Role of cardiac magnetic resonance imaging in the detection of cardiac amyloidosis.
OBJECTIVE
Our aim was to evaluate the role and mechanism of late gadolinium enhancement (LGE) cardiac magnetic resonance (CMR) in identifying cardiac amyloidosis (CA) and to investigate associations between LGE and clinical, morphologic, functional, and biochemical features.


BACKGROUND
CA can be challenging to diagnose by echocardiography. Recent studies have demonstrated an emerging role for LGE-CMR.


METHODS
LGE-CMR was performed in 120 patients with amyloidosis. Cardiac histology was available in 35 patients. The remaining 85 patients were divided into those with and without echocardiographic evidence of CA.


RESULTS
Of the 35 patients with histologically verified CA, abnormal LGE was present in 34 (97%) patients and increased echocardiographic left ventricular wall thickness in 32 (91%) patients. Global transmural or subendocardial LGE (83%) was most common and was associated with greater interstitial amyloid deposition (p = 0.03). Suboptimal myocardial nulling (8%) and patchy focal LGE (6%) were also observed. LGE distribution matched the deposition pattern of interstitial amyloid. Among patients without cardiac histology, LGE was present in 86% of those with evidence of CA by echocardiography and in 47% of those without evidence of CA by echocardiography. In patients without echocardiographic evidence of CA, the presence of LGE was associated with worse clinical, electrocardiographic (ECG), and cardiac biomarker profiles. In all patients, LGE presence and pattern was associated with New York Heart Association functional class, ECG voltage, left ventricular mass index, right ventricular wall thickness, troponin-T, and B-type natriuretic peptide levels.


CONCLUSIONS
LGE is common in CA and detects interstitial expansion from amyloid deposition. Global transmural or subendocardial LGE is most common, but suboptimal myocardial nulling and focal patchy LGE are also observed. LGE-CMR may detect early cardiac abnormalities in patients with amyloidosis with normal left ventricular thickness. The presence and pattern of LGE is strongly associated with clinical, morphologic, functional, and biochemical markers of prognosis.
Division of Cardiovascular Diseases, Mayo Clinic, Rochester, Minnesota 55905, USA. syed.imran@mayo.edu
Imran S
IS
Syed
James F
JF
Glockner
Dali
D
Feng
Philip A
PA
Araoz
Matthew W
MW
Martinez
William D
WD
Edwards
Morie A
MA
Gertz
Angela
A
Dispenzieri
Jae K
JK
Oh
Diego
D
Bellavia
A Jamil
AJ
Tajik
Martha
M
Grogan
D000368:Aged; D000686:Amyloidosis / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000473:pathology; D015415:Biomarkers / Q000097:blood; D001706:Biopsy; D009202:Cardiomyopathies / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000473:pathology; D016009:Chi-Square Distribution; D003287:Contrast Media; D042241:Early Diagnosis; D004562:Electrocardiography; D005260:Female; D019786:Gadolinium DTPA; D006801:Humans; D019028:Magnetic Resonance Imaging, Cine; D008297:Male; D008875:Middle Aged; D009206:Myocardium / Q000473:pathology*; D015588:Observer Variation; D011237:Predictive Value of Tests; D011379:Prognosis; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012720:Severity of Illness Index; D014463:Ultrasonography
D015415:Biomarkers; D003287:Contrast Media; C064925:gadodiamide; D019786:Gadolinium DTPA