BACKGROUND: Adults with transposition of the great arteries (TGA) and systemic right ventricle (SRV) are at risk for heart failure (HF) and decreased survival. Ventricular-arterial coupling (VAC) quantifies the interaction between myocardial contractile function and the load imposed by the arterial circulation and may be valuable in identifying subclinical SRV dysfunction. The purpose of our study is to determine the association of VAC with adverse clinical outcomes in adults with TGA and SRV. METHODS: A single center, retrospective cohort study of subjects ≥ 16 years of age with TGA and SRV who underwent a cardiac magnetic resonance (CMR) examination. VAC was calculated as the ratio between CMR-derived SRV end-systolic volume and stroke volume. Cox proportional hazards regression analysis was performed to assess the association of VAC with clinical outcomes. RESULTS: One hundred sixty-seven subjects (mean age 32 ± 10 years, 59% males) were evaluated. VAC predicted the composite outcome of death, cardiac arrest and HF hospitalizations (hazard ratio (HR) 2.09
95% CI: 1.12-3.92, p = 0.02), as well as other cardiovascular hospitalizations including device implantation and percutaneous or surgical structural intervention (HR 1.65, 95% CI: 1.09-2.49, p = 0.02) after adjustment for age, sex, and the presence of significant tricuspid regurgitation. CONCLUSIONS: VAC is associated with major clinical adverse outcomes in patients with TGA and SRV, and may improve risk stratification of this complex population.