Heart Scarring in Older Endurance Athletes Linked to Increased Risk of Dangerous Arrhythmias

Recent research published in Circulation: Cardiovascular Imaging highlights a potential health concern for older endurance athletes. The study reveals that long-term, healthy male athletes aged 50 and above who engage in intensive training may develop scar tissue in their hearts, which is associated with abnormal heart rhythms and increased risk of sudden cardiac death.

The study, named VENTOUX after a famous Tour de France mountain climb, involved 106 male cyclists and triathletes who trained at least 10 hours weekly for over 15 years and showed no symptoms of heart disease. Participants underwent advanced imaging techniques, including cardiovascular magnetic resonance (CMR), to detect signs of scarring, along with implantable ECG recorders for continuous heart monitoring.

Findings showed that nearly 50% of these athletes displayed signs of scarring in the left ventricle of the heart. Notably, about 3% experienced sustained ventricular tachycardia—a potentially fatal fast heart rhythm originating from the heart's lower chambers—while 19% had shorter episodes of rapid heartbeats.

These irregular heart rhythms, especially ventricular tachycardia, are among the most dangerous arrhythmias and can lead to sudden cardiac arrest, which remains a leading cause of death among athletes, particularly older men. Although myocardial fibrosis, or scarring, has been linked to arrhythmias in patients with heart muscle disease, its occurrence in otherwise healthy endurance athletes was unexpected.

Lead researcher Dr. Peter Swoboda expressed his surprise at the strength of the association between heart scarring and arrhythmic events in healthy athletes. The findings underscore the importance of cardiovascular screening for older athletes, especially if they experience symptoms such as chest pain, dizziness, or palpitations during exercise.

While the study's sample size was limited and may not be representative of the broader athletic population—including women and non-European athletes—it opens avenues for further research into the impact of lifelong intense exercise on cardiac health. The authors emphasize that early detection and awareness can help mitigate the risk of severe arrhythmias and sudden cardiac death.

Experts recommend that athletes and sports professionals familiarize themselves with basic life-saving techniques, like CPR and the use of defibrillators, to respond effectively in emergencies. Continued research is vital to understand whether the observed scarring is a cause of arrhythmias or a marker for other underlying processes.

In conclusion, this study sheds light on a previously underrecognized risk among aging endurance athletes, emphasizing the need for proactive cardiac health management in this group.