Left ventricular strain and fibrosis in adults with repaired tetralogy of Fallot: A case-control study

• Published in: International journal of cardiology 2021-01, Vol.323, p.34-39
• Main Authors: de Alba, Cesar Gonzalez, Khan, Abigail, Woods, Patricia, Broberg, Craig S.
• Format: Article
• Language: English
• Subjects: Cardiac magnetic resonance; Feature-tracking; Strain; T1-mapping; Tetralogy of Fallot
• ISSN: 0167-5273; 1874-1754
• DOI: 10.1016/j.ijcard.2020.08.092

Left ventricular (LV) systolic dysfunction and myocardial fibrosis have prognostic implications in repaired tetralogy of Fallot (rTOF), but their relationship with myocardial strain is not well understood. We evaluated systolic strain and fibrosis (extracellular volume fraction, ECV) of the left ventricle (LV) using feature tracking with magnetic resonance and determine their association with each other and clinical outcome. Adults with rTOF and age-matched controls underwent CMR to measure LV-ECV. Feature-tracking was used to quantify radial, circumferential, and longitudinal strain in both 2 and 3 dimensions. Clinical events (death, arrhythmia and heart-failure hospitalization) were obtained through chart review. Associations between strain, ECV and clinical events were explored. 48 rTOF subjects (age 40.5 ± 14.3, 42% female) and 20 healthy controls were included. Both LV 2D and 3D global circumferential strain (GCS) and global longitudinal strain (GLS) were lower in rTOF subjects (p ≤0.01 for all). There was no association between strain and LV-ECV. Strain parameters correlated with ventricular volumes and function. After a median follow-up of 8.5 years (range 1–10.9 years) there were 5 deaths, 6 hospitalizations and 9 new arrhythmias. By multivariate Cox-regression, GLS was an independent predictor of both hospitalization and death, whereas LV-ECV was an independent predictor of arrhythmia. While both LV strain abnormalities and fibrosis are present in rTOF, they are associated with different types of clinical outcome, and not to each other. The findings suggest that these measures reflect different long-term adverse adaptations to abnormal hemodynamics. •LV 2D and 3D GCS and GLS were lower in rTOF subjects compared to age-matched healthy subjects.•There was no association between LV strain and LV-ECV.•GLS was an independent predictor of hospitalization and death; LV-ECV was an independent predictor of arrhythmia.•Our findings suggest that LV strain ad LV-ECV reflect different long-term adverse adaptations to abnormal hemodynamics.