Heart rate variability as a predictor of mortality in patients with AA and AL amyloidosis

Arrhythmic Risk Stratification in Cardiac Amyloidosis: A Review of the Current Literature

Cardiac amyloidosis is the most frequent infiltrative disease caused by the deposition of misfolded proteins in the cardiac tissue, leading to heart failure, brady- and tachyarrhythmia and death. Conduction disorders, atrial fibrillation (AF) and ventricular arrhythmia (VA) significantly impact patient outcomes and demand recognition. However, several issues remain unresolved regarding early diagnosis and optimal management. Extreme bradycardia is the most common cause of arrhythmic death, while fast and sustained VAs can be found even in the early phases of the disease. Risk stratification and the prevention of sudden cardiac death are therefore to be considered in these patients, although the time for defibrillator implantation is still a subject of debate. Moreover, atrial impairment due to amyloid fibrils is associated with an increased risk of AF resistant to antiarrhythmic therapy, as well as recurrent thromboembolic events despite adequate anticoagulation. In the last few years, the aging of the population and progressive improvements in imaging methods have led to increases in the diagnosis of cardiac amyloidosis. Novel therapies have been developed to improve patients' functional status, quality of life and mortality, without data regarding their effect on arrhythmia prevention. In this review, we consider the latest evidence regarding the arrhythmic risk stratification of cardiac amyloidosis, as well as the available therapeutic strategies.

Electrocardiographic features and rhythm disorders in cardiac amyloidosis

Cardiac amyloidosis (CA) is an infiltrative cardiomyopathy caused by extracellular deposition of amyloid fibrils, mainly derived from transthyretin, either wild-type or hereditary variants, or immunoglobulin light chains misfolding. It is characterized by an increased left ventricular (LV) mass and diastolic dysfunction, which can lead to heart failure with preserved ejection fraction and/or conduction disturbances. The diagnosis is based on invasive pathology demonstration of amyloid deposits, or non-invasive criteria using advanced cardiovascular imaging techniques. Nevertheless, 12-lead electrocardiogram (ECG) remains of crucial importance in the assessment of patients with CA, since they can manifest peculiar features such as low QRS voltages, in discordance with the LV hypertrophy, but also pseudo-infarction patterns, sinus node dysfunction, atrioventricular blocks, premature supraventricular and ventricular beats, which support the presence of a myocardial disease. Great awareness of these common ECG characteristics of CA is needed to increase diagnostic performance and improve patient's outcome. In the present review, we discuss the current role of the ECG in the diagnosis and management of CA, focusing on the most common ECG abnormalities and rhythm disorders.

Autonomic control of ventricular function in health and disease: current state of the art

PURPOSE

Cardiac autonomic dysfunction is one of the main pillars of cardiovascular pathophysiology. The purpose of this review is to provide an overview of the current state of the art on the pathological remodeling that occurs within the autonomic nervous system with cardiac injury and available neuromodulatory therapies for autonomic dysfunction in heart failure.

METHODS

Data from peer-reviewed publications on autonomic function in health and after cardiac injury are reviewed. The role of and evidence behind various neuromodulatory therapies both in preclinical investigation and in-use in clinical practice are summarized.

RESULTS

A harmonic interplay between the heart and the autonomic nervous system exists at multiple levels of the neuraxis. This interplay becomes disrupted in the setting of cardiovascular disease, resulting in pathological changes at multiple levels, from subcellular cardiac signaling of neurotransmitters to extra-cardiac, extra-thoracic remodeling. The subsequent detrimental cycle of sympathovagal imbalance, characterized by sympathoexcitation and parasympathetic withdrawal, predisposes to ventricular arrhythmias, progression of heart failure, and cardiac mortality. Knowledge on the etiology and pathophysiology of this condition has increased exponentially over the past few decades, resulting in a number of different neuromodulatory approaches. However, significant knowledge gaps in both sympathetic and parasympathetic interactions and causal factors that mediate progressive sympathoexcitation and parasympathetic dysfunction remain.

CONCLUSIONS

Although our understanding of autonomic imbalance in cardiovascular diseases has significantly increased, specific, pivotal mediators of this imbalance and the recognition and implementation of available autonomic parameters and neuromodulatory therapies are still lagging.

