Utility of Biomarkers in Cardiac Amyloidosis

Prognostic value of plasma big endothelin-1 in patients with light chain cardiac amyloidosis

BACKGROUND

Light chain cardiac amyloidosis (AL-CA) is associated with a high incidence of mortality. Big endothelin-1 (ET-1), the precursor of endothelial-vasoconstrictive ET-1, is closely related to the concentration of bioactive ET-1. Association between big ET-1 and prognosis of AL-CA has not yet been documented. The purpose of this study was to evaluate the prognostic value of big ET-1 for poor outcomes in moderate to severe AL-CA.

METHODS

Big ET-1 levels were determined on admission in patients with newly diagnosed AL-CA with modified Mayo 2004 stage II or III. Primary outcome was all-cause mortality. The secondary outcomes included death from cardiac cause and the composite of the primary outcome or hospitalisations due to worsening heart failure.

RESULTS

Overall, 141 patients were retrospectively included (57 stage II, 34 stage IIIa, 50 stage IIIb). During a median follow-up time of 25.7 months, 84 (59.6%) patients died. Patients with big ET-1 levels of ≤0.88 pmol/L had longer survival than those with >0.88 pmol/L (median survival time: 34.1 months vs 15.3 months, log-rank p<0.001), which was also observed in the validation cohort (log-rank p=0.026). Higher big ET-1 levels were predictive for all-cause mortality after multivariable adjustment (HR 1.91, 95% CI 1.05 to 3.49, p=0.035). Big ET-1 levels added an incremental prognostic value over modified Mayo 2004 stage (C-index: from 0.671 to 0.696, p=0.025; integrated discrimination improvement 0.168, p=0.047).

CONCLUSIONS

Big ET-1 is a strong and independent predictor of mortality in patients with moderate to severe AL-CA, which may indicate a possible role for risk stratification in patients with this disease.

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.

Late gadolinium enhanced cardiac MR derived radiomics approach for predicting all-cause mortality in cardiac amyloidosis: a multicenter study

OBJECTIVES

To evaluate the prognostic value of radiomics features based on late gadolinium enhancement (LGE) cardiac magnetic resonance (CMR) images in patients with cardiac amyloidosis (CA).

METHODS

This retrospective study included 120 CA patients undergoing CMR at three institutions. Radiomics features were extracted from global and three different segments (base, mid-ventricular, and apex) of left ventricular (LV) on short-axis LGE images. Primary endpoint was all-cause mortality. The predictive performance of the radiomics features and semi-quantitative and quantitative LGE parameters were compared by ROC. The AUC was used to observe whether Rad-score had an incremental value for clinical stage. The Kaplan-Meier curve was used to further stratify the risk of CA patients.

RESULTS

During a median follow-up of 12.9 months, 30% (40/120) patients died. There was no significant difference in the predictive performance of the radiomics model in different LV sections in the validation set (AUCs of the global, basal, middle, and apical radiomics model were 0.75, 0.77, 0.76, and 0.77, respectively; all p > 0.05). The predictive performance of the Rad-score of the base-LV was better than that of the LGE total enhancement mass (AUC:0.77 vs. 0.54, p < 0.001) and LGE extent (AUC: 0.77 vs. 0.53, p = 0.004). Rad-score combined with Mayo stage had better predictive performance than Mayo stage alone (AUC: 0.86 vs. 0.81, p = 0.03). Rad-score (≥ 0.66) contributed to the risk stratification of all-cause mortality in CA.

CONCLUSIONS

Compared to quantitative LGE parameters, radiomics can better predict all-cause mortality in CA, while the combination of radiomics and Mayo stage could provide higher predictive accuracy.

CLINICAL RELEVANCE STATEMENT

Radiomics analysis provides incremental value and improved risk stratification for all-cause mortality in patients with cardiac amyloidosis.

KEY POINTS

• Radiomics in LV-base was superior to LGE semi-quantitative and quantitative parameters for predicting all-cause mortality in CA. • Rad-score combined with Mayo stage had better predictive performance than Mayo stage alone or radiomics alone. • Rad-score ≥ 0.66 was associated with a significantly increased risk of all-cause mortality in CA patients.

