Cardiac magnetic resonance T2 mapping and feature tracking in athlete's heart and HCM

Abstract

Objectives: Distinguishing hypertrophic cardiomyopathy (HCM) from left ventricular hypertrophy (LVH) due to systematic training (athlete's heart, AH) from morphologic assessment remains challenging. The purpose of this study was to examine the role of T2 mapping and deformation imaging obtained by cardiovascular magnetic resonance (CMR) to discriminate AH from HCM with (HOCM) or without outflow tract obstruction (HNCM).

Methods: Thirty-three patients with HOCM, 9 with HNCM, 13 strength-trained athletes as well as individual age- and gender-matched controls received CMR. For T2 mapping, GRASE-derived multi-echo images were obtained and analyzed using dedicated software. Besides T2 mapping analyses, left ventricular (LV) dimensional and functional parameters were obtained including LV mass per body surface area (LVMi), interventricular septum thickness (IVS), and global longitudinal strain (GLS).

Results: While LVMi was not significantly different, IVS was thickened in HOCM patients compared to athlete's. Absolute values of GLS were significantly increased in patients with HOCM/HNCM compared to AH. Median T2 values were elevated compared to controls except in athlete's heart. ROC analysis revealed T2 values (AUC 0.78) and GLS (AUC 0.91) as good parameters to discriminate AH from overall HNCM/HOCM.

Conclusion: Discrimination of pathologic from non-pathologic LVH has implications for risk assessment of competitive sports in athletes. Multiparametric CMR with parametric T2 mapping and deformation imaging may add information to distinguish AH from LVH due to HCM.

Key points: • Structural analyses using T2 mapping cardiovascular magnetic resonance imaging (CMR) may help to further distinguish myocardial diseases. • To differentiate pathologic from non-pathologic left ventricular hypertrophy, CMR including T2 mapping was obtained in patients with hypertrophic obstructive/non-obstructive cardiomyopathy (HOCM/HNCM) as well as in strength-trained athletes. • Elevated median T2 values in HOCM/HNCM compared with athlete's may add information to distinguish athlete's heart from pathologic left ventricular hypertrophy.

Keywords: Athletes; Cardiomyopathy, hypertrophic; Hypertrophy; Left ventricular; Multiparametric magnetic resonance imaging.

Fig. 1

Global T2 values in all entities of LVH. Median T2 values of global myocardial analysis for patients with HOCM, HCNM, and AH. AH, athlete’s heart; HOCM, hypertrophic obstructive cardiomyopathy; HNCM, hypertrophic non-obstructive cardiomyopathy

Fig. 2

Segmental analysis of T2 values. Upper panel, end-diastolic 4-chamber cine view for the calculation of IVS (white double arrows). Lower panel, mean T2 value segmental analysis for patients with HOCM, HNCM, and AH. Red arrows indicate reduced T2 values compared with both entities of LVH, orange arrows to only HOCM. AH, athlete’s heart; HOCM, hypertrophic obstructive cardiomyopathy; HNCM, hypertrophic non-obstructive cardiomyopathy

Fig. 3

Receiver operating characteristics to differentiate AH from HOCM/HNCM. Besides IVS, LVEDV, and LVEF, AUC identified median T2 values (AUC = 0.78) and GLS (AUC = 0.91) as good parameters to differentiate between AH and pathologic LVH. AH, athlete’s heart; AUC, area under the curve; GLS, global longitudinal strain; IVS, interventricular septum; LVEDV, left ventricular end-diastolic volume; LVEF, left ventricular ejection fraction; LVH, left ventricular hypertrophy; LVMi, left ventricular mass per body surface area; SR_cc, peak early circumferential strain rate

Fig. 4

Receiver operating characteristics to differentiate AH from only HNCM. Area under the curve identified median T2 values (AUC = 0.81) and GLS (AUC = 0.94) as good parameters for the differentiation between HNCM and AH. AH, athlete’s heart; GLS, global longitudinal strain; HNCM, hypertrophic non-obstructive cardiomyopathy