High prevalence of cardiac amyloidosis with increasing age

Abstract Background A high number of unreported cases of cardiac amyloidosis in elderly patients is suspected. Since more and more specific treatment options are being established, the question of prevalence is important. This study systematically investigated the presence of manifest cardiac amyloidosis in deceased patients over the age of 70. Method Heart tissue samples from 592 deceased and autopsied patients were histopathologically examined (including Congo red staining, ATTR and AA) (Male: n=343; Female: n=249). These samples were collected during autopsies conducted between 2020 and 2023 at the municipal hospital in Goerlitz (Goerlitz Autopsy Registry). Patients were selected solely based on their age of at least 70 years (mean age = 80.8 years; max = 100 years). The reliability of the positive samples was then verified through independent secondary examinations. Additionally we compared available echocardiographic measurements (IVSd) (n= 230) with parameters obtained during autopsy. Results In total, relevant cardiac amyloid deposits were detected in 108 of the 592 examined deceased patients (18.2%). Among these, 98 samples were positively stained for ATTR (90,7%) and 3 samples for AA Amyloid (2.7%). A significant association was observed between increasing age and Congo red-positive cases (p 0.001; OR = 1.19). The prevalence of ATTR in different age groups was as follows: Age group 70–79 years (AG1): ATTR detected in 8 of 240 cases (3.3%). Age group 80–89 years (AG2): ATTR detected in 65 of 291 cases (22.3%). Age group 90–100 years (AG3): ATTR detected in 25 of 61 cases (40.98%). Regarding the degree of amyloid infiltration, the following average percentages were observed in each age group: AG1: 5.45%; AG2: 9.42%; AG3: 7.81%. The degree of amyloid infiltration was a significant predictor of interventricular septal thickness (IVSd) (p = 0.04; R² = 0.03). However, 39% of those with amyloid deposition had an IVSd of smaller than 12 mm. Furthermore positively correlated the cardiac weight / m² with the degree of amyloid infiltration (p=0,017). Conclusion In the examined cohort of autopsied elderly patients, a high prevalence of cardiac ATTR amyloidosis was observed. The prevalence increases significantly with age. Given the availability of treatment options to effectively slow the progression of cardiac amyloid deposits, early detection, even before visible hypertrophy, of this disease is essential.