Diagnostic and Prognostic Value of Non-late Gadolinium Enhancement Cardiac Magnetic Resonance Parameters in Cardiac Amyloidosis

Early diagnosis is crucial for the improvement of outcomes of patients with cardiac amyloidosis (CA). Emerging non-late gadolinium enhancement (LGE) based cardiac magnetic resonance (CMR) parameters may facilitate early identification of CA. We sought to investigate the diagnostic and prognostic value of T1, T2 mapping and extracellular volume (ECV) in CA. This single-center prospective analysis included 88 patients with CA, 33 patients with aortic stenosis (AS) and left ventricular hypertrophy (LVH), and 15 healthy controls who completed 3T cardiac MRI at the time of their diagnosis and were assessed with T1, T2 (modified Look-Locker inversion recovery), and ECV mapping of the heart and spleen. Echocardiographic, and biochemical parameters and clinical characteristics and outcomes were collected and analyzed. Of the patients with CA, 71 had light-chain (AL) and 17 had transthyretin (ATTR) amyloidosis. Native T1, native T2 and ECV were significantly higher in patients with CA compared to both patients with LVH-AS (P<0.001) and healthy controls (P<0.001). Good diagnostic accuracy was also demonstrated by measuring the area under the curve (AUC) of the receiver operating characteristic (ROC) curves for native T1 in the region of interest (ROI) (AUC=0.90), native T2 ROI (AUC=0.88), and ECV (AUC=0.90). Furthermore, native T1 ROI, native T2 ROI and ECV, correlated with both NT-proBNP levels and Mayo stage of patients (with AL). Spleen ECV was significantly increased in patients with AL versus ATTR amyloidosis (38.5 vs 30.5; P=0.004) and demonstrated good diagnostic accuracy in differentiating between the two types (AUC=0.79). Native T2 ROI was prognostic of mortality in AL CAwith a HR of 1.97 per 5 ms increase (P=0.001) and remained prognostic after adjustment for age, and Mayo stage. Non-LGE based CMR techniques correlated with established markers of disease and demonstrated good diagnostic accuracy, while native T2 ROI was also prognostic of mortality, thus reinforcing their use in the diagnosis and prognosis of CA.

Recent Advances in Serum Biomarkers for Risk Stratification and Patient Management in Cardio-Oncology

PURPOSE OF REVIEW

Following significant advancements in cancer therapeutics and survival, the risk of cancer therapy-related cardiotoxicity (CTRC) is increasingly recognized. With ongoing efforts to reduce cardiovascular morbidity and mortality in cancer patients and survivors, cardiac biomarkers have been studied for both risk stratification and monitoring during and after therapy to detect subclinical disease. This article will review the utility for biomarker use throughout the cancer care continuum.

RECENT FINDINGS

A recent meta-analysis shows utility for troponin in monitoring patients at risk for CTRC during cancer therapy. The role for natriuretic peptides is less clear but may be useful in patients receiving proteasome inhibitors. Early studies explore use of myeloperoxidase, growth differentiation factor 15, galectin 3, micro-RNA, and others as novel biomarkers in CTRC. Biomarkers have potential to identify subclinical CTRC and may reveal opportunities for early intervention. Further research is needed to elucidate optimal biomarkers and surveillance strategies.

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 importance of pathways to facilitate early diagnosis and treatment of patients with cardiac amyloidosis

Cardiac amyloidosis (CA) is a condition caused by extracellular deposition of amyloid fibrils in the heart. It is an underdiagnosed disease entity which can present with a variety of cardiac and non-cardiac manifestations. Diagnosis usually follows an initial suspicion based on clinical evaluation or imaging findings before confirmation with subsequent imaging (echocardiography, cardiac magnetic resonance imaging, 3,3-diphosphono-1,2-propanodicarboxylic acid scintigraphy) in combination with biochemical screening for monoclonal dyscrasia (serum free light chains and serum and urine electrophoresis) and/or histology (bone marrow trephine, fat or endomyocardial biopsy). More than 95% of CA can be classified as either amyloid light-chain (AL) CA or amyloid transthyretin (ATTR) CA; these two conditions have very different management strategies. AL-CA, which may be associated with multiple myeloma, can be managed with chemotherapy agents, autologous stem cell transplantation, cardiac transplant and supportive therapies. For ATTR-CA, there is increasing importance in making an early diagnosis because of novel treatments in development, which have transformed this once incurable disease to a potentially treatable disease. Timely diagnosis is crucial as there may only be a small window of opportunity where patients can benefit from treatment beyond which therapies may be less effective. Reviewing the existing patient pathway provides a basis to better understand the complexities of real-world activities which may be important to help reduce missed opportunities related to diagnosis and treatment for patients with CA. With healthcare provider interest in improving the care of patients with CA, the development of an optimal care pathway for the condition may help reduce delays in diagnosis and treatment and thus enhance patient outcomes.

