Use of biomarkers to diagnose and manage cardiac amyloidosis

Cardiopulmonary exercise testing in transthyretin amyloid cardiomyopathy patients: a long-term follow-up study

AIMS

Patients with transthyretin amyloid cardiomyopathy (ATTR-CM) experience reduced functional capacity. We evaluated changes in functional capacity over extensive follow-up using cardiopulmonary exercise testing (CPX).

METHODS

ATTR-CM patients underwent CPX and blood testing at baseline, first [V1, 8 (6-10) months] and second follow-up (V2) at 35 (26-41) months after start of disease-specific therapy.

RESULTS

We included 34 ATTR-CM patients, aged 77 (±6) years (88.2% men). CPX showed two patterns with functional capacity improvement at V1 and deterioration at V2. Peak work capacity (P = 0.005) and peak oxygen consumption (VO2, P = 0.012) increased at V1 compared with baseline and decreased at V2. The ventilation to carbon dioxide relationship slope (VE/VCO2) increased at V2 compared with baseline and V1 (P = 0.044). A cut-off for peak VO2 at 14 ml/kg·min showed more events (composite of death and heart failure hospitalization): less than 14 vs. greater than 14 ml/kg·min (P = 0.013). Cut-offs for VE/VCO2 slope at 40 showed more events greater than 40 vs. less than 40 (P = 0.009).

CONCLUSION

ATTR-CM patients showed an improvement and deterioration in the short-term and long-term follow-up, respectively, with a better prognosis for those with peak VO2 above 14 ml/kg·min and for a VE/VCO2 slope below 40.

Pathophysiology of Cardiac Amyloidosis

Amyloidosis refers to a heterogeneous group of disorders sharing common pathophysiological mechanisms characterized by the extracellular accumulation of fibrillar deposits consisting of the aggregation of misfolded proteins. Cardiac amyloidosis (CA), usually caused by deposition of misfolded transthyretin or immunoglobulin light chains, is an increasingly recognized cause of heart failure burdened by a poor prognosis. CA manifests with a restrictive cardiomyopathy which progressively leads to biventricular thickening, diastolic and then systolic dysfunction, arrhythmias, and valvular disease. The pathophysiology of CA is multifactorial and includes increased oxidative stress, mitochondrial damage, apoptosis, impaired metabolism, and modifications of intracellular calcium balance.

Clinical Use of Biomarkers in Cardiac Amyloidosis

Amyloidosis is a systemic condition characterized by multiple organs involvement. A multidisciplinary and multimodal approach in assessing patients is pivotal and recommended by the international scientific societies. Biomarkers represent an essential noninvasive tool to increase the suspicion of disease and orient further workup and clinical management of patients. This review provides an updated contemporary focus on the clinical use of biomarkers in cardiac amyloidosis, emphasizing their role in both the diagnostic and prognostic setting and discussing future perspective of emerging biomarkers.

Role of Antitroponin Antibodies and Macrotroponin in the Clinical Interpretation of Cardiac Troponin

Cardiac troponin is extensively used as a biomarker in modern medicine due to its diagnostic capability for myocardial injury, as well as its predictive and prognostic value for cardiac diseases. However, heterophile antibodies, antitroponin antibodies, and macrotroponin complexes can be observed both in seemingly healthy individuals and patients with cardiac diseases, potentially leading to false positive or disproportionate elevation of cTn (cardiac troponin) assay results and introducing discrepancies in clinical interpretations with impact on medical management. In this review article, we describe the possible mechanisms of cTn release and the sources of variations in the assessment of circulating cTn levels. We also explore the pathophysiological mechanisms underlying antitroponin antibody development and discuss the influence exerted by macrotroponin complexes on the results of immunoassays. Additionally, we explore approaches to detect these complexes by presenting various clinical scenarios encountered in routine clinical practice. Finally, unsolved questions about the development, prevalence, and clinical significance of cardiac autoantibodies are discussed.

Safety and efficacy of levosimendan in patients with cardiac amyloidosis

BACKGROUND

Patients with cardiac amyloidosis (CA) often experience heart failure (HF) episodes. No evidence is available on inotropic therapy. This study aims to fill this gap by examining the safety and efficacy of levosimendan.

METHODS

We retrieved all HF patients receiving ≥1 levosimendan infusion from 2013 to 2023. CA patients were matched with HF patients without CA (controls) based on sex, age, and left ventricular ejection fraction (LVEF). The response to levosimendan was measured as changes in daily urinary output, body weight, N-terminal pro-B-type natriuretic peptide (NT-proBNP), and estimated glomerular filtration rate (eGFR).

