Carpal Tunnel Syndrome and Amyloid Cardiomyopathy

Study Overview
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Brief Summary
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The investigators will prospectively evaluate tissue samples obtained from patients undergoing carpal tunnel release surgery for amyloid in the soft tissue that is removed. Patients who have tissue that stains positive for amyloid will undergo cardiac testing to look for evidence of cardiac involvement.

Detailed Description
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Since the 1970s, the connection between amyloidosis and carpal tunnel syndrome has been described, with tenosynovial tissue staining positive for amyloid fibril deposition. Up to 30% of patients in prior studies with idiopathic carpal tunnel syndrome have biopsy tissue that stains positive for amyloid deposition. However, the prevalence of cardiac involvement at the time of carpal tunnel syndrome surgery has not been established. Furthermore, the role of TTR kinetic stability in the disease progression of amyloidosis is unclear. Diagnosing TTR amyloidosis at the time of carpal tunnel involvement could lead to an earlier identification of the disease at a stage where the cardiomyopathy may be occult or less advanced. In addition, abnormal TTR kinetics may even precede tissue deposition in the flexor tendon retinaculum. As several emerging pharmacological strategies are in development that may slow or even halt TTR amyloidosis, earlier diagnosis is advantageous. Identification and implementation of therapy for prevention or early disease treatment may alter the natural history of this progressive systemic disease.

Official Title
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Carpal Tunnel Syndrome and Amyloid Cardiomyopathy

Conditions
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Amyloidosis, Cardiomyopathy, Transthyretin Amyloidosis, Senile Systemic Amyloidosis, Carpal Tunnel Syndrome

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Males ≥ 50 years of age Females ≥ 60 years of age Undergoing carpal tunnel release surgery (adequate symptoms are not responding to conservative management requiring surgery) Able to consent Underwent carpal tunnel surgery and biopsy within last 30 days, if the study was discussed prior to surgery by one of the study physicians. Exclusion Criteria: Secondary CTS (Hemodialysis, rheumatoid arthritis, trauma) Known diagnosis of amyloidosis

Ages Eligible for Study
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Minimum Age: 50 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Patients with carpal tunnel syndrome.<br>Patients undergoing carpal tunnel release surgery. | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Incidence of transthyretin (TTR) amyloidosis in patients undergoing carpal tunnel release surgery | Identify the incidence of TTR amyloid deposits in the soft tissue of patients undergoing carpal tunnel surgery for idiopathic carpal tunnel syndrome | Biopsy completed on day of surgery | 
| Cardiac progression of transthyretin (TTR) amyloidosis in carpal tunnel biopsy-positive patients | Assess the progression of cardiac disease in patients with TTR deposits found in soft tissue removed at the time of carpal tunnel surgery | 4 years from baseline cardiac assessment. | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Prevalence of abnormal transthyretin (TTR) kinetics in patients undergoing carpal tunnel surgery | Identify the prevalence of abnormal TTR kinetics in patients undergoing carpal tunnel surgery for idiopathic carpal tunnel syndrome (develop a new test that aids identification of misfolded TTR intermediates that is more specific and sensitive to diagnosis this disease in the blood or tissue) | One-time kinetics test for biopsy-negative patients; baseline kinetics and annually for 4 years in biopsy-positive patients | 
| Early transthyretin (TTR) amyloid cardiomyopathy identification in carpal tunnel biopsy-positive patients | Investigate whether early TTR cardiomyopathy can be identified in patients who have TTR amyloid deposits identified in the soft tissue removed at the time of carpal tunnel surgery using cardiac biomarkers, echocardiography with strain, and nuclear bone scintigraphy | Baseline and annual testing for 4 years in biopsy-positive patients | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Amyloidosis, Carpal tunnel syndrome