High sensitivity cardiac troponin T in patients with immunoglobulin light chain amyloidosis

A 2D-STI echocardiographic diagnostic model established for cardiac amyloidosis complicated with multiple myeloma

OBJECTIVE

This study aimed to investigate the clinical characteristics of multiple myeloma(MM) with amyloidosis(AL) and evaluate the diagnostic utility of two-dimensional speckle tracking imaging(2D-STI) echocardiography in MM with cardiac amyloidosis(CA), with the goal of providing guidance for early screening and differentiation.

METHODS

Among 616 newly diagnosed multiple myeloma (NDMM) patients, 359 met the inclusion and exclusion criteria, and divided into MM-AL and MM without AL according to the histopathological results. MM-AL patients were subdivided into MM-CA and MM without CA subgroups according to cardiac involvement criteria. Baseline characteristics and 2D-STI echocardiographic parameters were comparatively analyzed. Variables potentially predictive of MM-CA were identified through univariate analysis, with accuracy assessed by area under the curve (AUC). Variables were dichotomized using optimal cut-off values to construct a multivariate logistic regression model.

RESULTS

The initial symptoms of MM-AL were mainly bone pain and anemia, but the incidence of ostealgia was lower (45.7 %) and the prevalence of congestive heart failure (CHF) was higher (12.8 %) compared with MM without AL patients. No significant differences were observed in myocardial injury biomarkers, tumor burden, or t(11,14) translocation. MM-CA patients presented with 40.0 % severe heart failure (HF) NYHA class III-IV at diagnosis and experienced 33.3 % adverse cardiovascular events. An echocardiographic model incorporating left ventricular ejection fraction(LVEF), pulmonary artery systolic pressure(PASP), hydropericardium, and global longitudinal strain (GLS) demonstrated the highest diagnostic accuracy for MM-CA, with an AUC of 0.90 (95 % CI, 0.81-1.00) (sensitivity: 95.6 %, specificity: 80.0 %, accuracy: 90.8 %).

CONCLUSION

There was no specific difference between the clinical manifestations and routine examinations of MM with or without AL patients. This study introduces a novel multi-parameter echocardiographic model for MM-CA diagnosis, providing a clinically valuable tool for early screening and differentiation.

High-Sensitivity and Conventional Cardiac Troponin-I Assays in AL Amyloidosis

BACKGROUND

Circulating cardiac troponin-I (cTnI) plays a crucial role in biomarker staging systems, offering important information for prognostification and risk stratification of patients with AL amyloidosis. High-sensitivity cTnI (HS-cTnI) assays have been introduced in practice; however, the data on the concordance between conventional and HS-cTnI and the utility of HS-cTnI in cardiac biomarker staging are lacking.

METHODS

Seventy-eight consecutive patients with AL amyloidosis who were prospectively evaluated at the Boston University Amyloidosis Center from October 2022 through March 2023 were included. cTnI was measured using the Abbott Architect cTnI chemiluminescent microparticle immunoassay (CMIA) and HS-cTnI using the Abbott Alinity HS-cTnI CMIA assay. Assay results were compared by Deming regression and Bland-Altman analyses, and cardiac biomarker stages were assigned and compared using both assay results.

RESULTS

Median cTnI and HS-cTnI concentrations were 13.0 and 7.0 ng/L, respectively. Bland-Altman analysis demonstrated a negative bias with HS-cTnI results (mean percent difference between assays: -49.8%) and the greatest variance occurring below 50 ng/L. Deming regression supported this negative discordance (slope, 0.66; intercept, -1.9). The use of HS-cTnI assay downgraded cardiac biomarker staging assignments from stage IIIA to stage II (n = 3) and from stage IIIB to stage II (n = 1).

CONCLUSIONS

Overall agreement was demonstrated; however, a negative bias for HS-cTnI assay was noted at low concentrations. The application of the conventional cTnI threshold of >100 ng/L to HS-cTnI-based Boston University cardiac staging showed a trend toward downgraded staging assignments. The prognostic utility of HS-cTnI assay in biomarker staging warrants further investigation in patients with AL amyloidosis.

Cardiac amyloidosis: Innovations in diagnosis and treatment

Cardiac amyloidosis (CA) is a progressive, underdiagnosed condition caused by the deposition of misfolded proteins in the myocardium, forming amyloid fibrils that impair cardiac structure and function. This review highlights recent advances in the diagnosis and treatment of amyloid light-chain (AL) and transthyretin (ATTR) CA, which globally account for most cases of CA. Novel diagnostic tools, including artificial intelligence-enhanced analysis and advanced imaging modalities like positron emission tomography with amyloid-specific tracers, might improve detection rates and diagnostic accuracy to enable non-invasive subtype differentiation. Furthermore, many innovative treatments are being investigated. For AL-CA, anti-fibril therapies are showing promising results, complementing traditional chemotherapy and autologous stem cell transplantation. In ATTR-CA, gene silencing and anti-fibril therapies are being tested in clinical trials and hold promise of halting disease progression and reducing amyloid deposits, respectively.

Accuracy of Established Prognostic Staging Systems for Cardiac Transthyretin Amyloidosis in the Tafamidis Era

BACKGROUND

Biomarker-based prognostic staging systems, including the National Amyloidosis Centre (NAC) and the Mayo staging systems, are widely-used but have only been validated for treatment-naive patients with cardiac transthyretin amyloidosis (ATTR-CA).

OBJECTIVES

The purpose of this study was to assess the accuracy of the NAC and Mayo staging systems in patients with ATTR-CA treated with tafamidis.

METHODS

A retrospective observational study following patients with ATTR-CA from initiation of tafamidis (baseline) to time of all-cause death was conducted. Patients were stratified according to the NAC and an adapted Mayo staging system incorporating high-sensitivity cardiac troponin T. Agreement was assessed using weighted Cohen's kappa. The staging systems' ability to identify subgroups with distinct overall survival was assessed using Kaplan-Meier analyses and pairwise log-rank tests.

RESULTS

A total of 251 patients with wild-type ATTR-CA treated with tafamidis were followed for a median of 521 (IQR: 262-842) days. There was substantial agreement (weighted kappa = 0.661; P < 0.001) between the NAC and the adapted Mayo staging system. Significant differences in estimated overall survival were observed across all disease stages of the adapted Mayo staging system (I vs II: P = 0.032; I vs III: P < 0.001; II vs III: P = 0.036). Accordingly, estimated overall survival was significantly lower in NAC III compared to NAC I (P < 0.001) and NAC II (P = 0.015). However, there was no significant difference between NAC I and NAC II (P = 0.340).

CONCLUSIONS

Both staging systems identified a distinct group of patients with ATTR-CA at the highest risk of death but only the adapted Mayo staging system could accurately distinguish between low- and intermediate-risk patients in the setting of disease-modifying treatment with tafamidis.

Cardiac Troponin in Patients With Light Chain and Transthyretin Cardiac Amyloidosis: JACC: CardioOncology State-of-the-Art Review

Cardiac amyloidosis (CA) is an infiltrative disease caused by amyloid fibril deposition in the myocardium; the 2 forms that most frequently involve the heart are amyloid light chain (AL) and amyloid transthyretin (ATTR) amyloidosis. Cardiac troponin (cTn) is the biomarker of choice for the detection of myocardial injury and is frequently found to be elevated in patients with CA, particularly with high-sensitivity assays. Multiple mechanisms of myocardial injury in CA have been proposed, including cytotoxic effect of amyloid precursors, interstitial amyloid fibril infiltration, coronary microvascular dysfunction, amyloid- and non-amyloid-related coronary artery disease, diastolic dysfunction, and heart failure. Regardless of the mechanisms, cTn values have relevant prognostic (and potentially diagnostic) implications in both AL and ATTR amyloidosis. In this review, the authors discuss the significant aspects of cTn biology and measurement methods, potential mechanisms of myocardial injury in CA, and the clinical application of cTn in the management of both AL and ATTR amyloidosis.

