Native T₁ mapping times are strongly influenced by elite athlete status

Limited data indicates that athletes’ hearts demonstrate decreased native T₁, but this assertion has not been replicated in large cohorts of extreme phenotypes of elite athletes. Therefore, we investigated differences in native T₁ between elite athletes and healthy non-athletic controls.

Cross-sectional analysis comparing native T₁ between elite athletes (≥16 years; ≥10 h of exercise/week) and age-matched healthy non-athletic controls. All participants underwent cardiovascular magnetic resonance imaging on a 1.5 tesla MRI machine. We included 240 elite athletes [50% women; age 28 years (25–32)] and 80 non-athlete healthy controls [50% women; age 28 years (23–39)]. Elite athletes demonstrated lower native T₁ than non-athlete healthy controls (960 ± 21 ms vs. 983 ± 26 ms, P < 0.001), also when stratified by sex (male athletes vs. controls 953 ms ±19 vs. 968 ms ±16, P < 0.001; female athletes vs. controls 968 ms ±20 vs. 999 ms ±25, P < 0.001). Multivariate linear regression identified elite athlete status (β = −13.34, P < 0.001), heart rate (β = 0.6, P < 0.001), average left-ventricular wall thickness (β = −8.28, P < 0.001) and native blood pool T₁ (β = 0.09, P < 0.001) as independent determinants of native T₁ (adjusted R² = 51.4%, P < 0.001).

Elite athletes have lower native T₁ compared with non-athletes, both in women and men. Athlete- and sex-specific reference ranges should be applied when interpreting native T₁ in athlete populations, especially in female athletes.