What is the clinical evidence from this study?

Study design: Cohort. Population: cardiac AL amyloidosis (n=176). Intervention: CMR progression (increase in extracellular volume ≥0.05) at 6 months vs. CMR stable or regression. Primary outcome: Death (HR 3.82, 95% CI 1.95-7.49, p=<0.001).

July 26, 2022Open Access

Cardiovascular magnetic resonance in light-chain amyloidosis to guide treatment

Q: What are the key findings of this study?

CMR progression at 6 months, defined by an increase in extracellular volume, predicted death (HR 3.82; 95% CI 1.95-7.49; P<0.001) independent of haematological response and other known predictors.

Key Result

CMR progression at 6 months, defined by an increase in extracellular volume, predicted death (HR 3.82; 95% CI 1.95-7.49; P<0.001) independent of haematological response and other known predictors.

Study Design

Type

Cohort (n=176)

Structured PICO

Does cardiovascular magnetic resonance with ECV mapping predict prognosis and correlate with haematological response in patients with cardiac AL amyloidosis undergoing chemotherapy?

Population

176 patients with cardiac AL amyloidosis undergoing chemotherapy, assessed with serial CMR and biomarkers over a mean follow-up of 40 months.

Exposure

Cardiovascular magnetic resonance (CMR) with T1 and extracellular volume (ECV) mapping at diagnosis and subsequently 6, 12, and 24 months after starting chemotherapy

Outcome

Changes in extracellular volume (ECV) in response to chemotherapy, correlation with haematological response, and association with prognosis (death)surrogate

Changes in extracellular volume measured by CMR predict mortality and correlate with haematological response in patients with cardiac AL amyloidosis undergoing chemotherapy.

Main Result

Hazard Ratio: 3.82 (95% CI 1.95–7.49)

p-value: p=<0.001

Abstract

AIMS: To assess the ability of cardiovascular magnetic resonance (CMR) to (i) measure changes in response to chemotherapy; (ii) assess the correlation between haematological response and changes in extracellular volume (ECV); and (iii) assess the association between changes in ECV and prognosis over and above existing predictors. METHODS AND RESULTS: In total, 176 patients with cardiac AL amyloidosis were assessed using serial N-terminal pro-B-type natriuretic peptide (NT-proBNP), echocardiography, free light chains and CMR with T1 and ECV mapping at diagnosis and subsequently 6, 12, and 24 months after starting chemotherapy. Haematological response was graded as complete response (CR), very good partial response (VGPR), partial response (PR), or no response (NR). CMR response was graded by changes in ECV as progression (≥0.05 increase), stable (<0.05 change), or regression (≥0.05 decrease). At 6 months, CMR regression was observed in 3% (all CR/VGPR) and CMR progression in 32% (61% in PR/NR; 39% CR/VGPR). After 1 year, 22% had regression (all CR/VGPR), and 22% had progression (63% in PR/NR; 37% CR/VGPR). At 2 years, 38% had regression (all CR/VGPR), and 14% had progression (80% in PR/NR; 20% CR/VGPR). Thirty-six (25%) patients died during follow-up (40 ± 15 months); CMR response at 6 months predicted death (progression hazard ratio 3.82; 95% confidence interval 1.95-7.49; P < 0.001) and remained prognostic after adjusting for haematological response, NT-proBNP and longitudinal strain (P < 0.01). CONCLUSIONS: Cardiac amyloid deposits frequently regress following chemotherapy, but only in patients who achieve CR or VGPR. Changes in ECV predict outcome after adjusting for known predictors.