Background: Data on cardiac remodeling in veteran athletes are conflicting but of clinical importance.
Methods: Sixty-nine clinically stable and healthy individuals >50 years were identified (median 55 (IQR 52-64), 26% female). Echocardiographic features were identified in individuals, who have performed endurance sports at 70% of their maximum heart rate for at least 1 hour 3 times/ week over the previous 5 years.
Results: Median training time in all participants was 6 hours per week. Therefore, based on these 6 hours of weekly training, participants were grouped into 45 ambitious endurance-trained amateur athletes (EAA) and 24 recreationally active endurance-trained athletes (RAP) training ≥6 hours (6-10) and <6 hours (3.5-5), respectively. Left ventricular (LV) diameters were slightly larger in EAA than in RAP (27 mm/m2 (25-28) vs. 25 mm/m2 (24-27), p = 0.023) and EAA showed preserved diastolic function (p = 0.028) with lower E/E' ratio (7 (6-9) vs. 9 (7-10), p = 0.039). Interventricular septal thickness and relative wall thickness ratio were similar. Global right ventricular and LV strain were similar, but left atrial (LA) reservoir strain was higher in EAA than in RAP (27% (22-34) vs. 20% (15-29), p = 0.002).
Conclusions: Endurance training in healthy athletes >50 years is not associated with chamber dilatation or LV hypertrophy. A weekly training duration of ≥6 hours seems beneficial to preserve diastolic function associated with an increased LA reservoir function.