Cardiac Amyloidosis Multimodal Imaging of Disease Activity and Response to Treatment

Cardiac amyloidosis (CA) is a disease characterized by the deposition of misfolded protein deposits in the myocardial interstitium. Although advanced CA confers significant morbidity and mortality, the magnitude of deposition and ensuing clinical manifestations vary greatly. Thus, an improved understanding of disease pathogenesis at both cellular and functional levels would afford critical insights that may improve outcomes. This review will summarize contemporary therapies for the 2 major types of CA, transthyretin and light chain amyloidosis, and outline the capacity of imaging modalities to both diagnose CA, inform prognosis, and follow response to available therapies. We explore the current landscape of echocardiography, cardiac magnetic resonance, and bone scintigraphy in the assessment of functional and cellular parameters of dysfunction in CA throughout disease pathogenesis. Finally, we examine the impact of concurrent advances in both therapeutics and imaging on future research questions that improve our understanding of underlying disease mechanisms. Multimodal imaging in CA affords an indispensable tool to offer individualized treatment plans and improve outcomes in patients with CA

Outcomes by Cardiac Stage in Patients With Newly Diagnosed AL Amyloidosis: Phase 3 ANDROMEDA Trial

BACKGROUND: Patients with amyloid light chain amyloidosis and severe cardiac dysfunction have a poor prognosis. Treatment options that induce rapid and deep hematologic and organ responses, irrespective of cardiac involvement, are needed. OBJECTIVES: The aim of this study was to evaluate the impact of baseline cardiac stage on efficacy and safety outcomes in the phase 3 ANDROMEDA trial. METHODS: Rates of overall complete hematologic response and cardiac and renal response at 6 months and median major organ deterioration–progression-free survival and major organ deterioration–event-free survival were compared across cardiac stages (I, II, or IIIA) and treatments (daratumumab, bortezomib, cyclophosphamide, and dexamethasone [D-VCd] or bortezomib, cyclophosphamide, and dexamethasone [VCd]). Rates of adverse events (AEs) were summarized for patients with and without baseline cardiac involvement and by cardiac stage. RESULTS: Median follow-up duration was 15.7 months. The proportions of stage I, II, and IIIA patients were 23.2%, 40.2%, and 36.6%. Across cardiac stages, hematologic and organ response rates were higher and major organ deterioration–progression-free survival and major organ deterioration–event-free survival were longer with D-VCd than VCd. AE rates were similar between treatments and by cardiac stage; serious AE rates were higher in patients with cardiac involvement and increased with increasing cardiac stage. The incidence of cardiac events was numerically greater with D-VCd vs VCd, but the rate of grade 3 or 4 events was similar. The exposure-adjusted incidence rate for cardiac events was lower with D-VCd than VCd (median exposure 13.4 and 5.3 months, respectively). CONCLUSIONS: These findings demonstrate the efficacy of D-VCd over VCd in patients with newly diagnosed amyloid light chain amyloidosis across cardiac stages, thus supporting its use in patients with cardiac involvement. (NCT03201965

ASNC/AHA/ASE/EANM/HFSA/ISA/SCMR/SNMMI expert consensus recommendations for multimodality imaging in cardiac amyloidosis: Part 2 of 2—Diagnostic criteria and appropriate utilization

Cardiac amyloidosis is emerging as an underdiagnosed cause of heart failure and mortality. Growing literature suggests that a noninvasive diagnosis of cardiac amyloidosis is now feasible. However, the diagnostic criteria and utilization of imaging in cardiac amyloidosis are not standardized. In this paper, Part 2 of a series, a panel of international experts from multiple societies define the diagnostic criteria for cardiac amyloidosis and appropriate utilization of echocardiography, cardiovascular magnetic resonance imaging, and radionuclide imaging in the evaluation of patients with known or suspected cardiac amyloidosis

ASNC/AHA/ASE/EANM/HFSA/ISA/SCMR/SNMMI Expert Consensus Recommendations for Multimodality Imaging in Cardiac Amyloidosis: Part 1 of 2—Evidence Base and Standardized Methods of Imaging

