Response to Letters Regarding Article, "Prognostic Value of Late Gadolinium Enhancement Cardiovascular Magnetic Resonance in Cardiac Amyloidosis"

We thank Aquaro, Cohen, and colleagues for their interest in our article.1 Cardiac involvement is a chief driver of prognosis in systemic amyloidosis, and the stratification of patients is essential for prognosis and choosing management strategies. Cardiovascular magnetic resonance with late gadolinium enhancement has good diagnostic accuracy for cardiac amyloidosis, but its prognostic impact was uncertain.2–6 This study confirms incremental prognostic information after adjusting for known prognosis factors. We note the comments of Aquaro and colleagues regarding cardiac biopsy, but point out that microscopic histological analyses of these tiny samples is not only open to sampling error, but, crucially, the presence of amyloid in heart muscle is not actually proof of cardiac amyloidosis. It is essential to make the distinction between the presence of amyloid deposits and the clinical syndromes of amyloidosis. Amyloid deposits occur widely throughout the tissues in patients with systemic amyloidosis, often without any clinical consequences, providing the basis for rectal, salivary gland, skin, and fat biopsies to support diagnosis. It is likely …