Carpal Tunnel Syndrome and Other Predictors of Amyloidosis.

Purpose: Amyloidosis comprises a broad category of pathologies characterized by extracellular deposits of amyloid. Deposition in the myocardium causes cardiac amyloidosis, a progressive and frequently fatal disease. Recent studies have reported that elderly patients with carpal tunnel syndrome (CTS) may have amyloid deposits in their flexor tenosynovium at the time of carpal tunnel release. However, the overall risk of these patients having amyloidosis is low, and there is a need to identify additional risk factors to guide surgeons in deciding which patients should undergo biopsies. This study sought to identify and rank risk factors based on their impact on increasing amyloidosis rates among carpal tunnel patients. Methods: We conducted a retrospective cohort study of patients with CTS between 2010 and 2019 using the TriNetX Research Network to determine the incidence of amyloidosis within 6 years following a CTS diagnosis and identify preexisting risk factors. Men and women were analyzed separately, and all risk factors were examined in yearly increments from 1 to 6 years after CTS diagnosis and risk differences were reported. Results: Of the 30 hypothesized risk factors, 18 were notable for men aged ≥50 and 19 were notable for women aged ≥50, each increasing the likelihood of developing amyloidosis within 6 years of a CTS diagnosis. The strongest risk factor for both sexes was heart failure, though the absolute risk difference was lower in women than in men, with an increased risk of 261 per 100,000 compared to 702 per 100,000. Conclusions: For both men and women with CTS, there are several preexisting conditions associated with an increased risk of developing amyloidosis within six years of a CTS diagnosis.