In April, blood clots emerged as one of the many mysterious symptoms attributed to Covid-19, a disease that had initially been thought to largely affect the lungs in the form of pneumonia. Quickly after came reports of young people dying due to coronavirus-related strokes. Next it was Covid toes — painful red or purple digits.
What do all of these symptoms have in common? An impairment in blood circulation. Add in the fact that 40% of deaths from Covid-19 are related to cardiovascular complications, and the disease starts to look like a vascular infection instead of a purely respiratory one.
Months into the pandemic, there is now a growing body of evidence to support the theory that the novel coronavirus can infect blood vessels, which could explain not only the high prevalence of blood clots, strokes, and heart attacks, but also provide an answer for the diverse set of head-to-toe symptoms that have emerged.
“All these Covid-associated complications were a mystery. We see blood clotting, we see kidney damage, we see inflammation of the heart, we see stroke, we see encephalitis [swelling of the brain],” says William Li, MD, president of the Angiogenesis Foundation. “A whole myriad of seemingly unconnected phenomena that you do not normally see with SARS or H1N1 or, frankly, most infectious diseases.”
“If you start to put all of the data together that’s emerging, it turns out that this virus is probably a vasculotropic virus, meaning that it affects the [blood vessels],” says Mandeep Mehra, MD, medical director of the Brigham and Women’s Hospital Heart and Vascular Center.
In a paper published in April in the scientific journal The Lancet, Mehra and a team of scientists discovered that the SARS-CoV-2 virus can infect the endothelial cells that line the inside of blood vessels. Endothelial cells protect the cardiovascular system, and they release proteins that influence everything from blood clotting to the immune response. In the paper, the scientists showed damage to endothelial cells in the lungs, heart, kidneys, liver, and intestines in people with Covid-19.
“The concept that’s emerging is that this is not a respiratory illness alone, this is a respiratory illness to start with, but it is actually a vascular illness that kills people through its involvement of the vasculature,” says Mehra.
Image Credit: Envato/ Amanda Scott
![]()
News This Week
Very low LDL-cholesterol correlates to fewer heart problems after stroke
Brigham and Women's Hospital's TIMI Study Group reports that in patients with prior ischemic stroke, very low achieved LDL-cholesterol correlated with fewer major adverse cardiovascular events and fewer recurrent strokes, without an apparent increase [...]
“Great Unified Microscope” Reveals Hidden Micro and Nano Worlds Inside Living Cells
University of Tokyo researchers have created a powerful new microscope that captures both forward- and back-scattered light at once, letting scientists see everything from large cell structures to tiny nanoscale particles in a single shot. Researchers [...]
Breakthrough Alzheimer’s Drug Has a Hidden Problem
Researchers in Japan found that although the Alzheimer’s drug lecanemab successfully removes amyloid plaques from the brain, it does not restore the brain’s waste-clearing system within the first few months of treatment. The study suggests that [...]
Concerning New Research Reveals Colon Cancer Is Skyrocketing in Adults Under 50
Colorectal cancer is striking younger adults at alarming rates, driven by lifestyle and genetic factors. Colorectal cancer (CRC) develops when abnormal cells grow uncontrollably in the colon or rectum, forming tumors that can eventually [...]
Scientists Discover a Natural, Non-Addictive Way To Block Pain That Could Replace Opioids
Scientists have discovered that the body can naturally dull pain through its own localized “benzodiazepine-like” peptides. A groundbreaking study led by a University of Leeds scientist has unveiled new insights into how the body manages pain, [...]
GLP-1 Drugs Like Ozempic Work, but New Research Reveals a Major Catch
Three new Cochrane reviews find evidence that GLP-1 drugs lead to clinically meaningful weight loss, though industry-funded studies raise concerns. Three new reviews from Cochrane have found that GLP-1 medications can lead to significant [...]
How a Palm-Sized Laser Could Change Medicine and Manufacturing
Researchers have developed an innovative and versatile system designed for a new generation of short-pulse lasers. Lasers that produce extremely short bursts of light are known for their remarkable precision, making them indispensable tools [...]
New nanoparticles stimulate the immune system to attack ovarian tumors
Cancer immunotherapy, which uses drugs that stimulate the body’s immune cells to attack tumors, is a promising approach to treating many types of cancer. However, it doesn’t work well for some tumors, including ovarian [...]
New Drug Kills Cancer 20,000x More Effectively With No Detectable Side Effects
By restructuring a common chemotherapy drug, scientists increased its potency by 20,000 times. In a significant step forward for cancer therapy, researchers at Northwestern University have redesigned the molecular structure of a well-known chemotherapy drug, greatly [...]
Lipid nanoparticles discovered that can deliver mRNA directly into heart muscle cells
Cardiovascular disease continues to be the leading cause of death worldwide. But advances in heart-failure therapeutics have stalled, largely due to the difficulty of delivering treatments at the cellular level. Now, a UC Berkeley-led [...]
The basic mechanisms of visual attention emerged over 500 million years ago, study suggests
The brain does not need its sophisticated cortex to interpret the visual world. A new study published in PLOS Biology demonstrates that a much older structure, the superior colliculus, contains the necessary circuitry to perform the [...]
AI Is Overheating. This New Technology Could Be the Fix
Engineers have developed a passive evaporative cooling membrane that dramatically improves heat removal for electronics and data centers Engineers at the University of California San Diego have created an innovative cooling system designed to greatly enhance [...]
New nanomedicine wipes out leukemia in animal study
In a promising advance for cancer treatment, Northwestern University scientists have re-engineered the molecular structure of a common chemotherapy drug, making it dramatically more soluble and effective and less toxic. In the new study, [...]
Mystery Solved: Scientists Find Cause for Unexplained, Deadly Diseases
A study reveals that a protein called RPA is essential for maintaining chromosome stability by stimulating telomerase. New findings from the University of Wisconsin-Madison suggest that problems with a key protein that helps preserve chromosome stability [...]
Nanotech Blocks Infection and Speed Up Chronic Wound Recovery
A new nanotech-based formulation using quercetin and omega-3 fatty acids shows promise in halting bacterial biofilms and boosting skin cell repair. Scientists have developed a nanotechnology-based treatment to fight bacterial biofilms in wound infections. The [...]
Researchers propose five key questions for effective adoption of AI in clinical practice
While Artificial Intelligence (AI) can be a powerful tool that physicians can use to help diagnose their patients and has great potential to improve accuracy, efficiency and patient safety, it has its drawbacks. It [...]















