Global clinical trials examining the potential of blood thinners to treat moderately ill COVID-19 patients have proven so successful that doctors should immediately start using them in standard care, some Canadian physicians say.
Investigators at Toronto’s University Health Network (UHN) say interim results of clinical trials spanning five continents in more than 300 hospitals suggest full-dose blood thinners could significantly prevent severe cases now straining hospital intensive care units (ICUs).
The study involved more than 1,300 moderately ill patients admitted to hospital, including some at UHN.
Investigators say full doses of heparin blood thinner improved outcomes and decreased the need for life support.
The full dose, similar to what’s given to people who have a blood clot, such as deep vein thrombosis, was also more effective than the lower dose typically administered to prevent blood clots in hospitalized patients.
Findings could develop ‘new standard of care’
The findings could transform care, said critical care doctor Ewan Goligher, a co-chair on one of the clinical trials, which haven’t yet been published or peer reviewed to flag errors.
Many people around the world end up in intensive care because of COVID-19, Goligher said.
“They’re very, very ill, they’re often in the ICU for a long time. It’s a devastating life event,” Goligher, a critical care
physician at Toronto General Hospital, said of the patients he sees.
“Even if they do survive, it means immense suffering, and to prevent people from becoming critically ill is huge.”
Goligher said heparin is cheap and widely available worldwide,
Ryan Zarychanski, associate professor, hematologist and critical care physician at the University of Manitoba, said the findings were promising.
“In a disease with a limited number of effective therapies, our results have the potential to define a new standard of care for moderately ill hospitalized COVID-19 patients around the world,” Zarychanski said.
Dr. Douglas Fraser, an ICU doctor at London Health Sciences Centre and a researcher at Western University who has studied blood clots in COVID-19, called the interim results of the trials important.
“It will likely change therapy in a global, more uniformed manner,” Fraser said.
But questions remain including:
- Which patients should be treated this way?
- Is this the best way to stop clots compared with giving heparin together with anticoagulants?
- How long should the treatment last?
Dr. Theresa Tam, Canada’s chief public health officer, said Friday she welcomed more evidence on treatments for COVID-19.
“We are, I think, really relying on our clinical experts who are on the ground treating patients,” Tam said. “They will look at the individuals in question to figure out what is really in their best interest.”
Harmful for critically ill patients
Doctors noticed early in the pandemic that COVID-19 patients suffered an increased rate of blood clots and inflammation. This led to complications including lung failure, heart attack and stroke.
Back in December, investigators found that giving full-dose blood thinners to critically ill ICU patients did not help, and was actually harmful.
The trials are supported by international funding organizations including the Canadian Institutes of Health Research, the NIH National Heart, Lung & Blood Institute in the United States, the National Institute for Health Research in the United Kingdom, and the National Health and Medical Research Council in Australia.