Design: Prospective, multicentre, single-group diagnostic accuracy study, blinded reads
Population: 170 adults with suspected cardiac amyloidosis at 18 US centres
Primary outcome: Sensitivity and specificity against expert-adjudicated diagnosis
Effect: Sensitivity 94% (85-98%); specificity 86% (77-92%)

REVEAL was a prospective, single-group diagnostic study at 18 US centres. It enrolled adults with suspected but undiagnosed cardiac amyloidosis and imaged them with 124I-evuzamitide, an investigational tracer that binds amyloid deposits whatever the precursor protein. Readers blind to clinical data interpreted the scans; a separate expert panel blind to the scans made the reference diagnosis.

In 170 analysed patients (median age 72), sensitivity was 94% (95% CI 85% to 98%) and specificity 86% (77% to 92%). The negative predictive value was 94%.

Bone-tracer scintigraphy detects transthyretin amyloid but not light-chain disease, which is the form that needs urgent haematology. A single test covering both would help, but this tracer is not approved and its regulatory status in India is unknown. For now, the standard pathway stands.

Keep using bone scintigraphy plus serum and urine tests for monoclonal protein as the standard work-up.
Check free light chains and immunofixation before calling a positive bone scan transthyretin amyloid.
Suspect amyloidosis in heart failure with thick walls and low voltage, carpal tunnel syndrome or unexplained low-flow aortic stenosis.
Treat this tracer as research-stage until it is approved and available.

Why it matters

A single test that finds light-chain as well as transthyretin amyloid could shorten the most dangerous diagnostic delay in cardiology.

The statistics, in plain English

Sensitivity of 94% means about six in 100 patients with amyloidosis would be missed. Specificity of 86% means about 14 in 100 without it would test positive. These figures come from specialist centres with a high prevalence of disease, and accuracy often falls in broader use.