Coefficient of R-R interval variations under deep breathing load in patients with wild-type transthyretin amyloid cardiomyopathy: A case-control study

BACKGROUND AND AIMS

An autonomic nervous disorder is an important characteristic of cardiac amyloidosis; however, the prevalence of autonomic dysfunction in wild-type transthyretin amyloidosis (ATTRwt) has not been established. Analysis of the R-R interval coefficient of variation (CVR-R) is a noninvasive method to measure parasympathetic activity. We aimed to assess autonomic dysfunction of ATTRwt and determine the utility of CVR-R for the detection of ATTRwt in other cardiac diseases.

METHODS

This is a single-center, retrospective, case-control study. Fifty patients with heart failure (HF) were studied. The etiologies of HF were as follows: ATTRwt, n = 10; previous myocardial infarction (MI), n = 20; and left ventricular hypertrophy (LVH) due to other disease processes (e.g., aortic stenosis), n = 20. We measured the CVR-R at rest (CVR-Rrest), CVR-R with deep breaths (CVR-Rbreath), and the change rate (CVR-Rdiff rate). The relative change formula is as follows: CVR-Rdiff rate = (CVR-Rbreath - CVR-Rrest)/CVR-Rrest×  100 (%).

RESULTS

There was no difference in the CVR-Rrest levels among the three groups. The CVR-Rdiff rate levels in the ATTRwt group were significantly lower (ATTRwt: -8.77 [-43.8 to 10.9]; LVH: 67.4 [38.7 to 89.4]; MI: 83.7 [60.4 to 142.9]). Based on the receiver operative characteristic curve analysis to identify ATTRwt in HF, the best cut-off value for the CVR-Rdiff rate was 19.7 (area under the curve: 0.848).

CONCLUSION

Our data suggested autonomic dysfunction in patients with ATTRwt. Measurement of the CVR-R in HF patients may be a convenient support tool for the detection of ATTRwt.

Generalised autonomic failure as a prognostic factor in systemic light-chain (AL) amyloidosis

BACKGROUND

In the present study, it was investigated whether autonomic dysfunction could predict prognosis in light-chain (AL) amyloidosis patients.

PATIENTS AND METHODS

Seventy-two patients with biopsy-proven AL amyloidosis were included and underwent an autonomic function test (AFT) between January 2016 and June 2019. Autonomic failure was evaluated using the Composite Autonomic Severity Score (CASS). Survival curves and the three-year overall survival (OS) rate were estimated using the Kaplan-Meier curve, and the Cox proportional hazards regression method was used to evaluate the variables that influenced survival.

RESULTS

Autonomic dysfunction was observed in 69 (96%) patients with AL amyloidosis, and the three-year OS rate was 67%. Generalised autonomic failure (GAF) was observed in 31 (43%) patients. In the Kaplan-Meier curve, the three-year OS rates in patients with sudomotor dysfunction or GAF were lower than that in control patients (35 vs. 84%, and 33 vs. 81%, respectively). In Cox proportional hazards regression model, female, bone marrow plasma cell percentage, left ventricular systolic dysfunction, and GAF were significant independent variables associated with survival.

CONCLUSION

The results of this study indicate that GAF on the AFT is an independent adverse prognostic factor for survival in AL amyloidosis patients.

Arrhythmic Sudden Cardiac Death and the Role of Implantable Cardioverter-Defibrillator in Patients with Cardiac Amyloidosis-A Narrative Literature Review

Cardiac amyloidosis (CA) is considered to be associated with an increased risk of sudden cardiac death (SCD) due to ventricular tachyarrhythmias and electromechanical dissociation. However, current arrhythmic risk stratification and the role of an implantable cardioverter-defibrillator (ICD) for primary prevention of SCD remains unclear. This article provides a narrative review of the literature on electrophysiological abnormalities in the context of ventricular arrhythmias in patients with CA and the role of ICD in terms of survival benefit in this group of patients.

Autonomic dysfunction in cardiac amyloidosis assessed by heart rate variability and heart rate turbulence

BACKGROUND

Cardiac amyloidosis (CA) is characterized by left ventricular hypertrophy (LVH) and autonomic nervous imbalance due to amyloid infiltration. However, autonomic dysfunction is often seen in heart failure (HF) with LVH from other etiologies. We aimed to characterize autonomic dysfunction in CA from other etiologies of LVH.

