In this multi-center, retrospective study, we identified 2,699 patients with CA, of whom 162 patients with a usable brain MRI performed within one year of CA diagnosis were included. Baseline data on clinical and demographic variables were collected. Brain MRIs were reviewed and graded for the presence of probable CAA(Boston 2.0 criteria) and SVD markers. Patients with and without CAA were then compared across CA subtypes.

Among 162 CA patients analyzed, prevalence of CAA was 14.2%(n=23). CAA prevalence was numerically higher in AL(25%) compared to ATTR(12.7%) amyloidosis(p=0.168). The baseline characteristics of patients with and without CAA were similar, except for the higher prevalence of chronic kidney disease in the CAA group(p=0.030). Patients with CAA had a significantly higher burden of all SVD markers (p<0.001). In patients with ATTR amyloidosis(n=126), the prevalence of CAA increased numerically across severity stages (Stage 1:10%, Stage 2:15.7%, Stage 3:20%), though not significantly after adjustment for age, sex and race. However, deep white matter hyperintensity burden increased significantly with advancing ATTR stage(p=0.002) irrespective of CAA status.

Our findings suggest that CAA is prevalent in patients with cardiac amyloidosis, with a non-significant trend towards higher rates in the AL subtype. Increasing ATTR-CA stage is associated with progressive microvascular injury on brain MRI, independent of the presence of CAA. Additional studies are needed to understand the shared mechanisms linking cardiac and cerebral amyloidosis.