RESULTS

CA patients (median age 77 years, 73% men, 59% with ATTR-CA) and controls were compared. Levosimendan infusion was stopped because of hypotension in 2 cases with CA and (in 1 case) worsening renal function, and in 2 controls because of ventricular tachycardia episodes and (in 1 case) hypotension. CA patients showed a trend toward increased daily urinary output (p = 0.078) and a significant decrease in body weight (p < 0.001), without significant changes in NT-proBNP (p = 0.497) and eGFR (p = 0.732). Both CA patients and controls displayed similar changes in urinary output, weight, and eGFR, but NT-proBNP decreased more significantly among controls (p < 0.001). No differences were noted in rehospitalization rates, but CA patients experienced higher mortality at 6 and 12 months (p = 0.003 and p = 0.001, respectively).

CONCLUSIONS

Levosimendan appears safe for CA patients needing inotropic support. The diuretic response and weight decrease during hospitalization were comparable between CA patients and matched HF patients, despite the greater mortality of CA patients after discharge.

Challenges and Uncertainties in the Diagnosis of Cardiac Amyloidosis: A Case Report

Amyloidosis is the condition when starch-like misfolded proteins form insoluble fibrils that deposit in tissues and cause dysfunction. Cardiac amyloidosis occurs due to the deposition of amyloid fibrils at the cardiac level and is an important cause of heart failure. This case reveals a patient with significant heart failure and arrhythmia, which later on turned out to be caused by cardiac amyloidosis. While regarded as a rare disease in practice, in retrospect, there are a lot of signs and imaging indicators, particularly in echocardiography that warrant an investigation of cardiac amyloidosis. In this case review, red flags in echocardiography that should endorse further testing for underlying cardiac amyloidosis are highlighted.

Biomarkers of axonal damage to favor early diagnosis in variant transthyretin amyloidosis (A-ATTRv)

Early identification of ATTRv amyloidosis disease onset is still often delayed due to the lack of validated biomarkers of this disease. Light chain neurofilament (NfL) have shown promising results in early diagnosis in this disease, but data is still needed, including with alternative measuring methods. Our aim was to study the levels of NfL measured by ELISA. Furthermore, interstitial matrix metalloproteinase type 1 (MMP-1) serum levels were measured as a potential new biomarker in ATTRv. Serum NfL and MMP-1 were measured using ELISA assays in 90 participants (29 ATTR-V30M patients, 31 asymptomatic V30M-TTR variant carriers and 30 healthy controls). Median NfL levels among ATTRv amyloidosis patients were significantly higher (116 pg/mL vs 0 pg/mL in both comparison groups). The AUC comparing ATTRv amyloidosis patients and asymptomatic carriers was 0.90 and the NfL concentration of 93.55 pg/mL yielded a sensitivity of 79% and a specificity of 87%. NfL levels had a significant positive correlation with NIS values among patients. We found a negative significant correlation between eGFR and NfL levels. Finally, MMP1 levels were not different between groups. Evidence of NfL use for early diagnosis of ATTR-PN amyloidosis is growing. ELISA seems a reliable and available technique for it quantification. Decreased GFR could influence NfL plasma levels.

A Straining Heart: Transthyretin Amyloidosis as a Cause of Heart Failure

Cardiac amyloidosis is a disease caused by the deposition of amyloid fibrils in the extracellular space of the heart, most often by immunoglobulin light chains or by transthyretin. It is often underdiagnosed because the signs and symptoms are nonspecific or due to the false perception that the diagnosis always requires an endomyocardial biopsy. Transthyretin amyloidosis is being increasingly recognized as a cause of heart failure, particularly in patients with heart failure with preserved ejection fraction (HFpEF). We present the clinical case of an 86-year-old man whose diagnosis was based on signs and symptoms compatible with cardiac amyloidosis and in which imaging performed a preponderant role. This case reminds clinicians to consider the diagnosis in older patients with HFpEF, left ventricular hypertrophy and rhythm disturbances. It highlights the importance of evaluating global longitudinal strain (GLS) in a standard echocardiographic evaluation.

