POPULAR SCIENCE – Far more COVID patients suffer from blood clots after leaving the hospital than previously realized, according to recent research published in the journal Blood.
“There’s anywhere from a three to fivefold risk of blood clots compared to the pre-COVID era,” says Alex Spyropoulos, the study’s senior author and a professor at the Feinstein Institutes for Medical Research, which is a part of the New York hospital system Northwell Health. “I’ve never seen this type of blood clot risk in my life.”
It was well known that hospitalized COVID patients, and especially those in intensive care, faced a high risk of clots. But Spyropoulos says “this study shows for the first time that heightened risk of blood clots persists after patients leave the hospital.”
COVID can lead to blood clots by provoking an overwhelming immune response called a cytokine storm. The cytokine storm causes inflammation and does localized damage to blood vessels and organ linings, which prompts the body’s clotting systems to kick in.
That risk appears to remain high even after someone has recovered from the most life-threatening phases of COVID.
“It takes a long time for immune mechanisms to calm down,” Spyropoulos says. “The inflammatory system and the immune system and the coagulation system don’t know that the patient has left the hospital.”
The study examined more than 11,000 people who were hospitalized with COVID at 12 Northwell Health hospitals in the spring of 2020.
About 3,000 of them died of the disease. The researchers were able to follow another 4,000 patients after they left the hospital, and document any deaths that occurred in the group.
Nearly five percent of those patients died in the 90 days following their discharge, and about three percent experienced a major blood clot. (The groups overlap somewhat, because some patients had blood clots and passed away.)
Those older than 75, who had been in the ICU, or who had a history of clotting, heart disease, or kidney disease were at highest risk.
The clotting rates are higher than have been documented in other studies … Click here to read more.