Figure 3.

Reduced FA in HCM Even After Adjustment for Fibrosis

Diastolic FA, averaged across the mid-ventricular slice, was reduced in HCM compared with healthy control subjects (A, slice mean ± SD). The wide standard deviation of FA in HCM demonstrates the heterogeneity within this disease population, and only a subset of patients had a lower FA than control subjects. HCM patients with late gadolinium enhancement (LGE) (n = 22; orange) had lower FA than those without LGE (p < 0.001). LGE and ECV, which are markers of fibrosis, were significant predictors of FA (p < 0.001). Yet FA adjusted for LGE and ECV remained reduced in HCM (B, linear mixed-effects model estimated marginal means with 95% confidence intervals), indicating that low FA may also demonstrate sensitivity to disarray. These results imply that fibrosis (presence of LGE and/or elevated ECV) contributes to low FA (C). However, in the absence of fibrosis, low FA may instead represent disarray. Abbreviations as in Figure 1.