Abstract 12603: Global T1 Mapping and Late Gadolinium Enhancement Cardiac MR in Myocardial Fibrosis Compared with Amyloid Cardiomyopathy
Background: Myocardial fibrosis is a feature of non-ischemic cardiomyopathy (NICM) and can be identified in approximately 25-40% of cases by cardiac MR (CMR) with late gadolinium enhancement (LGE) imaging. Amyloid fibril deposition in cardiac amyloidosis is identifiable by LGE-CMR in approximately 90% of patients. Myocardial T1 mapping is a technique that may permit more sensitive detection of fibrosis or deposition.
Methods: We sought to compare T1 values and the presence of abnormal LGE in two distinct cardiomyopathies. Contrast enhanced CMR with LGE was performed in n=14 patients (8 with cardiac amyloidosis and 6 with NICM) and 4 controls subjects. Global myocardial T1 maps were generated from post contrast Look-Locker sequences following 0.2 mmol/kg gadolinium. Statistical testing employed ANOVA (for continuous variables) and Fisher's exact test (for categorical variables) with p<0.05 considered significant.
Results: T1 values were 233±21ms for amyloidosis, 273±41ms for NICM, and 304±30 ms for normal (p=0.01). Abnormal LGE was seen in all amyloid patients, but only 17% of NICM patients, and none of the controls (p<0.01). There were no differences in creatinine, hematocrit, or BSA between the groups.
Conclusions: While abnormal myocardial T1 was observed in both NICM and cardiac amyloidosis, a disparity was seen in the presence of LGE. These data suggest that T1 determination may identify myocardial fibrosis or amyloid deposition before LGE is evident, irrespective of cardiomyopathic phenotype.
- © 2012 by American Heart Association, Inc.