Cardiac amyloidosis (CA) is a cardiomyopathy characterized by the deposition of amyloid proteins in the myocardium, leading to structural and functional impairments. This study aimed to assess myocardial ischaemia in CA patients using cardiovascular magnetic resonance (CMR) with multiparametric mapping and histopathological analysis. Ninety-three patients with CA (42 with light-chain amyloidosis, 51 with transthyretin amyloidosis) and 97 without CA underwent CMR and histopathological evaluation. CMR showed severely reduced myocardial blood flow (MBF) in CA patients compared to those without CA, with lower values in CA patients than in those with three-vessel coronary disease, unobstructed coronary arteries, and healthy volunteers. Histopathological analysis revealed amyloid deposits in myocardial interstitium and vascular walls, leading to structural changes and reduced capillary density. These findings suggest that CA is associated with severe inducible myocardial ischaemia, which can be detected by histology and CMR stress perfusion mapping. The study highlights the complex pathophysiology of CA, involving amyloid infiltration of epicardial arteries and capillary disruption, contributing to myocardial ischaemia. The results indicate that CA is associated with reduced myocardial perfusion, which may be a key factor in the adverse clinical outcomes seen in these patients. The study also emphasizes the importance of assessing myocardial perfusion in CA patients to better understand the disease and guide treatment.Cardiac amyloidosis (CA) is a cardiomyopathy characterized by the deposition of amyloid proteins in the myocardium, leading to structural and functional impairments. This study aimed to assess myocardial ischaemia in CA patients using cardiovascular magnetic resonance (CMR) with multiparametric mapping and histopathological analysis. Ninety-three patients with CA (42 with light-chain amyloidosis, 51 with transthyretin amyloidosis) and 97 without CA underwent CMR and histopathological evaluation. CMR showed severely reduced myocardial blood flow (MBF) in CA patients compared to those without CA, with lower values in CA patients than in those with three-vessel coronary disease, unobstructed coronary arteries, and healthy volunteers. Histopathological analysis revealed amyloid deposits in myocardial interstitium and vascular walls, leading to structural changes and reduced capillary density. These findings suggest that CA is associated with severe inducible myocardial ischaemia, which can be detected by histology and CMR stress perfusion mapping. The study highlights the complex pathophysiology of CA, involving amyloid infiltration of epicardial arteries and capillary disruption, contributing to myocardial ischaemia. The results indicate that CA is associated with reduced myocardial perfusion, which may be a key factor in the adverse clinical outcomes seen in these patients. The study also emphasizes the importance of assessing myocardial perfusion in CA patients to better understand the disease and guide treatment.