Natriuretic Peptides and Cardiac Troponins: Markers of Disease Progression and Risk in Light Chain Cardiac Amyloidosis

PURPOSE OF REVIEW

Light chain (AL) amyloidosis can cause an infiltrative cardiomyopathy that can result in symptomatic heart failure. The vague, nonspecific onset of signs and symptoms may lead to a delay in diagnosis and treatment leading to poor outcomes. Cardiac biomarkers, such as troponins and natriuretic peptides, play a pivotal role in diagnosis, determining prognosis, and assessing treatment response in patients with AL amyloidosis. Because of the evolving landscape for both diagnosis and treatment of AL cardiac amyloidosis, we review the critical role these and other biomarkers play in the clinical management of this disease.

RECENT FINDINGS

A number of conventional cardiac and noncardiac serum biomarkers are commonly used in AL cardiac amyloidosis and may be surrogates for cardiac involvement and inform prognosis. These include typical heart failure biomarkers such as levels of circulating natriuretic peptides as well as cardiac troponins. Other noncardiac biomarkers frequently measured in AL cardiac amyloidosis included difference between the involved and uninvolved free light chains (dFLC) and markers of endothelial cell activation and damage such as von Willebrand factor antigen and matrix metalloproteinases. AL amyloidosis can lead to cardiac involvement which has been associated with poor outcomes, especially if not identified and treated early. Natriuretic peptides and cardiac troponins are cornerstones for the diagnosis and management of AL cardiac amyloidosis. Their levels may represent cardiac stress, injury, and possibly degree of cardiac involvement, and they play a key role in AL amyloidosis disease staging.

Impact of cytogenetic abnormalities on treatment outcomes in patients with amyloid light-chain amyloidosis: subanalyses from the ANDROMEDA study

BACKGROUND

Cytogenetic abnormalities are common in patients with amyloid light-chain (AL) amyloidosis; some are associated with poorer outcomes. This post hoc analysis of ANDROMEDA evaluated the impact of certain cytogenetic abnormalities on outcomes in this patient population.

METHODS

Patients with newly diagnosed AL amyloidosis were randomised 1:1 to daratumumab, bortezomib, cyclophosphamide, and dexamethasone (D-VCd) or VCd. Outcomes were evaluated in the intent-to-treat (ITT) population and in patients with t(11;14), amp1q21, del13q14, and del17p13.

RESULTS

Overall, 321 patients had cytogenetic testing (D-VCd, n = 155; VCd, n = 166); most common abnormalities were t(11;14) and amp1q21. At a median follow-up of 20.3 months, haematologic complete response rates were higher with D-VCd vs VCd across all cytogenetic subgroups and organ response rates were numerically higher with D-VCd vs VCd across most subgroups. Point estimates for hazard ratio of major organ deterioration-PFS and -EFS favoured D-VCd over VCd for all cytogenetic subgroups. Deep haematologic responses (involved minus uninvolved free light chains [FLC] <10 mg/L or involved FLC ≤20 mg/L) were seen in more patients with D-VCd than VCd in all ITT and t(11;14) cohorts.

CONCLUSIONS

These results support the use of D-VCd as standard of care in patients with newly diagnosed AL amyloidosis regardless of cytogenetic abnormalities.

Patisiran for the Treatment of Transthyretin-mediated Amyloidosis with Cardiomyopathy

Transthyretin (TTR) is a tetrameric protein, synthesized primarily by the liver, that acts as a physiological transport protein for retinol and thyroxine. TTR can misfold into pathogenic amyloid fibrils that deposit in the heart and nerves, causing a life-threatening transthyretin amyloidosis cardiomyopathy (ATTR-CM), and a progressive and debilitating polyneuropathy (ATTR-PN). Recent therapeutic advances have resulted in the development of drugs that reduce TTR production. Patisiran is a small interfering RNA that disrupts the complimentary mRNA and inhibits TTR synthesis, and is the first gene-silencing medication licensed for the treatment of ATTR amyloidosis. After encouraging results following the use of patisiran for the treatment of patients with ATTR-PN, there has been increasing interest in the use of patisiran for the treatment of ATTR-CM. Various studies have demonstrated improvements across a wide range of cardiac biomarkers following treatment with patisiran, and have changed the perception of ATTR-CM from being thought of as a terminal disease process, to now being regarded as a treatable disease. These successes represent a huge milestone and have the potential to revolutionize the landscape of treatment for ATTR-CM. However, the long-term safety of patisiran and how best to monitor cardiac response to treatment remain to be determined.

Association of high-sensitivity troponin T with outcomes in asymptomatic non-severe aortic stenosis: a post-hoc substudy of the SEAS trial

BACKGROUND

High-sensitivity Troponin T (hsTnT), a biomarker of cardiomyocyte overload and injury, relates to aortic valve replacement (AVR) and mortality in severe aortic stenosis (AS). However, its prognostic value remains unknown in asymptomatic patients with AS. We aimed to investigate if an hsTnT level >14 pg/mL (above upper limit of normal 99th percentile) is associated with echocardiographic AS-severity, subsequent AVR, ischaemic coronary events (ICE), and mortality in asymptomatic patients with non-severe AS.

METHODS

In this post-hoc sub-analysis of the multicentre, randomised, double-blind, placebo-controlled SEAS trial (ClinicalTrials.gov, NCT00092677), we included asymptomatic patients with mild to moderate-severe AS. We ascertained baseline and 1-year hsTnT concentrations and examined the association between baseline levels and the risk of the primary composite endpoint, defined as the first event of all-cause mortality, isolated AVR (without coronary artery bypass grafting (CABG)), or ICE. Multivariable regressions and competing risk analyses examined associations of hsTnT level >14 pg/mL with clinical correlates and 5-year risk of the primary endpoint.

FINDINGS

Between January 6, 2003, and March 4, 2004, a total of 1873 patients were enrolled in the SEAS trial, and 1739 patients were included in this post-hoc sub-analysis. Patients had a mean (SD) age of 67.5 (9.7) years, 61.0% (1061) were men, 17.4% (302) had moderate-severe AS, and 26.0% (453) had hsTnT level >14 pg/mL. The median hsTnT difference from baseline to 1-year was 0.8 pg/mL (IQR, -0.4 to 2.3). In adjusted linear regression, log(hsTnT) did not correlate with echocardiographic AS severity (p = 0.36). In multivariable Cox regression, a hsTnT level >14 pg/mL vs. hsTnT ≤14 pg/mL was associated with an increased risk of the primary composite endpoint (HR, 1.41; 95% CI, 1.18-1.70; p = 0.0002). In a competing risk model of first of the individual components of the primary endpoint, a hsTnT level >14 pg/mL was associated with ICE risk (HR 1.71; 95% CI, 1.23-2.38; p = 0.0013), but not with isolated AVR (p = 0.064) or all-cause mortality (p = 0.49) as the first event.

INTERPRETATION

hsTnT level is within the reference range (≤14 pg/mL) in 3 out of 4 non-ischaemic patients with asymptomatic mild-to-moderate AS and remains stable during a 1-year follow-up regardless of AS-severity. An hsTnT level >14 pg/mL was mainly associated with subsequent ICE, which suggest that hsTnT concentration is primarily a risk marker of subclinical coronary atherosclerotic disease.

