Key TakeawaysCardiac arrest and heart attacks account for nearly half of all on-duty firefighter deathsHeart-related deaths among firefighters have steadily increased over the past three decadesEnlarged heart mass appears to play a role.MONDAY, Oct. 26, 2026 (HealthDay News) — Cardiac arrest and heart attacks account for nearly half of all on-duty firefighter deaths in the United States, a new study says.Heart-related deaths in the line of duty have steadily increased over the past three decades, researchers reported Oct. 21 in the journal JACC: Advances.The results suggest that annual health screenings for firefighters might miss heart conditions that increase their risk of death during the stress and strain of battling a blaze or responding to a wreck, researchers said.“Our research shows there may be a blind spot when it comes to routine heart screenings for firefighters in the United States,” senior researcher Dr. Alan Kwan said in a news release. He is an assistant professor of cardiology at Cedars-Sinai Medical Center in Los Angeles. For example, most of these deaths were not related to clogged arteries, but to enlarged heart muscle mass, researchers said.“It’s possible that national firefighter health guidelines need to be updated to include screening for excess heart muscle mass,” researcher Dr. Susan Cheng, chair of cardiology at Cedars-Sinai, said in a news release. “It’s not clear why firefighters appear to be at risk for this condition, and so we need to learn more through additional research.”For the study, researchers analyzed federal data documenting more than 3,400 on-duty firefighter deaths between 1990 and 2025.Results showed that 43% of the deaths were related to cardiac arrest or heart attack.Clogged arteries were involved in 57% of cardiac cases, but enlarged heart mass was noted in 79% of cases, researchers found.Rigorous firefighter training builds heart muscle, which can change heart structure in ways that might mask or contribute to dangerous cardiac conditions, researchers said.“Identifying heart conditions when they can be treated is key to addressing these new findings,” Kwan said.Over the decades, the odds that any given death was heart-related increased by more than 2% each year among on-duty firefighters, even as the odds of heart-related deaths for the general public fell by more than 1% each year.“This trend suggests that prevention of on-duty cardiac death has not kept pace with other domains of firefighter safety,” Kwan said. “This work builds on prior research reporting that cardiac events are a major cause of death for firefighters. We plan to continue our study of firefighter health risks to inform prevention efforts.”More informationThe National Volunteer Fire Council has more on its heart-healthy firefighter program.SOURCE: Cedars-Sinai Medical Center, news release, Oct. 21, 2026 .What This Means For YouFirefighters should be aware of their increased risk of cardiac death and seek screening to assess their heart health..Sign up for our weekly HealthDay newsletter