Abstract 10114: Cardiovascular Magnetic Resonance Measurement of Myocardial Extracellular Volume by T1 Mapping Differentiates Athlete's Heart From Hypertrophic Cardiomyopathy
Introduction: Athletes who train regularly can develop left ventricular (LV) hypertrophy, which can be difficult to differentiate from hypertrophic cardiomyopathy (HCM), the leading cause of sudden cardiac death in young athletes. Cardiovascular magnetic resonance (CMR) T1 and extracellular volume (ECV) mapping provide quantitative assessment of myocardial composition.
Hypothesis: ECV can differentiate athletic from pathological remodelling.
Methods: 35 athletes, 25 HCM patients and 35 volunteers underwent 3.0T CMR protocol including 5b(3s)3b Modified Look-Locker Inversion (MOLLI) T1 maps before and 15 minutes after administration of 0.15mmol/kg intravenous gadobutrol. Native T1 and ECV were measured for each subject and each segment of the American Heart Association model.
Results: Native T1 and ECV were both significantly lower in athletes than HCM (1182.8±38.1ms vs 1264.6±50.3ms, P<0.001 and 23.2±2.9% vs 32.3±5.9%, P<0.001 respectively). On receiver operator curve analysis the area under the curve (AUC) to differentiate HCM from athlete for native T1 was 0.91 and ECV 0.95. The AUC to differentiate indeterminate 8-15mm thick segments (Figure) were native T1 0.83, ECV 0.92 and segment thickness 0.80 (P<0.001 for all). The diagnostic accuracy of ECV was superior to native T1 and segment thickness (P=0.001 for both). The optimal cut-off to diagnose HCM in an indeterminate segment was ECV>24.7% (sensitivity 91.7% & specificity 83.2%) and native T1>1226ms (sensitivity 60.0% & specificity 96.7%).
Conclusions: ECV measurement by CMR is able to distinguish HCM and athletic remodelling with high diagnostic accuracy and has a potential role in the exclusion of HCM in athletes presenting with left ventricular hypertrophy.
Figure: ROC curves for segmental wall thickness (mm), native T1 (ms) and ECV (%) for the detection of HCM against athletes in intermediate wall thickness segments (8-15mm thick). AUCs were 0.80, 0.83, and 0.92 respectively (P<0.001 for all).
Author Disclosures: P.P. Swoboda: None. A.K. Mcdiarmid: None. B. Erhayiem: None. D.A. Broadbent: None. G.K. Lyall: None. R.E. Lancaster: None. L.E. Dobson: None. D.P. Ripley: None. T.A. Musa: None. P. Garg: None. C. Ferguson: None. S.P. Page: None. J.P. Greenwood: None. S. Plein: None.
- © 2015 by American Heart Association, Inc.