Background/Objective: The impact of subpulmonary left ventricle (LV) dysfunction in patients with a systemic right ventricle (SRV) is insufficiently characterized, with only a few studies suggesting its prognostic significance. Additionally, its evaluation through imaging techniques is a challenge. To assess the correlation between quantitative cardiac magnetic resonance-feature tracking (CMR-FT) data and the risk of clinical events related to the natural history of SRV failure. Methods: In this cross-sectional study, 21 patients with a diagnosis of transposition of the great arteries (TGA) and atrial switch operation (AtSO) or congenitally corrected transposition (ccTGA) were recruited. All participants underwent CMR-FT analysis. Considered clinical events included NYHA class deterioration (from I-II to III-IV), increased diuretic therapy, arrhythmias, sudden cardiac death, and hospitalizations. Results: The cohort consisted of 52.4% males (mean age: 25.4 ± 11.9 years). Eleven patients were diagnosed with ccTGA. Of the 10 patients with TGA post-AtSO, 50% had undergone Mustard repair. Clinical events occurred in 11 patients, with 47.6% experiencing hospitalizations and 28.6% developing arrhythmias. Left ventricular global longitudinal strain (LV GLS) was significantly associated with event-risk in both univariate and multivariate analyses (p = 0.011; p = 0.025). A cut-off value of LV GLS > −19.24 was proposed to stratify high-risk patients (p = 0.001). Conclusions: Our study confirms the role of subpulmonary LV function in determining outcomes of SRV patients. The assessment of LV GLS by using CMR-FT could significantly enhance clinical management during follow-up.

Systemic right ventricle (sRV) dysfunction is frequent in patients with congenitally corrected transposition of great arteries (cc-TGA) and those with dextro-transposition of great arteries (D-TGA) after Mustard/Senning operations. This condition should be identified promptly. We aimed to compare echocardiographic parameters with cardiac magnetic resonance (CMR)-derived parameters in patients with sRV and to evaluate their correlation with clinical variables and exercise capacity. Patients with cc-TGA and D-TGA after Mustard/Senning who underwent standard and advanced (speckle tracking and 3D) echocardiography and CMR (including feature-speckle tracking) were included. Clinical and imaging parameters were collected. Echocardiographic-derived right ventricle end-diastolic area and end-systolic area correlated with 3D echocardiographic-derived right ventricle end-diastolic and end-systolic volume (r=0.6, p=0.006 and r=0.8, p=0.002). 3D ejection fraction (EF) correlated with fractional area change and tricuspid annular plane systolic excursion (TAPSE) (r=0.8, p=0.001 and r=0.7, p=0.03). sRV global longitudinal strain correlated with systemic atrial strain (sAS) (r=-0.6, p=0.01). CMR-derived EF correlated with CMR-derived global longitudinal strain (GLS) both endocardial and myocardial (r=-0.7, p=0.007 and r=-0.6, p=0.005). sRV areas as assessed by echo correlated with CMR-derived volumes (r=0.9, p=0.0001 for diastole and r=0.8, p=0.0001 for systole). Similarly, a correlation was found between sRV echo-derived GLS and CMR-derived GLS, both endocardial and myocardial (r=0.8, p=0.001 and r=0.7, p=0.01). The only imaging parameter which correlated with peak V02 was sAS (r=0.55, p=0.04). When comparing cc-TGA and D-TGA, the former showed better GLS-derived values as assessed by CMR (CMR-derived right ventricle endocardial longitudinal strain -23.2% versus -17.2%, p=0.002; CMR-derived right ventricle myocardial longitudinal strain -21.2% versus -16.7%; p=0.05), bigger systemic atrial area (20.2 cm2/m2 versus 8.4 cm2/m2, p=0.005) and higher TAPSE values (16.2 mm versus 12.2 mm, p=0.04). Echocardiography is valid to screen for sRV dilatation and function and to guide the timing for CMR. The investigation of atrial deformation imaging may help to better understand diastolic function. Patients with cc-TGA show better cardiac function compared to patients after atrial switch. Further investigations are needed to identify imaging parameters linked to exercise capacity.