Diagnostic pathways, cardiac manifestations and outcomes in light chain amyloidosis: analysis of a US claims database

BACKGROUND: Patients with light chain (AL) amyloidosis, a rare life-threatening disease, often go through a lengthy diagnostic journey. We qualitatively and quantitatively characterised the diagnostic pathway and the impact of delayed diagnosis on health outcomes among patients with AL amyloidosis. METHODS: We conducted a retrospective cohort analysis of adults (age ≥18 years) with ≥2 AL amyloidosis diagnoses (index date: first diagnosis date) using the IQVIA PharMetrics Plus US claims data from 1 January 2016 to 31 December 2022. We stratified patients based on time from first cardiovascular (CV) manifestation onset to diagnosis. Patients were categorised as having a delayed diagnosis if the first CV manifestation occurred >1 year prior to diagnosis, and patients were categorised as without a delayed diagnosis if the first CV manifestation occurred <1 year prior to diagnosis. RESULTS: Our study included 470 patients (mean age 61.8 years, 60% males). In the 24 months before diagnosis, CV manifestations occurred in 86% of patients and renal manifestations in 74%. Patients most frequently visited on average four different cardiologists. Patients were most frequently diagnosed by haematologists/oncologists (49.8%). Patients with a delayed diagnosis (179/470, 38.1%) were twice as likely as those without a delayed diagnosis to have CV-related emergency room visits (adjusted OR: 1.98; 95% CI: 1.21 to 3.24; p<0.010). Patients with a delayed diagnosis were one and a half times more likely than those without a delayed diagnosis to have CV-related inpatient hospitalisations (adjusted OR: 1.65; 95% CI: 1.1 to 2.46; p=0.020). CONCLUSIONS: This claims database study suggests that patients with delayed diagnosis experienced more CV-related emergency room visits and inpatient hospitalisations, underscoring the need for timely diagnosis of AL amyloidosis and the role of cardiologists in the diagnostic pathway.