Amyloid Deposits and Fibrosis on Left Ventricular Endomyocardial Biopsy Correlate With Extracellular Volume in Cardiac Amyloidosis

Figure 1. Late gadolinium enhancement, histologic, and immunohistochemical findings in patients with focal and diffuse amyloid deposition. Cardiac magnetic resonance 4‐chamber views (A, F, K, and P) and left ventricular endomyocardial biopsy fragments showing focal interstitial (B and G) or diffuse fibrosis (L and Q) by Masson's trichrome staining, and focal (C and H) or diffuse (M and R) green refringent deposits by Congo red staining under polarized light, focal (D and I) or diffuse (N and S) immunoreactivity for lambda light‐chain (AL) or transthyretin (ATTR) deposits, and a few (E and J) or multifocal (O and T) CD3+ T‐lymphocytes (B, G, L, and Q: Masson's trichrome staining, original magnification: B and G ×10, I and O ×20; C, H, M, and R: Congo red staining under polarized light, original magnification: C ×10, H, M, and R ×20; D and N: immunoperoxidase staining with hematoxylin counterstaining for lambda light‐chain, original magnification: D ×10, N ×20; I and S, immunoperoxidase staining with hematoxylin counterstaining for transthyretin, original magnification I ×10. S ×20; E, J, O, and T, immunoperoxidase staining with hematoxylin counterstaining for CD3+ T‐lymphocyte antigen,…

Figure 2. Distribution of amyloid deposits and fibrosis. Endocardial (EF) and interstitial (F) fibrosis in the left ventricle endomyocardial biopsy from a transthyretin‐positive (A and C) and a lambda+ AL (B and D) CA showing a brilliant, strong blue color by Masson's trichrome staining; it is associated with subendocardial and interstitial amyloid (A) deposits that stain blue‐gray on the same Masson's trichrome staining. Myocytes (M) are encircled by fibrosis and by amyloid (Masson's trichrome staining; original magnification: A and B, ×40, C and D, ×100).

Figure 3. Correlations between the extent of amyloid and fibrotic deposits and extracellular volume (ECV). ECV values are in a log‐scale. AL indicates amyloid light chain amyloidosis; and ATTR, amyloid transthyretin amyloidosis.

Figure 4. Correlations between the extent of amyloid and fibrosis and high‐sensitivity troponin T (hs‐TnT). hs‐TnT values are in a log‐scale. AL indicates amyloid light chain amyloidosis; and ATTR, amyloid transthyretin amyloidosis.