Abstract 11686: Pericellular Amyloid Infiltration in Biopsy-proven Cardiac Amyloidosis

Background: Cardiac amyloidosis is a rare disease characterized by the myocardial infiltration of amyloid. There are several histopathological patterns of amyloid accumulation, of which pericellular amyloid pattern is classified when amyloid is observed around each cardiomyocyte in endomyocardial biopsy. However, the relationship between pericellular amyloid deposition pattern and clinical characteristics has not yet been investigated. Objective: We retrospectively investigated endomyocardial biopsy-proven cardiac amyloidosis with pericellular amyloid deposition. Methods: Thirty cardiac amyloidosis patients in our institution were included. Results: Thirteen patients (43%) were pathologically classified into pericellular amyloid deposition. In the baseline characteristics, the patients with pericellular deposition had significantly lower age (69 ± 9 vs. 75 ± 6 years, p = 0.032) and higher brain natriuretic peptide levels (681 ± 516 vs. 267 ± 393 pg/ml, p = 0.003), compared with those without pericellular deposition. Electrocardiographic findings revealed that patients with pericellular amyloid deposition had significantly higher incidence of low voltage (46 vs. 12%, p = 0.045) and pseudoinfarction pattern (46 vs. 6%, p = 0.015), compared with patients without pericellular deposition. Echocardiography revealed that patients with pericellular deposition had significantly decreased deceleration time (152 ± 49 vs. 191 ± 50 ms, p = 0.049). Hemodynamic findings did not show significant difference between groups. High-sensitivity cardiac troponin-T levels were also analyzed in 14 cardiac amyloidosis patients without ischemic heart disease. Patients with pericellular amyloid deposition had significantly higher high-sensitivity cardiac troponin-T levels, compared with patients without pericellular deposition (0.128 ± 0.07 vs. 0.046 ± 0.03 pg/ml, p = 0.016). Conclusion: Pericellular amyloid deposition pattern was associated with electrocardiographic abnormalities, diastolic dysfunction, and ongoing myocardial damage. Our data suggest direct amyloid infiltration around the cardiomyocytes may cause myocardial damage, providing possible pathophysiological implication of the failing heart in cardiac amyloidosis.