Age impacts left atrial functional remodeling in athletes

Long-term left atrial adaptations to reduced training load in former elite athletes: a long-term follow-up longitudinal observational study

Objective

Our objective was to evaluate the effects of long-term reduced training on the left atrium (LA) in elite endurance athletes and to elucidate sex-specific differences in LA detraining patterns.

Methods

In this long-term longitudinal echocardiographic study of 50 active elite endurance athletes a follow-up examination was performed 7 years after retirement from the elite programme. All echocardiographic measurements were indexed for body surface area. We analysed the changes between baseline and follow-up measures using analysis of covariance models adjusted for baseline level, sex and enrolment age as covariates. Results are reported as least squares means with two-sided 95% CIs.

Results

LA enlargement (left atrial maximum volume index) remained unchanged from baseline (change from baseline: 1.4mL/m2, 95% CI: -0.7 to 3.5 mL/m2) despite significant reductions in VO2max (change from baseline: -864mL/min, 95% CI: -1091 to -637 mL/min). In contrast, left ventricular (LV) end-diastolic volume was reduced (change from baseline: -8mL/m2, 95% CI: -11 to -5 mL/m2), consistent with reduced VO2max. LA contraction strain was increased (change from baseline: 1.4%, 95% CI: 0.4% to 2.5%), while LV filling pressure increased (E/e' change from baseline: 0.4, 95% CI: 0.1 to 0.7).

Conclusions

7 years of reduced training does not reverse exercise-induced LA enlargement in former elite endurance athletes. LA contractile function improved with higher LV filling pressure, suggesting that age-related LV pressure increases may contribute to chronic LA dilation, though irreversible adaptations like fibrosis cannot be ruled out.

Trial registration number

NCT05555849.

Certainties and Uncertainties of Cardiac Magnetic Resonance Imaging in Athletes

Prolonged and intensive exercise induces remodeling of all four cardiac chambers, a physiological process which is coined as the “athlete’s heart”. This cardiac adaptation, however, shows overlapping features with non-ischemic cardiomyopathies, such as dilated, arrhythmogenic and hypertrophic cardiomyopathy, also associated with athlete’s sudden cardiac death. Cardiac magnetic resonance (CMR) is a well-suited, highly reproducible imaging modality that can help differentiate athlete’s heart from cardiomyopathy. CMR allows accurate characterization of the morphology and function of cardiac chambers, providing full coverage of the ventricles. Moreover, it permits an in-depth understanding of the myocardial changes through specific techniques such as mapping or late gadolinium enhancement. In this narrative review, we will focus on the certainties and uncertainties of the role of CMR in sports cardiology. The main aspects of physiological adaptation due to regular and intensive sports activity and the application of CMR in highly trained athletes will be summarized.