World Heart Federation Consensus on Transthyretin Amyloidosis Cardiomyopathy (ATTR-CM)

Transthyretin amyloid cardiomyopathy (ATTR-CM) is a progressive and fatal condition that requires early diagnosis, management, and specific treatment. The availability of new disease-modifying therapies has made successful treatment a reality. Transthyretin amyloid cardiomyopathy can be either age-related (wild-type form) or caused by mutations in the TTR gene (genetic, hereditary forms). It is a systemic disease, and while the genetic forms may exhibit a variety of symptoms, a predominant cardiac phenotype is often present. This document aims to provide an overview of ATTR-CM amyloidosis focusing on cardiac involvement, which is the most critical factor for prognosis. It will discuss the available tools for early diagnosis and patient management, given that specific treatments are more effective in the early stages of the disease, and will highlight the importance of a multidisciplinary approach and of specialized amyloidosis centres. To accomplish these goals, the World Heart Federation assembled a panel of 18 expert clinicians specialized in TTR amyloidosis from 13 countries, along with a representative from the Amyloidosis Alliance, a patient advocacy group. This document is based on a review of published literature, expert opinions, registries data, patients' perspectives, treatment options, and ongoing developments, as well as the progress made possible via the existence of centres of excellence. From the patients' perspective, increasing disease awareness is crucial to achieving an early and accurate diagnosis. Patients also seek to receive care at specialized amyloidosis centres and be fully informed about their treatment and prognosis.

Prognostic value of soluble ST2 in AL and TTR cardiac amyloidosis: a multicenter study

Background

Both light-chain (AL) amyloidosis and transthyretin (ATTR) amyloidosis are types of cardiac amyloidosis (CA) that require accurate prognostic stratification to plan therapeutic strategies and follow-ups. Cardiac biomarkers, e.g., N-terminal pro-B-type natriuretic peptide (NT-proBNP) and high-sensitivity cardiac troponin T (Hs-cTnT), remain the cornerstone of the prognostic assessment. An increased level of soluble suppression of tumorigenesis-2 (sST2) is predictive of adverse events [all-cause death and heart failure (HF) hospitalizations] in patients with HF. This study aimed to evaluate the prognostic value of circulating sST2 levels in AL-CA and ATTR-CA.

Methods

We carried out a multicenter study including 133 patients with AL-CA and 152 patients with ATTR-CA. During an elective outpatient visit for the diagnosis of CA, Mayo Clinic staging [NT-proBNP, Hs-cTnT, differential of free light chains (DFLCs)] and sST2 were assessed for all AL patients. Gillmore staging [including estimated glomerular filtration rate (eGFR), NT-proBNP] and Grogan staging (including NT-proBNP and Hs-cTnT) were assessed for TTR-CA patients.

Results

The median age was 73 years [interquartile range (IQR) 61-81], and 53% were men. The endpoint was the composite of all-cause death or first HF-related hospitalization. The median follow-up was 20 months (IQR 3-34) in AL amyloidosis and 33 months (6-45) in TTR amyloidosis. The primary outcome occurred in 70 (53%) and 99 (65%) of AL and TTR patients, respectively. sST2 levels were higher in patients with AL-CA than in patients with ATTR-CA: 39 ng/L (26-80) vs. 32 ng/L (21-46), p < 0.001. In AL-CA, sST2 levels predicted the outcome regardless of the Mayo Clinic score (HR: 2.16, 95% CI: 1.17-3.99, p < 0.001). In TTR-CA, sST2 was not predictive of the outcome in multivariate models, including Gillmore staging and Grogan staging (HR: 1.17, CI: 95% 0.77-1.89, p = 0.55).

Conclusion

sST2 level is a relevant predictor of death and HF hospitalization in AL cardiac amyloidosis and adds prognostic stratification on top of NT-proBNP, Hs cTnT, and DFLC.

Cardiovascular toxicity from therapies for light chain amyloidosis

Amyloid light-chain (AL) amyloidosis is a hematological disorder characterized by abnormal proliferation of a plasma cell clone producing monoclonal free light chains that misfold and aggregate into insoluble fibrils in various tissues. Cardiac involvement is a common feature leading to restrictive cardiomyopathy and poor prognosis. Current first-line treatments aim at achieving hematological response by targeting the plasma cell clones, and these have been adapted from multiple myeloma therapy. Patients with AL amyloidosis often exhibit multiorgan involvement, making them susceptible to cancer therapy-related cardiovascular toxicity. Managing AL amyloidosis is a complex issue that requires enhanced knowledge of the cardio-oncological implications of hematological treatments. Future research should focus on implementing and validating primary and secondary prevention strategies and understanding the biochemical basis of oncological therapy-related damage to mitigate cardiovascular toxicity.

Classification of patients with cardiac amyloidosis using machine learning models on Italian electronic clinical health records

Amyloidosis refers to a range of medical conditions in which misshapen proteins accumulate in various organs and tissues, forming insoluble fibrils. Cardiac amyloidosis is frequently linked to the buildup of misfolded transthyretin (TTR) or immunoglobulin light chains (AL). Delayed diagnosis, due to lack of disease awareness, results in a poor prognosis, especially in patients with AL amyloidosis. Early identification is therefore a key factor to improve patient outcomes. This study investigates the use of supervised machine-learning algorithms to support clinicians in classifying amyloidosis and control subjects. The aim of this work is to foster model interpretability reporting the most important risk factors in predicting the presence of cardiac amyloidosis. We analyzed electronic health records (EHRs) of 418 participants acquired in a time window of 12 years as part of a case-control study conducted in Fondazione Toscana Gabriele Monasterio (Italy) clinical practice. This work paves the way for the creation of digital health solutions that can aid in amyloidosis screening. The effective handling, analysis, and interpretation of these solutions can have a transformative effect on modern healthcare, offering new opportunities for improved patient care.