METHODS

Fifty-five HF patients with LVH (35 males, mean age 65 ± 16 years) were enrolled. LVH was defined as left ventricular mass index measured by echocardiography >95 g/m2 in women and 115 g/m2 in men. The etiology was as follows: amyloid light chain (AL)-CA, n = 14; hypertrophic cardiomyopathy, n = 21; and aortic stenosis (AS), n = 20. With the patient in a clinically stable condition, heart rate variability (HRV) and heart rate turbulence (HRT), which reflect autonomic dysfunction, were measured using Holter monitoring and compared among the three groups.

RESULTS

Brain natriuretic peptide levels, LVH severity, left ventricular ejection fraction, and tissue Doppler index E/e' did not differ among the three groups. However, severe abnormalities of HRV and HRT were obtained in AL-CA. In the ROC analysis to identify AL-CA in HF with LVH, the best cutoff value for standard deviation of all R-R intervals, standard deviation of the 5-min mean R-R intervals, turbulence onset, and turbulence slope were 68.5 ms (AUC: 0.865), 58.5 ms (AUC: 0.834), 0.25% (AUC: 0.813), and 1.00 ms/RR (AUC 0.736), respectively.

CONCLUSION

Autonomic dysfunction is a hallmark of AL-CA, and its noninvasive assessment by Holter monitoring may be a useful tool for differential diagnosis of HF with LVH.

Hereditary Transthyretin Amyloidosis: Clinical Presentation and Management Updates

Hereditary transthyretin amyloidosis, once a rare progressive neuropathy and/or cardiomyopathy, is now recognized with increasing worldwide frequency, various phenotypes, and over 130 gene mutations identified to date. This inherited disorder develops as a result of mutated transthyretin amyloid aggregation and systematic deposition throughout the body. With increasing knowledge about the pathophysiology of this disease, new disease-modifying therapies are being developed. In addition to slowing progression, these new agents were found to improve quality of life and reduce the severity of neuropathic symptoms. Two new gene-modifying therapies recently received Food and Drug Administration approval following the positive results from phase III trials. These include an antisense oligonucleotide, inotersen, and small interfering RNA, patisiran, which were reported to reduce the production of transthyretin and had promising safety profiles. Additional novel therapies are being explored with hopes to prolong survival. Therefore, early diagnosis of this treatable disorder has become increasingly important in clinical practice.

Trifascicular block as primary presentation of the cardiac amyloidosis; A rare case report

BACKGROUND

Amyloidosis is a severe systemic disorder produces by the accumulation of inappropriately amyloid deposition in tissues. Cardiac involvement, as a main type of amyloidosis, has a major impact on prognosis. We describe a biopsy-proven cardiac amyloidosis in an old man with unexpected presentation.

CASE REPORT

A 70-year-old man, with a complaint of severe weakness, lightheadedness, and lower limb paresthesia, was admitted to the emergency department. Electrocardiography revealed right bundle branch block and Trifascicular block. Echocardiography study showed a moderately increased thickness of left ventricular wall with concentric pattern as well. Laboratory investigations including serum and urine electrophoresis, and serum free light chain examination as immunofixation assay revealed that κ chains predominated over λ chains in a ratio of 3:2. Our patient with final diagnosis of amyloid light-chain (AL) amyloidosis underwent chemotherapy with melphalan combined with high-dose dexamethasone, CPHPC and monoclonal antibodies for 2 weeks.

CONCLUSION

It shows that rapid diagnosis of AL amyloidosis can enhance the prognosis. Applying an optimal strategy for the treatment leads to effective therapy, too.

Recent advances in the noninvasive strategies of cardiac amyloidosis

The heart, like any organ in the body, is susceptible to amyloid deposition. Although more than 30 types of protein can cause amyloidosis, only two types commonly deposit in the ventricular myocardium: amyloid light chain and amyloid transthyretin. Amyloid cardiomyopathy is usually a major determinant of patient outcomes, and the diagnosis of heart involvement can be often relatively under-diagnosed, owing to nonspecific presenting symptoms and signs at a subclinical stage. The diagnosis of cardiac amyloidosis is usually performed by endomyocardial biopsy; however, the invasive nature and related high-risk complications restrict its wide use in clinical settings. Recently, with the advent of innovative techniques used for evaluating cardiac amyloidosis, noninvasive methods become increasingly important, especially in earlier diagnosis, distinguishing typing, risk prediction and response to treatment. Here, we will review recent developments in the noninvasive methods used in the assessment of cardiac amyloidosis, focused on the laboratory biomarkers and imaging modalities.

