Integrated diagnostic approach to wild-type transthyretin cardiac amyloidosis with the use of high-sensitivity cardiac troponin T measurement and 99mTc-pyrophosphate scintigraphy

Abstract

Background: The diagnosis of wild-type transthyretin cardiac amyloidosis (ATTRwt) is frequently missed or delayed because of the limited specificity of manifestations. We investigated the utility of combined assessment of high-sensitivity cardiac troponin T (hs-cTnT) measurement and 99m Tc-pyrophosphate ( 99m Tc-PYP) scintigraphy as diagnostic modalities in ATTRwt. Methods: We divided 39 consecutive ATTRwt patients into two groups depending on whether serum hs-cTnT measurement and 99m Tc-PYP scintigraphy were adopted as diagnostic tools: group A patients (n = 8) who were diagnosed before the introduction of these two tools and group B patients (n = 31) who were diagnosed after the introduction of the two tools. We retrospectively evaluated the two groups. Results: Diagnostic yield was higher in group B than in group A (1.2 vs. 5.4 ATTRwt patients per 1000 hospitalized patients, p < 0.01). Group B patients presented broad clinical features that were different from group A patients with classical characteristics. Atrial fibrillation was more frequent (12.5% vs. 58.1%, p = 0.044) and inter-ventricular septum (IVS) thickness and relative wall thickness (RWT) were smaller in group B patients than in group A patients (IVS thickness: 16.1 AE 2.4 mm vs. 13.6 AE 2.8 mm, p = 0.023; RWT: 0.71 AE 0.11 mm vs. 0.58 AE 0.13 mm, p = 0.014). Furthermore, left ventricular hypertrophy (LVH) (IVS thickness !15 mm) was more frequent in patients in group A than in patients in group B (87.5% vs. 33.3%, p = 0.013). No significant difference was observed in the mean value of left ventricular ejection fraction (LVEF), whereas the dispersion of LVEF was high in group B (interquartile range: 47-58% vs. 39-57%). Conclusions: An integrated approach consisting of hs-cTnT measurement and 99m Tc-PYP scintigraphy significantly increases the diagnostic rate of ATTRwt and has a high potential to identify ATTRwt patients with a variety of clinical phenotypes.

The true population and diversity of ATTR cardiac amyloidosis revealed by new diagnostic tools

“…And the cohort study conducted in Spain indicated that in 108 cases diagnosed with ATTRwt using PYP scintigraphy (including cases not undergoing biopsy), about 20% were unexpectedly women, low voltage in limb leads in ECG was less frequent (22%), not only concentric LVH but also asymmetric hypertrophy existed to some extent (23.1%), and there were also many patients with heart failure with reduced ejection fraction with decreased left ventricular contractility among ATTR-CM patients with heart failure (left ventricular ejection fraction <50%: 36.8%) [9]. Thus, in response to the current global progress in which the diversity of clinical features in ATTR-wt is being elucidated by new effective diagnostic methods, Ochi et al demonstrate novel findings for the diversity of this disease in Japan through the present study [10]. They compared two groups before and after using a protocol to diagnose with 99mTc-PYP scintigraphy and high-sensitivity cardiac troponin T, a representative high-sensitive marker of myocardial injury.…”

Impact of Delayed Diagnosis and Misdiagnosis for Patients with Transthyretin Amyloid Cardiomyopathy (ATTR-CM): A Targeted Literature Review

“…Twelve studies collected data in North America [ 18 – 29 ], three in Asia [ 30 – 32 ], six in Europe [ 3 , 33 – 37 ], and two were conducted internationally [ 38 , 39 ]. Fourteen publications reported data for ATTRwt-CM [ 40 ], eleven for ATTRv-CM [ 3 , 18 , 21 , 22 , 24 – 26 , 29 , 30 , 33 , 39 ] and seven for mixed ATTR-CM populations (ATTRwt-CM and ATTRv-CM [ 18 , 19 , 23 , 24 , 27 , 28 , 37 ]).…”

Use of biomarkers to diagnose and manage cardiac amyloidosis

“…There are no studies specifically addressing the diagnostic performance of hs‐troponins in ATTR amyloidosis. Nonetheless, the apparent prevalence of this condition has increased steadily since the introduction of hs‐TnT measurement and 99m Tc‐pyrophosphate scintigraphy in patients with clinical suspicion of ATTRwt 79 …”