Invasive and Non-Invasive Diagnostic Pathways in the Diagnosis of Cardiac Amyloidosis

The appropriate diagnosis and subtyping of cardiac amyloidosis (CA) is frequently missed or delayed due to its vague presentation, clinical overlapping, and diagnostic pitfalls. Recent developments in both invasive and non-invasive diagnostic techniques have significantly changed the diagnostic approach of CA. With the present review, we aim to summarize the current diagnostic approach of CA and to underline the indications of tissue biopsy, either surrogate site or myocardial. The most important factor for timely diagnosis is increased clinical suspicion, especially in certain clinical scenarios. Appropriate imaging with echocardiography or cardiac magnetic resonance (CMR) can provide significant evidence for the diagnosis of CA. Importantly, all patients should undergo monoclonal proteins assessment, with these results significantly determining the steps to follow. A negative monoclonal protein assessment will lead to a non-invasive algorithm which, in combination with positive cardiac scintigraphy, can establish the diagnosis of ATTR-CA. The latter is the only clinical scenario in which the diagnosis can be established without the need of biopsy. However, if the imaging results are negative but the clinical suspicion remains high, a myocardial biopsy should be performed. In the case of the presence of monoclonal protein, an invasive algorithm follows, first by surrogate site sampling and then by myocardial biopsy if the results are inconclusive or prompt diagnosis is needed. The role of endomyocardial biopsy, even though limited by current advances in other techniques, is highly valuable in selected patients and is the only method to reliably establish a diagnosis in challenging cases.

Risk Stratification in Transthyretin Cardiac Amyloidosis: The Added Value of Lung Spirometry

Transthyretin cardiac amyloidosis (ATTR-CA) is an increasingly recognized disease that often results in heart failure and death. Traditionally, biological staging systems are used to stratify disease severity. Reduced aerobic capacity has recently been described as useful in identifying higher risk of cardiovascular events and death. Assessment of lung volume via simple spirometry might also hold prognostic relevance. We aimed to assess the combined prognostic value of spirometry, cardiopulmonary exercise testing (CPET) and biomarker staging in ATTR-CA patients in a multi-parametric approach. We retrospectively reviewed patient records with pulmonary function and CPET testing. Patients were followed until study endpoint (MACE: composite of heart-failure-related hospitalization and all-cause death) or censure (1 April 2022). In total, 82 patients were enrolled. Median follow-up was 9 months with 31 (38%) MACE. Impaired peak VO₂ and forced vital capacity (FVC) were independent predictors of MACE-free survival, with peak VO₂ < 50% and FVC < 70% defining the highest risk group (HR 26, 95% CI: 5-142, mean survival: 15 months) compared to patients with the lowest risk (peak VO₂ ≥ 50% and FVC ≥ 70%). Combined peak VO₂, FVC and ATTR biomarker staging significantly improved MACE prediction by 35% compared to ATTR staging alone, with 67% patients reassigned a higher risk category (p < 0.01). In conclusion, combining functional and biological markers might synergistically improve risk stratification in ATTR-CA. Integrating simple, non-invasive and easily applicable CPET and spirometry in the routine management of ATTR-CA patients might prove useful for improved risk prediction, optimized monitoring and timely introduction of newer-generation therapies.

Prognostic Factors and Survival of Chinese Patients with Cardiac Amyloidosis

Purpose

To identify the survival and prognostic factors for cardiac amyloidosis (CA) in Chinese patients.

Methods

This was a prospective cohort study of 72 patients diagnosed with CA and admitted to the PLA General Hospital between November 2017 and April 2021. Demographic, clinical, laboratory, electrocardiographic, conventional ultrasound, endocardial LS during LV systole (LV ENDO LSsys), and myocardial strain data were recorded. Survival was assessed. All-cause mortality was the endpoint. Follow-up was censored on September 30, 2021.

