Early Diagnosis of Amyloid Cardiomyopathy

We read with great interest the original research paper by Arora et al. (1). In the Nationwide Readmissions Database, hospitalizations for heart failure (HF) in patients with a secondary diagnosis of amyloidosis were associated with an increased odds of in-hospital mortality. An important observation was that only 0.18% of the total hospitalized patients with HF had amyloidosis; this was significantly lower than expected but similar to a previous report (2). We agree with the investigators’ conclusion that more effective screening strategies are necessary to assist in the earlier diagnosis of amyloidosis in patients with HF. Amyloid cardiomyopathy with decompensated HF is considered an advanced stage of disease, and the prognosis of these patients is typically poor. In such situations, despite newer therapies and the potential for improved outcomes (3), the efficacy of newer agents may be more limited. Therefore, detection of amyloid cardiomyopathy at an earlier stage, before the onset of decompensated HF, could result in improved outcomes. We should suspect amyloidosis not only at the time of a HF hospitalization but also in the ambulatory setting.

We performed a retrospective review of patients with cardiac amyloidosis at Keio University hospital, an advanced medical tertiary institution in Japan, and determined that of the 63 patients diagnosed with transthyretin amyloid cardiomyopathy between 2016 and 2020 (median age 71 years; interquartile range: 76 to 81 years; 88.9% men), 33 (52.4%) were diagnosed after an admission for acute decompensated HF. None of them had a previous evaluation for amyloid cardiomyopathy, despite that most (n = 25; 75.8%) patients had a previous evaluation with a cardiologist for cardiovascular diseases, such as arrhythmia, cardiac hypertrophy, or HF. A history of carpal tunnel syndrome was also seen in 13 (39.3%) patients.

Overall, these results suggest an opportunity for the earlier diagnosis of amyloid cardiomyopathy in some patients before overt decompensation. The delay in diagnosis despite the history of outpatient cardiology visits may be related not only to the difficulty of the diagnosis of amyloidosis at an early stage, but also because of oversight of this rare and sometimes forgotten disease. With the advent of recent diagnostic imaging modalities, it is essential to facilitate better collaborative care between family doctors and specialists, as well as the entire multidisciplinary care team to identify patients with cardiac amyloidosis at an earlier stage and maximize the benefits of the newer therapeutic agents.