FUNDING

Merck & Co., Inc., the Schering-Plough Corporation, the Interreg IVA program, Roche Diagnostics Ltd., and Gangstedfonden. Open access publication fee funding provided by prof. Olav W. Nielsen and Department of Cardiology, Bispebjerg University Hospital, Denmark.

RNA Targeting and Gene Editing Strategies for Transthyretin Amyloidosis

Transthyretin (TTR) is a tetrameric protein synthesized primarily by the liver. TTR can misfold into pathogenic ATTR amyloid fibrils that deposit in the nerves and heart, causing a progressive and debilitating polyneuropathy (PN) and life-threatening cardiomyopathy (CM). Therapeutic strategies, which are aimed at reducing ongoing ATTR amyloid fibrillogenesis, include stabilization of the circulating TTR tetramer or reduction of TTR synthesis. Small interfering RNA (siRNA) or antisense oligonucleotide (ASO) drugs are highly effective at disrupting the complementary mRNA and inhibiting TTR synthesis. Since their development, patisiran (siRNA), vutrisiran (siRNA) and inotersen (ASO) have all been licensed for treatment of ATTR-PN, and early data suggest these drugs may have efficacy in treating ATTR-CM. An ongoing phase 3 clinical trial will evaluate the efficacy of eplontersen (ASO) in the treatment of both ATTR-PN and ATTR-CM, and a recent phase 1 trial demonstrated the safety of novel in vivo CRISPR-Cas9 gene-editing therapy in patients with ATTR amyloidosis. Recent results from trials of gene silencer and gene-editing therapies suggest these novel therapeutic agents have the potential to substantially alter the landscape of treatment for ATTR amyloidosis. Their success has already changed the perception of ATTR amyloidosis from a universally progressive and fatal disease to one that is treatable through availability of highly specific and effective disease-modifying therapies. However, important questions remain including long-term safety of these drugs, potential for off-target gene editing, and how best to monitor the cardiac response to treatment.Kindly check and confirm the processed running title.This is correct.

Amyloidosis of the Heart and Kidney

Amyloidosis encompasses a collection of disorders of pathological protein folding. The extracellular location where these "amyloid fibril" proteins are deposited determines the clinical presentation of the disease. The abnormal architecture of these fibrils makes them insoluble and not easily removed, leading to disruption of normal tissue structure and interference with normal physiology. Amyloidosis of the heart and kidney can be inherited, secondary to unrelated diseases, or due to a plasma cell disorder. This review will focus on immunoglobulin light chain amyloidosis, which is life-threatening and must be diagnosed as early as possible by employing precise and accurate typing to ensure timely and frequently curative therapy.

Proposed Cardiac End Points for Clinical Trials in Immunoglobulin Light Chain Amyloidosis: Report From the Amyloidosis Forum Cardiac Working Group

Immunoglobulin light chain amyloidosis is a rare, multisystemic, phenotypically heterogenous disease affecting cardiovascular, renal, neurological, and gastrointestinal systems to varying degrees. Its underlying cause is a plasma cell dyscrasia characterized by misfolding of monoclonal immunoglobulin light chains which leads to aggregation and deposition of insoluble amyloid fibrils in target organs. Prognosis is primarily dependent on extent of cardiac involvement and depth of hematologic response to treatment. To facilitate development of new therapies, a public-private partnership was formed between the nonprofit Amyloidosis Research Consortium and the US Food and Drug Administration Center for Drug Evaluation and Research. In 2020, the Amyloidosis Forum launched an initiative to identify novel/composite end points and analytic strategies to expedite clinical trials for development of new therapies for the primary hematologic disorder and organ system manifestations. Specialized working groups identified organ-specific end points; additional working groups reviewed health-related quality of life measures and statistical approaches to data analysis. Each working group comprised amyloidosis experts, patient representatives, statisticians, and representatives from the Food and Drug Administration, the UK Medicines and Healthcare Products Regulatory Agency, and pharmaceutical companies. This review summarizes the proceedings and recommendations of the Cardiac Working Group. Using a modified Delphi method, the group identified, reviewed, and prioritized cardiac end points relevant to immunoglobulin light chain amyloidosis in the context of an antiplasma cell therapy. Prioritized cardiovascular end points included overall survival, hospitalization, N-terminal pro-B-type natriuretic peptide level, 6-minute walk test, Kansas City Cardiac Questionnaire, and cardiac deterioration progression-free survival. These recommended components will be further explored through evaluation of clinical trial datasets and formal guidance from regulatory authorities.

Role of Cardiac Biomarkers in Cancer Patients

Simple Summary

Cardiac biomarkers have proved increasingly useful in the various branches of cardiology, not sparing the field of cardio-oncology. With specific reference to the latter subject, they have been investigated as predictors and/or diagnostic and monitoring tools, as well as prognostic factors, with the purpose of allowing the early prevention of many cardiovascular complications related to the direct action of some cancer types or related to the toxicity of its treatments. However, despite this great potential and excellent cost-effectiveness, their usefulness in some areas still seems to be limited due to lack of sufficient specificity or sensitivity. In fact, in clinical practice, while their use is nowadays standard in some circumstances, evidence does not yet support their routine use in other cases.

Abstract

In patients with cancer—and especially some specific subtypes—the heart can be pathologically affected due to the direct action of the tumor or its secretion products or due to the toxicity of some oncological treatments. Cardiac biomarkers have been investigated as inexpensive and easily accessible tools for prediction, early diagnosis, monitoring, or prognosis of various forms of cancer-related cardiac diseases. However, their clinical usefulness was not always clearly demonstrated in every area of cardioncology. For the identification of anthracycline related cardiotoxicity in the very early stages troponins proved to be more efficient detectors than imaging methods. Nevertheless, the lack of a standardized dosage methodology and of cardiotoxicity specific thresholds, do not yet allow to outline the precise way to employ them in clinical routine and to incorporate them into appropriate diagnostic or managing algorithms. Cardiac biomarkers proved also effective in patients with primary cardiac amyloidosis, in which both troponins and natriuretic peptides were able to predict adverse outcome, and carcinoid heart disease, where a precise diagnostic cut-off for N-terminal prohormone of brain natriuretic peptide (NT-proBNP) was identified to screen patients with valvular involvement. Likewise, NT-proBNP proved to be an excellent predictor of postoperative atrial fibrillation (POAF). On the contrary, evidence is still not sufficient to promote the routine use of cardiac biomarkers to early diagnose myocarditis due to immune check points inhibitors (ICIs), radiotherapy induced cardiotoxicity and cardiac complications related to androgenetic deprivation. In this review we present all the evidence gathered so far regarding the usefulness and limitations of these relatively inexpensive diagnostic tools in the field of cardio-oncology.

Prognostic Value of N-Terminal Pro-Brain Natriuretic Peptide and High-Sensitivity Troponin T Levels in the Natural History of Transthyretin Amyloid Cardiomyopathy and Their Evolution after Tafamidis Treatment

BACKGROUND

We assesse the evolution and prognostic value of N-terminal pro-brain natriuretic peptide (NT-proBNP) and high-sensitivity troponin T (cTnT-HS) in transthyretin amyloid cardiomyopathy (ATTR-CA) before and after tafamidis treatment.

METHODS AND RESULTS

454 ATTR-CA patients without tafamidis (Cohort A) and 248 ATTR-CA with tafamidis (Cohort B) were enrolled. Event-free survival (EFS) events were death, heart transplant, or acute heart failure. In Cohort A, 27% of patients maintained NT-proBNP < 3000 ng/L and 14% cTnT-HS < 50 ng/L at 12 months relative to baseline levels. In Cohort B, the proportions were 49% and 29%, respectively. In Cohort A, among the 333 patients without an increased NT-proBNP > 50% relative to baseline EFS was extended compared to the 121 patients with an increased NT-proBNP > 50% (HR: 0.75 [0.57; 0.98]; p = 0.032). In Cohort A, baseline NT-proBNP > 3000 ng/L and cTnT-HS > 50 ng/L and a relative increase of NT-proBNP > 50% during follow-up were independent prognostic factors of EFS. The slopes of logs NT-proBNP and cTnT-HS increased with time before and stabilized after tafamidis.

