Some types of heart disease increase COVID-19 risk. While it has been documented that certain types of heart disease increase the risk of severe illness and death from COVID-19, the underlying reasons for this link have not been entirely clear.
In a new study from Mayo Clinic, researchers have found evidence that one specific type of heart disease, obstructive hypertrophic cardiomyopathy (HCM), may leave patients particularly susceptible to the development of severe COVID-19 infection. According to the researchers, HCM increases production of the ACE2 RNA transcript and the translated ACE2 protein.
The elevated expression of ACE2 makes it easier for the new coronavirus, SARS-CoV-2, to launch its attack within the human body. This is because SARS-CoV-2 is known to hijack ACE2 receptors to gain entry into cells.
The virus not only invades the body through ACE2 receptors, but also holds the ACE2 protein captive. As a result, an important signaling pathway is silenced that normally helps to regulate vascular function.
The Mayo Clinic researchers analyzed frozen samples of heart muscle tissue from more than 100 patients who had surgery for obstructive hypertrophic cardiomyopathy. The control group consisted of heart tissue from 39 healthy donor hearts.
Study senior author Dr. Michael Ackerman is director of the Windland Smith Rice Sudden Death Genomics Laboratory at Mayo Clinic.
“Of all the RNA transcripts in the entire human genome, our research revealed that the single most upregulated RNA transcript in the heart muscle was ACE2,” said Dr. Ackerman.
“In fact, we confirmed a fivefold increase in ACE2 protein levels in the heart muscle of these patients with obstructive HCM.”
This could connect the dots and potentially explain why patients with certain heart diseases might fare worse with COVID-19.”
Next, the team will analyze heart tissue from patients who have died from hypertension and other heart diseases to look for elevated ACE2 levels. Lung tissue from COVID-19 victims also could be analyzed to see if ACE2 levels are elevated.
“This discovery provides another reason for patients taking angiotensin-converting enzyme (ACE) inhibitors and angiotensin II receptor blockers to stay on their heart medications, as recommended by all major cardiac societies,” said Dr. Ackerman. “Removing these medications in a patient whose heart has elevated protein levels of ACE2 could cause even more tissue damage.”
The study is published in the journal Mayo Clinic Proceedings.