Epidemiology of Cardiac Amyloidosis-Associated Heart Failure Hospitalizations Among Fee-for-Service Medicare Beneficiaries in the United States.

Background Cardiac amyloidosis is a substantially underdiagnosed disease, and contemporary estimates of the epidemiology of amyloidosis are lacking. This study aims to determine the incidence and prevalence of cardiac amyloidosis among Medicare beneficiaries from 2000 to 2012. Methods and Results Medicare beneficiaries were counted in the prevalence cohort in each year they had (1) ≥1 principal or secondary International Classification of Diseases, Ninth Revision code for amyloidosis and (2) ≥1 principal or secondary International Classification of Diseases, Ninth Revision code for heart failure or cardiomyopathy within 2 years after the systemic amyloidosis code. A beneficiary was counted in the incidence cohort only during the first year in which they met criteria. Primary outcomes included the prevalence and incidence of hospitalizations for cardiac amyloidosis. There were 4746 incident cases of cardiac amyloidosis in 2012 and 15 737 prevalent cases in 2012. There was also a significant increase in the prevalence rate (8 to 17 per 100 000 person-years) and incidence rate (18 to 55 per 100 000 person-years) from 2000 to 2012, most notable after 2006. Incidence and prevalence increased substantially more among men, the elderly, and in blacks. Conclusions The incidence and prevalence rates of cardiac amyloidosis are higher than previously thought. The incidence and prevalence rates of cardiac amyloidosis among hospitalized patients have increased since 2000, particularly among specific patient subgroups and after 2006, suggesting improved amyloidosis awareness and higher diagnostic rates with noninvasive imaging. In light of these trends, cardiac amyloidosis should be considered during the initial work up of patients ≥65 years old hospitalized with heart failure.

Early Detection of Multiorgan Light-Chain Amyloidosis by Whole-Body 18F-Florbetapir PET/CT.

Immunoglobulin light-chain (AL) amyloidosis affects multiple systemic organs. However, determination of the precise extent of organ involvement remains challenging. Targeted amyloid imaging with 18F-florbetapir PET/CT offers the potential to detect AL deposits in multiple organs. The primary aim of this study was to determine the distribution and frequency of AL deposits in the various organs of subjects with systemic AL amyloidosis using 18F-florbetapir PET/CT. Methods: This prospective study included 40 subjects with biopsy-proven AL amyloidosis including active AL amyloidosis (n = 30) or AL amyloidosis in hematologic remission for more than 1 y (n = 10). All subjects underwent 18F-florbetapir PET/CT, skull base to below the kidney scan field, from 60 to 90 min after injection of radiotracer. Volume-of-interest measurements of SUVmax were obtained using Hermes software for the parotid gland, tongue, thyroid, lung, gastric wall, pancreas, spleen, kidney, muscle, abdominal fat, lower thoracic spine, vertebral body, and humeral head. Uptake in each organ was visually compared with that in spine bone marrow. An SUVmax of at least 2.5 was considered abnormal in all organs other than the liver. Results: Compared with the international consensus definition of organ involvement, 18F-florbetapir PET/CT identified amyloid deposits in substantially higher percentages of subjects for several organ systems, including parotid gland (50% vs. 3%), tongue (53% vs. 10%), and lung (35% vs. 10%). In several organ systems, including kidney (13% vs. 28%) and abdominal wall fat (10% vs. 13%), PET identified involvement in fewer subjects than did international consensus. Quantitative analysis of 18F-florbetapir PET/CT revealed more frequent organ involvement than did visual analysis in the tongue, thyroid, lung, pancreas, kidney, muscle, and humeral head. Extensive organ amyloid deposits were observed in active AL as well as in AL remission cohorts, and in both cardiac and noncardiac AL cohorts. Conclusion:18F-florbetapir PET/CT detected widespread organ amyloid deposition in subjects with both active AL and AL hematologic remission. In most instances, amyloid deposits in the various organs were not associated with clinical symptoms and, thus, were unrecognized. Early recognition of systemic organ involvement may help tailor treatment, and noninvasive monitoring of organ-level disease may guide management with novel fibril-resorbing therapies.