Cardiovascular magnetic resonance in cardiac amyloidosis.

BACKGROUND: Cardiac amyloidosis can be diagnostically challenging. Cardiovascular magnetic resonance (CMR) can assess abnormal myocardial interstitium. METHODS AND RESULTS: Late gadolinium enhancement CMR was performed in 30 patients with cardiac amyloidosis. In 22 of these, myocardial gadolinium kinetics with T1 mapping was compared with that in 16 hypertensive controls. One patient had CMR and autopsy only. Subendocardial T1 in amyloid patients was shorter than in controls (at 4 minutes: 427+/-73 versus 579+/-75 ms; P<0.01), was shorter than subepicardium T1 for the first 8 minutes (P< or =0.01), and was correlated with markers of increased myocardial amyloid load, as follows: left ventricular (LV) mass (r=-0.51, P=0.013); wall thickness (r=-0.54 to -0.63, P<0.04); interatrial septal thickness (r=-0.52, P=0.001); and diastolic function (r=-0.42, P=0.025). Global subendocardial late gadolinium enhancement was found in 20 amyloid patients (69%); these patients had greater LV mass (126+/-30 versus 93+/-25 g/m2; P=0.009) than unenhanced patients. Histological quantification showed substantial interstitial expansion with amyloid (30.5%) but only minor fibrosis (1.3%). Amyloid was dominantly subendocardial (42%) compared with midwall (29%) and subepicardium (18%). There was 97% concordance in diagnosis of cardiac amyloid by combining the presence of late gadolinium enhancement and an optimized T1 threshold (191 ms at 4 minutes) between myocardium and blood. CONCLUSIONS: In cardiac amyloidosis, CMR shows a characteristic pattern of global subendocardial late enhancement coupled with abnormal myocardial and blood-pool gadolinium kinetics. The findings agree with the transmural histological distribution of amyloid protein and the cardiac amyloid load and may prove to have value in diagnosis and treatment follow-up.

Sequential heart and autologous stem cell transplantation for systemic AL amyloidosis.

Extensive cardiac amyloid deposition in systemic AL amyloidosis is associated with a grave prognosis. Heart transplantation is rarely performed because of the systemic and progressive nature of the disease. Patients with severe cardiac amyloid infiltration are ineligible for the preferred treatment of melphalan chemotherapy with stem cell transplantation (SCT) rescue because of the high risk for treatment-related mortality. Heart transplantation followed by SCT was performed in 5 patients with AL amyloidosis and predominant cardiomyopathy. Patients were followed up for a median of 95 months (range, 37-118 months) from diagnosis. At censor, 3 of 5 patients were well without evidence of intracardiac or extracardiac amyloid accumulation, and median overall survival by Kaplan-Meier estimate was not reached. Two patients died of progressive amyloidosis 33 and 90 months after heart transplantation after relapse of their underlying plasma cell dyscrasia. Heart transplantation followed by SCT is feasible in selected patients with cardiac AL amyloidosis and may confer substantial survival benefit.