Results

The mean follow-up was 17.1 ± 12.9 months. Among the 72 patients, 39 died, 23 survived, and 10 were lost to follow-up. Mean survival for all patients was 24.7 ± 2.2 months. Mean survival was 32.7 ± 2.4 months among patients with NYHA class II, 26.6 ± 3.4 months for NYHA class III, and 5.8 ± 1.1 months for NYHA class IV. The multivariate Cox proportional hazard regression model showed that NYHA class (HR = 3.42, 95% CI: 1.36-8.65, P = 0.002), log-proBNP level (HR = 1.40, 95% CI: 1.17-5.83, P = 0.03), and ENDO LSsys of the LV basal level (HR = 1.25, 95% CI: 1.05-1.95, P = 0.004) were independent prognostic factors for CA.

Conclusion

NYHA class, proBNP level, and ENDO LSsys of the LV basal level were independently associated with the survival of patients with CA.

Cardiac Amyloidosis

Amyloidosis is a pathologic and clinical condition resulting from the accumulation of insoluble aggregates of misfolded proteins in tissues. Extracellular deposition of amyloid fibrils in the myocardium leads to cardiac amyloidosis, which is often overlooked as a cause of diastolic heart failure. Although cardiac amyloidosis was previously believed to have a poor prognosis, recent advances in diagnosis and treatment have emphasized the importance of early recognition and changed management of this condition. This article provides an overview of cardiac amyloidosis and summarizes current screening, diagnosis, evaluation, and treatment options.

The short and long-term characteristics and outcomes of patients with grade 1 myocardial uptake on cardiac scintigraphy

AIMS

This study aimed to characterize the final diagnosis and prognosis of patients with grade 1 myocardial scintigraphy uptake, which is an unequivocal result for the diagnosis of transthyretin cardiac amyloidosis (ATTR-CA) requiring further invasive investigation with tissue biopsy.

METHODS AND RESULTS

We retrospectively compared the clinical and imaging parameters of patients suspected for ATTR-CA (based on clinical and echocardiographic parameters) with grade 1 vs. grades 2/3 technetium pyrophosphate uptake on cardiac scintigraphy. Prospectively, grade 1 patients underwent re-evaluation for ATTR-CA at long term. Of the 132 ATTR-CA suspected patients, 89 (67%) were diagnosed as grade 1 and 43 (33%) as grades 2/3 uptake. Grade 1 vs. grades 2/3 patients were younger and female predominant with lower biomarker levels and left ventricular mass. Based on available imaging and pathology findings, only 6 out of the 89 patients with grade 1 uptake (7%) were finally diagnosed with light-chain cardiac amyloidosis, whereas no patient was diagnosed with ATTR-CA. At 2 [interquartile range (IQR) 0.75, 3.25] years of follow-up, the survival of patients with grade 1 vs. grades 2/3 uptake was significantly better [hazard ratio 0.271 (95% confidence interval 0.130 to 0.563, P = 0.0005)]. Prospectively, 30 patients with grade 1 uptake were re-evaluated at a median follow-up of 3.2 (IQR 2.2, 3.9) years. Their New York Heart Association class, biomarker levels, and echocardiography findings remained stable. No patient (0/25) demonstrated grades 2/3 uptake at repeated long-term scintigraphy.

CONCLUSIONS

Patients with suspected ATTR-CA and a grade 1 scintigraphy uptake demonstrate a stable clinical, laboratory, imaging, and scintigraphy phenotype along with a benign survival profile at long-term follow-up. Larger studies should define the optimal evaluation strategy in this population.

Case Report and Literature Review of Cardiac Amyloidosis: A Not-So-Rare Cause of Heart Failure

Restrictive cardiomyopathy secondary to cardiac amyloidosis is an underdiagnosed cause of heart failure and it is associated with significant morbidity and mortality. The most common types of amyloidosis are light chain amyloidosis, transthyretin amyloidosis and secondary amyloidosis. We report the case of a 84-year-old man that presented with new onset signs and symptoms of heart failure. Multimodality imaging with echocardiogram and bone tracer cardiac scintigraphy along with biomarkers, monoclonal proteins analysis and genetic test allowed to diagnosed a wild-type transthyretin amyloidosis. We discuss the clinical and diagnostic features and review the current literature about cardiac amyloidosis. This paper aims to increase clinicians' awareness of cardiac amyloidosis to promptly recognize, diagnose and treat it.

Value of the HFA-PEFF and H2 FPEF scores in patients with heart failure and preserved ejection fraction caused by cardiac amyloidosis

AIMS

The HFA-PEFF and H₂ FPEF scores have been developed to diagnose heart failure with preserved ejection fraction (HFpEF), and hold prognostic value. Their value in patients with HFpEF caused by cardiac amyloidosis (CA) has never been investigated.

