Abstract 4140767: MRI-Measured Myocardial Strain as a Predictor of Clinical Outcomes in Systemic RV.

Background: Systemic RV dysfunction is a common concern in patients with d-Transposition of the great arteries (d-TGA) after atrial switch and congenitally corrected TGA (ccTGA). We investigated myocardial strain on MRI to predict clinical outcomes. Methods: We analyzed 50 MRI studies (33 d-TGA with atrial switch, 17 ccTGA, mean age 42 ± 13 years) after excluding studies with fewer than 30 phases or incomplete images. Feature-tracking of SSFP cine was retrospectively utilized to quantify radial, circumferential, and longitudinal strain in both 2 and 3 dimensions. Physiological class (PC) was determined by clinicians according to the 2018 AHA/ACC guidelines. Clinical events (e.g., change in PC, initiation or escalation of diuretics, mortality, arrhythmias, heart failure hospitalization) over a 5-year period were obtained through chart review. Results: Deterioration of PC was significantly associated with worsening of all strain measures (p ≤0.05 for each) except 3D global radial strain. RV ejection fraction (EF) was also significant (p ≤0.05). Importantly, in patients experiencing new clinical events within 5 years, baseline absolute values of global longitudinal strain (2D and 3D) were significantly worse (p ≤0.05 for both), whereas RVEF was not (Figure). Conclusion: MRI-measured global longitudinal strain holds promise as a prognostic indicator for clinical outcomes in adults with systemic RV dysfunction. These findings underscore its potential utility in risk stratification and guiding management decisions.