A frequent extracardiac amyloidosis presentation, bilateral carpal tunnel syndrome (CTS) typically develops several years before overt cardiac amyloidosis (CA). According to screening studies on patients having CTS surgery, the carpal ligament has a significant incidence of amyloid but a modest yield of CA (2.0%). It was unknown what percentage of people with amyloid in the carpal ligament go on to develop CA. For a study, researchers sought to determine the frequency of undetected CA 5-15 years following bilateral CTS surgery.

The investigators identified patients aged 60 to 85 with prior CTS surgery using national registries; the initial treatment on the second wrist was carried out 5 to 15 years earlier. Mail was used to distribute invitations to participate in the study. The initial cardiac evaluation comprised echocardiography, 99mtechnetium-pyrophosphate scintigraphy, and the detection of monoclonal proteins in blood and urine in accordance with worldwide standards.

The research included 250 participants, or 35.7% of those who were invited. 50% of the population was female, and the median age was 70.4. Twelve individuals (4.8%; 95% CI: 2.5%-8.2%) were found to have CA, and all instances were of wild-type transthyretin amyloidosis (ATTRwt). Men’s prevalence of ATTRwt was 8.8% (95% CI: 4.5%-15.2%; n = 11), while male participants ≥70 of age with a BMI of <30 kg/m2 had a prevalence of 21.2% (95% CI: 11.1%-34.7%). Except for 2, all individuals with an ATTRwt diagnosis had the least severe illness severity (Mayo score).

About 5% of individuals with prior bilateral CTS surgery who were screened for CA had early-stage transthyretin CA. Focusing on nonobese males ≥70 years showed a greater clinical yield (>1 in 5), indicating the potential for systematic screening.

Reference: jacc.org/doi/10.1016/j.jacc.2022.06.026