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The prevalence of FD in Japanese male patients with a clinical diagnosis of HCM was found to be 1.1%. These patients showed late onset and concentric LVH at initial presentation.

Background: With recent advances in non-invasive diagnostic tools, some studies indicate that wild-type transthyretin amyloidosis (ATTRwt) may be more common in females than previously reported. However, the clinical characteristics of female ATTRwt patients have not been determined. Methods and Results:Of the 78 consecutive patients with ATTRwt in our cohort, 14 (17.9 %) were female. Compared with male patients, female ATTRwt patients had smaller left ventricular (LV) wall thicknesses (ventricular septum thickness 12.9 vs. 14.2 mm [P=0.081]; posterior wall thickness 12.7 vs. 13.6 mm [P=0.035]) and a higher LV ejection fraction (EF; mean [±SD] 58.4±8.9% vs. 48.9±11.8%; P=0.006). However, the severity of heart failure (HF), as assessed by HF stage, New York Heart Association functional class and B-type natriuretic peptide concentrations, did not differ between female and male patients. Moreover, LV mass index and relative wall thickness were increased and the stroke volume index was reduced in both female and male patients. In organ biopsies, female patients had a higher sensitivity to transthyretin deposition from abdominal fat than male patients (positive abdominal fat biopsy 80.0 % vs. 26.5%; P=0.016). Conclusions:This study suggests that a relatively large proportion of elderly females have ATTRwt. Female ATTRwt patients had HF symptoms even at the stage of mild LV hypertrophy and preserved EF. Abdominal fat biopsy may be useful to diagnose ATTRwt, especially in female patients with HF.

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.

Background: Tafamidis has emerged as an effective treatment for patients with wild-type transthyretin cardiac amyloidosis (ATTRwt CA). The early experience of tafamidis treatment for Japanese patients with ATTRwt CA is reported here. Methods and Results:Over the past 2 years, in 82 patients with ATTRwt CA (mean age of 81.7±6.0 years), tafamidis treatment was initiated for 38 patients. The remaining 44 patients were not administered tafamidis. The most frequent reason for non-administration of tafamidis was advanced heart failure and the second most reason was the patient's frailty. In patients who received tafamidis treatment, there was no discontinuation of tafamidis due to adverse events, the rate of cardiovascular-related hospitalizations per year was 0.19, and the 1-year survival rate was 92%. In the patients who continued tafamidis for 12-18 months, there was no significant deterioration from baseline for high-sensitivity cardiac troponin T level, plasma B-type natriuretic peptide level, left ventricular ejection fraction, inter-ventricular septum wall thickness, or value of left ventricular longitudinal strain.Conclusions: Tafamidis treatment was introduced for approximately half of the study patients with ATTRwt CA in real-world practice. Tafamidis is likely to be safe and may maintain the status of disease severity in the short-term in selected Japanese patients with ATTRwt CA. Further research is needed to determine appropriate patient selection for tafamidis treatment and efficacy of tafamidis in the long term.