Evolving trends in epidemiology and natural history of cardiac amyloidosis: 30-year experience from a tertiary referral center for cardiomyopathies

Objective

Natural history of cardiac amyloidosis (CA) is poorly understood. We aimed to examine the changing mortality of different types of CA over a 30-year period.

Patients and methods

Consecutive patients included in the "Trieste CA Registry" from January 1, 1990 through December 31, 2021 were divided into a historical cohort (diagnosed before 2016) and a contemporary cohort (diagnosed after 2016). Light chain (AL), transthyretin (ATTR) and other forms of CA were defined according to international recommendations. The primary and secondary outcome measures were all-cause mortality and cardiac death, respectively.

Results

We enrolled 182 patients: 47.3% AL-CA, 44.5% ATTR-CA, 8.2% other etiologies. The number of patients diagnosed with AL and ATTR-CA progressively increased over time, mostly ATTR-CA patients (from 21% before 2016 to 67% after 2016) diagnosed non-invasively. The more consistent increase in event-rate was observed in the long-term (after 50 months) in ATTR-CA compared to the early increase in mortality in AL-CA. In the contemporary cohort, during a median follow up of 16 [4-30] months, ATTR-CA was associated with improved overall and cardiac survival compared to AL-CA. At multivariable analysis, ATTR-CA (HR 0.42, p = 0.03), eGFR (HR 0.98, p = 0.033) and ACE-inhibitor therapy (HR 0.24, p < 0.001) predicted overall survival in the contemporary cohort.

Conclusion

Incidence and prevalence rates of ATTR-CA and, to a less extent, of AL-CA have been increasing over time, with significant improvements in 2-year survival of ATTR-CA patients from the contemporary cohort. Reaching an early diagnosis and starting disease-modifying treatments will improve long-term survival in CA.

Transthyretin cardiac amyloidosis

Transthyretin cardiac amyloidosis (ATTR-CA) is an increasingly recognized cause of heart failure (HF) and mortality worldwide. Advances in non-invasive diagnosis, coupled with the development of effective treatments, have shifted ATTR-CA from a rare and untreatable disease to a relatively prevalent condition that clinicians should consider on a daily basis. Amyloid fibril formation results from age-related failure of homoeostatic mechanisms in wild-type ATTR (ATTRwt) amyloidosis (non-hereditary form) or destabilizing mutations in variant ATTR (ATTRv) amyloidosis (hereditary form). Longitudinal large-scale studies in the United States suggest an incidence of cardiac amyloidosis in the contemporary era of 17 per 100 000, which has increased from a previous estimate of 0.5 per 100 000, which was almost certainly due to misdiagnosis and underestimated. The presence and degree of cardiac involvement is the leading cause of mortality both in ATTRwt and ATTRv amyloidosis, and can be identified in up to 15% of patients hospitalized for HF with preserved ejection fraction. Associated features, such as carpal tunnel syndrome, can preceed by several years the development of symptomatic HF and may serve as early disease markers. Echocardiography and cardiac magnetic resonance raise suspicion of disease and might offer markers of treatment response at a myocardial level, such as extracellular volume quantification. Radionuclide scintigraphy with 'bone' tracers coupled with biochemical tests may differentiate ATTR from light chain amyloidosis. Therapies able to slow or halt ATTR-CA progression and increase survival are now available. In this evolving scenario, early disease recognition is paramount to derive the greatest benefit from treatment.