Restrictive Cardiomyopathies: The Importance of Noninvasive Cardiac Imaging Modalities in Diagnosis and Treatment-A Systematic Review

Restrictive cardiomyopathy (RCM) is the least common among cardiomyopathies. It can be idiopathic, familial, or secondary to systematic disorders. Marked increase in left and/or right ventricular filling pressures causes symptoms and signs of congestive heart failure. Electrocardiographic findings are nonspecific and include atrioventricular conduction and QRS complex abnormalities and supraventricular and ventricular arrhythmias. Echocardiography and cardiac magnetic resonance (CMR) play a major role in diagnosis. Echocardiography reveals normal or hypertrophied ventricles, preserved systolic function, marked biatrial enlargement, and impaired diastolic function, often with restrictive filling pattern. CMR offering a higher spatial resolution than echocardiography can provide detailed information about anatomic structures, perfusion, ventricular function, and tissue characterization. CMR with late gadolinium enhancement (LGE) and novel approaches (myocardial mapping) can direct the diagnosis to specific subtypes of RCM, depending on the pattern of scar formation. When noninvasive studies have failed, endomyocardial biopsy is required. Differentiation between RCM and constrictive pericarditis (CP), nowadays by echocardiography, is important since both present as heart failure with normal-sized ventricles and preserved ejection fraction but CP can be treated by means of anti-inflammatory and surgical treatment, while the treatment options of RCM are dictated by the underlying condition. Prognosis is generally poor despite optimal medical treatment.

Amyloid cardiomyopathy

Amyloidosis is a heterogeneous group of diseases characterized by the deposition of amyloid. It is caused by extracellular deposition of insoluble fibrils with beta-pleated sheet configuration. The protein misfolding abnormalities result in amyloid fibrils and may manifest as primary, secondary, or familial amyloidosis. Amyloid deposition can occur in multiple organs (eg, heart, liver, kidney, skin, eyes, lungs, nervous system) resulting in a variety of clinical manifestations. Cardiac involvement can occur as part of a systemic disease or as a localized phenomenon. Cardiac involvement in all types of amyloidosis represents a major negative prognostic factor. Early diagnosis, multi-disciplinary cooperation and proper therapy are key aspects of care for patients with amyloid cardiomyopathy. Early diagnosis is crucial, especially in AL amyloidosis, as patients with advanced heart disease are unsuitable candidates for modern, effective hematological treatment including autologous stem cell transplantation. Despite signal development in diagnostics and therapy, the prognosis for patients with advanced cardiac involvement remains poor. This article is an overview of amyloidosis, providing information about the characteristics of cardiac amyloidosis, and present a structured approach to diagnosis, treatment and prognosis of this condition.

New and Evolving Concepts Regarding the Prognosis and Treatment of Cardiac Amyloidosis

Systemic amyloidoses are rare and proteiform diseases, caused by extracellular accumulation of insoluble misfolded fibrillar proteins. Prognosis is dictated by cardiac involvement, which is especially frequent in light chain (AL) and in transthyretin variants (ATTR, both mutated, (ATTRm), and wild-type, (ATTRwt)). Recently, ATTRwt has emerged as a potentially relevant cause of a heart failure with preserved ejection fraction (HFpEF). Cardiac amyloidosis is an archetypal example of restrictive cardiomyopathy, with signs and symptoms of global heart failure and diastolic dysfunction. Independent of the aetiology, cardiac amyloidosis is associated with left ventricular concentric "hypertrophy" (i.e. increased wall thickness), preserved (or mildly depressed) ejection fraction, reduced midwall fractional shortening and global longitudinal function, as well as evident diastolic dysfunction, up to an overly restrictive pattern of the left ventricular filling. Cardiac biomarkers such as troponins and natriuretic peptides are very robust and widely accepted diagnostic as well as prognostic tools. Owing to its dismal prognosis, accurate and early diagnosis is mandatory and potentially life-saving. Although pathogenesis is still not completely understood, direct cardiomyocyte toxicity of the amyloidogenic precursor proteins and/or oligomer aggregates adds on tissue architecture disruption caused by amyloid deposition. The clarification of mechanisms of cardiac damage is offering new potential therapeutic targets, and several treatment options with a relevant impact on prognosis are now available.

