Study: How to cut firefighter heart attacks

A Johns Hopkins University School of Medicine study shows prevention is critical reducing firefighter cardiac events

By Dominique Ashen, Ph.D., CRNP

How you live your life today may determine whether or not you die in the line of duty. Exercise, diet and family history may have more to do with your risk of dying on a scene than what you do when responding to an incident.

The sobering fact is that heart disease causes nearly half of firefighter line of duty deaths, with the highest risk occurring during fire suppression. For 2012, the U.S. Fire Administration reported that of the 82 firefighters who died in the line of duty, 45 percent died of a cardiovascular event — more than any other cause of death. And of those cardiovascular events, heart attack was the most common. 

"As we review the fatality reports each year, it has become increasingly obvious that the number one reason for firefighter fatalities is cardiovascular events," said Chief Ronald J. Siarnicki, executive director of the National Fallen Firefighters Foundation. "And age is not necessarily the determining factor, as many people may presume. We're seeing firefighters in their 40s and 50s, who otherwise seem healthy, succumbing to a heart attack on a scene or soon after returning from a call."

9 risk factors

The cardiovascular risk factors you bring to a fire that may increase your risk for a heart attack or stroke including:

  • High blood pressure (>140/>90).
  • High cholesterol (total cholesterol >200).
  • Poorly controlled blood sugar (fasting >100) or diabetes (HbA1C >7%).
  • Age (over 45 in men and over 50 in women).
  • Family history of heart attack or stroke (at age ≤ 55 in a father, brother or son or at age ≤ 65 in a mother, sister or daughter).

Poor lifestyle habits that increase your risk for a heart attack including:

  • Poor dietary choices.
  • Lack of regular exercise.
  • Tobacco use.
  • Overweight or obesity.

This may not seem surprising since it is widely recognized that firefighters are exposed to extreme environments, wear heavy equipment, are under high stress and are exposed to many toxins. But, there are studies that indicate that these on-duty cardiovascular events occur almost exclusively among susceptible firefighters with underlying heart disease.

Fatty Plaque
Someone who is susceptible has risk factors for cardiovascular disease, which is the development of fatty plaque in blood vessels. The plaque reduces blood flow to organs, especially the heart and brain, which can result in heart attack and stroke. 

A common symptom of reduced blood flow to the heart is chest pain during activity. But, that is not always the case. Some individuals have fatty plaque build-up in their heart vessels and have no symptoms, even with heavy exertion.

Studies show that high blood pressure and obesity in firefighters increase cardiovascular risk and that high fasting blood sugar and high cholesterol are common risk factors in firefighters with underlying fatty plaque in the heart and neck vessels.

The key is to identify those firefighters at risk for a cardiovascular event before they get to a fire and, thus, prevent heart attack or stroke.

New study
Dr. Elizabeth Ratchford and I lead the team of researchers at the Johns Hopkins Ciccarone Center for the Prevention of Heart Disease and the Johns Hopkins Center for Vascular Medicine who believe that disability and death from a heart attack in firefighters is preventable.

We recently completed a pilot study, funded by the National Fallen Firefighters Foundation, on designing a cost-effective, cardiovascular disease prevention program. The goal was to develop a program that would identify at-risk firefighters through evaluating cardiovascular risk factors and fatty plaque, risk factor reduction, intensive lifestyle counseling, and referral for medication management if necessary. 

"We were very excited about this partnership between the Foundation and Johns Hopkins and the potential for finding a way to help firefighters recognize their risk for cardiovascular incidents so that they could take appropriate steps to improve their health management," said Siarnicki.

Sample size
Fifty firefighters (both men and women) were recruited from two county fire departments in Maryland. To be included in the study, firefighters had to be at least 40 years old, have no history of cardiovascular event or diabetes, have operational duties and have a primary care provider. 

Each firefighter had blood work to check cholesterol and blood sugar, a physical exam to check weight and blood pressure, evaluation of family history and lifestyle habits, and intensive lifestyle counseling. The researchers also used common screening technology (CT scan and ultrasound) to determine if there was fatty plaque in the heart and neck vessels indicating early vascular disease. 

When reviewing the risk factors in this population of firefighters (ranging in age from 40 to 58), there was clear evidence for obesity, elevated blood pressure, blood sugar, and cholesterol, as well as poor lifestyle habits. 

  • 32 percent had a family history of cardiovascular disease.
  • 48 percent had above normal, though not high blood pressure.
  • 48 percent were obese; only 14 percent had a normal body mass index.
  • 50 percent had high fasting blood sugar in the pre-diabetes range.
  • 66 percent of men were over 45.
  • 90 percent or more had poor diet and/or exercise habits.

Surprise findings
What was very surprising was the evidence of early, underlying vascular disease, that is fatty plaque, in the heart and neck vessels of firefighters who did not have any symptoms that would suggest the presence of disease, such as chest pain. We found one out of every five firefighters had fatty plaque in the heart vessels and 33 percent had fatty plaque in the neck vessels.

The research team discovered something even more important: there was no difference in traditional cardiovascular risk factors, including blood pressure, blood sugar, age, tobacco use and weight, between firefighters with fatty plaque in their heart and neck vessels and those without fatty plaque. 

In other words, had we not looked inside to detect early vascular disease and instead relied only on evaluation of traditional cardiovascular risk factors, we would not have identified those firefighters at risk for heart attack and stroke.

The results of this study, including identification of cardiovascular risk factors and the presence of fatty plaque in heart and neck vessels, are similar to those found in other studies of firefighters and clearly point to increased risk of heart attack and stroke. What makes this study so important is the development of a prevention program.

Early detection needed
Our findings clearly illustrate that it is time to implement a nationwide program that focuses on early detection and prevention of heart attack and stroke starting when firefighters enter the workforce and continuing throughout their careers.

The Johns Hopkins study focused on firefighters 40 and older because the tests that look inside are more likely to detect fatty plaque in this age group. However, these researchers agree that the cardiovascular risks among firefighters under 40 should not be ignored. 

It is equally important to work with young firefighters to identify risk factors for cardiovascular disease, implement lifestyle modifications and medication, if necessary, in order to prevent the development of future cardiovascular disease and events, such as a heart attack or stroke, while on the job. A program of prevention that covers the lifespan of a firefighter's career requires a focused team approach.

Siarnicki agrees.

"If more firefighters are aware of their potential risks for cardiovascular disease and receive guidance on how to manage their lifestyles, the fire service may continue to see fewer incident-related deaths," he said. "There will always be incidents that are beyond our control, and there will continue to be line of duty deaths, but when there is something like this that can be corrected, it just makes sense to take those preventative steps."

Molly Natchipolsky, a writer for the National Fallen Firefighters Foundation, contributed to this article.

About the author

Dominique Ashen Ph.D., CRNP is from the Johns Hopkins Ciccarone Center for the Prevention of Heart Disease. She can be reached at

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