Lifelong endurance exercise and its relationship with coronary atherosclerosis

Presented at the ACC.23 by: Ruben de Bosscher, MD, PhD - Leuven, Belgium

Introduction and methods

Exercise helps reduce blood pressure, cholesterol levels and blood glucose levels which leads to less coronary syndromes. However, in endurance athletes there seems to be a paradox. Endurance athletes were previously found to have higher CAC scores and more coronary plaques compared to controls. An important nuance is that the composition of the plaques in athletes were found to be different compared to controls, with a higher prevalence of calcified plaques which are considered to be more stable and less prone to rupture than mixed plaques. However, previous studies included subjects with CV risk factors. The dose response relationship and the absolute prevalence of calcified, non-calcified and mixed plaques in participants without CV risk factors had not been investigated so far.

The Masters@heart study investigated whether lifelong endurance exercise associated with more coronary atherosclerosis than the standard of care (defined as a low CV risk profile and up to 3 hours exercise per week). The study included men between 45-70 years old without CV risk factors and with at least 6 months of endurance training (≥8h/week cycling or ≥6h/week running) or no endurance training (≤3h/week). Participants were part of one of three groups: lifelong endurance athletes (starting age <30 years, n=191), late-onset endurance athletes (starting age >30 years, n=191) or control group (n=176). The primary endpoint was the prevalence of coronary plaques (calcified, mixed, and non-calcified) on CT coronary angiography.

Main results

• The mean age of all participants was 56±6 years and similar between the groups. Individuals in the control group had a higher body weight, BMI and fat percentage compared to lifelong athletes and athletes who started endurance sports at a later age. There was no difference in blood pressure, total cholesterol, LDL-c and HbA1c between the groups. Lifelong athletes trained an average of 11 (10-14) hours per week, athletes who started later in life 10 (9-20) hours per week and controls 1 (0-3) hour per week.
• Lifelong athletes had a higher prevalence of ≥1 plaque (OR 186, 95%CI 1.17-2.94), ≥1 proximal plaque (OR 1.96, 95%CI 1.24-3.11) and >50% stenosis (OR 2.79, 95%CI 1.20-6.48), compared to controls
• There was no difference in the distribution of plaque types. Calcified plaques was the predominant plaque type in all three groups, followed by mixed plaques and non-calcified plaques.
• When looking at each plaque type individually, lifelong athletes had a higher prevalence of ≥1 calcified plaques (OR 1.58, 95%CI 1.01-2.49), ≥1 non-calcified plaques (OR 1.95, 95%CI 1.12-3.40) and ≥1 mixed plaques (OR 1.78, 95%CI 1.06-2.98) compared to controls. In addition, lifelong athletes had a higher prevalence of >50% stenosis for non-calcified plaques compared to late-onset athletes (OR 8.17, 95%CI 1.01-66.18).
• The prevalence of vulnerable plaques (defined as ≥2 high risk features) was generally low in all groups, but was found to be significantly lower in livelong endurance athletes compared to controls (OR 0.11, 95%CI 0.01-0.91).

Conclusion

Among men aged 45 to 70 years old without CV risk factors, lifelong endurance athletes (≥8h/week cycling or ≥6h/week running, started before the age of 30 years) have a higher coronary plaque burden compared to participants who exercise for up to 3 hours a week, irrespective of the plaque type.

De Bosscher ended his presentation by noting: “The worst thing that you can do, is doing nothing at all and your only relationship with exercise would be watching it from TV or grandstands whilst eating junk food. But as soon as you do a little bit of exercise, a little bit of walking or jogging up to 3 hours per week, it seems that you get the most benefit. As you then increase your exercise dose, we tend to see an increase in coronary plaque burden.”

-Our reporting is based on the information provided at the ACC.23/WCC-

This study was simultaneously published in Eur. Heart J