Carpal Tunnel Syndrome as a Potential Indicator of Cardiac Amyloidosis: A Systematic Review and Meta-Analysis.

Carpal tunnel syndrome (CTS) and cardiac amyloidosis (CA) are seemingly disparate medical conditions but may be linked. CTS can be a sign of early CA, and CA can be a hidden cause of heart failure. Therefore, in this systematic review and meta-analysis, we aim to investigate the expected correlation between the occurrence of CTS and CA. A comprehensive search was conducted across multiple databases, including PubMed, Web of Science, Scopus, and Cochrane Library, to get relevant studies previously published before June 2023. No language restrictions were applied. Randomized clinical trials and observational studies have been included to investigate the proportion of patients reporting CA among patients with an established diagnosis of CA, and also the incidence of patients who have CTS among patients with CA has been investigated with a pooled estimation of the expected time from the diagnosis of CTS till the development of CA. Studies that did not report data on CTS or CA or lacked sufficient details were excluded. Meta-analysis of data for each outcome was performed using R version R.4.3.2 software (R Foundation for Statistical Computing, Vienna, Austria) using the Meta package. Heterogeneity across studies was assessed using the I² statistic. A meta-analysis of 15 studies, including 1416 patients, evaluated the relationship between CTS and CA. Among these, 495 patients with CTS were assessed for the presence of CA, and 915 patients with CA were evaluated for the presence of CTS. The pooled meta-analysis of eight studies, which included 915 patients with CA, revealed that 38% (95% CI: 35%-41%) had a history of CTS. Conversely, the proportion of patients with CTS who developed CA was 13% (95% CI: 4%-35%). The pooled mean time from CTS to the development of CA, based on 639 patients across four studies, was 6.02 years (95% CI: 3.76-8.36). Significant heterogeneity was noted for some outcomes (e.g., proportion of CA in patients with CTS: I²=93%), likely influenced by variations in study populations, age distributions, and diagnostic criteria. Our review of the literature suggests that there may be a link between CTS and CA. However, more research is needed to confirm this link and to understand how the two conditions are related. It is important to consider the possibility of CA in patients with CTS, as screening, early detection, and timely treatment can improve outcomes by slowing disease progression and reducing complications.