Impact of Tafamidis on [99mTc]Tc-pyrophosphate Scintigraphy in Ala97Ser Hereditary Transthyretin amyloid cardiomyopathy: significant initial reduction with stable Long-Term effects

An-Li Yu; Yi-Chieh Chen; Cheng-Hsuan Tsai; Chi-Chao Chao; Mao-Yuan Su; Chia-Tung Shun; Hsueh-Wen Hsueh; Jyh-Ming Jimmy Juang; Ming-Jen Lee; Ping-Huei Tseng; Sung-Tsang Hsieh; Mei-Fang Cheng; Yen-Hung Lin

doi:10.1007/s00259-025-07079-4

Impact of Tafamidis on [^99mTc]Tc-pyrophosphate Scintigraphy in Ala97Ser Hereditary Transthyretin amyloid cardiomyopathy: significant initial reduction with stable Long-Term effects

Eur J Nucl Med Mol Imaging. 2025 Jan 13. doi: 10.1007/s00259-025-07079-4. Online ahead of print.

Authors

An-Li Yu¹, Yi-Chieh Chen², Cheng-Hsuan Tsai^{3

4}, Chi-Chao Chao⁵, Mao-Yuan Su^{6

7}, Chia-Tung Shun⁸, Hsueh-Wen Hsueh⁵, Jyh-Ming Jimmy Juang³, Ming-Jen Lee⁵, Ping-Huei Tseng⁹, Sung-Tsang Hsieh⁵, Mei-Fang Cheng^#^{10

11}, Yen-Hung Lin^#^{12

13}

Affiliations

¹ Department of Internal Medicine, Division of Cardiology, National Taiwan University Hospital Hsinchu Branch, Hsinchu, Taiwan.
² Department of Nuclear Medicine, National Taiwan University Hospital, National Taiwan University College of Medicine, No. 7, Zhongshan S. Rd., Zhongzheng Dist., Taipei, 100, Taiwan.
³ Department of Internal Medicine, Division of Cardiology, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan.
⁴ Graduate Institute of Clinical Medicine, National Taiwan University College of Medicine, Taipei, Taiwan.
⁵ Department of Neurology, National Taiwan University Hospital, National Taiwan University College of Medicine, Taipei, Taiwan.
⁶ Department of Medical Imaging, National Taiwan University Hospital, Taipei, Taiwan.
⁷ Department of Medical Imaging and Radiological Technology, Yuanpei University of Medical Technology, Hsinchu, Taiwan.
⁸ Department of Forensic Medicine and Pathology, National Taiwan University Hospital, Taipei, Taiwan.
⁹ Department of Internal Medicine, Division of Gastroenterology, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan.
¹⁰ Department of Nuclear Medicine, National Taiwan University Hospital, National Taiwan University College of Medicine, No. 7, Zhongshan S. Rd., Zhongzheng Dist., Taipei, 100, Taiwan. meifang@ntuh.gov.tw.
¹¹ Institute of Environmental and Occupational Health Sciences, National Taiwan University, Taipei, Taiwan. meifang@ntuh.gov.tw.
¹² Department of Internal Medicine, Division of Cardiology, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan. austinr34@gmail.com.
¹³ Cardiovascular Center, Division of Cardiology, Department of Internal Medicine, National Taiwan University Hospital, No. 7, Zhongshan S. Rd., Zhongzheng Dist., Taipei, 100, Taiwan. austinr34@gmail.com.

^# Contributed equally.

PMID: 39800807
DOI: 10.1007/s00259-025-07079-4

Abstract

Objective: Tafamidis has shown potential in slowing disease progression in patients with transthyretin amyloid cardiomyopathy (ATTR-CM). This study aimed to evaluate serial changes on [^99mTc]Tc-pyrophosphate (PYP) scintigraphy during tafamidis treatment for hereditary ATTR-CM.

Methods: We retrospectively analyzed a prospectively collected cohort of Ala97Ser (A97S) hereditary ATTR-CM patients treated with tafamidis (61 mg/day) and a control group comprising A97S hereditary ATTR-CM patients who had not received disease-modifying medications. The tafamidis group was further divided into two cohorts: cohort A received [^99mTc]Tc-PYP SPECT/CT scans at baseline, 1 year, and 2 years; cohort B at baseline, 2 years, and 3 years. Visual score, planar heart to contralateral lung (H/CL) ratio, and volumetric heart to lung (H/L) ratio were measured.

Results: Nineteen patients were enrolled in the tafamidis group and nine in the control group. After 2 years of follow-up, a significant decrease in volumetric H/L ratio (3.86 ± 0.91 to 3.01 ± 0.19, p < 0.001) was noted in the tafamidis group, while there was no significant change in the control group. When evaluated over time, a significant decrease in volumetric H/L ratio was observed during the first year of tafamidis treatment (3.75 ± 0.37 to 2.82 ± 0.15, p = 0.004), followed by stable [^99mTc]Tc-PYP uptake in the subsequent two years (2.82 ± 0.15 to 2.83 ± 0.18, p = 0.934 and 3.20 ± 0.14 to 3.09 ± 0.16, p = 0.404, respectively).

Conclusion: A significant reduction in [^99mTc]Tc-PYP uptake was observed in hereditary ATTR-CM patients after tafamidis treatment, particularly within the first year. While the effect appeared to be sustained, stable [^99mTc]Tc-PYP uptake without further significant reductions was observed in the subsequent years.

Keywords: Heart failure; Hereditary transthyretin amyloidosis; Tafamidis; [99mTc]Tc-pyrophosphate single-photon emission computed tomography/Computed tomography.

Grants and funding

Pfizer/Pfizer