Heart rate variability--current diagnosis of the cardiac autonomic neuropathy. A review

BACKROUND

The autonomic nervous system is one of the major homeostatic regulatory systems of the body. Detection of cardiac autonomic neuropathy (CAN), reflected by reduced heart rate variability (HRV), is an independent adverse prognostic factor: sympathovagal balance failure with a sympathetic dominance is the main trigger for lethal arrhythmias and sudden death.

METHODS AND RESULTS

PubMed database based on original articles from 1983 to 2013 and the author´s clinical experience. This review covers the current status of the methodology and the clinical uses of HRV, especially in the field of internal medicine.

CONCLUSION

Heart rate variability is making a valuable contribution to the diagnosis of cardiovascular autonomic dysfunction and CAN. It can be assessed from short-term and long-term ECG recordings. It is one of the few methods that allow outpatient CAN diagnosis, monitoring the progress, therapeutic effect and evaluation of patient prognosis. It is used as an independent prognostic factor in combination with other recognized risk factors in risk stratifying after myocardial infarction. It is a unique method of CAN diagnosis particularly in diabetology. Its diagnostic and prognostic potential in other medical fields is being intensively explored.

Role of imaging in the diagnosis and management of patients with cardiac amyloidosis: state of the art review and focus on emerging nuclear techniques

Amyloidosis is an infiltrative disease characterized by deposition of amyloid fibrils within the extracellular tissue of one or multiple organs. Involvement of the heart, cardiac amyloidosis, is recognized as a common cause of restrictive cardiomyopathy and heart failure. The two major types of cardiac amyloidosis are cardiac amyloid light-chain (AL) and transthyretin-related cardiac amyloidosis (ATTR, mutant and wild types) (Nat Rev Cardiol 2010;7:398-408). While early recognition of cardiac amyloidosis is of major clinical importance, so is the ability to differentiate between subtypes. Indeed, both prognosis and therapeutic options vary drastically depending on the subtype. While endomyocardial biopsy with immunostaining is considered the gold standard, advances in imaging provide an attractive non-invasive alternative. Currently, electrocardiography, echocardiography, and cardiac magnetic resonance imaging are all used in the evaluation of cardiac amyloidosis with varying diagnostic and prognostic accuracy. Yet, none of these modalities can effectively differentiate the cardiac amyloid subtypes. Recent data with (99m)Tc-phosphate derivatives, previously used as bone seeking radioactive tracers, have shown promising results; these radiotracers selectively bind ATTR, but not AL subtype, and can differentiate subtypes with high diagnostic accuracy. This review will initially present the non-radionuclide imaging techniques and then focus on the radionuclide imaging techniques, particularly (99m)Tc-DPD and (99m)Tc-PYP, mechanism of action, performance and interpretation of the study, diagnostic accuracy, prognostic value, future clinical perspective, and outlook.

Cardiac amyloidosis: updates in diagnosis and management

Amyloidosis is a severe systemic disease. Cardiac involvement may occur in the three main types of amyloidosis (acquired monoclonal light-chain, hereditary transthyretin and senile amyloidosis) and has a major impact on prognosis. Imaging the heart to characterize and detect early cardiac involvement is one of the major aims in the assessment of this disease. Electrocardiography and transthoracic echocardiography are important diagnostic and prognostic tools in patients with cardiac involvement. Cardiac magnetic resonance imaging better characterizes myocardial involvement, functional abnormalities and amyloid deposition due to its high spatial resolution. Nuclear imaging has a role in the diagnosis of transthyretin amyloid cardiomyopathy. Cardiac biomarkers are now used for risk stratification and staging of patients with light-chain systemic amyloidosis. Different types of cardiac complications may occur, including diastolic followed by systolic heart failure, atrial and/or ventricular arrhythmias, conduction disturbances, embolic events and sometimes sudden death. Senile amyloid and hereditary transthyretin amyloid cardiomyopathy have better prognoses than light-chain amyloidosis. Cardiac treatment of heart failure is usually ineffective and is often poorly tolerated because of its hypotensive and bradycardiac effects. The three main types of amyloid disease, despite their similar cardiac appearance, have specific new aetiological treatments that may change the prognosis of this disease. Cardiologists should be aware of this disease to allow early treatment.

