Benefits of Four-Tiered Classification of Exercise-Induced Left Ventricular Hypertrophy in Adolescent Athletes

Background: Exercise-induced left ventricular hypertrophy (LVH) has been extensively investigated in adolescent athletes using the conventional two-tiered classification (2TC). However, the four-tiered classification (4TC) allows further differentiation of LVH patterns by incorporating three-dimensional information on left ventricular (LV) geometry. This study aimed to compare LVH assessment using the two classification systems and characterize the reclassification patterns. Methods: A total of 121 adolescent athletes (mean age: 15.1 ± 1.6 years) and 114 adult athletes (mean age: 22.9 ± 3.7 years), all competing at the national level, underwent comprehensive echocardiographic and anthropometric evaluations. Results: The application of 4TC resulted in redistribution across LV geometric categories compared with conventional 2TC. Twenty-three (19.0%) adolescent and 25 (22%) adult athletes were reclassified, including seven (5.8%) and 17 (15%), respectively, who shifted from normal geometry under the 2TC to different LVH categories under the 4TC. Reclassification was observed across sex and sporting discipline subgroups, although the patterns varied. In runners and triathletes, the combined prevalence of eccentric non-dilated and eccentric dilated LVH was 22.7% using the 4TC versus 4.5% eccentric LVH under the 2TC classification. LVM was strongly associated with the combined contribution of cumulative training duration, lean body mass, and body surface area (r = 0.785, p < 0.001), whereas training duration alone was not significantly associated with the LVH parameters. Conclusions: The 2TC and 4TC approaches result in different assessments of LV geometry in highly trained athletes, with the 4TC providing additional characterization of LVH patterns by considering the presence or absence of LV dilatation. Reclassification patterns varied according to sex and sporting discipline, highlighting the importance of sport-related characteristics when interpreting exercise-induced LV remodeling in athletes.