Biomarkers in heart failure: Relevance in the clinical practice

Early detection and risk stratification of patients with heart failure (HF) are crucial to improve outcomes. Given the complexity of the pathophysiological processes of HF and the involvement of multi-organ systems in different stages of HF, clinical prognostication of HF can be challenging. In this regard, several biomarkers have been investigated for diagnosis, screening, and risk stratification of HF patients. These biomarkers can be classified as biomarkers of myocardial stretch such as B-type natriuretic peptide, biomarkers of neurohormonal activation, biomarkers of inflammation and oxidative stress and biomarkers of cardiac hypertrophy, fibrosis and remodeling. In this paper, we summarize current evidence supporting the use of selected biomarkers in HF. We review their diagnostic, prognostic and therapeutic role in the management of HF. We also discuss potential factors limiting the use of these novel biomarkers in the clinical practice and highlight the challenges of adopting a multi-biomarker strategy.

Incidence and Risk Factors for Pacemaker Implantation in Light Chain and Transthyretin Cardiac Amyloidosis

AIMS

The incidence and risk factors of pacemaker (PM) implantation in patients with cardiac amyloidosis (CA) are largely unexplored. We sought to characterise the trends in the incidence of permanent PM and to identify baseline predictors of future PM implantation in light chain (AL) and transthyretin (ATTR) CA.

METHODS AND RESULTS

Consecutive patients with AL and ATTR-CA diagnosed at participating Centres (2017-2020) were included. Clinical data recorded within ±1 month from diagnosis were collected from electronic medical records. The primary study outcome was the need for clinically-indicated PM implantation. Patients with PM (n = 41) and/or permanent defibrillator in situ (n = 13) at CA diagnosis were excluded. The study population consisted of 405 patients: 29.4% AL, 14.6% variant ATTR and 56% wild-type ATTR; 82.5% were males, median age 76 years. During a median follow-up of 33 months (interquartile range 21-46), 36 (8.9%) patients experienced the primary outcome: 10 AL-CA, 2 variant ATTR-CA and 24 wild-type ATTR-CA (p = 0.08 at time-to-event analysis). At multivariable analysis, history of atrial fibrillation (hazard ratio [HR] 3.80, p = 0.002), PR interval (HR 1.013, p = 0.002) and QRS >120 ms (HR 4.7, p = 0.001) on baseline ECG were independently associated with PM implantation. The absence of these 3 factors had a negative predictive value of 92% with an area under the curve of 91.8% at 6 months.

CONCLUSION

In a large cohort of AL and ATTR-CA patients, 8.9% implanted a PM in the 3 years following diagnosis. History of atrial fibrillation, PR >200 ms and QRS >120 ms predicted future PM implantation.

New Advanced Imaging Parameters and Biomarkers-A Step Forward in the Diagnosis and Prognosis of TTR Cardiomyopathy

Transthyretin amyloid cardiomyopathy (ATTR-CM) is an infiltrative disorder characterized by extracellular myocardial deposits of amyloid fibrils, with poor outcome, leading to heart failure and death, with significant treatment expenditure. In the era of a novel therapeutic arsenal of disease-modifying agents that target a myriad of pathophysiological mechanisms, timely and accurate diagnosis of ATTR-CM is crucial. Recent advances in therapeutic strategies shown to be most beneficial in the early stages of the disease have determined a paradigm shift in the screening, diagnostic algorithm, and risk classification of patients with ATTR-CM. The aim of this review is to explore the utility of novel specific non-invasive imaging parameters and biomarkers from screening to diagnosis, prognosis, risk stratification, and monitoring of the response to therapy. We will summarize the knowledge of the most recent advances in diagnostic, prognostic, and treatment tailoring parameters for early recognition, prediction of outcome, and better selection of therapeutic candidates in ATTR-CM. Moreover, we will provide input from different potential pathways involved in the pathophysiology of ATTR-CM, on top of the amyloid deposition, such as inflammation, endothelial dysfunction, reduced nitric oxide bioavailability, oxidative stress, and myocardial fibrosis, and their diagnostic, prognostic, and therapeutic implications.

