A cycle of blood clotting and inflammation may contribute to the breathing difficulties of some patients with COVID-19. A forthcoming clinical trial will assess whether a type of drug already approved for the prevention of blood clots after a heart attack or stroke could help prevent these difficulties.
Critical patients may develop a severe inflammatory lung condition called Acute Respiratory Difficulty Syndrome (ARSD), which affects their ability to breathe unaided.
As part of this cycle of blood clotting and inflammation, uncontrolled development of microconbales in the small blood vessels of the lungs and microfibrin plugs in the small air sacs of some COVID-19 patients contribute to severe breathing difficulties.
Established uses
In 1996, the Food and Drug Administration (FDA) approved the drug, called a tissue plasminogen activator (tPA), to prevent blood clots in people who have suffered a stroke, pulmonary embolism, or heart attack.
It is an enzyme that occurs naturally in the blood and tissues, where it acts as an anticoagulant by breaking down fibrin, which forms airway plugs and platelet and fibrin clots in the small vessels of the lungs.
Researchers have begun enrolling some of the COVID-19 patients admitted to the medical center in a clinical trial of the drug. They also aim to identify “biomarkers,” such as blood levels of clotting factors, which, in the future, will help identify patients who are most likely to benefit from therapy.
These multiple small clots in the blood vessels of the lungs reduce the ability of these organs to carry oxygen into the bloodstream and remove carbon dioxide.
Pathologists have found signs of what researchers call “aggressive coagulation” in lung samples from people with COVID-19. There have also been reports of abnormal coagulation intensive care units outside the lungs in patients with COVID-19 with EZR.
“We are anecdotally hearing that a subset of PATIENTS with COVID-19-induced SDRA are abnormally clotting around their catheters and lines
“We suspect that these patients with aggressive coagulation will show the greatest benefit of tPA treatment, and this new clinical trial will reveal whether that is the case.”
– Dr. Michael B. Yaffe, Ph.D.
