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11 Dec 2022

Study reveals recommended anticoagulant therapy for COVID patients

Media release

The AustralaSian COVID-19 Trial (ASCOT) has pinpointed the most efficient level of blood thinning treatment needed for patients hospitalised with COVID-19, in a study published in the New England Journal of Medicine Evidence and presented at the American Society for Hematology conference today. 

The COVID-19 global pandemic remains a major public health challenge. ASCOT researchers aim to discover which treatments are most effective in patients hospitalised with COVID-19. 

Patients in hospital with COVID-19 are at increased risk of blood clots (or thromboses), which in turn may contribute to development of organ failure. Almost all these patients will receive some degree of blood thinning medication. 

In an international study, the ASCOT team conducted a randomised clinical trial to test different levels of anticoagulation (or blood thinning) in more than 1,500 patients in Australia, New Zealand, India and Nepal. 

They found that an intermediate level of anticoagulation had an 86% probability of being better than low dose anticoagulation. A higher therapeutic dose did not show any benefit. 

ASCOT Principal Investigator Professor Steven Tong, an infectious diseases clinician at the Royal Melbourne Hospital and co-lead of clinical research at the Doherty Institute, said that the findings will inform WHO sponsored guidelines. 

“Current practice in Australia is for low dose of anticoagulation, while international guidelines recommend the high therapeutic dose of anticoagulation. Therefore, our findings provide evidence that a middle ground may be most beneficial,” Professor Tong said. 

Quote attributable to Associate Professor Zoe McQuilten, Monash University Transfusion Research Unit Deputy Director and consultant haematologist with Monash University and Monash Health, Australia 

“We are pleased to have our study selected for presentation at the American Society of Hematology Annual Meeting & Exposition, which is the premier haematology conference internationally." 

"Importantly, we didn't find any evidence that the intermediate dose of anticoagulation resulted in increased risk of bleeding. While we didn't find evidence of benefit from the high therapeutic dose of anticoagulation, we enrolled fewer patients into that arm of the trial." 


Quote attributable to Professor Bala Venkatesh, Professorial Fellow at The George Institute for Global Health, Australia 

“This study highlights the importance of conducting clinical trials in different health care systems. Low- and middle-income countries (LMIC) have been under-represented in Covid-19 studies and ASCOT is one of the few studies to have a major involvement of LMIC regions. The results of the ASCOT trial are expected to have a significant influence on clinical guidelines.” 


Quote attributable to Dr Susan Morpeth, Clinical Microbiologist and Infectious Diseases Physician at Middlemore Hospital, NZ 

“We are pleased to be able to contribute to COVID-19 treatment trials on the ASCOT platform from Aotearoa, New Zealand. Throughout this pandemic, it has been of critical importance to accrue randomised clinical trial evidence in real time to inform clinical guidelines and patient management.” 


Quote attributable to Professor Vivekanand Jha, Executive Director at The George Institute for Global Health, India 

“Even as the case numbers were low in Australia and New Zealand, existing network relationships allowed us to take the trial to India and Nepal, where COVID-19 was active and successfully complete this study that asks a question of global relevance. The rapid subject recruitment during the difficult time of the delta wave is a testimony to the commitment of site investigators and study staff in these centres.” 


ASCOT is supported by the Australian Partnership for Preparedness Research on Infectious Disease Emergencies (APPRISE), The BHP Foundation, Health Research Council of New Zealand, Hospital Research Foundation, The Macquarie Group Foundation, The Minderoo Foundation, The Pratt Foundation, Royal Brisbane and Women’s Hospital Foundation, The Common Good (The Prince Charles Hospital Foundation), Wesley Medical Research, Chong Kun Dang Pharmaceutical Corporation, NSW Office for Health and Medical Research, Medical Research Future Fund (MRF2002132), and the Russell and Womersley Foundation.