How COVID and Many Other Infections Cause Heart Disease

Ask most doctors what causes heart disease and you will likely be told that it’s “bad” cholesterol. For decades, we have been advised that the culprits behind clogged coronary arteries are total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C). Triglycerides (TGL) and lipoprotein(a), also known as Lp(a), might also be blamed for contributing to cardiovascular disease (CVD). What very few people learn is that a surprisingly large number of infections cause heart disease. Could viruses, bacteria and fungi also contribute to CVD?

The Silo Effect Is Dangerous!

There is a growing realization that modern medicine creates silos. Cardiologists tend to communicate with other cardiologists. Infectious disease (ID) specialists hang out with other ID experts. Gastroenterologists go to GI meetings and orthopedic surgeons bone up on the latest surgical strategies.

Everyone is so busy that they may not have much opportunity to read journal articles in other specialties. This silo effect suggests that specialists may miss developments in fields that, while seemingly irrelevant to them, might be relevant to their patients.

Cardiology and Cholesterol:

For decades, most cardiologists have looked upon statins as their # 1 tool to prevent heart disease. That is why atorvastatin (Lipitor) has been the most prescribed drug in America for years. At last count, over 28 million people take this medicine daily. If you add in simvastatin, rosuvastatin, pravastatin and lovastatin, the number exceeds 50 million people taking a statin-type cholesterol-lowering drug every day.

When you think that the best tool you have is a statin, then LDL cholesterol becomes the only nail you look at. There is only one problem with this approach. It has not cured heart disease. After decades of aggressive cholesterol control with statins and other medications, heart disease remains the major killer of Americans (Circulation, Jan. 27, 2025).

One might imagine that if LDL cholesterol is the # 1 nail in the heart disease coffin, we would have more made more progress against this deadly disease. Statins are amazingly effective at lowering LDL cholesterol. You can read more about this paradox at this link:

“If Statins Save Lives, Why Is Heart Disease Still #1 Killer?”

Could it be that there are many risk factors for heart disease? If we focus on just one or two blood lipids, are we missing other contributors to this persistent health problem?

What If Infections Cause Heart Disease Too?

What if infections harm your heart? Research indicates that a variety of infectious agents can increase the risk for heart disease. For example, a number of studies suggest that COVID-19 could raise the the chances of cardiovascular complications in the future.

Rates of COVID-19 are currently low, but researchers are learning more about long-term cardiac complications. A study in JAMA Network Open (June 9, 2025) reveals that people who were seriously ill with the infection may have reduced blood flow in the small vessels feeding the heart. This condition, called coronary microvascular dysfunction, limits blood to the heart under stress. This in turn may impair cardiac function. This is just one of a number of cardiovascular complications that may linger after people seemingly recover from COVID-19.

COVID Infects Coronary Arteries:

Most people associate long COVID with shortness of breath, brain fog, intense fatigue, dizziness on standing and rapid heart rate. There is also a recognition that the SARS-CoV-2 virus can cause blood clots and harm small blood vessels in various parts of the body.

A study published in Nature Cardiovascular Medicine (Sept. 28, 2023) tells a further story.  It is titled:

“SARS-CoV-2 infection triggers pro-atherogenic inflammatory responses in human coronary vessels”

In other words, the virus that causes COVID and damages the lungs can also invade coronary arteries. That can lead to inflammation and accelerate the development of arterial plaque.

The authors of this research state in their introduction:

“AMI [acute myocardial infarction aka heart attack] and stroke can be triggered by several acute respiratory viral infections, including influenza virus. However, patients with COVID-19 are >7-fold more likely to have a stroke than patients with influenza, and their risk for both AMI and stroke remains high for up to 1 year after infection.”

Can COVID Infections Harm Your Heart?

Did you appreciate the significance of the quote above? The authors point out that people who caught COVID-19 were at least 7 times more likely to experience a stroke than people who caught influenza. And people who catch influenza are more likely to experience a stroke than healthy folks who do not catch the flu.