DETRENDED FLUCTUATION ANALYSES OF SHORT-TERM HEART RATE VARIABILITY IN SURGICAL INTENSIVE CARE UNITS

We examine the dynamics of complex physiologic fluctuations using methods developed very recently in statistical physics. The method based on detrended fluctuation analysis (DFA) has been used to investigate the profile of different types of physiologic states under long term (i.e., 24 hr) analysis of heart rate variability (HRV). In this paper, this method to investigate the output of central physiologic control system under short term (i.e., 1 hr) of HRV in surgical intensive care units (SICU). Electrocardiograph (ECG) signals lasting around 1 hr were collected from ten college student volunteers as group A. Ten computes-generates white noise signals as group B also provided ECG signals lasting around 1 hr. Finally, seventeen patients representing 37 cases undergoing different types of neurosurgery were studied as group C. From this group, 25 cases were selected from 15 patients with brain injury and 12 cases were selected from 2 patients with septicemia. Group A and B were used as high and low limits of baseline for comparison with pathologic states in the SICU. The a values of DFA of groups A, B, and C were 0.958 ± 0.034, 0.521 ± 0.010, and 0.815 ± 0.183, respectively. It was found that the α value of patients in the SICU was significantly lower (P < 0.05) than that of healthy volunteers and significantly higher (P < 0.05) than white noise signals. Hence, it can be concluded that α values based on the DFA statistical concept can clearly distinguish pathologic states in SICU patients from the healthy group and from white noise signals.

Cardiac amyloidosis responding to bortezomib: case report and review of literature

We report a case of a 53-year old patient with symptoms of congestive heart failure in whom a restrictive cardiomyopathy and a kappa-chain monoclonal gammopahty were diagnosed. Treatment with eight cycles of Bortezomib, a proteasome inhibitor, resulted in a significant regression of myocardial amyloid deposition and a notable clinical and hemodynamic improvement. Over the last few years, the management of cardiac amyloidosis has taken advantage of many of the advances of the chemotherapeutic regimens, as well as the wider availability of stem cell transplantation. The management of cardiac amyloidosis is also expected to evolve and improve with the better understanding of the specific mechanisms of amyloidogenesis and myocardial deposition. This will probably make certain molecules targeting specific sites in this process, as potentially effective and minimally toxic compared therapy with the currently used ones. In this article, we describe one of the first reported cases of cardiac amyloidosis, successfully treated with Bortezomib. We describe and discuss the mechanisms of action of Bortezomib and provide a detailed review of cardiac amyloidosis, from pathophysiology to diagnosis and treatment.

Heart rate variability and length of survival in hospice cancer patients

We examined the association between heart rate variability (HRV) and survival duration to evaluate the usefulness of HRV as a prognostic factor for hospice cancer patients. In terminally ill cancer patients who visited the Hospice clinic, we checked demographic data, Karnofsky performance scale (KPS), HRV, dyspnea, anorexia, as well as fasting blood glucose and total cholesterol. After following up their duration of survival, we examined meaningful prognostic factors for predicting life expectancy through the survival analysis. A total of 68 patients were included in final analysis. As KPS was lower, or when combined with dyspnea or anorexia, the survival duration was much shorter. HRV parameters except heart rate were all impaired in most patients. In particular, the group with mean heart rate of 100 or more beats per minute and the group with standard deviations of normal-to-normal R-R intervals (SDNN) of 21.3 ms (75 percentile) or less showed significantly shorter survival duration. The final multivariate analysis adjusting for age, gender, fasting blood glucose, and total cholesterol showed that KPS, dyspnea, anorexia, and SDNN were significant prognostic factors in survival duration. For the first time, we report that SDNN is a prognostic factor in terminal cancer patients.

Long-term TNF-alpha blockade in patients with amyloid A amyloidosis complicating rheumatic diseases

OBJECTIVE

To evaluate the effectiveness and safety of anti-tumor necrosis factor therapy in patients with amyloid A amyloidosis.

METHODS

Multicenter, controlled, dynamic prospective cohort study of 36 patients with amyloid A amyloidosis (94% kidney involvement) treated with anti-tumor necrosis factor agents (drug exposure of 102.97 patient-years). As an external control group, 35 propensity score-matched non-amyloid patients were chosen from the Base de Datos de Productos Biológicos de la Sociedad Española de Reumatología registry. The end points were kidney response and progression, anti-tumor necrosis factor continuation rate, patient survival, and adverse events.

