Excessive blood clotting and stroke in COVID-19 patients

By Angela Betsaida B. Laguipo, BSNMay 21 2020

The coronavirus disease COVID-19 is causing excessive blood clotting and stroke in young and healthy people, a new study has found.

A team of stroke specialists at the Medical College of Georgia and Augusta University Health System revealed that stroke is an emerging complication of COVID-19, which is caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).

Over the past months, the world has grappled with the coronavirus disease, with over 5 million people infected and 332,000 succumbing to the disease. Though the clinical course of the disease is more severe in older adults, patients with comorbidities, and those who are immunocompromised, some neurological symptoms were also reported, even in patients who are young and healthy.

SARS-CoV-2 viruses binding to ACE-2 receptors on a human cell, the initial stage of COVID-19 infection. Illustration Credit: Kateryna Kon / Shutterstock

Neurological symptoms of COVID-19

The coronavirus disease is a respiratory ailment causing pneumonia and respiratory distress. The most common symptoms of COVID-19 include fever, cough, and difficulty of breathing. In some patients, however, neurological symptoms appear, such as anosmia or loss of smell, hypogeusia, or the reduced ability to taste, seizures, and stroke.

The researchers highlighted that aside from stroke, these symptoms may indicate a risk for developing cognitive and other neurological problems. In other patients, they develop brain involvement, called encephalopathy, that may significantly impact consciousness and cause confusion, headaches, and seizures.

The SAR-CoV-2 virus is known to target the respiratory tract, but recent data shows that it also attacks the brain. The virus can be transmitted through droplets when an infected person coughs or sneezes nearby. The virus can enter the body through the nasal passages, eyes, and even the mouth.

Once it enters the nose, it can infect the airways, or it can make its way through the olfactory bulb found in the frontal area of the brain. The function of this structure is to pick up and process odors, explaining why some patients with COVID-19 may experience anosmia or loss of smell.

When it invades the cells in the olfactory bulb, it can spread throughout the brain. Further, the mouth can also directly take the virus to the brain. Neurologists also believe that in an infected person, the virus can take both ways to access the central nervous system.  

That is why COVID-19 is challenging to treat since it can attack multiple body systems at the same time. The researchers of the study also noted that some patients are on their way to recovery, but then, they just stop breathing. While respiratory failure is the most common cause of COVID-19 deaths, they suspect that lung invasion and infection of breathing centers in the brain are the culprits.

Excessive blood clotting and stroke

The researchers noted that excessive blood clotting and stroke occur in some COVID-19 patients.  In some cases, a stroke may also lead to a ruptured blood vessel, causing bleeding in the brain.

A stroke occurs when a blood clot obstructs the vessel supplying blood to the brain. It may lead to the lack of oxygen supply for the neurons to function, which may cause severe and potentially fatal complications.

Many pathogens, such as the viruses that cause influenza and shingles, result in excessive inflammation that can lead to increased coagulation. Inflammation may also cause the production of microscopic clots in the alveoli, the lung’s tiny air sacs. All these can contribute to respiratory distress syndrome, which is a significant cause of severe disease and death tied to COVID-19.

The researchers also noted that the blood of the patients would have high levels of D-dimer, which is a protein produced when a clot is degraded. The patients may also experience a faster blood clotting process.

Traditional stroke treatments

The study authors recommend that traditional stroke treatments such as tissue plasminogen activators (tPA), which are proteins that break down blood clots, and the surgical removal of big clots in the brain can be suitable interventions for patients with COVID-19 who had a stroke.  

One promising treatment involves supplying exogenous angiotensin-converting enzyme 2 (ACE2) by administering recombinant soluble ACE2 (hrsACE2). The treatment helped hamper the coronavirus infection in engineered human blood cell organoids. The treatment may help restore healthier ACE2 levels and interfere with the ability of the coronavirus to bind with cells. Currently, this treatment was seen to be safe in a pilot clinical trial and has been tagged to start clinical trials for COVID-19.

“This controlled trial will assess the efficacy, safety, and clinical impact of the Angiotensin-(1-7) infusion in a cohort of COVID-19 patients requiring mechanical ventilation. The results of this trial may provide useful information for the management of this disease,” the authors of the clinical trial said.