(CNN) Blood thinning drugs could help save some patients who are the most severely affected by the new coronavirus, doctors reported Wednesday.
The findings from a team at Mount Sinai Hospital could help with a troubling problem that has shocked and horrified doctors treating coronavirus patients around the world -- blood clots throughout the body that complicate an already hard-to-treat disease.
The team now says it is running experiments to see which anticoagulants may work best, and at which doses.
"The patients who received anticoagulants did better than those who didn't," Dr. Valentin Fuster, director of Mount Sinai Heart and physician-in-chief of The Mount Sinai Hospital, told CNN.
"This has implications already. People, I believe, should treat these patients with antithrombotics," he added.
The findings are not clear enough yet to make solid recommendations. The team noted that patients who were already severely ill were more likely to be given the blood thinners.
Fuster and colleagues looked at more than 2,700 patients treated at Mount Sinai in New York City, which has been hit hard by the coronavirus. Starting in March, some patients were given anti-clotting drugs based on bedside decisions made by doctors.
The team started taking a systematic look at whether the drugs made a difference. They did, especially for patients who were put on ventilators to help them breathe.
They found 29% of patients on ventilators who were given blood thinners died, compared to 63% of patients on ventilators who were not given blood thinners.
"Our findings suggest that systemic anticoagulants may be associated with improved outcomes among patients hospitalized with Covid-19," they wrote in their report, published in the Journal of the American College of Cardiology.
The researchers did not find that the patients who received blood thinners were significantly more likely to develop bleeding problems -- one of the risks of the drugs.
Different patients received different doses and different types of blood thinners, so it will be important to systematically study which combination of dose and drug works best, Fuster said.
His team has started such a study and going forward will test varying doses of either the classic blood thinner heparin or one of the newer, oral anticoagulant drugs such as dabigatran, a direct thrombin inhibitor.
There's no doubt that blood clotting is a major factor in the deaths of patients with Covid-19, Fuster said.
"We have done 75 autopsies and clotting is a problem, without any question," he said.
"It starts with the lungs, followed by the kidneys, the heart and it ends up in the brain."
The consequences, he said, are devastating. "It is so dramatic for all of us. You feel that you can do very little except to sustain the life of the patient," Fuster said.
Fuster would also like to study whether blood thinners could help patients who are not sick enough to be hospitalized. Some hospitals have reported a troubling increase in strokes among people under age 50 who would normally not be at risk. Many of these patients have later been found to be infected with the coronavirus.
It's not yet clear why the virus is causing blood to clot, but increased clotting can be a side effect of the severe inflammation caused by some viral infections.