CMR-Based Differentiation of AL and ATTR Cardiac Amyloidosis.ppt

CMR-Based Differentiation ofAL and ATTR Cardiac Amyloidosis February 2014,JACC Systemic amyloidosis is a condition characterized by extracellular deposition of pathologic insoluble fibrillar proteins. Cardiac light chain amyloid (AL) amyloidosis, in which amyloidfibrils are derived from monoclona immunoglobulin light chains, is associated with poor prognosis, with a median survival from diagnosis of 12 months. The prognosis of transthyretinrelated amyloidosis (ATTR) is typically 3 to 5 years. Transthyretin (TTR) is a plasma protein, predominantly synthesized in the liver, which acts as a transporter for thyroxine and retinol-binding protein. Senile systemic amyloidosis due to nonmutant (wild-type) TTR is a sporadic disease among older people presenting as isolated cardiomyopathy. Hereditary ATTR amyloidosis is an autosomal dominant disease associated with 100 transthyretin gene mutations. Cardiac involvement is now known to occur in association with most hereditary ATTR variants. There has been a marked increase (143%) in new cases of ATTR amyloidosis referred to our center in the past 5 years. The increased detection of ATTR amyloidosis correlates with increased availability of cardiac magnetic resonance (CMR) for investigation of cardiomyopathy. Gadolinium-enhanced CMR visualizes expansion of the interstitial space and may be used to demonstrate the accumulation of abundant amyloid in this site. An early CMR study in cardiac amyloidosis described altered gadolinium kinetics, difficulty nulling the myocardium, and a global subendocardial pattern of late gadolinium enhancement (LGE). However, the precise pattern of LGE has been reported to be more variable in recent studies. Our impression has been that LGE is often diffuse in ATTR amyloidosis,but very few ATTR patients have been included in CMR studies, and there are no reports of differences in LGE patterns according to amyloid fibril protein type. We report here the standard CMR measurements an