Prognostic Value of Late Gadolinium Enhancement Cardiovascular Magnetic Resonance in Cardiac Amyloidosis
Background—The prognosis and treatment of the two main types of cardiac amyloidosis, immunoglobulin light chain (AL) and transthyretin (ATTR) amyloidosis are substantially influenced by cardiac involvement. Cardiovascular magnetic resonance (CMR) with late gadolinium enhancement (LGE) is a reference standard for the diagnosis of cardiac amyloidosis, but its potential for stratifying risk is unknown.
Methods and Results—250 prospectively recruited subjects underwent LGE CMR comprising 122 with ATTR amyloid, 9 asymptomatic mutation carriers, and 119 patients with AL amyloidosis. Subjects were followed up for a mean of 24±13 months. LGE was performed with phase sensitive inversion recovery (PSIR) and without (magnitude only, MAG-IR). These were compared with extracellular volume measured with T1 mapping (ECV). PSIR was superior to MAG-IR LGE since PSIR nulled always the tissue (blood or myocardium) with the longest T1 (least gadolinium). LGE was classified into 3 patterns: none, subendocardial and transmural, which were associated with increasing amyloid burden as defined by ECV (p<0.0001) with transitions from none to subendocardial LGE at an ECV of 0.40-0.43(AL), 0.39-0.40(ATTR); and to transmural at 0.48-0.55(AL), 0.47-0.59(ATTR). Sixty seven (27%) patients died. Transmural LGE predicted death (HR=5.4, 95%CI: 2.1-13.7,p<0.0001) and remained independent after adjusting for NT-proBNP, ejection fraction, stroke volume index, E/E' and left ventricular mass index (HR=4.1, 95%CI: 1.3-13.1,p<0.05).
Conclusions—There is a continuum of cardiac involvement in systemic AL and ATTR amyloidosis. Transmural LGE is determined reliably by PSIR and represents advanced cardiac amyloidosis. The PSIR technique provides incremental information on outcome even after adjusting for known prognostic factors.
- Received March 22, 2015.
- Revision received July 23, 2015.
- Accepted August 3, 2015.
Circulation is published on behalf of the American Heart Association, Inc., by Wolters Kluwer. This is an open access article under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0/), which permits use, distribution, and reproduction in any medium, provided that the original work is properly cited.