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Usefulness of relative apical longitudinal strain index to predict positive 99m Tc‐labeled pyrophosphate scintigraphy findings in advanced‐age patients with suspected transthyretin amyloid cardiomyopathy
Author(s) -
Usuku Hiroki,
Takashio Seiji,
Yamamoto Eiichiro,
Kinoshita Yui,
Nishi Masato,
Oike Fumi,
Marume Kyohei,
Hirakawa Kyoko,
Tabata Noriaki,
Oda Seitaro,
Misumi Yohei,
Ueda Mitsuharu,
Kawano Hiroaki,
Kaikita Koichi,
Matsushita Kenichi,
Ando Yukio,
Matsui Hirotaka,
Tsujita Kenichi
Publication year - 2020
Publication title -
echocardiography
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.404
H-Index - 62
eISSN - 1540-8175
pISSN - 0742-2822
DOI - 10.1111/echo.14892
Subject(s) - scintigraphy , medicine , confidence interval , odds ratio , nuclear medicine , transthyretin , logistic regression , cardiology
Background We previously reported that a high score (2 or 3 points) according to the Kumamoto criteria, a combination of high‐sensitivity cardiac troponin T (hs‐cTnT) ≥0.308 ng/mL, the length of QRS ≥ 120 ms in electrocardiogram, and left ventricular (LV) posterior wall thickness ≥ 13.6 mm, increases the pretest probability of 99m Tc‐labeled pyrophosphate ( 99m Tc‐PYP) scintigraphy in patients with suspected transthyretin amyloid cardiomyopathy (ATTR‐CM). However, some patients with a low score (0 or 1 point) show positive findings on 99m Tc‐PYP scintigraphy. Therefore, we evaluated the usefulness of additional examinations, including echocardiographic assessment of myocardial strain, to raise the pretest probability of 99m Tc‐PYP scintigraphy for these patients. Methods and Results We examined 109 consecutive patients aged ≥70 years with low scores according to the Kumamoto criteria who underwent 99m Tc‐PYP scintigraphy. Nineteen patients (17%) had positive 99m Tc‐PYP scintigraphy findings. The relative apical longitudinal strain (LS) index (apical LS/ basal LS + mid LS) (RapLSI) was significantly higher in patients with positive than negative 99m Tc‐PYP scintigraphy findings (1.04 ± 0.37 vs 0.70 ± 0.28, P < .01). Multivariable logistic regression analysis revealed that a high RapLSI (≥1.04) was significantly associated with 99m Tc‐PYP positivity (odds ratio, 14.14; 95% confidence interval, 3.36‐59.47; P < .01). The sensitivity, specificity, and accuracy of the diagnostic model using the RapLSI for identification of 99m Tc‐PYP positivity were 53%, 94%, and 87%, respectively. Conclusions A high RapLSI can raise the pretest probability of 99m Tc‐PYP scintigraphy in patients with a low score according to the Kumamoto criteria. The RapLSI can assist clinicians in determining strategies for these patients.