Validation of the Kumamoto criteria for prediction of 99m technetium pyrophosphate scintigraphy positivity as a strategy for diagnosis of transthyretin cardiac amyloidosis: A retrospective cohort study in Kochi

J Cardiol. 2021 Feb;77(2):124-130. doi: 10.1016/j.jjcc.2020.06.019. Epub 2020 Oct 22.


Background: Early diagnosis of transthyretin cardiac amyloidosis (ATTR-CA) is important. The aim of this study was to validate the 'Kumamoto criteria' for prediction of technetium-99m pyrophosphate (99mTc-PYP) scintigraphy positivity.

Methods: One hundred fifty patients (median age: 79.4 years, 117 males) with the possibility of ATTR-CA who underwent 99mTc-PYP scintigraphy were assessed. We divided the patients into 4 groups (groups with score of 0-3) according to the Kumamoto criteria by total points for the following 3 factors: high-sensitivity cardiac troponin T (hs-cTnT) ≥0.0308 ng/ml, left ventricle posterior wall thickness ≥13.6 mm, and wide QRS (QRS ≥ 120 ms).

Results: Seventy patients (46.7%) were positive for 99mTc-PYP scintigraphy. 99mTc-PYP positivity rates in the groups with score of 0, 1, 2, and 3 were 4%, 39%, 69%, and 89%, respectively. Compared with the original Kumamoto cohort, our patients in the score 1 group showed a relatively high rate of 99mTc-PYP positivity because hs-cTnT as one of the positive factors had high ability to discriminate the disease. The sensitivity and negative predictive value of hs-cTnT ≥0.0308 ng/ml for 99mTc-PYP positivity were 97.1% and 93.9%.

Conclusions: In the Kochi validation cohort, the Kumamoto criteria were useful for predicting 99mTc-PYP positivity. However, patients in the score 1 group should be assessed cautiously for the possibility of ATTR-CA if the hs-cTnT value is high.

Keywords: (99m) Technetium pyrophosphate scintigraphy; High-sensitivity cardiac troponin T; Kumamoto criteria; Transthyretin cardiac amyloidosis.

Publication types

  • Research Support, Non-U.S. Gov't
  • Validation Study

MeSH terms

  • Aged
  • Aged, 80 and over
  • Amyloidosis / diagnosis
  • Amyloidosis / diagnostic imaging*
  • Cardiomyopathies / diagnostic imaging*
  • Female
  • Heart / diagnostic imaging
  • Heart Ventricles / diagnostic imaging
  • Heart Ventricles / pathology
  • Humans
  • Male
  • Prealbumin / analysis*
  • Predictive Value of Tests
  • Radionuclide Imaging / methods
  • Radionuclide Imaging / statistics & numerical data*
  • Radiopharmaceuticals*
  • Reproducibility of Results
  • Retrospective Studies
  • Sensitivity and Specificity
  • Technetium Tc 99m Pyrophosphate*


  • Prealbumin
  • Radiopharmaceuticals
  • Technetium Tc 99m Pyrophosphate