Trends in cardiac amyloidosis hospital admissions and associated mortality risk over 20 years: a population-based study using healthcare administrative databases.

Abstract

Cardiac amyloidosis (CA) remains substantially underdiagnosed despite greater awareness. This study evaluated hospital admissions for CA as a proxy of its incidence in Lombardy over the last two decades and the risk of mortality. Using the regional administrative database, we estimated the incidence of hospitalization for amyloidosis (AH) from 2005 to 2024, divided into CA and no-CA subgroups. Amyloidosis was considered CA if concomitant with heart failure, arrhythmia, cardiomyopathy during or within 2 years of AH and/or admission to a cardiology department. Annual incidence was analysed overall and by sex and age. Mortality was also evaluated. Among 3290 AH patients, 1032 (31.4%) were identified as CA. CA patients were older (76.1 ± 10.7 vs 70.8 ± 11.5 years) and more frequently male (73.2% vs 56.1%) compared to the no-CA. The incidence of first AH diagnosis increased from 1.43 in 2005 to 3.85 per 100,000 person-year in 2024, corresponding to an annual IRR of 1.06 (CI 95%, 1.04-1.07; p < 0.05). The annual IRR was 1.12 (CI 95%, 1.10-1.14) for CA and 1.03 (1.02-1.05) for no-CA (p < 0.05), ranging from 0.3 to 1.7 and 1.2-2.2 per 100,000 person-years, respectively. Incidence remained stable among younger adults while rose among individuals >65 years after 2016, particularly in males. CA patients had higher mortality risk than those cardiac involvement. AHs have increased steadily over the past few decades, largely due to CA since 2016. Although improved diagnosis partially explains this trend, persistently high mortality highlights the need for early identification and timely treatment of CA.