CONCLUSION

ATTR-CA patients with increasing NT-proBNP had an increased risk of EFS. Tafamidis stabilize NT-proBNP and cTnT-HS increasing, even if initial NT-proBNP levels were >3000 ng/L. Thus suggesting that all patients, irrespective of baseline NT-proBNP levels, may benefit from tafamidis.

Biomarkers in AL Amyloidosis

Systemic AL amyloidosis is a rare complex hematological disorder caused by clonal plasma cells which produce amyloidogenic immunoglobulins. Outcome and prognosis is the combinatory result of the extent and pattern of organ involvement secondary to amyloid fibril deposition and the biology and burden of the underlying plasma cell clone. Prognosis, as assessed by overall survival, and early outcomes is determined by degree of cardiac dysfunction and current staging systems are based on biomarkers that reflect the degree of cardiac damage. The risk of progression to end-stage renal disease requiring dialysis is assessed by renal staging systems. Longer-term survival and response to treatment is affected by markers of the underlying plasma cell clone; the genetic background of the clonal disease as evaluated by interphase fluorescence in situ hybridization in particular has predictive value and may guide treatment selection. Free light chain assessment forms the basis of hematological response criteria and minimal residual disease as assessed by sensitive methods is gradually being incorporated into clinical practice. However, sensitive biomarkers that could aid in the early diagnosis and that could reflect all aspects of organ damage and disease biology are needed and efforts to identify them are continuous.

Treatment of AL Amyloidosis: Mayo Stratification of Myeloma and Risk-Adapted Therapy (mSMART) Consensus Statement 2020 Update

Immunoglobulin light chain (AL) amyloidosis is a clonal plasma cell disorder leading to progressive and life-threatening organ failure. The heart and the kidneys are the most commonly involved organs, but almost any organ can be involved. Because of the nonspecific presentation, diagnosis delay is common, and many patients are diagnosed with advanced organ failure. In the era of effective therapies and improved outcomes for patients with AL amyloidosis, the importance of early recognition is further enhanced as the ability to reverse organ dysfunction is limited in those with a profound organ failure. As AL amyloidosis is an uncommon disorder and given patients' frailty and high early death rate, management of this complex condition is challenging. The treatment of AL amyloidosis is based on various anti-plasma cell therapies. These therapies are borrowed and customized from the treatment of multiple myeloma, a more common disorder. However, a growing number of phase 2/3 studies dedicated to the AL amyloidosis population are being performed, making treatment decisions more evidence-based. Supportive care is an integral part of management of AL amyloidosis because of the inherent organ dysfunction, limiting the delivery of effective therapy. This extensive review brings an updated summary on the management of AL amyloidosis, sectioned into the 3 pillars for survival improvement: early disease recognition, anti-plasma cell therapy, and supportive care.

The Role of Light Kappa and Lambda Chains in Heart Function Assessment in Patients with AL Amyloidosis

There are reports indicating that myocardial dysfunction in systemic immunoglobulin light chain amyloidosis (AL amyloidosis) stems not only from the amyloid deposit in the organ but also the cardiotoxicity of the amyloid precursor free light chains (FLCs) circulating in the blood. The aim of the study is to analyze the role of sFLC κ and λ in the assessment of heart involvement and the degree of myocardial damage in AL amyloidosis. The study involved 71 patients diagnosed with primary AL amyloidosis. The relationship between sFLC concentrations and cardiac biochemical and echocardiographic parameters was assessed. The median concentrations of N-terminal pro b-type natriuretic peptide(NT-proBNP) and troponin I (TnI) were significantly higher in patients with amyloids formed from monoclonal λ chains compared to patients with monoclonal κ proliferation. In patients with heart involvement by amyloids formed from monoclonal FLC, the study demonstrated a statistically significant positive correlation between the concentration of monoclonal antibody λ chain and TnI (R = 0.688; p < 0.05), NT-proBNP (R = 0.449; p < 0.05), and the value of diastolic dimension of the interventricular septum (IVS; R = 0.496, p < 0.05). The above data indicate that the presence of monoclonal λ chains in patients with AL amyloidosis may be associated with more severe damage to cardiomyocytes and dysfunction of the myocardium.

Use of biomarkers to diagnose and manage cardiac amyloidosis

Amyloidoses are characterized by the tissue accumulation of misfolded proteins into insoluble fibrils. The two most common types of systemic amyloidosis result from the deposition of immunoglobulin light chains (AL) and wild-type or variant transthyretin (ATTRwt/ATTRv). Cardiac involvement is the main determinant of outcome in both AL and ATTR, and cardiac amyloidosis (CA) is increasingly recognized as a cause of heart failure. In CA, circulating biomarkers are important diagnostic tools, allow to refine risk stratification at baseline and during follow-up, help to tailor the therapeutic strategy and monitor the response to treatment. Among amyloid precursors, free light chains are established biomarkers in AL amyloidosis, while the plasma transthyretin assay is currently being investigated as a tool for supporting the diagnosis of ATTRv amyloidosis, predicting outcome and monitor response to novel tetramer stabilizers or small interfering RNA drugs in ATTR CA. Natriuretic peptides (NPs) and troponins are consistently elevated in patients with AL and ATTR CA. Plasma NPs, troponins and free light chains hold prognostic significance in AL amyloidosis, and are evaluated for therapy decision-making and follow-up, while the value of NPs and troponins in ATTR is less well established. Biomarkers can be usefully integrated with clinical and imaging variables at all levels of the clinical algorithm of systemic amyloidosis, from screening to diagnosis and prognosis, and treatment tailoring.

Daratumumab plus CyBorD for patients with newly diagnosed AL amyloidosis: safety run-in results of ANDROMEDA

Although no therapies are approved for light chain (AL) amyloidosis, cyclophosphamide, bortezomib, and dexamethasone (CyBorD) is considered standard of care. Based on outcomes of daratumumab in multiple myeloma (MM), the phase 3 ANDROMEDA study (NCT03201965) is evaluating daratumumab-CyBorD vs CyBorD in newly diagnosed AL amyloidosis. We report results of the 28-patient safety run-in. Patients received subcutaneous daratumumab (DARA SC) weekly in cycles 1 to 2, every 2 weeks in cycles 3 to 6, and every 4 weeks thereafter for up to 2 years. CyBorD was given weekly for 6 cycles. Patients had a median of 2 involved organs (kidney, 68%; cardiac, 61%). Patients received a median of 16 (range, 1-23) treatment cycles. Treatment-emergent adverse events were consistent with DARA SC in MM and CyBorD. Infusion-related reactions occurred in 1 patient (grade 1). No grade 5 treatment-emergent adverse events occurred; 5 patients died, including 3 after transplant. Overall hematologic response rate was 96%, with a complete hematologic response in 15 (54%) patients; at least partial response occurred in 20, 22, and 17 patients at 1, 3, and 6 months, respectively. Renal response occurred in 6 of 16, 7 of 15, and 10 of 15 patients, and cardiac response occurred in 6 of 16, 6 of 13, and 8 of 13 patients at 3, 6, and 12 months, respectively. Hepatic response occurred in 2 of 3 patients at 12 months. Daratumumab-CyBorD was well tolerated, with no new safety concerns versus the intravenous formulation, and demonstrated robust hematologic and organ responses. This trial was registered at www.clinicaltrials.gov as #NCT03201965.