Cardiac amyloidosis is a form of restrictive infiltrative cardiomyopathy that confers significant mortality. Because of the relative rarity of cardiac amyloidosis, clinical and diagnostic expertise in the recognition and evaluation of individuals with suspected amyloidosis is mostly limited to a few expert centers. Electrocardiography, echocardiography, and radionuclide imaging have been used for the evaluation of cardiac amyloidosis for over 40 years.1, 2, 3 Although cardiovascular magnetic resonance (CMR) has also been in clinical practice for several decades, it was not applied to cardiac amyloidosis until the late 1990s. Despite an abundance of diagnostic imaging options, cardiac amyloidosis remains largely underrecognized or delayed in diagnosis.4 Although advanced imaging options for noninvasive evaluation have substantially expanded, the evidence is predominately confined to single-center small studies or limited multicenter larger experiences, and there continues to be no clear consensus on standardized imaging pathways in cardiac amyloidosis. This lack of guidance is particularly problematic given that there are numerous emerging therapeutic options for this morbid disease, increasing the importance of accurate recognition at earlier stages. Imaging provides noninvasive tools for follow-up of disease remission/progression complementing clinical evaluation. Additional areas not defined include appropriate clinical indications for imaging, optimal imaging utilization by clinical presentation, accepted imaging methods, accurate image interpretation, and comprehensive and clear reporting. Prospective randomized clinical trial data for the diagnosis of amyloidosis and for imaging-based strategies for treatment are not available. A consensus of expert opinion is greatly needed to guide the appropriate clinical utilization of imaging in cardiac amyloidosis

Native T1 and Extracellular Volume in Transthyretin Amyloidosis

OBJECTIVES: This study evaluated the prognostic potential of native myocardial T1 in cardiac transthyretin amyloidosis (ATTR) and compared native T1 with extracellular volume (ECV) in terms of diagnostic accuracy and prognosis. BACKGROUND: ATTR is an increasingly recognized cause of heart failure that has an overlapping clinical phenotype with hypertrophic cardiomyopathy (HCM). Native T1 mapping by cardiac magnetic resonance (CMR) is useful for diagnosis in cardiac amyloidosis but its prognostic potential has never been assessed. METHODS: A total of 134 patients with wild-type ATTR (ATTRwt) (122 men; age 76 ± 7 years), 81 patients with hereditary-type ATTR (ATTRm) (60 men; age 69 ± 11 years), 44 patients with HCM (32 men; age 51 ± 13 years), and 12 asymptomatic mutation carriers (4 men; age 47 ± 10 years) were studied. All subjects underwent CMR with T1 mapping and ECV measurement. ATTR patients also underwent99mTc-3,3-diphosphono-1,2-propanodicarboxylic acid (99mTc-DPD) scintigraphy. RESULTS: Native T1 and ECV were elevated in ATTR compared with HCM (p < 0.001) and were both associated with a high diagnostic accuracy (area under the curve [AUC]: 0.87; 95% confidence interval [CI]: 0.82 to 0.91) for T1 and an AUC of 0.91 (95% CI: 0.87 to 0.94) for ECV. No significant difference in native T1 and ECV was found between ATTRwt and ATTRm, and ECV correlated well with99mTc-DPD scintigraphy. During follow-up of a mean of 32 ± 17 months, 55 ATTRwt and 40 ATTRm patients died. Native T1 and ECV predicted death (T1: hazard ratio [HR]: 1.225 for each 59-ms increase; 95% CI: 1.010 to 1.486; p < 0.05; ECV: HR: 1.155 for each 3% increase; 95% CI: 1.097 to 1.216; p < 0.001), but only ECV remained independently predictive after adjustment for age, N-terminal pro-B-type natriuretic peptide, left ventricular ejection fraction, E/E', left ventricular mass index, DPD grade, and late gadolinium enhancement. CONCLUSIONS: Native T1 mapping and ECV are good diagnostic techniques for cardiac ATTR that are associated with prognosis. Both parameters correlated with mortality, but only ECV remained independently predictive of prognosis, suggesting that it is a more robust marker in cardiac ATTR