Prevalence, characteristics, and mortality of patients with transthyretin amyloid cardiomyopathy in the Nordic countries.

AIMS: Transthyretin amyloid cardiomyopathy (ATTR-CM) is a progressive condition caused by deposition of transthyretin amyloid fibrils in the heart and is associated with poor quality of life and a shortened lifespan. This study aimed to describe the prevalence, clinical characteristics, and mortality of patients with ATTR-CM, using multiple national health registers in Denmark, Finland, Norway, and Sweden. METHODS AND RESULTS: Transthyretin amyloid cardiomyopathy patients were identified during 2008-2018 using a combination of diagnosis codes for amyloidosis and heart disease and were matched to patients with non-ATTR heart failure (HF). An identical study design was used in each country to facilitate comparison and aggregation of results. A total of 1930 ATTR-CM patients were identified from national health registers in the four countries. In 2018, prevalence of ATTR-CM per 100 000 inhabitants ranged from 1.4 in Denmark to 5.0 in Sweden; a steep increase over time was observed in Sweden and Norway. Median survival from diagnosis was 30 months for ATTR-CM patients and 67 months for matched HF patients. Survival was significantly lower for female than for male ATTR-CM patients (median survival: 22 and 36 months), while no significant difference was observed in the HF cohort. CONCLUSIONS: This study provides the first nationwide estimates of the prevalence, clinical characteristics, and mortality of patients with ATTR-CM, using identical study design across several countries. Findings corroborate previous case series showing high mortality in ATTR-CM, two-fold higher than for other HF patients and higher in women than men, highlighting the need for more precise and early diagnosis to reduce the disease burden.

Healthcare resource use of patients with transthyretin amyloid cardiomyopathy.

AIMS: Transthyretin amyloid cardiomyopathy (ATTR-CM) is the cardiac manifestation of transthyretin amyloidosis (ATTR). The aim of this study was to estimate healthcare resource use for ATTR-CM patients compared with heart failure (HF) patients, in Denmark, Finland, Norway, and Sweden. METHODS AND RESULTS: Data from nationwide healthcare registers in the four countries were used. ATTR-CM patients were defined as individuals diagnosed with amyloidosis and cardiomyopathy or HF between 2008 and 2018. Patients in the ATTR-CM cohort were matched to patients with HF but without ATTR-CM diagnosis. Resource use included number of visits to specialty outpatient and inpatient hospital care. A total of 1831 ATTR-CM and 1831 HF patients were included in the analysis. The mean number of hospital-based healthcare contacts increased in both the ATTR-CM and HF cohort during 3 years pre-diagnosis and was consistently higher for the ATTR-CM cohort compared with the HF cohort, with 6.1 [CI: 5.9-6.3] vs. 3.2 [CI: 3.1-3.3] outpatient visits and 1.03 [CI: 0.96-1.1] vs. 0.7 [CI: 0.7-0.8] hospitalizations. In the first year following diagnosis, patients with ATTR-CM continued to visit outpatient care (10.2 [CI: 10.1, 10.4] vs. 5.7 [CI: 5.6, 5.9]) and were admitted to hospital more frequently (3.3 [CI: 3.2, 3.4] vs. 2.5 [CI: 2.5, 2.6]) than HF patients. CONCLUSIONS: Transthyretin amyloid cardiomyopathy imposes a high burden on healthcare systems with twice as many outpatient specialist visits and 50% more hospitalizations in the year after diagnosis compared with HF patients without ATTR-CM. Studies to investigate if earlier diagnosis and treatment of ATTR-CM may lower resource use are warranted.