Comparison of 2D Speckle Tracking Echocardiography and Cardiac MRI Feature Tracking for Bi-Atrial Strain Assessment in Elite Athletes

Background: Data on Feature-tracking Cardiac Magnetic Resonance imaging (FT-CMR) in athletes is limited, and direct comparison of Speckle Tracking Transthoracic Echocardiography (STE) and FT-CMR-derived bi-atrial strain are lacking. Aim: To compare STE and FT-CMR longitudinal bi-atrial strain in a well-defined cohort of elite athletes and to determine the level of agreement between these modalities. Methods: Agreement between FT-CMR and STE derived bi-atrial strain was assessed in elite athletes from the Evaluation of Lifetime participation in Intensive Top-level sports and Exercise (ELITE) cohort (>16 years; exercise >10h/week; (inter)national or Olympic level). Absolute agreement was evaluated using a two-way mixed-effects model (ICC(3,1)). Results: We included 194 elite athletes (51% women; mean age 30 ±7 years). The interval between TTE and CMR was <24h in 93.3% of athletes. There was poor-to-moderate absolute agreement in two-way-mixed-effects model with single measure reliability in left atrial reservoir- (0.34 (95% CI: 0.21 ? 0.46, p < .001), conduit- (0.39 (95% CI: 0.26 ? 0.50, p < .001), and contractile strain (0.48 (95% CI: 0.36 ? 0.58, p < .001). There was no agreement in right atrial reservoir- (0.02, 95% CI: -0.12 ? 0.16, p = .4) and conduit strain (0.09, 95% CI: -0.07 ? 0.21, p = .17. There was poor agreement in RA contractile strain (0.218, 95% CI 0.080 ? 0.48, p = 0.001). Conclusion: There are important modality-dependent differences in bi-atrial strain in elite athletes. The poor-to-moderate agreement between longitudinal STE and FT-CMR left atrial strain and a lack of agreement in right atrial strain highlights the need to interpret observed values in the context of modality-specific elite athlete reference ranges. Clinicians should avoid direct cross-modality comparison in elite athlete populations.