Having Shingles May Increase Long-Term Risk of Heart Attack, Stroke

People who have had shingles—the reactivation of the chickenpox virus—may also have an increased risk of a major cardiovascular event, like stroke or heart attack, even in the long term, new research shows.

The study, published in November in the Journal of the American Heart Association, found that shingles is associated with a nearly 30% higher long-term risk of a major cardiovascular event, for as many as 12 or more years following the illness. The heightened risk may also be greater for those who are immunocompromised.

Past research on shingles, also known as herpes zoster, has linked the viral illness to an increased risk of stroke and heart attack in the short term—up to a year after having shingles—but limited information on the long-term implications of shingles exists.

“Although some previous studies showed a higher short-term risk of stroke and heart attack around the time of shingles infection, it was not known whether this higher risk persisted in the long term,” lead study author Sharon G. Curhan, MD, a physician and epidemiologist in the Channing Division of Network Medicine at Brigham and Women’s Hospital, told Health.

Most Middle-Aged Americans at Risk for Shingles 

Shingles is a viral infection that causes a painful rash to break out on one part of the body, such as one arm or one side of the torso. It’s caused by the varicella zoster virus (VZV), which is the same virus that causes chickenpox. 

After a person has chickenpox, VZV stays in their body for the rest of their life. Years and even decades later, the virus may reactivate as shingles. According to Dr. Curhan, almost everyone in the US ages 50 years and older has been infected with VZV and is therefore at risk for shingles. About one-third of Americans will develop shingles in their lifetime, according to the Centers for Disease Control and Prevention (CDC). 

“There is a growing body of evidence that links the varicella zoster virus to vascular disease,” said Dr. Curhan, adding that VZV is the only human virus known to replicate in the arteries and lead to vasculopathy, or issues that affect the blood vessels.

Experts believe that this damage, often due to inflammation, is what increases a person’s risk for stroke or heart attack after having shingles.

To determine how long this risk may last, Dr. Curhan and her team used data from three large US studies—two Nurses’ Health Studies and the Health Professionals Follow‐Up Study—which followed people for up to 16 years. They included more than 200,000 people in total and excluded anyone who had a history of cardiovascular disease.

After adjusting for other risk factors that could have caused heart disease, the researchers determined that having shingles was associated with a nearly 30% higher long-term risk of a major cardiovascular event, specifically stroke or heart attack, and that the risk lasted for as long as 12 years—and possibly longer—after a person had shingles.

Since it was an observational study, rather than one that tested an intervention, it does not provide, “complete proof that it’s shingles, but it does start to lead a new thought process,” Ashok Krishnaswami, MD, a member of the American College of Cardiology’s Geriatric Cardiology Council and cardiologist in San Jose, California, who was not involved with the new research, told Health.

The study also highlights the importance of prevention—particularly due to the availability of a safe and effective shingles vaccine.

Shingles Vaccination Is the Only Way to Protect Against the Disease

Most of the data in the new study was collected before a shingles vaccine was available in the US, and Dr. Curhan said that even when a vaccine became available, there was very little uptake. She said the results of the study highlight shingles as a public health threat and the importance of preventing the condition.

In 2017, the CDC started recommending the two-dose Shingrix vaccine—which is not a live vaccine—to prevent complications from shingles in adults over 50. The agency also recommends the vaccine for anyone over 19 who has a weakened immune system. A live shingles vaccine, called Zostavax, is no longer available in the US as of 2020 since the Shingrix vaccine is both safer and more effective at preventing shingles.

According to Dr. Curhan, as uptake of the newer shingles vaccine increases, future studies will need to determine whether or not vaccination status influences a person’s risk of developing shingles-related cardiovascular disease.

Cardiovascular disease deaths account for about 1 in 3 deaths in the US, according to the CDC. Dr. Krishnaswami noted that getting shingles is far from the only risk factor associated with heart disease, so getting vaccinated alone is not enough to prevent cardiovascular disease in the future. 

“Along with that, you should really try to get the other risk factors in control,” he said. 

These include having high blood pressure, high low-density lipoprotein (LDL) cholesterol, smoking or being exposed to secondhand smoke, having diabetes or obesity, eating an unhealthy diet, and not getting enough exercise.