Light-chain cardiac amyloidosis: a case report of extraordinary sustained pathological response to cyclophosphamide, bortezomib, and dexamethasone combined therapy

Background

Heart involvement represents the most ominous prognostic factor in light-chain amyloidosis (AL), often foreclosing curative therapies such as high-dose chemotherapy followed by autologous stem cell transplantation (ASCT). Heart transplantation (HTx) may be considered before ASCT in rigorously selected cases of advanced AL cardiac amyloidosis (CA). In ASCT-ineligible patients, chemotherapy with cyclophosphamide, bortezomib, and dexamethasone combined (CyBorD) regimen, even at low-dose, is feasible and effective in obtaining hematological and organ response.

Case Summary

A previously healthy 50-year-old woman presented with severely symptomatic new-onset heart with preserved ejection fraction, significant cardiac hypertrophy, and an ‘apical sparing’ pattern. Bone marrow and abdominal fat biopsy revealed AL amyloidosis due to a smouldering micromolecular λ-type myeloma with severe cardiac involvement, and the patient was judged a good candidate to HTx followed by ASCT. Despite fragile conditions, she tolerated a full course of low-dose combination therapy with bortezomib and was withdrawn from HTx list because of unexpected persistent complete hematologic response and major cardiac improvement. Disease remission was achieved in the long term (&gt;3 years).

Discussion

We report a case of exceptional persistent hematologic and cardiac response after CyBorD therapy in a patient with advanced AL-CA who left the transplantation lists (both HTx and ASCT). In ASCT-ineligible patients, chemotherapy with CyBorD regimen, even at low-dose, can lead to durable remission of the disease with excellent cardiac response.

Multimodal Imaging and Biomarkers in Cardiac Amyloidosis

Amyloidosis is a progressive infiltrative disease instigated by the extracellular deposition of amyloid fibrils in various organs such as the heart, kidney, and peripheral nerves. Cardiac amyloid deposits cause restrictive cardiomyopathy, leading to a poor prognosis in systemic amyloidosis. The most common etiologies of cardiac amyloidosis (CA) are immunoglobulin light chain deposits (AL-CA) and misfolded transthyretin deposits (ATTR-CA). In recent years, many developments have been accomplished in the field of diagnosis and treatment of CA. At present, ATTR-CA can be noninvasively diagnosed if the following two conditions are fulfilled in the setting of typical echocardiographic/cardiac MRI findings: (1) grade 2 or 3 myocardial uptake in bone scintigraphy confirmed by SPECT and (2) absence of monoclonal protein confirmed by serum-free light chain assay, and serum/urine protein electrophoresis with immunofixation test. Effective therapies are evolving in both types of CA (tafamidis for ATTR-CA and immunologic treatments for AL-CA). Thus, early suspicion and prompt diagnosis are crucial for achieving better outcomes. In this review, we have summarized the role of multimodal imaging (e.g., echocardiography, cardiac MRI, and bone scintigraphy) and biomarkers (e.g., troponin, BNP) in the diagnosis, risk stratification, and treatment monitoring of CA.

High Serum Carbohydrate Antigen (CA) 125 Level Is Associated With Poor Prognosis in Patients With Light-Chain Cardiac Amyloidosis

Background and Aims: Patients with light-chain cardiac amyloidosis (AL-CA) are characterized by high levels of serum carbohydrate antigen 125 (CA 125). However, studies have not explored the correlation between CA 125 and AL-CA. The aim of this study was to explore the clinical implications of an increase in CA 125 in patients with AL-CA.

