Cardiovascular magnetic resonance in cardiac amyloidosis.
BACKGROUND
Cardiac amyloidosis can be diagnostically challenging. Cardiovascular magnetic resonance (CMR) can assess abnormal myocardial interstitium.


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.
Maceira
Alicia Maria
AM
Cardiovascular Magnetic Resonance Unit, Royal Brompton Hospital, London, UK.
Joshi
Jayshree
J
Prasad
Sanjay Kumar
SK
Moon
James Charles
JC
Perugini
Enrica
E
Harding
Idris
I
Sheppard
Mary Noelle
MN
Poole-Wilson
Philip Alexander
PA
Hawkins
Philip Nigel
PN
Pennell
Dudley John
DJ
D000368:Aged; D000686:Amyloidosis / Q000175:diagnosis / Q000000981:diagnostic imaging / Q000473:pathology*; D001706:Biopsy; D009202:Cardiomyopathies / Q000175:diagnosis / Q000000981:diagnostic imaging / Q000473:pathology*; D003287:Contrast Media / Q000493:pharmacokinetics; D005260:Female; D019786:Gadolinium DTPA / Q000097:blood / Q000493:pharmacokinetics; D006801:Humans; D006973:Hypertension / Q000473:pathology; D017379:Hypertrophy, Left Ventricular / Q000000981:diagnostic imaging / Q000209:etiology / Q000473:pathology; D007457:Iodine Radioisotopes / Q000493:pharmacokinetics; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009929:Organ Size; D011446:Prospective Studies; D011877:Radionuclide Imaging; D000683:Serum Amyloid P-Component / Q000493:pharmacokinetics; D013318:Stroke Volume; D014463:Ultrasonography; D018487:Ventricular Dysfunction, Left / Q000209:etiology / Q000503:physiopathology
D003287:Contrast Media; D007457:Iodine Radioisotopes; D000683:Serum Amyloid P-Component; D019786:Gadolinium DTPA