The prevalence of TTR cardiac amyloidosis among patients undergoing bone scintigraphy

J Nucl Cardiol. 2021 Jun;28(3):825-830. doi: 10.1007/s12350-021-02575-0. Epub 2021 Mar 16.

Abstract

Background: Radiolabeled bisphosphonates bone scintigraphy is highly sensitive in detecting transthyretin (TTR) cardiac amyloidosis; data on the true prevalence of cardiac involvement in TTR amyloidosis are lacking.

Methods and results: This retrospective observational, monocentric study aims to estimate the prevalence of positive bone scan suspect for TTR cardiac amyloidosis among an all-comers population who underwent a bone scintigraphy. ECG, echocardiography and clinical status of patients with unexpected cardiac uptake (Perugini score 2-3) who underwent bone scintigraphy with [99mTc]-HDP or [99mTc]-DPD at San Luigi Gonzaga University Hospital between January 2015 and May 2020 have been collected. The prevalence of bone scintigraphy suspect for cardiac involvement was 0.54% (23/4,228). The bone scintigraphy was mainly performed using [99mTc]-HDP (82.9%) and the dominant indication for the test was oncology in the 47.9% of cases. 8 Subjects had a history of neuropathy (34.8%) and 5 of carpal tunnel syndrome (21.7%). 11 Patients suffered a previous episode of heart failure (48%) while 5 patients (21.7%) were totally asymptomatic, without any sign or symptom before the bone scintigraphy making the nuclear examination crucial for an early diagnosis of TTR amyloidosis.

Conclusion: Bone scintigraphy allows suspecting TTR amyloidosis in a pre-clinical stage of the disease in an all-comers population of patients undergoing bone scintigraphy mainly for oncology reasons.

Keywords: Amyloidosis; Bone scintigraphy; Perugini score; Transthyretin.