These researchers found that the virus that causes COVID homes in on foam cells that infiltrate arterial walls.

They state:

“We found evidence of SARS-CoV-2 replication in all analyzed human autopsy coronaries…Our data conclusively demonstrate that SARS-CoV-2 is capable of infecting and replicating in macrophages within the coronary vasculature of patients with COVID-19.”

The patients in the study already had cardiovascular disease, so these results should not be generalized to young, healthy people. Nevertheless, COVID-19 appears to increase the risk for cardiovascular complications.

This Is Really Important!

These authors demonstrated that severe COVID infections cause heart disease. That’s a big deal. If the virus can trigger inflammation and atherosclerosis in coronary arteries, then we may need other strategies to prevent this kind of cardiovascular disease.

The long-term consequences of this virus may not yet be appreciated. A study in the journal AJPM Focus (Oct. 6, 2024) concludes:

 “Individuals with a COVID-19 diagnosis had almost 2 times the total medical costs, double the number of inpatient admissions, and 4–5 times longer inpatient stays associated with HD [heart disease] than individuals without a COVID-19 diagnosis.”

The world could gradually see an uptick in cardiovascular disease over the coming years because so many people caught COVID.

What Other Infections Cause Heart Disease?

Cardiologists are quite familiar with a condition called endocarditis. It means inflammation of the membrane that lines the internal surface of the heart. This is a life-threatening condition because it can damage heart valves.

A variety of pathogens can cause endocarditis. Most are bacterial: strep, staph and enterococci. There are several other nasty bacteria that can also invade the heart, but they are in the minority. Fungal endocarditis is quite rare, but it is especially dangerous. Candida and Aspergillus can also invade the internal heart lining, especially in people with compromised immune systems.

No physician will argue about infections that cause endocarditis. It is a recognized medical crisis. More controversial, however, is the idea that infections harm your heart by targeting coronary arteries. Remember, we started this article by noting that heart disease is attributed to cholesterol and other nasty lipids circulating in the blood stream. What if infections also promote atherosclerosis and coronary artery disease?

Evidence That Microbial Infections Harm Your Heart:

Dutch researchers wrote an article titled “Infection and Atherosclerosis: An Alternative View on an Outdated Hypothesis” (Pharmacological Reports, Jan.-Feb, 2008). The authors point out that by the end of the 19th century there were indications that infections might lead to clogged coronary arteries. By the 20th century there was evidence that avian herpes virus contributed to atherosclerotic plaques in chickens.

They go on to note:

“Since then, several pathogens have been related to the development of cardiovascular diseases, such as Helicobacter pylori, the periodontal pathogen Porphyromonas gingivalis, hepatitis A virus, influenza virus and various Herpesviridae [herpes viruses]. As a prominent member of the latter, cytomegalovirus (CMV) has frequently been associated with cardiovascular diseases.”

Another pathogen linked to atherosclerosis is Chlamydia pneumoniae (Cpn). The same germ has been associated with hard-to-treat asthma. We (The People’s Pharmacy Press) even published a book called “A Cure for Asthma: What Your Doctor Isn’t Telling You—And Why” by David L. Hahn, MD, MS). Should you be interested in learning more about how this bacteria could contribute to challenging asthma cases, here is a link.

How Do Infections Cause Heart Disease?

Because most of the research of the last decades has focused on lipids and heart disease, scientists do not have a clear understanding of how infections cause heart disease. For reasons that mystify me, cardiologists have not paid very much attention to the relationship between gum infections (periodontitis) and cardiovascular disease (CVD).

Inflammation is a key player in this drama. An editorial in the journal Frontiers in Dental Medicine (May, 2025) offers this explanation:

“This inflammation plays a critical role in the development and progression of atherosclerosis—the buildup of fatty plaques in the arteries—which can lead to heart attacks and strokes. A key mechanism that links periodontitis to CVD [cardiovascular disease] is the impact of oral bacteria on endothelial function. Endothelial cells line the blood vessels and play a critical role in maintaining vascular health. The introduction of bacterial endotoxins from periodontal infections can damage endothelial cells, contributing to atherosclerotic plaque formation with certain immunomodulatory pathways.”