Methods and Results: A total of 95 patients diagnosed with AL-CA at the Second Xiangya Hospital were enrolled in this study. Out of the 95 patients with AL-CA, 57 (60%) patients had elevated serum CA 125 levels. The mean age was 59.7 ± 10.0 years with 44 (77.2%) men in the high serum CA 125 group, and 61.8 ± 9.6 years with 28 (73.7%) men in the normal group. Patients with high CA 125 showed higher rates of polyserositis (79.3% vs. 60.5%, p = 0.03), higher levels of hemoglobin (117.4 ± 21.9 g/L vs. 106.08 ± 25.1 g/L, p = 0.03), serum potassium (4.11 ± 0.47 mmol/L vs. 3.97 ± 0.40 mmol/L, p = 0.049), low-density lipoprotein-cholesterol (3.0 ± 1.6 mmol/L vs. 2.3 ± 1.10 mmol/L, p = 0.01), and cardiac troponin T (96.0 pg/mL vs. 91.9 pg/mL, p = 0.005). The median overall survival times for patients with high or normal serum CA 125 were 5 and 25 months, respectively (p = 0.045). Multivariate Cox hazard analysis showed that treatment without chemotherapy (HR 1.694, 95% CI 1.121–2.562, p = 0.012) and CA 125 (HR 1.002, 95% CI 1.000–1.004, p = 0.020) was correlated with high all-cause mortality. The time-dependent receiver operating characteristic (t-ROC) curve showed that the prediction accuracy of CA 125 was not inferior to that of cardiac troponin T, N-terminal pro-B-type natriuretic peptide (NT-proBNP), and lactate dehydrogenase (LDH) based on the area under the curve.

Conclusions: CA 125 is a novel prognostic predictor. High serum CA 125 values are correlated with low overall survival, and the accuracy of predicting prognosis is similar to that of traditional biomarkers in AL-CA.

Congestive heart failure associated with POEMS syndrome that was adequately distinguished from cardiac amyloidosis: a case report and literature review

Congestive heart failure (CHF) is a common complication in patients with AL amyloidosis but is rare in another plasma cell dyscrasia, POEMS syndrome. A 52-year-old man developed POEMS syndrome with a solitary plasmacytoma complicated by CHF mimicking cardiac amyloidosis (CA). His neurological symptoms and CHF did not improve after radiotherapy (50 Gy) targeting the plasmacytoma. Based on typical findings of noninvasive examinations such as elevated serum NT-proBNP (12,631 pg/mL), a pseudo-infarct pattern on electrocardiography, interventricular septal thickening with a granular sparkling appearance and an apical sparing pattern of longitudinal strain on echocardiography, and late gadolinium enhancement of the left ventricular wall on cardiac magnetic resonance imaging (MRI), severe CA ineligible for autologous peripheral blood stem cell transplantation (auto-PBSCT) was strongly suspected. However, myocardial biopsy failed to reveal amyloid deposits, and CHF markedly improved after only one cycle of chemotherapy with melphalan and dexamethasone. Accordingly, CA was denied as the etiology of his heart failure, and the patient was finally diagnosed with POEMS syndrome. As a result, high-dose melphalan followed by auto-PBSCT improved his neurological symptoms. Careful evaluation is therefore needed to appropriately treat patients with POEMS syndrome complicated by CHF, even when the results of non-invasive examinations are typical for AL amyloidosis.

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.

Electrochemical Aptasensors: Current Status and Future Perspectives

This article reviews the progress of diversity of electrochemical aptasensor for target analytes detection. The immobilization strategies of aptamers on an electrode surface are addressed. The aptasensors are also introduced in compliance with the assay platforms. Many electrochemical aptasensors are nearly identical to conventional immunochemical approaches, sandwich and competition assays using electroactive signaling moieties. Others are "signal-on" and "sign-off" aptasensors credited to the target binding-induced conformational change of aptamers. Label-free aptasensors are also highlighted. Furthermore, the aptasensors applied for clinically important biomarkers are emphasized.

Transthyretin amyloid cardiomyopathy: An uncharted territory awaiting discovery

Transthyretin amyloid cardiomyopathy (ATTR-AC) is an under-recognized and underdiagnosed disease. Although traditionally considered a rare condition, the epidemiology of the disease is rapidly changing due to the possibility of non-invasive diagnosis through cardiac scintigraphy with bone tracers and novel disease-modifying treatments providing survival advantages. Nevertheless, many questions and grey areas have to be addressed, such as the natural history of ATTR-AC, the role and implications of genotype-phenotype interactions, the best clinical management, prognostic stratification and the most appropriate treatments, including those already recommended for patients with heart failure. Clinicians have to cope with old beliefs and evolving concepts in ATTR-AC. A wide horizon of possibilities for physicians of many specialties is unfolding and awaits discovery.