Blood thinners may boost survival rates of coronavirus patients: Study

Treating coronavirus patients with blood thinners may help in boosting their prospects for survival, according to preliminary findings from physicians at New York City's largest hospital system that offers another source of hope in treating the deadly infection.

The Washington Post reported that the results of the analysis, conducted over 2,733 patients, were published on Wednesday in the Journal of the American College of Cardiology.

In an interview to the newspaper, Valentin Fuster, a physician in chief at Mount Sinai Hospital and one of the study's authors, said that the observations were based only on a review of medical records and that more rigorous and randomised studies are needed to draw broader conclusions.

But the results have been promising, he said.

"My opinion is cautious, but I must tell you I think this is going to help. This is the opening of the door for what drugs to use and what questions to answer," the physician further stated.

Since March, when coronavirus hit Europe and the United States, doctors have been reporting mysterious blood clots, which can be gel-like or even semisolid, in a significant subset of coronavirus patients. Autopsies of patients who died of respiratory arrest have shown that some had unusual micro clots in their lungs rather than the typical damage expected.

Last month, doctors reported in the New England Journal of Medicine on five unusual cases of Covid-19 positive people in their 30s and 40s experiencing large strokes.

The Mount Sinai study focused on hospitalised patients who were treated from March 14 to April 11. Among the patients, those who were not on ventilators and treated with blood thinners died at similar rates in comparison to those who did not receive blood thinners. But the group of patients who received blood thinners lived longer -- a median of 21 days compared to 14 days, the study said.

For patients on ventilators, the difference was more significant. About 63 per cent of patients who did not receive the medications died compared with 29 per cent who received the treatment.

Another critical finding of the study was that giving blood thinners to these patients appeared to be relatively safe. There was not a significant difference in the most dangerous side effect of anticoagulants -- bleeding -- in those who were on the drugs and those who were not.

Fuster said that as a result of the analysis, the hospital system changed its treatment protocols several days ago to begin giving higher doses of blood thinners to the patients infected with Covid-19.

Deepak Bhatt, a professor at Harvard Medical School who specialises in interventional cardiology, called the paper "a very important study" with the blood issues in Covid-19 patients having evolved from just a suspicion to a well-recognised complication of the virus. "What we are figuring now is what do we do now that we know in terms of treatments," he said.

A number of medical societies, including the International Society on Thrombosis and Haemostasis and the American Society of Hematology, have put out guidance recommending the use of blood thinners for some Covid-19 patients, but the advice has taken a conservative approach.

"It is a delicate balance between clotting and bleeding, especially when patients are as sick as some of the ones who have Covid-19," said Geoffrey Barnes, an assistant professor at the University of Michigan who works in cardiovascular medicine.

"A week ago, we were making some educated guesses on how to prevent blood clots. This is the first time we have seen data that says higher doses may possibly be effective and safe," he was quoted as saying.

Doctors caring for the sickest coronavirus patients confront a limited arsenal of treatments. On May 1, the Food and Drug Administration issued an emergency use authorisation for the antiviral drug remdesivir in patients who are hospitalised and seriously ill.

But trials of other treatments, including those involving Hydroxychloroquine, a malaria drug touted by US President Donald Trump, have been stopped because of a lack of efficacy and concerns about toxicity.

In late April, scientists also reported that an arthritis drug made by Regeneron and Sanofi that had drawn enthusiasm from investors early on produced disappointing results in clinical trials, according to The Washington Post.