Changes in the diagnostic landscape of transthyretin amyloid cardiomyopathy (ATTR-CM): a comparison of tests ordered and test Intervals in 2020 Q4 and 2023 Q4

Abstract Background Transthyretin Amyloid Cardiomyopathy (ATTR-CM) is a genetic disease caused when misfolded transthyretin protein is deposited in the myocardium. Amyloidosis driven stiffness in heart muscles results in heart failure symptoms. ATTR-CM is underdiagnosed, requiring specialized tests to identify the condition. Purpose This paper examines and compares diagnostic tests and the time intervals between rounds of testing conducted to identify ATTR-CM in 2020 Q4 and 2023 Q4 in France (FR), Germany (DE), Italy (IT), Spain (ES) and the United Kingdom (UK). Methods A multi-centre online medical chart review was performed between November and December 2020, with 210 (FR: 46, DE: 40, IT: 43, ES: 42, UK: 39) cardiologists/internists providing data on 320 (FR: 71, DE: 63, IT: 64, ES: 63, UK: 59) patients diagnosed with ATTR-CM; and between October and November 2023, with 225 (FR: 45, DE: 48, IT: 48, ES: 45, UK: 39) cardiologists/Internists providing data on 780 (FR: 151, DE: 163, IT: 172, ES: 175, UK: 119) patients. Participants were screened for ATTR-CM patient management. We analysed the diagnostic tests ordered and tracked the intervals between batteries of tests to understand how the timing of diagnosis has changed across the EU4+UK. Results The average number of ATTR-CM diagnostic tests received by reported patients rose from 5.9 in 2020 to 7.4 in 2023, with ECHO with strain imaging (87%), Genetic tests (78%), Cardiac MRI (74%), Laboratory tests (67%), and Scintigraphy tests (65%) as the top 5 tests in Q4 2023. There was a notable increase in the use of ECHO with strain imaging, Laboratory tests, and Scintigraphy tests recorded in the Spanish patient cohort (p<0.01). Reported patients in Italy, Spain & UK received an increased average number of tests (p<0.05) [Table 1]. The recorded interval between the 1st and 2nd test batteries remained consistent between Q4 2020 and Q4 2023 (4.8-4.9 wks.), but the interval between the 2nd to 3rd rounds increased from 4.3 to 5.0 weeks. Timings between batteries increased in the France, Germany, Italy and UK data. Reported patients in Germany continue to experience the shortest intervals between batteries of tests (4.1 wks. between 1st and 2nd; 4.4 wks. between 2nd and 3rd batteries). Between Q4 2020 and Q4 2023, reported patients in Spain had an increase in the average number of tests received from 5.2 to 7.2, and were the only group with decreased time intervals (7.3 to 4.5 wks. between 1st and 2nd; 5.8 to 5.1 wks. between 2nd and 3rd batteries) Conclusion Results indicate that the use of certain diagnostic tests as well as the number of tests used to diagnose ATTR-CM has increased, however, intervals between testing batteries have also increased. This suggests that the increase in the number of tests used to diagnose ATTR-CM is possibly negating the necessity for more frequent testing. Further research in needed to confirm this and assess its impact on early detection of ATTR-CM.Table 1:Diagnostic Procedures by RegionTable 2:Testing battery intervals