Clinical Scorecard: Evaluation of Extracellular Volume Changes via Cardiac MRI in Patients with Transthyretin Amyloidosis Undergoing Tafamidis Treatment

At a Glance

Key Highlights

• ATTR CA is characterized by myocardial amyloid deposition causing ECV expansion measurable by cardiac magnetic resonance (CMR) T1-mapping.
• Tafamidis treatment stabilizes or reduces ECV and amyloid burden in ATTR CA patients, potentially improving clinical outcomes.
• Serial non-invasive ECV quantification via CMR T1-mapping is a promising tool for monitoring disease progression and treatment response.

Guideline-Based Recommendations

Diagnosis

• Diagnose ATTR CA with Perugini grade ≥ 2 myocardial tracer uptake on bone scintigraphy and exclusion of paraprotein presence.
• Confirm diagnosis via endomyocardial biopsy with Congo red staining and anti-ATTR antibody reaction if non-invasive tests are inconclusive.
• Offer gene sequencing to all diagnosed ATTR CA patients.

Management

• Initiate tafamidis treatment to stabilize transthyretin and reduce amyloid deposition in ATTR CA patients.
• Use NAC staging system based on NT-proBNP and eGFR to assess disease severity and guide management.

Monitoring & Follow-up

• Perform baseline and follow-up CMR with T1 mapping to quantify ECV and monitor amyloid burden changes.
• Schedule follow-up imaging between 6 and 24 months after baseline to assess treatment response.
• Monitor clinical parameters including NYHA class, 6-minute walk distance, NT-proBNP, troponin T, and eGFR.

Risks

• Endomyocardial biopsy carries procedural risks and may not be suitable for serial assessments due to heterogeneous amyloid distribution.
• High costs of tafamidis necessitate identifying patients most likely to benefit from therapy.

Patient & Prescribing Data

Patients with confirmed ATTR cardiac amyloidosis undergoing tafamidis treatment

Tafamidis stabilizes or reduces myocardial ECV and amyloid burden as measured by CMR and nuclear imaging, correlating with improved clinical outcomes and reduced progression.

Clinical Best Practices

• Utilize non-invasive CMR T1-mapping for serial assessment of myocardial ECV to monitor disease progression and treatment efficacy.
• Apply NAC staging to stratify patients and tailor clinical management accordingly.
• Incorporate comprehensive clinical and laboratory assessments alongside imaging to guide prognosis and therapeutic decisions.
• Ensure multidisciplinary care in specialized centers with expertise in amyloidosis and advanced cardiac imaging.

References

• Rettl et al. - Tafamidis effects on ATTR CA
• Perugini grading and diagnosis criteria
• NAC staging system for ATTR CA
• CMR T1-mapping and ECV quantification methods