Former NFL players were more likely to have enlarged aortas, but further study is needed to determine whether that puts them at greater risk for life-threatening aneurysms, researchers found.
The former National Football League players were twice as likely to have enlarged aortas as those in a control group, even after adjusting for their typically larger size and other factors, said researchers with the Dallas Heart Study at UT Southwestern Medical Center, from which the control group was drawn.
"Whether that translates to the same risk for these former elite athletes as a dilated, or enlarged, aorta does for the general population is unclear," said cardiologist Dr. Parag Joshi, Assistant Professor of Internal Medicine and one of the study's authors. "Is this a normal adaptation from having trained at the elite level throughout their youth, or is this a bad adaptation that puts them more at risk for problems?"
Former linemen – players who tend to be larger and engage in more strength training than nonlinemen – were more likely to cross the threshold into the enlarged aorta range, suggesting that increased aortic diameter is an adaptation to the demands placed on a player's heart during his career, said co-author and fellow cardiologist Dr. James de Lemos, Professor of Internal Medicine and Medical Director for the Dallas Heart Study.
Nearly 30 percent of the former NFL players studied had enlarged aortas compared with fewer than 9 percent in the comparison group from the Dallas Heart Study, a one-of-a-kind population-based study to identify new genetic, protein, and imaging biomarkers that can detect cardiovascular disease at its earliest stages, when prevention is most effective.
Researchers from UT Southwestern, Johns Hopkins Medicine, and MedStar Sports Medicine, which treats professional and college teams, collaborated in the study, led by the Cleveland Clinic. The findings appear in the journal Circulation: Cardiovascular Imaging.
The new study advises clinicians to note if a patient with an enlarged aorta has a history of long-standing athletic activity and calls for further research into what risks the enlarged aortas pose for these athletes.
Researchers used innovative imaging techniques to compare the size of the ascending aortas – arteries that carry blood out of the heart. Patients with enlarged aortas over 40 millimeters (about 1 ½ inches) in diameter are at increased risk to develop a tear that can require emergency surgery or even lead to death, said Dr. Joshi.
Earlier studies found larger aortas in active elite athletes, but the size was still within the normal range, Dr. Joshi said. However, a person's aorta tends to get bigger with age, so the former NFL players may have developed larger aortas while playing, then entered the enlarged range as their aortas continued to dilate with age.