OBJECTIVES: Transthyretin amyloid cardiomyopathy (ATTR-CM) is a rare and fatal cause of heart failure (HF) which is presumed to be underdiagnosed. This study aims to: (1) estimate and describe resource use of patients with ATTR-CM in Sweden prior to diagnosis and (2) to compare resources used relative to matched patients with all-cause HF without amyloidosis post diagnosis.

METHODS: This retrospective, observational study used nation-wide Swedish administrative health register data to identify ATTR-CM patients between 2008 and 2018. HF patients were matched 1:1 to ATTR-CM patients based on birth year, sex and diagnosis year. Equal length of follow-up time was required for ATTR-CM and HF cases. The mean number of visits to specialized outpatient care, hospitalizations and hospitalization days were estimated.

RESULTS: During the study period 994 diagnosed ATTR-CM patients were identified. Three years prior to diagnosis 70% of patients had at least one outpatient visit and 30% of patients were hospitalized. Percentages increased to 85% and 50% in the year prior to diagnosis for outpatient and inpatient hospitalizations. In the year following diagnosis, the number of outpatient visits and hospitalizations was higher among ATTR-CM than HF patients (11.5 vs. 7.8 visits, p-value<0.001) and longer (20.7 vs. 12.5 days, p-value<0.001). After diagnosis, the number of visits decreased, with more pronounced reduction over time for HF patients; -30% vs. -2% for outpatient visits, -59% vs. -43% for hospitalizations year 2 after diagnosis.

CONCLUSIONS: To our knowledge this is the first study estimating the resource use of ATTR-CM compared to HF patients. The high resource use before diagnosis indicates that symptoms present and that healthcare is provided some time before the accurate diagnosis is made. Higher resource use among ATTR-CM compared to HF patients highlights the severity and burden of ATTR-CM and importance of early diagnosis.