives, and a methodologist to develop recommendations on treatment with anticoagulants and antiplatelet agents for COVID-19 patients. The ISTH Guideline panel discussed additional topics to be well suited to a non-Grading of Recommendations Assessment, Development, and Evaluation (GRADE) for Good Practice Statements (GPS) to support good clinical care in the antithrombotic management of COVID-19 patients in various clinical settings. The GPS panel agreed on 17 GPS: 3 in the outpatient (pre-hospital) setting, 12 in the hospital setting both in non-critical care (ward) as well as intensive care unit settings, and 2 in the immediate post-hospital discharge setting based on limited evidence or expert opinion that supports net clinical benefit in enacting the statements provided. The antithrombotic therapies discussed in these GPS should be available in low- and middle-income countries.

Vitamin K: A Simple and Efficient Add-on to the Current Treatment Regime of COVID-19

Background:

: Intravascular thrombosis and pulmonary fibrosis in COVID-19 patients with pneumonia is significantly associated with the severity of disease. Vitamin K is known to balance the coagulation mechanisms and also prevents calcification and fibrosis of the extrahepatic soft tissues. This narrative review focuses on the role of Vitamin K as a linking factor for thrombotic as well as pulmonary complications of COVID-19.

Methods and Results:

Article search was performed in databases of WHO, PubMed, Scopus and Clinical Trial Registry using appropriate key words. Original articles included very few observational studies which showed a reduced level of Vitamin K as well as activated extrahepatic Vitamin K Dependent Proteins (VKDP) in COVID-19 patients when compared to healthy controls. Chronic treatment with Vitamin K Antagonists did not reduce the risk of in-hospital death. Docking study was performed using Swiss dock and it gave a significant interaction between menaquinone and SARS-CoV-2 main Protease (SARS-CoV-2 Mpro).

Discussion:

Deficiency of Vitamin K in COVID-19 can be due to excess use of antagonists or defective ingestion or absorption. This triggers an imbalance in the normal coagulation-anticoagulation mechanism by channelling the available Vitamin K to the liver and thereby causing a deficiency of the same in extrahepatic tissues and finally leading to thrombosis. This also prevents carboxylation and activation of extrahepatic VKDP required to prevent the calcification of soft tissues and thus leading to lung fibrosis.

Conclutions:

Supplementation of Vitamin K should be considered as a potentially modifiable risk factor in severe COVID-19. Randomized control trials are highly recommended to give clearer evidence on the same.

The Immediate Effect of COVID-19 Vaccination on Anticoagulation Control in Patients Using Vitamin K Antagonists

Background  In January 2021, the Dutch vaccination program against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was started. Clinical studies have shown that systemic reactions occur in up to 50% of vaccine recipients. Therefore, COVID-19 vaccination could affect anticoagulation control, potentially leading to an increased risk of thrombotic events and bleeding complications.

Aims  This article investigates whether the BNT162b2 vaccine affects anticoagulation control in outpatients using vitamin K antagonists (VKAs).

Methods  A case-crossover study was performed in a cohort of outpatient VKA users from four Dutch anticoagulation clinics who received a BNT162b2 vaccine. International normalized ratio (INR) results and VKA dosages before the first vaccination, the reference period, were compared with those after the first and second vaccination.

Results  A total of 3,148 outpatient VKA users were included, with a mean age (standard deviation) of 86.7 (8.7) years, of whom 43.8% were male, 67.0% used acenocoumarol, and 33.0% phenprocoumon. We observed a decrease of 8.9% of INRs within range in the standard intensity group (target INR 2.0–3.0). There was both an increased risk of supratherapeutic (odds ratio [OR] = 1.34 [95% confidence interval [CI] 1.08–1.67]) and subtherapeutic levels (OR = 1.40 [95% CI 1.08–1.83]) after first vaccination. In the high-intensity group (target INR 2.5–3.5), the risk of a supratherapeutic INR was 2.3 times higher after first vaccination (OR = 2.29 [95% CI 1.22–4.28]) and 3.3 times higher after second vaccination (OR = 3.25 [95% CI 1.06–9.97]).

Conclusion  BNT162b2 was associated with an immediate negative effect on anticoagulation control in patients treated with VKAs, so it is advisable to monitor the INR shortly after vaccination, even in stable patients.