The patient journey toward a diagnosis of hereditary transthyretin (ATTRv) amyloidosis

Background: Despite emerging treatments for hereditary transthyretin (ATTRv) amyloidosis, the disease is often misdiagnosed, with reported diagnostic delays of up to several years. Knowledge of the patient journey leading up to diagnosis may help to promote earlier intervention. The study's objective was to examine patient clinical characteristics and healthcare utilization prior to ATTRv amyloidosis diagnosis. Methods: Patients >= 18 years and newly diagnosed with ATTRv amyloidosis identified in IBM (R) MarketScan (R) Commercial and Medicare Supplemental data using a claims-based algorithm as follows: diagnosis required >= 1 medical claim with relevant amyloidosis diagnosis code (ICD-10-CM: E85.0-.4, E85.89, E85.9; excludes light chain and wild type) during identification (ID) period (1/1/2016-12/31/2017), and >= 1 occurrence of qualifying criteria during 2011-2017: >= 15 days diflunisal use without > 30-day gap, liver transplant, or claim with specific codes E85.1 or E85.2. The index date was defined as the date of first claim with amyloidosis diagnosis code in ID period. Patients had continuous enrollment >= 5 years pre-index date (look-back period). Occurrence of selected comorbid conditions and symptoms and healthcare utilization (testing, emergency department visits and hospitalization) measured during the look-back period; demographics, physician specialty, and Charlson comorbidity index (CCI) measured 1 year pre-index. Patients with an ICD-9/10 amyloidosis code during the look-back period were excluded. An ATTRv-free reference cohort was created from a random sample of enrollees who lacked any diagnosis of amyloidosis and matched 3:1 to ATTRv patients on age, gender, and region to provide reference values; same index and enrollment requirement as match. Results: For the 141 qualifying patients with ATTRv and 423 matched controls, mean (standard deviation) age was 62.5 (14.2) years and 53.9% were female. Mean CCI for ATTRv cohort was 2.7 (3.0) versus 1.1 (1.9) among controls. Selected comorbidities, testing, visits, and hospitalization were common among patients with ATTRv during the look-back period with higher rates versus controls. Conclusions: Patients with ATTRv amyloidosis experience multiple neurological, cardiovascular, and other clinical manifestations, testing, and hospitalization prior to diagnosis. Occurrence of potential markers of illness is most common in the year before diagnosis.