Table 4.

Consensus statements for aTTR-CM diagnosis by scintigraphy.

The role of scintigraphy in aTTR-CM diagnosis	Cardiology consensus rate %a	Nuclear medicine consensus rate %a
Clinical, ECG, and echocardiography findings of the patients are often satisfactory to suspect CA; therefore, patients with suspected CA can directly be referred to scintigraphy without resorting to CMR.	100	NA
If there is access to experienced radiology specialists and CMR for CA evaluation, patients with suspected CAb should be referred to CMR before or concurrently with scintigraphy.	70	NA
A diagnosis of aTTR-CM can be established* by scintigraphy in a patient with suspected CAb without a further investigation, in whom AL amyloidosis has been ruled outc and showed Grade ≥2 myocardial uptake with an H/CL ratio of ≥1.5 confirmed by SPECT**.	100	100
A diagnosis of aTTR-CM can be established* by scintigraphy in a patient with suspected CAb without a further investigation in whom AL amyloidosis has been ruled outc and showed Grade ≥2 myocardial uptake with H/CL ratio of ≥1.5 confirmed by SPECT-CT**.	100d	100d
Scintigraphy should be repeated by using SPECT-CT (if there is access within or outside the clinic), in a patient with suspected CAb, in whom AL amyloidosis has been ruled outc and whose cardiac scintigraphy showed inconsistent findings on radiotracer uptake for aTTR-CM (Grade ≥ 2 with H/CL <1.5, or Grade <2) assessed only by SPECT.	90	80
Scintigraphy should be repeated by using 99mTc-PYP before ruling out the aTTR-CM diagnosis in a patient with suspected CA, in whom AL amyloidosis has been ruled outc and whose cardiac scintigraphy performed by another radiotracer showed an inconsistent radiotracer uptake for aTTR-CM (Grade ≥2 with H/CL <1.5, or Grade <2).	50e	60e

^*Wording difference in consensus statements of nuclear medicine specialist as aTTR-CM differentiation can be achieved in a patient with suspected CA^b, in whom AL amyloidosis has been ruled out^c and showed Grade ≥2 myocardial uptake with an H/CL ratio of ≥1.5 confirmed by SPECT or SPECT-CT.

^**In an optimized/calibrated technical setting.

^a Consensus was defined as when 80% to 100% of the panel members marked the “agree/strongly agree” or “disagree/strongly disagree” option.

^b Based on clinical, ECG, and ECO findings.

^c By sFLC, SPIE, and UPIE.

^d The strength of the consensus was increased by 25% for the SPECT-CT compared with SPECT.

^e %50 of cardiologists agreed and 60% of nuclear medicine specialists disagreed with the statement.