METHODS AND RESULTS

We evaluated the diagnostic and prognostic value of the HFA-PEFF and H₂ FPEF scores in 304 patients from three cohorts with HFpEF caused by transthyretin CA (n = 160, 53%) or immunoglobulin light-chain CA (n = 144, 47%). A diagnosis of HFpEF was more likely using the HFA-PEFF score with 2 (1%), 71 (23%), and 231 (76%) patients ranked as having a low (0-1), intermediate (2-4), or high (5, 6) probability of HFpEF, respectively. Conversely, 36 (12%), 179 (59%) and 89 (29%) of patients ranked as having a low (0-1), intermediate (2-5), or high (6-9) probability of HFpEF using the H₂ FPEF score. During a median follow-up of 19 months (interquartile range 8-40), 132 (43%) patients died. The HFA-PEFF score, but not the H₂ FPEF score, predicted a high risk of all-cause death which remained significant after adjustment for age, AL-CA diagnosis, high-sensitivity troponin T, N-terminal pro-B-type natriuretic peptide, and echocardiographic parameters, including left ventricular global longitudinal strain, left ventricular diastolic function and right ventricular function (hazard ratio 1.51, 95% confidence interval 1.16-1.95, p = 0.002 for every 1-point increase in HFA-PEFF).

CONCLUSIONS

The HFA-PEFF score has a higher diagnostic utility in HFpEF caused by CA and holds independent prognostic value for all-cause mortality, while the H₂ FPEF score does not.

Update on Disease-Specific Biomarkers in Transthyretin Cardiac Amyloidosis

PURPOSE OF REVIEW

Transthyretin cardiac amyloidosis (ATTR-CM) is an infiltrative cardiomyopathy and an increasingly recognized cause of morbidity and mortality. There remains substantial delay between initial symptoms and diagnosis. With the recent emergence of various targeted therapies proven to reduce morbidity and mortality, there is an imperative to diagnose subclinical disease. Biomarkers may be well-suited for this role.

RECENT FINDINGS

Conventional markers of heart failure, such as natriuretic peptides and cardiac troponins, and estimated glomerular filtration rate are associated with risk in ATTR-CM. Circulating transthyretin (TTR) levels parallel TTR kinetic stability, correlate with disease severity, and may serve as indirect markers of ATTR-CM disease activity and response to targeted treatment. There is also growing evidence for the correlation of TTR to retinol-binding protein 4, a biomarker which independently associates with this disease. The rate-limiting step for ATTR pathogenesis is dissociation of the TTR homotetramer, which may be quantified using subunit exchange to allow for early risk assessment, prognostication, and assessment of treatment response. The protein species that result from the dissociation and misfolding of TTR are known as nonnative transthyretin (NNTTR). NNTTR is quantifiable via peptide probes and is a specific biomarker whose reduction is positively correlated with improvement in neuropathic ATTR amyloidosis. Neurofilament light chain (NfL) is released into the blood after axonal damage and correlates with neuropathic ATTR amyloidosis, but its clinical use in ATTR-CM is uncertain. Conventional markers of heart failure, transthyretin, retinol-binding protein 4, transthyretin kinetic stability, nonnative transthyretin, peptide probes, and neurofilament light chain have potential as biomarkers to enable early, subclinical diagnosis in patients with transthyretin cardiac amyloidosis.

Multimodality imaging in cardiac amyloidosis: State-of-the-art review

Amyloidosis is a systemic disease, characterized by deposition of amyloid fibrils in various organs, including the heart. For the diagnosis of cardiac amyloidosis (CA) it is required a high level of clinical suspicion and in the presence of clinical, laboratorial, and electrocardiographic red flags, a comprehensive multimodality imaging evaluation is warranted, including echocardiography, magnetic resonance, scintigraphy, and computed tomography, that will confirm diagnosis and define the CA subtype, which is of the utmost importance to plan a treatment strategy. We will review the use of multimodality imaging in the evaluation of CA, including the latest applications, and a practical flow-chart will sum-up this evidence.

Clinical Profile and Prognosis of Hereditary Transthyretin Amyloid Cardiomyopathy: A Single-Center Study in South China

Background

Hereditary transthyretin amyloid cardiomyopathy (ATTR-CM) is a genotypically heterogeneous disorder with a poor prognosis. There is limited literature describing the variants responsible for ATTRv in areas outside the United State, the United Kingdom and Europe. This study was performed to describe the clinical characteristics and genotypic profiles of this disease in South China.

Methods

This was a single-center retrospective study that evaluated 29 patients with a confirmed diagnosis of hereditary transthyretin amyloid cardiomyopathy enrolled from January 2016 to November 2021.

