The Burden of Transthyretin Amyloid Cardiomyopathy on Caregivers and Patients in Japan: A Cross‑Sectional Real‑World Survey

INTRODUCTION: Transthyretin amyloid cardiomyopathy (ATTR-CM) is a progressive disease predominantly affecting older men and is associated with increasing care needs. Previous international studies have reported that, as ATTR-CM progresses, caregivers experience substantial physical and emotional burden, as well as productivity impairment. However, real-world evidence on caregiver burden in Japan remains limited. This study aimed to characterize multidimensional caregiver and patient burden in Japan. METHODS: Data were drawn from the Adelphi ATTR Disease Specific Programme™, a cross-sectional survey of cardiologists and their consulting patients with ATTR-CM, conducted in Japan between October 2024 and January 2025. Cardiologists completed patient record forms, including patient demographics, clinical characteristics, and caregiving status. Patients and their non-professional caregivers also completed voluntary self-reported questionnaires. Caregiver outcomes included caregiving time, work productivity, and activity impairment (WPAI), and Zarit Burden Interview (ZBI) scores. Patient health status was assessed using the Kansas City Cardiomyopathy Questionnaire (KCCQ). Analyses were descriptive. RESULTS: Twenty-five physicians provided data for 120 patients (mean age 74.7 years; 78.3% male). Over half of patients (55.9%) had a caregiver, most commonly a spouse (72.6%). Caregivers (n = 22; mean age 64.0 years; 95.5% female) primarily lived with the patient (81.8%). Caregivers reported a median (interquartile range) of 20.0 (5.0-40.0) hours/week caregiving, and experienced substantial overall work productivity impairment [36.2% (SD 37.3%)] and daily activity impairment [47.7% (SD 31.5%)]. The mean ZBI score was 38.3 (SD 19.3), with 85% experiencing at least mild burden. CONCLUSION: This real-world study describes substantial burden among a sample of predominantly female spouses caring for patients with ATTR-CM in Japan. Furthermore, these findings underscore the importance of timely diagnosis and treatment for patients, alongside strengthening support for their caregivers within the Japanese healthcare system.