RESULTS

At the end of follow-up, a kidney response was observed in 12 of 22 patients (54.5%) and a kidney progression was observed in 6 of 36 patients (17%). The kidney amyloidosis remained stable in 16 of 36 patients (44%). The level of acute phase reactants diminished but did not reach the normal level. The continuation rates of anti-tumor necrosis factor drugs among patients with amyloid A amyloidosis after 1, 2, 3, and 4 or more years were 80%, 80%, 61%, and 52%, respectively, comparable to controls. The 5-year cumulative survival of amyloid A amyloidosis cases was 90.6%, and the 10-year survival was 78.5%. In a multivariate Cox regression analysis, the duration of amyloidosis and the level of proteinuria at the onset of anti-tumor necrosis factor treatment were independent predictors of treatment failure, whereas the level of proteinuria was the only factor that predicts mortality. Most adverse events were similar in both groups, although the number of infections was 3 times higher in amyloid A amyloidosis cases.

CONCLUSION

Anti-tumor necrosis factor drugs are effective in treating amyloid A amyloidosis, although they might increase the risk of infection.

Cardiac amyloidosis: approaches to diagnosis and management

Amyloidosis is a clinical disorder caused by the extracellular deposition of misfolded, insoluble aggregated protein with a characteristic ss pleated sheet configuration that produces apple-green birefringence under polarized light when stained with Congo red dye. The spectrum of organ involvement can include the kidneys, heart, blood vessels, central and peripheral nervous systems, liver, intestines, lungs, eyes, skin, and bones. Cardiovascular amyloidosis can be primary, a part of systemic amyloidosis, or the result of chronic systemic disease elsewhere in the body. The most common presentations are congestive heart failure because of restrictive cardiomyopathy and conduction abnormalities. Recent developments in imaging techniques and extracardiac tissue sampling have minimized the need for invasive endomyocardial biopsy for amyloidosis. Cardiac amyloidosis management will vary depending on the subtype but consists of supportive treatment of cardiac related symptoms and reducing the amyloid fibrils formation attacking the underlying disease. Despite advances in treatment, the prognosis for patients with amyloidosis is still poor and depends on the underlying disease type. Early diagnosis of cardiac amyloidosis may improve outcomes but requires heightened suspicion and a systematic clinical approach to evaluation. Delays in diagnosis, uncertainties about the relative merits of available therapies, and difficulties in mounting large-scale clinical trials in rare disorders combine to keep cardiac amyloidosis a challenging problem. This review outlines current approaches to diagnosis, assessment of disease severity, and treatment of cardiac amyloidosis.

Evaluation and management of the cardiac amyloidosis

Cardiac amyloidosis describes clinically significant involvement of the heart by amyloid deposition, which may or may not be associated with involvement of other organs. The purpose of this review is to summarize the current state of evidence for the effective evaluation and management of cardiac amyloidosis. Acquired systemic amyloidosis occurs in more than 10 per million person-years in the U.S. population. Although no single noninvasive test or abnormality is pathognomonic of cardiac amyloid, case-control studies indicate that echocardiographic evidence of left ventricular wall thickening, biatrial enlargement, and increased echogenicity in conjunction with reduced electrocardiographic voltages is strongly suggestive of cardiac amyloidosis. Furthermore, newer echocardiographic techniques such as strain and strain rate imaging can demonstrate impairment in longitudinal function before ejection fraction becomes abnormal. Recent observational studies also suggest that cardiovascular magnetic resonance imaging yields characteristic findings in amyloidosis, offering promise for the early detection of cardiac involvement, and the presence of detectable cardiac troponin and elevated B-type natriuretic peptide in serum of affected patients portends an adverse prognosis. Management strategies for cardiac amyloid are largely based on nonrandomized single-center studies. One of the few published randomized studies shows the superiority of oral prednisolone and melphalan compared with colchicine in systemic AL amyloidosis. Intermediate-dose infusional chemotherapy regimes (such as vincristine, adriamycin, and dexamethasone) and high-dose chemotherapy with peripheral stem cell rescue have been used widely, but treatment-related mortality remains substantial with chemotherapy. Recent studies also indicate promising strategies to stabilize the native structures of amyloidogenic proteins; inhibit fibril formation; and disrupt established deposits using antibodies, synthetic peptides, and small-molecule drugs.

Regionally heterogeneous tissue mechanics in cardiac amyloidosis

OBJECTIVE

The goal of this study was to examine in vitro tissue stiffness and contractile performance in myocardial amyloidosis.