Results

93.1% patients were male and the median age of symptom onset was 53 (46, 62.5) years old. The initial manifestations of ATTR-CM were cardiovascular symptoms (55.2%), neuropathy (41.4%) and vitreous opacity (3.4%). Phenotypes at diagnosis were mixed (82.8%), predominant cardiac (6.9%), neurological (6.9%) and ophthalmic (3.4%). Poor R-wave progression (41%), pseudo-infarct (31%) and low-voltage (31%) patterns were common findings on electrocardiogram. Unexplained increased wall thickness was observed in all 29 patients, with mean septal and posterior wall thicknesses of 14.25 ± 6.26 mm and 15.34 ± 2.84 mm, respectively. Diastolic dysfunction was also seen in all 29 patients, and 17 (58%) had a restrictive fill pattern at diagnosis. Nine different missense mutations of the TTR gene were found in 29 patients from 23 families, with c.349G>T (p.Ala117Ser) the most common mutation. The median survival time after diagnosis was 47.6 (95% CI 37.9-57.4) months, with 1, 3 and 5-year survival rates of 91.2%, 74% and 38% respectively. Patients with advanced heart failure (National Amyloidosis Staging stage II/III) had worse survival than stage I [Breslow (Generalized Wilcoxon), χ2 = 4.693, P = 0.03)].

Conclusions

ATTR amyloidosis genotypes and phenotypes are highly heterogeneous. Advanced heart failure predicts a poor prognosis. Understanding the different clinical profiles of ATTR cardiac amyloidosis with different genotype is important to its early recognition.

Transthyretin Amyloid Cardiomyopathy: Impact of Transthyretin Amyloid Deposition in Myocardium on Cardiac Morphology and Function

Background: Transthyretin (TTR) amyloid cardiomyopathy (ATTR-CM) is increasingly being recognized as a cause of left ventricular (LV) hypertrophy (LVH) and progressive heart failure in elderly patients. However, little is known about the cardiac morphology of ATTR-CM and the association between the degree of TTR amyloid deposition and cardiac dysfunction in these patients. Methods: We studied 28 consecutive patients with ATTR-CM and analyzed the relationship between echocardiographic parameters and pathological features using endomyocardial biopsy samples. Results: The cardiac geometries of patients with ATTR-CM were mainly classified as concentric LVH (96.4%). The relative wall thickness, a marker of LVH, tended to be positively correlated with the degree of non-cardiomyocyte area. The extent of TTR deposition was positively correlated with enlargement of the non-cardiomyocyte area, and these were positively correlated with LV diastolic dysfunction. Additionally, the extent of the area containing TTR was positively correlated with the percentage of cardiomyocyte nuclei stained for 8-hydroxy-2′deoxyguanosine, a marker of reactive oxygen species (ROS). ROS accumulation in cardiomyocytes was positively correlated with LV systolic dysfunction. Conclusion: Patients with ATTR-CM mainly displayed concentric LVH geometry. TTR amyloid deposition was associated with cardiac dysfunction via increased non-cardiomyocyte area and ROS accumulation in cardiomyocytes.

The revolution of ATTR amyloidosis in cardiology: certainties, gray zones and perspectives

Transthyretin (TTR) is a tetrameric protein synthesized mostly by the liver. As a result of gene mutations or as an ageing-related phenomenon, TTR molecules may misfold and deposit in the heart and in other organs as amyloid fibrils. Amyloid transthyretin cardiac amyloidosis (ATTR-CA) manifests typically as left ventricular pseudohypertrophy and/or heart failure with preserved ejection fraction and is an underdiagnosed disorder affecting quality of life and prognosis. This justifies the current search for novel tools for early diagnosis and accurate risk prediction, as well as for safe and effective therapies. In this review we will provide an overview of the main unsolved issues and the most promising research lines on ATTR-CA, ranging from the mechanisms of amyloid formation to therapies.

A Risk Score to Diagnose Cardiac Involvement and Provide Prognosis Information in Patients at Risk of Cardiac Light-Chain Amyloidosis

Background

Cardiac light-chain amyloidosis (AL CA) portends poor prognosis. Contrast cardiac magnetic resonance (CMR) with late gadolinium enhancement (LGE) imaging is an important tool in recognizing AL CA. But contraindications to contrast CMR would significantly restrict its clinical application value. Our study aims to construct a convenient risk score to help identify cardiac involvement in patients at risk of AL CA. Moreover, we also investigate whether this risk score could provide prognosis information.

Materials and Methods

Sixty-three patients at risk of AL CA were retrospectively included in our study. Basic clinical characters, lab results, 12-lead electrocardiogram data, and cardiac magnetic resonance image data were collected. AL CA was diagnosed according to typical CA LGE pattern. Logistic analysis was used to figure out predictive parameters of AL CA and their β coefficients, further constructing the risk score. Receiver operating characteristics (ROC) curve was used to find the cut-off point best distinguishing AL CA+ from AL CA–patients. Bootstrapping was used for internal validation. All patients were divided into high-risk and low-risk group according to the diagnostic cut-off point, and followed up for survival information. Kaplan-Meier plots and log-rank test were performed to analyze if this score had prognostic value.

