Elite athlete status, gender and mitchell sports classification strongly influence native t1 mapping times

Abstract Funding Acknowledgements Type of funding sources: Public Institution(s). Main funding source(s): Amsterdam Movement Sciences and the Dutch Olympic Committee. Background Cardiac magnetic resonance imaging (CMR) T1 mapping is an established tool for tissue characterisation. This is of particular interest in athletes as differentiation of the ‘grey zone’ between physiological adaptation to sports and pathology can be highly challenging. To correctly interpret individual T1 times, T1 times are conventionally compared to normal values derived from healthy controls. However, whether these values can be applied to elite athletes with different types of cardiac adaptation is unknown. Purpose To determine differences in native T1 times between elite athletes and healthy non-athletic controls and to determine differences in athletes with different types of cardiac remodelling. Methods This is a cross-sectional analysis of elite athletes included in the ELITE cohort. ELITE collects the preparticipation cardiovascular screenings data from all athletes that perform at the highest national, international and/or Olympic level in the Netherlands. All athletes were sixteen years or older. The screening includes cardiovascular magnetic resonance imaging on a Siemens Avanto fit 1.5T machine with cine-imaging, delayed hyperenhancement and a three-pulse shortened modified look-locker inversion recovery 5(3)3 sequence. For this analysis, all athletes with a history of cardiovascular disease or pathological late gadolinium enhancement were excluded. Athletes were classified according to the Mitchell Sports Classification based on the intensity (low (L) / moderate (M) / high (H)) of the dynamic (D) and static components (S). Native- and post-contrast T1 mapping times were calculated by manually tracing the endocardial- and epicardial contours. Results A total of 117 elite athletes (44% women; mean age 26±6.5; Mitchell sports classification: 47 HS/HD, 8 HS/LD, 5 HS/MD, 36 LS/HD, 16 MS/HD, 3 MS/MD, 3 missing) and 48 healthy non-athletic controls (54% women; mean age 39±15.1). Men had lower t1 times compared to women, both in athletes (949ms vs 964ms, p<0.05) and controls (969ms vs 1000ms, p<0.05). Moreover, elite athletes had a lower global native T1 time compared to healthy non-athletic controls (955 vs 983, p<0.05). There were significant differences in native T1 time between the Mitchel Sport classifications (Kruskal-Wallis p<0.05); left ventricular mass (LVM) (R=-0.47, p<0.05) and LVM divided by left ventricular end-diastolic volume (R=-0.4, p<0.05) were both negatively correlated with native T1 mapping time. Conclusion Men demonstrate markedly shorter T1 times compared to women in both athletes and controls. Moreover, native T1 times were associated with markers for cardiac remodelling. Sex- and athlete-specific characteristics should be taken into account when interpreting T1 times in athletes.