Wild-Type Transthyretin Amyloidosis in Female Patients　― Consideration of Sex Differences ―

Abstract

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.

Diagnostic and Therapeutic Strategy for Female Patients With Cardiac Amyloidosis

“…Ochi et al demonstrated that the prevalence of wild-type transthyretin amyloidosis in female patients was higher than in previous reports. 1 Female patients tended to have heart failure symptoms despite mild cardiac hypertrophy and preserved ejection fraction. Several concerns have been raised.…”

“…In the study of Ochi et al, the thickness of the left ventricular wall was less in female than male patients. 1 Thus, it may be more challenging to suspect cardiac amyloidosis in daily clinical practice among female patients. Were there any differences in the signs and chief complaints between female and male patients?…”

“…Given the difficulty in diagnosis, there may have been a selection bias in the study. 1 Of note, clinicians may not necessarily attempt to aggressively diagnose cardiac amyloidosis, particularly in elderly patients, given the lack of a definitive therapeutic strategy. Even the use of the recently introduced tafamidis may be challenging in elderly patients with advanced cardiac amyloidosis because of cost-effectiveness considerations.…”

“…Approximately 15% of female and 40% of male patients had a mid-range or reduced ejection fraction. 1 The use of neurohormonal blockers in patients with cardiac amyloidosis is controversial. 3 Do Ochi et al prescribe neurohormonal blockers for such a cohort?…”

Diagnostic and Therapeutic Strategy for Female Patients With Cardiac Amyloidosis ― Reply ―

“…We are grateful to Drs. Imamura and Nakamura for their interest in and comments on our study, 1 and for highlighting some issues regarding the diagnostic and therapeutic strategies for female patients with wild-type transthyretin amyloidosis (ATTRwt) in an aged Japanese community.…”