The bottom line seems to be that bacteria in the gums can migrate to the blood stream and cause inflammation in and damage to coronary arteries. That in turn can lead to atherosclerosis.

How many times has a cardiologist looked in your mouth or asked you about your gum health?

The Bandwagon Effect Dismisses the Idea that Infections Harm Your Heart:

Although cardiologists accept the idea that infections can cause endocarditis, they have not embraced the idea that infections can contribute to atherosclerosis and coronary artery disease (CAD). Let’s face it, they are all in on the lipid theory of CAD. Alternate hypotheses are not very welcome. And funding agencies are not likely to consider something considered so radical.

But an article in ARYA Atherosclerosis (Jan. 2016) offers this overview of “Infectious and Coronary Artery Disease”:

“Based on the studies in databases and our literature review, it is so clear that some microbes and infectious agents can be involved in the process of atherosclerosis…We think that the infectious agents can be involved in both direct and indirect mechanisms of inflammation effect on the process of atherosclerosis…We believe that infection should be considered as an important risk factor for atherosclerosis. Therefore, controlling each type of infections especially among people with a traditional risk factor for atherosclerosis should be taken into account for reducing the risk of CAD and atherosclerosis.”

Final Words:

In considering possible preventive strategies, we discovered an article in the American Journal of Medicine, May, 2023. The authors performed a meta-analysis of randomized influenza vaccine trials.

They reported that:

“Influenza vaccine is a cheap and effective intervention to reduce the risk for all-cause mortality, cardiovascular mortality, major acute cardiovascular events, and acute coronary syndrome among coronary artery disease patients, especially in those with acute coronary syndrome.”

They attribute the success of the flu shots to reduced inflammation. When someone catches influenza, there is inflammation throughout the body. That includes the heart. If there is increased inflammation within the coronary arteries, that could lead to plaque rupture and a heart attack.

There is also the possibility that influenza could make atherosclerosis worse. Remember, the article we cited above in Pharmacological Reports from 2008 listed influenza viruses as a contributing factor in cardiovascular diseases.

Take Home Message(s):

Here are the key concepts to consider from this article:

1. Heart disease remains our # 1 killer despite decades of effective cholesterol-lowering drugs.
2. There are many contributors to cardiovascular disease…not just cholesterol.
3. Because heart disease is multifactorial, prevention and treatment require multiple strategies.
4. Health care professionals need to provide patients meaningful support to overcome many of the factors that cause heart attacks and strokes. 

You can learn much more about the many contributing factors to heart disease and practical strategies for reducing risks in our eGuide to Cholesterol Control & Heart Health. This online resource can be found under the Health eGuides tab.

It will be challenging for many cardiologists to consider the concept that infections contribute to atherosclerosis and heart attacks. Without a paradigm shift, though, funding agencies like the National Institutes of Health are not likely to invest in such research. Incorporating anger management, infection prevention, exercise encouragement, gum treatment and other programs to mitigate heart dangers requires a team approach. Will the American College of Cardiology (ACC) and the American Heart Association (AHA) encourage such collaboration?

Drug companies are not particularly interested in vaccines against infections that might contribute to heart disease. Studies that demonstrate long-term cardiovascular benefits from vaccinations are extremely expensive. It is unlikely that they would provide a big return on investment (ROI). It is far more profitable to sell medications that must be taken regularly for the rest of a person’s life.

Pharmaceutical manufacturers are never going to conduct studies into the benefits of exercise, stress and anger management or infection prevention. There’s no ROI for them if a drug is not involved. Many of the priciest medications on the market for conditions such as rheumatoid arthritis, eczema, psoriasis and inflammatory bowel diseases actually lower immunity and increase the risk of serious infections.

Sorry to be so cynical…but we have been observing the pharmaceutical industry for 50+ years. Over that time, we have seen profits trump patients’ health almost every time.

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