Efficacy of Various “Classic” Echocardiographic and Laboratory Indices in Distinguishing the “Gray Zone” between Athlete's Heart and Hypertrophic Cardiomyopathy: A Pilot Study

Left ventricular hypertrophy (LVH) with intraventricular septum thickness (IVST) between 1.2 and 1.5 cm in athletes represents a “gray zone” between physiologic adaptation and mild hypertrophic cardiomyopathy (HCM). Various echo and laboratory parameters have been reported till now in the literature to discriminate the “gray zone” entities. Aim of this study was to assess the efficacy of these “classic” parameters in differentiating physiologic LVH in athletes from mild HCM in a highly selected population. Nine highly trained athletes with IVST (1.28 ± 0.07 cm), 9 patients with mild HCM (1.38 ± 0.11 cm), and 26 athletes without LVH (1.06 ± 0.09 cm; P  200 ms, isovolumic relaxation time >94 ms, tricuspid E/A  0.445, and a BNP value at rest >9.84 pg/mL had a greater possibility for having underlying cardiomyopathy. A 10-point score based on these parameters showed accuracy (area under the curve = 0.958 [95%CI: 0.738–1.0; P = 0.00005, standard error = 0.0342]) for revealing HCM in a gray zone athletic population. Differentiation of adaptive LVH versus HCM in a gray zone population could be facilitated by recognition of certain features referring to LV dimensions, diastolic function, and BNP.