Research Mentor Name

Dr. Charles Day

Research Mentor Email Address

cday9@hfhs.org

Institution / Department

Henry Ford Health Department of Orthopeadics

Document Type

Research Abstract

Research Type

clinicalresearch

Level of Research

no

Abstract

Introduction/Purpose:

Transthyretin amyloidosis occurs in two forms, hereditary transthyretin amyloidosis (hATTR), and wild-type ATTR (wtATTR)2. Amyloidosis can result in restrictive cardiomyopathy presenting as heart failure with preserved ejection fraction (HFpEF)4. A growing body of evidence demonstrates that amyloidosis may be underdiagnosed and can be caught earlier in the disease course5. The proteins causing amyloidosis can also deposit into various tissues including the carpal tunnel leading to carpal tunnel syndrome 2.

In this pilot study, we propose that early detection of amyloid via a biopsy of the transverse carpal ligament or tenosynovium in the carpal tunnel will allow early detection of systemic amyloidosis and referral to cardiology clinic for consideration of disease-modifying treatment. Furthermore, a calculation using incremental cost effectiveness ratio (ICER) was used to determine the value of these biopsies in early detection of this disease process.

Methods:

Patients undergoing carpal tunnel release who meet criteria for biopsy, as described by Donnelly et al. in 2019, are included 2. Qualifying patients meet two tier 1 criteria or one tier 1 criteria and one tier 2 criteria (inclusion criteria included in Figure 1). Tenosynovial biopsies are taken during open or endoscopic carpal tunnel release and are sent to pathology for congo red staining. If positive, patients are referred to high risk cardiology for additional evaluation and follow up for monitoring and treatment of cardiac involvement. Additionally, ICER calculations including cost of hospitalizations 9, cost of therapeutic intervention 5, cost of biopsy, relative risk reduction of hospitalization with amyloidosis pharmacotherapy 7, rate of hospitalizations stratified by New York Heart Association (NYHA) classification 1, incremental life extension due to early treatment 10, and a quality of life measurement were performed 4,12.

Results:

Of 48 patients matching eligibility criteria screened to date, 6 have had positive biopsy results and have been referred to high-risk cardiology. Of the 6 patients referred, two are currently undergoing advanced cardiac workup and 1 has begun treatment with Tafamadis. When treatment is initiated when the patient is in class 1 NYHA heart failure there is an estimated savings of $402.48 USD per quality adjusted life year when compared with class 4 initiation.

Discussion:

This study demonstrates a potential service line link between orthopedic surgery and cardiology. Hand surgeons could be a first point of contact for early diagnosis of wtATTR during carpal tunnel surgeries. With an estimated cost for screening pathology based on current procedural terminology (CPT) code of $65 per stain, one positive biopsy creates a savings that will offset 6 negative screens. A positivity rate of 14% is required to remain cost effective and offset the cost associated with a negative biopsy result.

Conclusion:

Early diagnosis of transthyretin amyloidosis via biopsy of the carpal tunnel as well as this interdisciplinary treatment pathway can allow for earlier treatment to alter the disease's course for patients with cardiac amyloidosis.

Disciplines

Cardiology | Cardiovascular Diseases | Medicine and Health Sciences | Musculoskeletal Diseases | Orthopedics | Pathological Conditions, Signs and Symptoms | Surgery

Comments

Special thanks to Dr. Charles Day for his continued mentorship and assistance with this project.

Additional thanks to Dr. John Spertus for his contribution of a crosswalk calculation utilized for the value component of this study.

Final thanks to the Henry Ford Health System, including residents, staff, and biostatisticians for their assistance in carrying out this study.

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