Algorithm for Clinical Diagnosis of ATTR-CM1

Transthyretin Amyloid Cardiomyopathy   >   Diagnosis of ATTR-CM   >   Diagnosis of ATTR-CM   >   Diagnostic Algorithm
Diagnostic Algorithm
Symptoms, ECG, Echo, MRI, or Biomarkers suggestive of
cardiac amyloidosis
Screen for the presence of a monoclonal protein Order the following three tests:
  • Serum kappa / lambda free light chain ratio (abnormal if ratio is <0.26 or >1.65)
  • Serum protein immunofixation (abnormal if monoclonal protein is detected)
  • Urine protein immunofixation (abnormal if monoclonal protein is detected)
1 or more abnormal
all normal
Referral to Hematology and
*Bone Scintigraphy Available?
Yes
No
Biopsy of clinically involved organ (cardiac
or renal) or fat pad* *If fat pad is negative, biopsy of involved
organ is required
  • Positive Congo Red and
  • Tissue typing by mass spectrometry or
    immunostaining
Yes
No
AL, ATTR, other amyloidosis
and/or MGUS
Cardiac
Amyloidosis
Unlikely
Non-invasive evaluation with
Bone Scintigraphy
  • Positive Bone Scintigraphy
Yes
Negative or
indeterminate
ATTR Amyloidosis
Genetic Testing
ATTRwt
ATTRm
Cardiac
Amyloidosis
Unlikely
Consider Heart
Biopsy if suspicion
is high
Referral for Bone Scintigraphy or invasive
evaluation with Heart Biopsy
  • Positive Congo Red and
  • Tissue typing by mass spectrometry or immunostaining
Yes
No
ATTR Amyloidosis
Genetic Testing
ATTRwt
ATTRm
Cardiac
Amyloidosis
Unlikely
+

*Bone scintigraphy is not FDA approved for the diagnosis of ATTR-CM. Please consult individual labeling for risks