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Canepa et al. Vessel Plus 2022;6:30 https://dx.doi.org/10.20517/2574-1209.2021.106 Page 3 of 13

Figure 1. Current concepts in the evolving epidemiology of cardiac amyloidosis. ATTR-CA: Transthyretin-related-cardiac amyloidosis;
HFpEF: heart failure with preserved ejection fraction; HCM: hypertrophic cardiomyopathy; SPECT: single photon emission computed
tomography.

The description of the evolving epidemiology of CA remains scant in the literature so far [1,3,4,9] . Data on AL-
CA from the Olmsted County from 1990 to 2015 show a stable incidence rate of 1.2 per 100,000 person-
years . A stable prevalence of AL-CA has also been recently reported in Italy, with data from a single-center
[9]
[10]
20-year study from Florence including 654 CA patients and a multi-center 5-year Italian survey
[11]
including 642 CA patients both showing an exponential increase in the number of ATTR-CA diagnoses
following 2016, the year of publication of the algorithm by Gillmore et al. . Both works demonstrated that
[7]
60%-70% of CA cases diagnosed in 2019 were in fact ATTRwt-CA, with only the remaining 20%-30% being
AL-CA. Data from the National Amyloidosis Center in London, which provides care to a large cohort in the
United Kingdom, suggest that the diagnosis of ATTRwt-CA has increased exponentially there as well .
[12]
Administrative data from Medicare Beneficiaries in the United States of America also demonstrate that both
the incidence and prevalence of CA have increased from 2000 to 2012 (no distinction between ATTR- and
AL-CA was available in this analysis), particularly among male patients ≥ 65 years old presenting with new-
onset HF . As for ATTRv-CA, this has been considered a disease with endemic regions due to the variable
[13]
geographical distribution of TTR mutations . Nonetheless, the growing use of genetic testing that should
[4]
follow the expanding use of bone scintigraphy will likely reveal the existence of additional endemic areas,
including clusters of ATTRv-CA patients with mutations once considered to be rare , determining an
[14]
enormous change in the apparently well-known geographical distribution of this disease. In conclusion, in
the words of the experts, “although the exact prevalence of ATTR-CA is unknown, this is almost certainly
[4]
the most common cause of CA” . A “higher-than-expected” prevalence of ATTR-CA in some at-risk
cardiovascular conditions has also been recently acknowledged within international rare diseases databases.