Long Distance Runners Have More Coronary Plaque?

Investigators performed computed tomography angiography on 25 people who had run at least one marathon a year since 1985, according to senior author Robert Schwartz, MD, of the Minneapolis Heart Institute and Foundation. They compared the athletes with 23 control patients who were undergoing the same scan for symptomatic or suspected heart abnormalities. 

In controls, the calcium plaque volume was 169 mm³ compared with 274 mm³ for the elite runners (P=0.028), the researchers reported at the American College of Cardiology meeting. The runners also had a higher calcium score and higher non-calcified plaque volume, although those differences did not reach statistical significance.

Lead author Jonathan Schwartz, MD, of the University of Colorado Health Science Center in Denver stated that the reasons for the high calcified plaque readings among hard-core athletes are elusive, "but the [runners'] favorable factors may be counterbalanced by metabolic and mechanical factors that enhance coronary plaque growth."

"You have to consider that these runners may be in a constant state of inflammation, and that may be why we are seeing more plaque," added Schwartz.

He said the researchers, who originally set out to compare their results with European studies using electron beam CT, sent letters to elite runners identified as having completed at least one marathon race in each of the last 25 years. "All the runners we contacted agreed to be in the study," he noted.

The investigators also identified a control group of 23 men who were undergoing coronary CT angiography for clinical reasons, typically for elevated risk factors or abnormal or/inconclusive stress tests.

The participants underwent 64-slice computed tomography angiography and were compared for blood pressure, heart rate, and serum lipids. The scan data were analyzed using commercial plaque characterization software for calcified and non-calcified plaque and calcium score.

No one is sure exactly what the plaque findings mean.

"I'm not sure you can make much from these data," added Maria Rosa Costanzo, MD, a spokesperson for the American Heart Association and medical director of the Edward Hospital Center for Advanced Heart Failure in Naperville, Ill. "We don't have any idea of the outcomes of these patients."

She also noted that the number of patients in the study was small.

But the investigators aren't finished. "More subjects are under study for clarification of these results," said the younger Schwartz.

• Explain to interested patients that this is a small study that needs further investigation and should not be used as the basis for reduction of exercise, which typically improves heart health.
• Note that this study was published as an abstract and presented at a conference. These data and conclusions should be considered preliminary until published in a peer-reviewed journal.

Schwartz J, et al "Does longterm endurance running enhance or inhibit coronary artery plaque formation? A prospective multidetector CTA study of men completing marathons for least 25 consecutive years" ACC 2010; Abstract 1271-330. ACC, American college of Cardiology