# Value of Early Diagnosis and Treatment of Amyloidosis: A Pilot Study of Synovial Biopsy During Carpal Tunnel Release

## TL;DR

This pilot study evaluates the cost-effectiveness of early amyloidosis diagnosis via synovial biopsy during carpal tunnel surgery and treatment with tafamadis.

## Contribution

Validates an algorithm for early amyloidosis detection and evaluates the cost-effectiveness of early treatment with tafamadis.

## Key findings

- Six out of 51 patients tested positive for amyloidosis.
- Early treatment at NYHA III stage costs $75,333.28 per QALY, which is closer to cost-effectiveness thresholds.
- Routine screening biopsies are not cost-effective with current therapy costs and positivity rates.

## Abstract

The purpose of this study is to calculate the value of early diagnosis and treatment of transthyretin amyloidosis with tafamadis prior to the development of the symptoms of heart failure. In this pilot study of 51 patients, we present the validation of a published algorithm for the early identification of patients at risk for amyloidosis via tenosynovial biopsy during carpal tunnel release. In addition, by integrating clinical data from this pilot study with published predictive models, we aim to calculate the value of routine screening biopsies for transthyretin amyloidosis.

Patients presenting for carpal tunnel release surgery had a tenosynovial biopsy collected at the time of surgery. Cost information was gathered from hospital records. In conjunction with published models, five incremental cost effectiveness ratio equations were generated to assess the value of these screening biopsies.

Of the 51 biopsied patients, six tested positive for amyloid, and one was started on tafamadis, a disease-modifying medication. Early diagnosis and treatment of patients with New York Heart Association class I (NYHA I) heart failure as opposed to NYHA IV results at a cost of $166,691.49 USD per quality adjusted life year (QALY). When treatment is initiated at NYHA class II stage compared with NYHA class IV, there is a cost of $155,977.22/QALY. For treatment at NYHA class III compared with NYHA class IV, the cost is $75,333.28/QALY.

This study validates the utility of previous criteria in identifying patients at high risk for systemic amyloidosis earlier in the disease course. Using the commonly accepted willingness to pay threshold of $50,000/QALY, early initiation of tafamadis does not represent a cost effective intervention. Routine biopsy of patients is not cost effective with the current cost of therapy and positivity rates of amyloidosis screening.

Prognostic IB.