Keys to early diagnosis of cardiac amyloidosis: red flags from clinical, laboratory and imaging findings

Cardiac involvement in systemic amyloidosis, due either to immunoglobulin light-chain or transthyretin amyloidosis, influences clinical presentation and is a strong predictor of unfavourable outcome. Until recently considered as a rare, incurable disease, cardiac amyloidosis, is still mis/underdiagnosed, although treatments effective in improving patient survival are now available for both subtypes, including chemotherapy regimens for immunoglobulin light-chain amyloidosis and tetramer stabiliser for transthyretin amyloidosis. Achieving a timely diagnosis allows initiating life-saving therapies and requires the early recognition of clinical, laboratory and imaging signs of cardiac involvement, some of them may be apparent well before the disease becomes clinically manifest. Given the systemic nature of amyloidosis, a close interaction among experts in multiple specialties is also required, including cardiologists, nephrologists, haematologists, neurologists, radiologists, nuclear medicine specialists and internists. As an increased awareness about disease presentation is required to ameliorate diagnostic performance, we aim to provide the clinician with a guide to the screening and early diagnosis of cardiac amyloidosis, and to review the clinical, biohumoral and instrumental ‘red flags’ that should raise the suspicion of cardiac amyloidosis.

Is the true clinical value of high-sensitivity troponins as a biomarker of risk? The concept that detection of high-sensitivity troponin 'never means nothing'

INTRODUCTION

High-sensitivity troponin (hs-cTn) assays are central to the diagnosis of myocardial infarction (MI). Their increased sensitivity has facilitated rapid pathways for the exclusion of MI. However, hs-cTn is now more readily detectable in patients without symptoms typical of MI, in whom a degree of myocardial injury is assumed. Recently, the practice of using the 99^th centile of hs-cTn as a working 'upper reference limit' has been challenged. There is increasing evidence that hs-cTn may provide useful prognostic information, regardless of any suspicion of MI, and as such these assays may have potential as a general biomarker for mortality. This raises the concept that detection of hs-cTn 'never means nothing.'

AREAS COVERED

In this review, we will evaluate the evidence for the use of hs-cTn assays outside their common clinical indication to rule out or diagnose acute MI.

EXPERT OPINION

The data presented suggest that hs-cTn testing may in the future have a generalized role as a biomarker of mortality risk and may be used less as a test for ruling in acute MI, but will remain a frontline test to exclude that diagnosis in ED. Further, the data suggest that the detection of hs-cTn 'never means nothing.'

Pittsburgh B Compound Positron Emission Tomography in Patients With AL Cardiac Amyloidosis

BACKGROUND

It remains unknown whether the noninvasive evaluation of the degree of amyloid deposition in the myocardium can predict the prognosis of patients with light chain (AL) cardiac amyloidosis.

OBJECTIVES

The purpose of this study was to demonstrate that ¹¹C-Pittsburgh B compound positron emission tomography (¹¹C-PiB PET) is useful for prognostication of AL cardiac amyloidosis by noninvasively imaging the myocardial AL amyloid deposition.

METHODS

This study consecutively enrolled 41 chemotherapy-naïve AL cardiac amyloidosis patients. The amyloid deposit was quantitatively assessed with amyloid P immunohistochemistry in endomyocardial biopsy specimens and was compared with the degree of myocardial ¹¹C-PiB uptake on PET. The primary endpoint was a composite of all-cause death, heart transplantation, and acute decompensated heart failure.

RESULTS

The degree of myocardial ¹¹C-PiB PET uptake was significantly higher in the cardiac amyloidosis patients compared with normal subjects and correlated well with the degree of amyloid deposit on histology (R² = 0.343, p < 0.001). During follow-up (median: 423 days, interquartile range: 93 to 1,222 days), 24 patients experienced the primary endpoint. When the cardiac amyloidosis patients were divided into tertiles by the degree of myocardial ¹¹C-PiB PET uptake, patients with the highest PiB uptake experienced the worst clinical event-free survival (log-rank p = 0.014). The degree of myocardial PiB PET uptake was a significant predictor of clinical outcome on multivariate Cox regression analysis (adjusted hazard ratio: 1.185; 95% confidence interval: 1.054 to 1.332; p = 0.005).

CONCLUSIONS

These proof-of-concept results show that noninvasive evaluation of myocardial amyloid load by ¹¹C-PiB PET reflects the degree of amyloid deposit and is an independent predictor of clinical outcome in AL cardiac amyloidosis patients.

Amyloidosis in Heart Failure

PURPOSE

Amyloidosis represents an increasingly recognized but still frequently missed cause of heart failure. In the light of many effective therapies for light chain (AL) amyloidosis and promising new treatment options for transthyretin (ATTR) amyloidosis, awareness among caregivers needs to be raised to screen for amyloidosis as an important and potentially treatable differential diagnosis. This review outlines the diversity of cardiac amyloidosis, its relation to heart failure, the diagnostic algorithm, and therapeutic considerations that should be applied depending on the underlying type of amyloidosis.

RECENT FINDINGS

Non-biopsy diagnosis is feasible in ATTR amyloidosis in the absence of a monoclonal component resulting in higher detection rates of cardiac ATTR amyloidosis. Biomarker-guided staging systems have been updated to facilitate risk stratification according to currently available biomarkers independent of regional differences, but have not yet prospectively been tested. Novel therapies for hereditary and wild-type ATTR amyloidosis are increasingly available. The complex treatment options for AL amyloidosis are improving continuously, resulting in better survival and quality of life. Mortality in advanced cardiac amyloidosis remains high, underlining the importance of early diagnosis and treatment initiation. Cardiac amyloidosis is characterized by etiologic and clinical heterogeneity resulting in a frequently delayed diagnosis and an inappropriately high mortality risk. New treatment options for this hitherto partially untreatable condition have become and will become available, but raise challenges regarding their implementation. Referral to specialized centers providing access to extensive and targeted diagnostic investigations and treatment initiation may help to face these challenges.

Prognosis and Staging of AL Amyloidosis

The treatment options for systemic light chain amyloidosis (AL) are currently widening in an unprecedented way, brought about by an expanding arsenal of anti-myeloma therapy as well as by novel approaches to target toxic light chains and, most recently, deposited amyloid directly. In this context, accurate estimates of prognosis in AL, which allow for reliable patient advice and for example comparison of different therapies, are particularly important to clinicians. Some biomarkers and especially the genetic background of the underlying clonal disease as evaluated by interphase fluorescence in situ hybridization even have predictive value, enabling an appropriate treatment selection. Derived from the most frequently involved organs in AL, heart and kidney, this review focuses on overall survival and renal survival. A comprehensive overview and summary of reported prognostic factors and biomarkers in AL is given and the most important and validated factors are highlighted. Finally, established staging systems in AL as well as validated and perspective response criteria are presented.

