Prevalence of transthyretin (ATTR) cardiac amyloidosis in the Australian population estimated using 99mTc hydroxymethylene diphosphonate and 99mTcmethylene diphosphonate planar bone scans

Abstract

Background. Nuclear medicine bone scans differentiate transthyretin (ATTR) cardiac amyloid from light chain (AL) cardiac amyloid and other infiltrative myocardial disorders. In appropriately selected individuals a diagnosis of cardiac ATTR can be made without endomyocardial biopsy. The detection of cardiac ATTR is becoming more important given that disease modifying therapies such as tafamidis have been shown to slow the decline in functional capacity and improve overall survival in this condition. Aims. To measure the prevalence of ATTR cardiac amyloidosis in the Australian population by assessing the presence of cardiac uptake on Tc- HDP and Tc-MDP bone scans Methods. Patients reviewed had attended a quaternary centre in Australia for clinically indicated bone scans during two time periods (HDP bone scans 2013-2018 and MDP bone scans 2005-2011). Whole body planar bone scans were retrieved and retrospectively reviewed by an experienced nuclear medicine physician and nuclear medicine registrar. The reviewers were blinded to the clinical history and previous report. Images were graded using the Perugini system and positive scans (grades 2 and 3) were reviewed jointly. All cardiac referrals were excluded. Results. A total of 6935 cases were reviewed (HDP 3493, MDP 3442). 17 positive studies were identified using HDP. No patient aged less than 65 had a positive scan. Only 1 positive study was identified using MDP. Conclusion. Our study demonstrates a prevalence of ATTR cardiac amyloid in Australia using HDP that is similar to studies performed in Europe using various agents (HDP, HEDP and DPD). MDP was not found to be effective.L6276487452019-05-17 <br />