Blood thinners could ease COVID-19 load on critical care units, Manitoba-led global study finds

Fewer COVID-19 patients could end up in intensive care units, easing the burden on overloaded health systems around the world, thanks to a Manitoba-led global study of the effects of a common blood thinner. 

For the study, COVID-19 patients were given a full dose of heparin — a widely available anticoagulant commonly given in small amounts to adults who require hospitalization — to see if it had any impact on the number of patients admitted to intensive care units (ICUs), and the length of time they required intensive care.

The results were so promising that the trial was called off early — "because it was obvious to them now that the full dose of heparin was causing better outcomes," said University of Manitoba hematologist Dr. Ryan Zarychanski.

Zarychanski led the study, involving a team spread across five continents and more than 300 hospitals. 

"This is a really exciting opportunity for Manitoba. We were able to lead a real global trial and bring other partners in and perform a trial around the world," said Zarychanski.

He had been studying the effects of full-dose heparin on patients with other infections. When the novel coronavirus first appeared on the world stage early last year, he said colleagues around the world reached out to him asking if they should adapt the protocols he was studying for a trial involving COVID-19 patients. 

Out of 1,300 patients in the study, about 20 per cent of those patients given the full dose of heparin required ICU admission, compared to about 30 per cent of those who received the smaller dose.

Given that heparin is available in hospitals anywhere in the world, the therapy has the potential to immediately ease the burden on health-care systems in developing countries as well as wealthier nations, Zarychanski said.

"This is a time where we need urgent therapies. If we can prevent poor outcomes, reduce burden on the health-care system with immediate changes, safely with data — not randomly with testimonials — then we're doing a good thing," he said. 

Widely used for preventing blood clots, heparin also has anti-inflammatory properties. COVID-19 patients often experience inflammation in vital organs, which can lead to complications such as lung failure, heart attack and stroke. 

By giving the drug to patients early on, they had a better chance of avoiding those serious complications which could require mechanical life support. 

Zarychanski believes the results of the study will lead to a new standard of care for COVID-19 patients around the world. 

In an earlier study last year, the team found that giving the same drug to COVID-19 patients after they were admitted to critical care wasn't beneficial and appeared to be harmful. 

The team is still analyzing the data to see if administering heparin to patients while their illness is still mild has any additional benefits, such as reducing the length of hospital stays or reducing mortality rates.