Beyond the Normal Ejection Fraction: Can Strain Echocardiography Unmask Early Myocardial Impairment in Adolescents with Substance-Use Disorders

Background: Substance use among adolescents is a growing global health problem, and psychoactive substances may damage the myocardium before conventional echocardiographic parameters change. We aimed to determine whether two-dimensional speckle-tracking strain echocardiography can unmask early myocardial impairment in adolescents with substance-use disorder. Methods: In this retrospective cross-sectional case–control study, 29 adolescents with substance-use disorder followed at a Child and Adolescent Substance Dependence Treatment Center and 29 age- and sex-matched healthy controls underwent conventional echocardiography and strain analysis (segmental, territorial, and global longitudinal strain [GLS]) performed by two blinded pediatric cardiologists. Between-group comparisons were adjusted for multiple testing; discriminative performance was assessed by receiver operating characteristic analysis with bootstrap internal validation, and multivariable logistic regression tested the independence of the association. Results: Patients had a median substance exposure of 3 years, and 75.9% reported polysubstance use (most commonly pregabalin, 41.4%, and methamphetamine, 34.5%). Current cigarette smoking was reported by 75.9% of patients and none of the controls. Ejection fraction was lower in patients but remained within the normal range (62.3% vs. 68.4%; p = 0.016). GLS was significantly impaired in the patient group (−17.0% vs. −20.4%; p < 0.001; median difference 3.4 percentage points; Hedges’ g = 2.00), with diffuse segmental involvement across all three apical views. GLS discriminated patients from controls with an area under the curve of 0.913; at the Youden-optimal cut-off of −19.3%, sensitivity was 79.3% and specificity 96.6%. Conclusions: Strain echocardiography can unmask early myocardial impairment in adolescent substance and tobacco users, while ejection fraction and other conventional parameters, although differing modestly, remained within their normal reference ranges. Adding GLS to routine cardiac surveillance may improve early detection; however, reversibility with abstinence and prognostic value require prospective longitudinal studies.