Usefulness of right ventricular free wall strain to predict quality of life in "repaired" tetralogy of Fallot

Abstract

After repair of tetralogy of Fallot, the left ventricular ejection fraction and the right ventricular ejection fraction are associated with clinical status and outcomes, but the relation of strain, a potentially earlier marker of dysfunction, to quality of life has not been evaluated. In 58 patients with tetralogy of Fallot (median age 29 years, interquartile range 20 to 41) who underwent cardiovascular magnetic resonance imaging and completed the Short Form 36, Version 2 (a validated quality-of-life assessment), left ventricular global circumferential strain, left ventricular global longitudinal strain, and right ventricular free wall longitudinal strain (RVLSFW) were measured from cine images using feature-tracking software. Age-adjusted z score ≤-1 for the physical component summary or subscales of physical functioning, role-physical, and general health was considered a clinically significant decrease in quality of life. Patients with RVLSFW less than the median had increased odds of decreased physical functioning (odds ratio [OR] 5.4, p = 0.01) and general health (OR 3.5, p = 0.04) subscale scores, which remained significant in patients with right ventricular ejection fractions ≥45% (physical functioning: OR 9.5, p = 0.03; general health: OR 5.9, p = 0.04). Left ventricular global circumferential strain and left ventricular global longitudinal strain did not predict decreased quality of life in this population. Intraobserver and interobserver variability was acceptable for left ventricular global circumferential strain (coefficients of variation 9.5% and 10.0%, respectively) but lower for left ventricular global longitudinal strain (coefficients of variation 17.2% and 16.8%, respectively) and poor for RVLSFW (coefficients of variation 19.9% and 28.8%, respectively). In conclusion, RVLSFW appears to have discriminative ability in this population for decreased quality of life and may yield incremental prognostic value beyond global right ventricular ejection fraction assessment, but further study is needed to evaluate methods to limit variability.