Cardiac magnetic resonance imaging of systemic amyloidosis patients with normal left ventricular ejection fraction: An initial study

Objective: The purpose of this study was to find whether Cardiac Magnetic Resonance (CMR) could assess the myocardial interstitium in patients suffering from systemic amyloidosis with normal left ventricular ejection fraction.

Methods: Twenty Six patients in whom systemic amyloidosis was confirmed by kidney biopsy were investigated. Five patients with normal left ventricular ejection fraction were selected. The heart function of the patients was diagnosed by two-dimensional transthoracic echocardiography. The main MR sequences include an inversion recovery prepared echo planar imaging perfusion sequence, inversion recovery TrueFISP sequence (delayed enhancement) and TrueFISP cine sequence for heart function measurement (including ejection fraction (EF), end diastolic volume (EDV), end systolic volume (ESV), stroke volume (SV) and cardiac output (CO)).

Results: Perfusion defects were seen in three patients. In these patients, myocardial enhancement was visible on late gadolinium enhancement images. The enhancement pattern was diffuse in three patients and focal in two patients. Heart dysfunction was mild, as follows: EF normal (range, 56-75%; mean, 69.4%), ESV normal (range, 15.7-30.0; mean, 23.0), EDV decreased (range, 42.1-96.6; mean, 72.7), SV decreased (range, 23.7-68.6; mean, 49.6) and CO normal (range, 2.6-5.9; mean, 3.9). Hematoxylin and eosin stain and Congo red stain demonstrated typical amyloid deposits. Amyloidosis was classified as amyloid light chain by kappa and lambda stain.

Conclusions: Cardiac Magnetic Resonance could detect abnormal myocardial interstitium in systemic amyloidosis patients with normal left ventricular ejection fraction.