Performance analysis of AL amyloidosis cardiac biomarker staging systems with special focus on renal failure and atrial arrhythmia

Systemic light chain amyloidosis is a rare and life-threatening disorder, for which accurate risk stratification is crucial. Current cardiac staging systems (MAYO2004, MAYO3b, and MAYO2012) are mainly based on biomarkers, which have uncertain reliability in the context of atrial fibrillation, arrhythmia or pacemaker stimulation as well as renal insufficiency. We compared the performance of the established staging systems with particular regard to these comorbidities in 1,224 patients with systemic light chain amyloidosis diagnosed at our center from July 2002 until March 2017. We first characterized the subsets with an estimated glomerular filtration rate <50 mL/min/1.73 m² (415 patients) and any kind of atrial arrhythmia (183 patients) as unique high-risk subgroups with similarly increased cardiac biomarkers (χ²-test, all P<0.001). This resulted in a shift towards higher risk stages and reduced median overall survival compared to those of patients with better kidney function or without atrial arrhythmia in univariate analyses (13 vs. 46 months and 17 vs. 53 months, respectively; both P<0.001). Performance analysis revealed that predictions in the entire cohort were least precise with the MAYO2004 staging system and most precise with the MAYO3b system. This performance pattern was almost preserved for patients with an estimated glomerular filtration rate <50 mL/min/1.73 m², but less so for those with atrial arrhythmias. The MAYO3b staging system was most robust. Importantly, atrial arrhythmia retained its prognostic value in multivariable analysis including age, difference between involved and uninvolved free light chains, and any staging system, while estimated glomerular filtration rate <50 mL/min/1.73 m² was not statistically significant in multivariable analysis with the MAYO3b staging system. In conclusion, our results favor the MAYO3b staging system due to its consistently best performance and retained applicability in the subgroups with atrial arrhythmia and estimated glomerular filtration rate <50 mL/min/1.73 m².

Diagnosis of cardiac amyloidosis: a systematic review on the role of imaging and biomarkers

BACKGROUND

Cardiac Amyloidosis (CA) pertains to the cardiac involvement of a group of diseases, in which misfolded proteins deposit in tissues and cause progressive organ damage. The vast majority of CA cases are caused by light chain amyloidosis (AL) and transthyretin amyloidosis (ATTR). The increased awareness of these diseases has led to an increment of newly diagnosed cases each year.

METHODS

We performed multiple searches on MEDLINE, EMBASE and the Cochrane Database of Systematic Reviews. Several search terms were used, such as "cardiac amyloidosis", "diagnostic modalities cardiac amyloidosis" and "staging cardiac amyloidosis". Emphasis was given on original articles describing novel diagnostic and staging approaches to the disease.

RESULTS

Imaging techniques are indispensable to diagnosing CA. Novel ultrasonographic techniques boast high sensitivity and specificity for the disease. Nuclear imaging has repeatedly proved its worth in the diagnostic procedure, with efforts now focusing on standardization and quantification of amyloid load. Because the latter would be invaluable for any staging system, those spearheading research in magnetic resonance imaging of the disease are also trying to come up with accurate tools to quantify amyloid burden. Staging tools are currently being developed and validated for ATTR CA, in the spirit of the acclaimed Mayo Staging System for AL.

CONCLUSION

Cardiac involvement confers significant morbidity and mortality in all types of amyloidosis. Great effort is made to reduce the time to diagnosis, as treatment in the initial stages of the disease is tied to better prognosis. The results of these efforts are highly sensitive and specific diagnostic modalities that are also reasonably cost effective.

Management of the elderly patient with AL amyloidosis

Systemic immunoglobulin light chain (AL) amyloidosis is an aging-associated protein misfolding and deposition disease. This condition is caused by a small and otherwise indolent plasma cell (or B cell) clone secreting an unstable circulating light chain, which misfolds and deposits as amyloid fibrils possibly leading to progressive dysfunction of affected organs. AL amyloidosis can occur in the typical setting of other, rarer forms of systemic amyloidosis and can mimic other more prevalent conditions of the elderly. Therefore, its diagnosis requires a high degree of clinical suspicion and reliable diagnostic tools for accurate amyloid typing, available at specialized referral centers. In AL amyloidosis, frailty is dictated by the type and severity of organ involvement, with heart involvement being the main determinant of morbidity and mortality. Still, given a similar disease stage, elderly patients with AL amyloidosis are often an even frailer group, due to significant comorbidities, associated disability and polypharmacotherapy, socioeconomic restrictions, and limited access to clinical trials. Recent improvements in the use of biomarkers for early diagnosis, risk stratification and response monitoring, the flourishing of novel, effective anti-plasma cell therapies developed against multiple myeloma and adapted to treat AL amyloidosis, and possibly the introduction of anti-amyloid therapies are rapidly changing the clinical management of this disease and are reflected by improved outcomes. Of note, hematologic and organ responses in elderly patients with AL amyloidosis do translate in better outcome, advocating the importance of treating these patients and striving for a rapid response to therapy also in this challenging clinical setting.

Current and future circulating biomarkers for cardiac amyloidosis

Cardiac amyloidosis (CA) comprises a heterogeneous group of medical conditions affecting the myocardium. It presents with proteinaceous infiltration with variable degrees of severity, prevalence and evolution. Despite this heterogeneity, erroneous protein folding is the common pathophysiologic process, yielding the formation of a single misfolded protein (monomer) that progressively evolves and ultimately forms amyloid fibers. Additionally, by seeding out from the organs of origin, intermediates called oligomers metastasize and restart the process. Such self-echoing behavior makes the secondary affected organs as important as the primary ones. Unfortunately, CA can be clinically challenging and only suggestive in a late stage of its natural history, leaving a narrow therapeutic time window available. In light of the evolutionary nature of amyloidosis, here, we propose a new classification of the currently used biomarkers based on time stages with different specificity and applicability across CA subtypes. Early markers (free light chains, serum amyloid A, β2-microglobulin, osteopontin and osteoprotegerin) can be employed for disease detection. Intermediate markers [soluble suppression of tumorigenicity 2 (sST-2), midregional proadrenomedullin (MR-proADM), von Willebrand factor (vWF), hepatocyte growth factor (HGF), matrix metalloproteinases (MMPs) and tissue inhibitor metalloproteinases (TIMPs)] can provide information on the biological mechanisms of myocardial damage. As in heart failure, late-stage biomarkers (troponins and natriuretic peptides) can help clinicians with prognosis and therapeutic response evaluation in CA. Such findings have generated a remarkable foundation for our current knowledge on CA. Nevertheless, we envision a future class of biomarkers targeted at upstream events capable of detecting folding defects, which will ultimately expand the therapeutic window.

Diagnostic utility of cardiac troponin T level in patients with cardiac amyloidosis

AIM

The aim of this study was to evaluate the diagnostic utility of high-sensitivity cardiac troponin T (hs-cTnT) levels in discriminating cardiac amyloidosis from patients with cardiac hypertrophy caused by aetiologies other than cardiac amyloidosis.

METHODS AND RESULTS

Serum hs-cTnT levels were measured in 96 patients with cardiac amyloidosis (light chain: 23, wild-type transthyretin amyloidosis: 40, and mutated transthyretin amyloidosis: 33), and 91 patients with other causes of cardiac hypertrophy who were confirmed to have no cardiac amyloidosis by endomyocardial biopsy (control group). The diagnostic utility and cut-off value of hs-cTnT were evaluated by receiver operating characteristic analysis. The median hs-cTnT levels were higher in cardiac amyloidosis than the control group [0.048 (0.029-0.073) vs. 0.016 (0.010-0.031) ng/mL; P < 0.001]. High levels of hs-cTnT were suggestive of cardiac amyloidosis (cut-off value: 0.0312 ng/mL, sensitivity: 0.74, specificity: 0.76, area under the curve: 0.788; 95% confidence interval: 0.723-0.854, P < 0.001), compared with brain natriuretic peptide and E/e' ratio. The hs-cTnT levels were also useful in differentiating each type of amyloidosis from the control group. Multivariate analysis identified log hs-cTnT as an independent diagnostic factor for cardiac amyloidosis (odds ratio: 2.22; 95% confidence interval: 1.30-3.80; P = 0.004).

CONCLUSIONS

High serum levels of hs-cTnT are highly suggestive of cardiac amyloidosis, allowing its differentiation from cardiac hypertrophy of other aetiologies. Further refined diagnostic approaches that include imaging modalities and histopathological examination are needed for these patients to avoid underdiagnosis of cardiac amyloidosis.

