1. Measurement of myocardial amyloid deposition in systemic amyloidosis: insights from cardiovascular magnetic resonance imaging.
- Author
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Barison, A., Aquaro, G. D., Pugliese, N. R., Cappelli, F., Chiappino, S., Vergaro, G., Mirizzi, G., Todiere, G., Passino, C., Masci, P. G., Perfetto, F., and Emdin, M.
- Subjects
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AMYLOIDOSIS , *TRANSTHYRETIN , *CARDIAC hypertrophy , *CARDIOLOGY , *HYPERTROPHY , *PATIENTS - Abstract
Background Cardiac involvement in systemic amyloidosis is caused by the extracellular deposition of misfolded proteins, mainly immunoglobulin light chains ( AL) or transthyretin ( ATTR), and may be detected by cardiovascular magnetic resonance ( CMR). The aim of this study was to measure myocardial extracellular volume ( ECV) in amyloid patients with a novel T1 mapping CMR technique and to determine the correlation between ECV and disease severity. Methods Thirty-six patients with biopsy-proven systemic amyloidosis (mean age 70 ± 9 years, 31 men, 30 with AL and six with ATTR amyloidosis) and seven patients with possible amyloidosis (mean age 64 ± 10 years, six men) underwent comprehensive clinical and CMR assessment, with ECV estimation from pre- and postcontrast T1 mapping. Thirty healthy subjects (mean age 39 ± 17 years, 21 men) served as the control group. Results Amyloid patients presented with left ventricular ( LV) concentric hypertrophy with impaired biventricular systolic function. Cardiac ECV was higher in amyloid patients (definite amyloidosis, 0.43 ± 0.12; possible amyloidosis, 0.34 ± 0.11) than in control subjects (0.26 ± 0.04, P < 0.05); even in amyloid patients without late gadolinium enhancement (0.35 ± 0.10), ECV was significantly higher than in the control group ( P < 0.01). A cut-off value of myocardial ECV >0.316, corresponding to the 95th percentile in normal subjects, showed a sensitivity of 79% and specificity of 97% for discriminating amyloid patients from control subjects (area under the curve of 0.884). Myocardial ECV was significantly correlated with LV ejection fraction ( R2 = 0.16), LV mean wall thickness ( R2 = 0.41), LV diastolic function ( R2 = 0.21), right ventricular ejection fraction ( R2 = 0.13), N-terminal fragment of the pro-brain natriuretic peptides ( R2 = 0.23) and cardiac troponin ( R2 = 0.33). Conclusion Myocardial ECV was increased in amyloid patients and correlated with disease severity. Thus, measurement of myocardial ECV represents a potential noninvasive index of amyloid burden for use in early diagnosis and disease monitoring. [ABSTRACT FROM AUTHOR]
- Published
- 2015
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