Results

The risk score finally consisted of 4 parameters: pericardial effusion (PE) (1 point), low electrocardiographic QRS voltages (LQRSV) (1 point), CMR-derived impaired global radial strain (GRS) (<15.14%) (1 point) and increased left ventricular maximum wall thickness (LVMWT) (>13 mm) (2 points). Total score ranged from 0 to 5 points. A cut-off point of 1.5 showed highest accuracy in diagnosing AL CA with an AUC of 0.961 (95% CI: 0.924–0.997, sensitivity: 90.6%, specificity: 83.9%). Kaplan-Meier plots and log-rank test showed that the high-risk group had significantly poor overall survival rates.

Conclusion

In patients at risk of AL CA, a risk score incorporating the presence of PE, LQRSV, and CMR-derived impaired GRS and increased LVMWT is predictive of a diagnosis of AL CA by LGE criteria. This risk score may be helpful especially when contrast CMR is not available or contraindicated, and further studies should be considered to validate this score.

Targeted therapies in genetic dilated and hypertrophic cardiomyopathies: From molecular mechanisms to therapeutic targets

Genetic cardiomyopathies are disorders of the cardiac muscle, most often explained by pathogenic mutations in genes encoding sarcomere, cytoskeleton, or ion channel proteins. Clinical phenotypes such as heart failure and arrhythmia are classically treated with generic drugs, but aetiology‐specific and targeted treatments are lacking. As a result, cardiomyopathies still present a major burden to society, and affect many young and older patients. The Translational Committee of the Heart Failure Association (HFA) and the Working Group of Myocardial Function of the European Society of Cardiology (ESC) organized a workshop to discuss recent advances in molecular and physiological studies of various forms of cardiomyopathies. The study of cardiomyopathies has intensified after several new study setups became available, such as induced pluripotent stem cells, three‐dimensional printing of cells, use of scaffolds and engineered heart tissue, with convincing human validation studies. Furthermore, our knowledge on the consequences of mutated proteins has deepened, with relevance for cellular homeostasis, protein quality control and toxicity, often specific to particular cardiomyopathies, with precise effects explaining the aberrations. This has opened up new avenues to treat cardiomyopathies, using contemporary techniques from the molecular toolbox, such as gene editing and repair using CRISPR‐Cas9 techniques, antisense therapies, novel designer drugs, and RNA therapies. In this article, we discuss the connection between biology and diverse clinical presentation, as well as promising new medications and therapeutic avenues, which may be instrumental to come to precision medicine of genetic cardiomyopathies.

Cardiovascular involvement in patients affected by multiple myeloma: a comprehensive review of recent advances

INTRODUCTION

Multiple Myeloma (MM) is hematological neoplasia originating from plasma cells, which accounts for almost 1% of all oncologic malignancies. The median age of patients at diagnosis is about 65 years old and over. In this age group, cardiovascular (CV) diseases often co-exist, increasing the risk of adverse events related to MM treatment. A comprehensive search on the main educational platforms was performed and high-quality original articles and reviews were included.

AREAS COVERED

Patients affected by MM are at risk for heart failure, uncontrolled systemic hypertension, accelerated ischemic heart disease, arterial/venous thromboembolism, and arrhythmias. These complications may be due to the effects of chemotherapy on the CV system, which may play on preexisting risk factors, and amyloid deposition at cardiac level.

EXPERT OPINION

This review provides an updated overview of the spectrum of CV diseases that may affect MM patients, highlighting possible treatment strategies according to the latest recommendations. Cooperation between onco-hematologist and cardiologist is crucial in managing this population, in particular for adequate risk assessment, early diagnosis of CV complications, and proper treatment.

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.

Integration of imaging and circulating biomarkers in heart failure: a consensus document by the Biomarkers and Imaging Study Groups of the Heart Failure Association of the European Society of Cardiology

Circulating biomarkers and imaging techniques provide independent and complementary information to guide management of heart failure (HF). This consensus document by the Heart Failure Association (HFA) of the European Society of Cardiology (ESC) presents current evidence-based indications relevant to integration of imaging techniques and biomarkers in HF. The document first focuses on application of circulating biomarkers together with imaging findings, in the broad domains of screening, diagnosis, risk stratification, guidance of treatment and monitoring, and then discusses specific challenging settings. In each section we crystallize clinically relevant recommendations and identify directions for future research. The target readership of this document includes cardiologists, internal medicine specialists and other clinicians dealing with HF patients.