AL amyloidosis patients with low amyloidogenic free light chain levels at first diagnosis have an excellent prognosis

AL patients with an initial dFLC <50 mg/L represent a distinct clinical subgroup with mostly renal disease and a favorable prognosis. These patients are evaluable for hematologic response including a novel low-dFLC partial response, which predict renal and overall survival.

Liver dysfunction as predictor of prognosis in patients with amyloidosis: utility of the Model for End-stage Liver disease (MELD) scoring system

Amyloidosis prognosis is often related to the onset of heart failure and a worsening that is concomitant with kidney-liver dysfunction; thus the Model for End-stage Liver disease (MELD) may be an ideal instrument to summarize renal-liver function. Our aim has been to test the MELD score as a prognostic tool in amyloidosis. We evaluated 128 patients, 46 with TTR-related amyloidosis and 82 with AL amyloidosis. All patients had a complete clinical and echocardiography evaluation; overall biohumoral assessment included troponin I, NT-proBNP, creatinine, total bilirubin and INR ratio. The study population was dichotomized at the 12 cut-off level of MELD scores; those with MELD score >12 had a lower survival compared to controls in the study cohort (40.7 vs 66.3 %; p = 0.006). Either as a continuous and dichotomized variable, MELD shows its independent prognostic value at multivariable analysis (HR = 1.199, 95 % CI 1.082-1.329; HR = 2.707, 95 % CI 1.075-6.817, respectively). MELD shows a lower prognostic sensitivity/specificity ratio than troponin I and NT-proBNP in the whole study population and AL subgroup, while in TTR patients MELD has a higher sensitivity/specificity ratio compared to troponin and NT-proBNP (ROC analysis-AUC: 0.853 vs 0.726 vs 0.659). MELD is able to predict prognosis in amyloidosis. A MELD score >12 selects a subgroup of patients with a higher risk of death. The predictive accuracy seems to be more evident in TTR patients in whom currently no effective scoring systems have been validated.

Rationale, application and clinical qualification for NT-proBNP as a surrogate end point in pivotal clinical trials in patients with AL amyloidosis

Amyloid light-chain (LC) amyloidosis (AL amyloidosis) is a rare and fatal disease for which there are no approved therapies. In patients with AL amyloidosis, LC aggregates progressively accumulate in organs, resulting in organ failure that is particularly lethal when the heart is involved. A significant obstacle in the development of treatments for patients with AL amyloidosis, as well as for those with any disease that is rare, severe and heterogeneous, has been satisfying traditional clinical trial end points (for example, overall survival or progression-free survival). It is for this reason that many organizations, including the United States Food and Drug Administration through its Safety and Innovation Act Accelerated Approval pathway, have recognized the need for biomarkers as surrogate end points. The international AL amyloidosis expert community is in agreement that the N-terminal fragment of the pro-brain natriuretic peptide (NT-proBNP) is analytically validated and clinically qualified as a biomarker for use as a surrogate end point for survival in patients with AL amyloidosis. Underlying this consensus is the demonstration that NT-proBNP is an indicator of cardiac response in all interventional studies in which it has been assessed, despite differences in patient population, treatment type and treatment schedule. Furthermore, NT-proBNP expression is directly modulated by amyloidogenic LC-elicited signal transduction pathways in cardiomyocytes. The use of NT-proBNP will greatly facilitate the development of targeted therapies for AL amyloidosis. Here, we review the data supporting the use of NT-proBNP, a biomarker that is analytically validated, clinically qualified, directly modulated by LC and universally accepted by AL amyloidosis specialists, as a surrogate end point for survival.

Long term outcomes of cardiac transplant for immunoglobulin light chain amyloidosis: The Mayo Clinic experience

AIM: To determine the outcome of orthotopic heart transplantation (OHT) in immunoglobulin light chain (AL) amyloidosis.

METHODS: The medical records of patients with AL who underwent orthotopic heart transplantation at the Mayo Clinic in Rochester Minnesota from 1992 to 2011 were reviewed. Patients met at least one of the following at: New York Heart Association class IV heart failure, ventricular thickness > 15 mm, ejection fraction < 40%. Selection guidelines for heart transplant included age < 60 years, absence of multiple myeloma and significant extra-cardiac organ involvement. Baseline characteristics including age, gender, organ involvement, and New York Heart Association functional class were recorded. Laboratory data, waiting time until heart transplant, and type of treatment of the underlying plasma cell disorder were recorded. Survival from the time of OHT was calculated using Kaplan-Meier survival curves. Survival of patients undergoing OHT for AL was compared to that of non-amyloid patients undergoing OHT during the same time period.

RESULTS: Twenty-three patients (median age 53 years) with AL received OHT. There were no deaths in the immediate perioperative period. Twenty patients have died post OHT. For the entire cohort, the median overall survival was 3.5 years (95%CI: 1.2, 8.2 years). The 1-year survival post OHT was 77%, the 2-year survival 65%, and the 5-year survival 43%. The 5-year survival for non-amyloid patients undergoing OHT during the same era was 85%. Progressive amyloidosis contributed to death in twelve patients. Of those without evidence of progressive amyloidosis, the cause of death included complications of autologous hematopoietic stem cell transplantation for 3 patients, post-transplant lymphoproliferative disorder for 2 patients; and for the remaining one death was related to each of the following causes: acute rejection; cardiac vasculopathy; metastatic melanoma; myelodysplastic syndrome; and unknown. Eight patients had rejection at a median of 1.8 mo post OHT (range 0.4 to 4.9 mo); only one patient died of rejection. Median survival of seven patients who achieved a complete hematologic response to either chemotherapy or autologous hematopoietic stem cell transplantation was 10.8 years.

CONCLUSION: Our data demonstrate that long term survival after heart transplant is feasible in AL patients with limited extra-cardiac involvement who achieve complete hematologic response.

Cardiotoxicity due to Chemotherapy: the Role of Biomarkers

An ever-increasing array of chemotherapeutic agents is being used in the treatment of solid organ or hematologic malignancies. The success of many of these agents has led to an increasing survival of patients with cancer. However, many of these agents, particularly anthracyclines and trastuzumab, are associated with the development of cardiotoxicity. The current standard for the evaluation of chemotherapy-associated cardiotoxicity typically involves the use of serial measurements of left ventricular (LV) function by echocardiogram (Echo) and radionuclide ventriculogram (MUGA). Unfortunately, this time-honored method offers low sensitivity to the early prediction or detection of cardiac events. Frequently, by the time cardiotoxicity is detected, significant LV dysfunction has occurred and ultimately this may not respond to standard cardioprotective treatment. Cardiac biomarkers, troponin I and B-type natriuretic peptide, may allow a more accurate and timely monitoring strategy. The current data and a summarized understanding of how to utilize cardiac biomarkers for the prevention and early detection of cardiac dysfunction during chemotherapy are presented.

What is new in diagnosis and management of light chain amyloidosis?

Light chain (AL) amyloidosis is caused by a usually small plasma cell clone producing a misfolded light chain that deposits in tissues. Survival is mostly determined by the severity of heart involvement. Recent studies are clarifying the mechanisms of cardiac damage, pointing to a toxic effect of amyloidogenic light chains and offering new potential therapeutic targets. The diagnosis requires adequate technology, available at referral centers, for amyloid typing. Late diagnosis results in approximately 30% of patients presenting with advanced, irreversible organ involvement and dying in a few months despite modern treatments. The availability of accurate biomarkers of clonal and organ disease is reshaping the approach to patients with AL amyloidosis. Screening of early organ damage based on biomarkers can help identify patients with monoclonal gammopathy of undetermined significance who are developing AL amyloidosis before they become symptomatic. Staging systems and response assessment based on biomarkers facilitate the design and conduction of clinical trials, guide the therapeutic strategy, and allow the timely identification of refractory patients to be switched to rescue therapy. Treatment should be risk-adapted. Recent studies are linking specific characteristics of the plasma cell clone to response to different types of treatment, moving toward patient-tailored therapy. In addition, novel anti-amyloid treatments are being developed that might be combined with anti-plasma cell chemotherapy.

Bortezomib-Induced Complete Heart Block and Myocardial Scar: The Potential Role of Cardiac Biomarkers in Monitoring Cardiotoxicity

Bortezomib is a proteasome inhibitor used to treat multiple myeloma and mantle cell lymphoma. Traditionally, bortezomib was thought to have little cardiovascular toxicity; however, there is increasing evidence that bortezomib can lead to cardiac complications including left ventricular dysfunction and atrioventricular block. We present the case of a 66-year-old man with multiple myeloma and persistent asymptomatic elevations of cardiac biomarkers who developed complete heart block and evidence of myocardial scar after his eighth cycle of bortezomib, requiring permanent pacemaker placement. In addition to discussing the cardiovascular complications of bortezomib therapy, we propose a potential role for biomarkers in the prediction and monitoring of bortezomib cardiotoxicity.

Immunoglobulin Light-Chain Amyloidosis: From Basics to New Developments in Diagnosis, Prognosis and Therapy

Immunoglobulin amyloid light-chain (AL) amyloidosis is the most common form of systemic amyloidosis, where the culprit amyloidogenic protein is immunoglobulin light chains produced by marrow clonal plasma cells. AL amyloidosis is an infrequent disease, and since presentation is variable and often nonspecific, diagnosis is often delayed. This results in cumulative organ damage and has a negative prognostic effect. AL amyloidosis can also be challenging on the diagnostic level, especially when demonstration of Congo red-positive tissue is not readily obtained. Since as many as 31 known amyloidogenic proteins have been identified to date, determination of the amyloid type is required. While several typing methods are available, mass spectrometry has become the gold standard for amyloid typing. Upon confirming the diagnosis of amyloidosis, a pursuit for organ involvement is essential, with a focus on heart involvement, even in the absence of suggestive symptoms for involvement, as this has both prognostic and treatment implications. Details regarding initial treatment options, including stem cell transplantation, are provided in this review. AL amyloidosis management requires a multidisciplinary approach with careful patient monitoring, as organ impairment has a major effect on morbidity and treatment tolerability until a response to treatment is achieved and recovery emerges.

Immunoglobulin Light Chain Systemic Amyloidosis

Immunoglobulin light chain amyloidosis (AL) is a rare, complex disease caused by misfolded free light chains produced by a usually small, indolent plasma cell clone. Effective treatments exist that can alter the natural history, provided that they are started before irreversible organ damage has occurred. The cornerstones of the management of AL amyloidosis are early diagnosis, accurate typing, appropriate risk-adapted therapy, tight follow-up, and effective supportive treatment. The suppression of the amyloidogenic light chains using the cardiac biomarkers as guide to choose chemotherapy is still the mainstay of therapy. There are exciting possibilities ahead, including the study of oral proteasome inhibitors, antibodies directed at plasma cell clone, and finally antibodies attacking the amyloid deposits are entering the clinic, offering unprecedented opportunities for radically improving the care of this disease.

Treatment of Immunoglobulin Light Chain Amyloidosis: Mayo Stratification of Myeloma and Risk-Adapted Therapy (mSMART) Consensus Statement

Immunoglobulin light chain amyloidosis (AL amyloidosis) has an incidence of approximately 1 case per 100,000 person-years in Western countries. The rarity of the condition not only poses a challenge for making a prompt diagnosis but also makes evidenced decision making about treatment even more challenging. Physicians caring for patients with AL amyloidosis have been borrowing and customizing the therapies used for patients with multiple myeloma with varying degrees of success. One of the biggest failings in the science of the treatment of AL amyloidosis is the paucity of prospective trials, especially phase 3 trials. Herein, we present an extensive review of the literature with an aim of making recommendations in the context of the best evidence and expert opinion.

Differentiation of infiltrative cardiomyopathy from hypertrophic cardiomyopathy using high-sensitivity cardiac troponin T: a case-control study

Background

Because infiltrative cardiomyopathy and hypertrophic cardiomyopathy (HCM) share clinical and hemodynamic features of left ventricular (LV) hypertrophy and abnormal diastolic function, it is often difficult to distinguish these entities.

Methods

We investigated the potential role of high-sensitivity cardiac troponin T (hs-cTnT) for differentiation of infiltrative cardiomyopathy from HCM.

Results

The study group consisted of 46 consecutive patients with infiltrative cardiomyopathies or HCM in whom sarcomere protein gene mutations were identified at Kochi Medical School Hospital; of these, there were 11 patients with infiltrative cardiomyopathy (cardiac amyloidosis in 8 patients and Fabry disease in 3 patients) and 35 HCM patients. Serum hs-cTnT level was significantly higher in patients who had infiltrative cardiomyopathy than in those who had HCM (0.083 ± 0.057 ng/ml versus 0.027 ± 0.034 ng/ml, p < 0.001), whereas brain natriuretic peptide levels did not differ between the two groups. In two age-matched the 2 cohorts (patients evaluated at > 40 years at age), hs-cTnT level, maximum LV wall thickness, posterior wall thickness, peak early (E) transmitral filling velocity, peak early diastolic (Ea) velocity of tissue Doppler imaging at the lateral corner and E/Ea ratios at both the septal and lateral corners were significantly different between the two groups. As for diagnostic accuracy to differentiate the two groups by using receiver operating characteristic analysis, hs-cTnT was the highest value of area under the curve (0.939) and E/Ea (lateral) was second highest value (0.914).

Conclusions

Serum hs-cTnT is a helpful diagnostic indicator for accurate differentiation between infiltrative cardiomyopathy and HCM.

Soluble suppression of tumorigenicity 2 (sST2), but not galactin-3, adds to prognostication in patients with systemic AL amyloidosis independent of NT-proBNP and troponin T

The use of soluble cardiac biomarkers such as N-terminal pro-brain natriuretic peptide (NT-proBNP) and troponin has revolutionized prognostication for patients with AL amyloidosis. Soluble ST2 (sST2) and galectin-3 have also been reported to have prognostic value in other cardiac patient populations. We identified 502 patients with AL amyloidosis, who provided a research sample and consent to review their medical records between 1/1/2006-12/31/2010 within 90 days of their diagnosis. Samples were assayed for sST2 and galectin-3. Within this AL amyloidosis population, overall survival (OS) was 25.5 months (95% CI 18, 35.7 months). Receiver operating curve analyses were done to detect the best cut-points for sST2 and galectin-3 to predict both 1- and 5-year OS. The respective cut points for sST2 were 30 and 29.7 ng/mL, while the median sST2 for the entire population was 31 ng/mL (IQR 19.8, 53.6). The respective cut points for galectin-3 were 11 and 10.4 ng/mL while the median for the entire population was 16.6 ng/mL (IQR 11.5, 24.0). Although on univariate analysis, both sST2 and galectin-3 were prognostic, upon multivariate analysis, only sST2 was independent of troponin, NT-proBNP, serum immunoglobulin free light chain, and blood pressure. Not only did sST2 add to previously reported prognostication systems, but a novel prognostication 5-point system including sST2 was possible. The addition of sST2 - but not galectin-3 - to existing prognostication systems for patients with AL amyloidosis strengthens the ability to predict for death.