BACKGROUND

Primary systemic amyloidosis involves the deposition of amyloid protein in mesodermal tissues including the heart. Functional assessment of cardiac amyloidosis is usually performed using echocardiography. However, this technique does not involve assessment of preload-dependent contractile reserve (the Frank-Starling mechanism).

METHODS

At the time of heart transplantation, isolated myocardial trabeculae were dissected from the right ventricle of a patient with primary systemic amyloidosis. In vitro length-tension experiments were performed and trabeculae were subsequently fixed, sectioned and stained with crystal violet to determine amyloid deposition.

RESULTS

Among the nine trabeculae capable of generating force transients, various combinations of myocardial stiffness and contractile performance were observed including normal stiffness and contractility, severely increased stiffness with impaired contractility and hybrid patterns. Histological analysis demonstrated varying degrees of amyloid deposition among sampled trabeculae.

CONCLUSIONS

Our findings extend previous reports of functional heterogeneity among patients by demonstrating functional heterogeneity within a single patient's heart. Our findings also highlight the functional interdependence of passive stiffness and systolic performance in the diseased myocardium and demonstrate the value of dynamic assessments of myocardial performance.

Definition of organ involvement and treatment response in immunoglobulin light chain amyloidosis (AL): a consensus opinion from the 10th International Symposium on Amyloid and Amyloidosis, Tours, France, 18-22 April 2004

We undertook this study to develop uniformly accepted criteria for the definition of organ involvement and response for patients on treatment protocols for immunoglobulin light-chain amyloidosis (AL). A consensus panel was convened comprising 13 specialists actively involved in the treatment of patients with amyloidosis. Institutional criteria were submitted from each, and a consensus was developed defining each organ involved and the criteria for response. Specific criteria have been developed with agreed on definitions of organ and hematologic response as a result of discussions at the 10th International Symposium on Amyloid and Amyloidosis held in Tours, France, April 2004. These criteria now form the working definition of involvement and response for the purposes of future data collection and reporting. We report criteria that centers can now use to define organ involvement and uniform response criteria for reporting outcomes in patients with light-chain AL.

Amyloid in the cardiovascular system: a review

The cardiovascular system is a common target of amyloidosis. This review presents the current clinical and diagnostic approach to amyloidosis, with the emphasis on cardiovascular involvement. It summarises recent nomenclature, classification, and pathogenesis of amyloidosis. In addition, non-invasive possibilities are discussed, together with endomyocardial biopsies in the diagnosis of cardiac amyloidosis. Finally, recent advances in treatment and prognostic implications are presented.

The systemic amyloidoses

PURPOSE OF REVIEW

Clinical management of the amyloidoses has historically been the province of rheumatologists, because of the relation to long-standing inflammation in rheumatoid arthritis, ankylosing spondylitis, and juvenile chronic arthritis. Currently, nephrologists, hematologist-oncologists, neurologists, and transplant surgeons all have a diagnostic or therapeutic interest. Current advances, using the tools of physical biochemistry, cell biology, and genetics, have begun to impact the diagnosis and clinical management of these disorders and raise questions regarding our notions of protein conformation in vivo and how nonnatively folded proteins may produce disease.

RECENT FINDINGS

It appears that all amyloidogenic precursors undergo some degree of misfolding that allows them to populate an immediate precursor pool from which they rapidly aggregate. Depending on the particular protein, a variety of mechanisms appear operative, some of which involve nonphysiologic proteolysis, defective physiologic proteolysis, mutations involving changes in thermodynamic or kinetic properties, and pathways that are yet to be defined. Whatever the particular process, the result is a tendency toward oligomeric aggregation followed by the assembly of higher order structures that become insoluble under physiologic conditions. Detailed analyses have been described for transthyretin (senile systemic amyloidosis and familial amyloid polyneuropathy), immunoglobulin light chains (light-chain amyloid), beta2 microglobulin (dialysis-related amyloid), and apolipoprotein A1, and are in process for others. SUMMARY Therapies have been proposed based on precursor stabilization (transthyretin), elimination of the synthesizing cell (light-chain amyloid), fibril disruption and immunization to induce host-mediated aggregate clearance (Alzheimer disease, light-chain amyloid, prions), and aggressive therapy of a primary inflammatory process (amyloid A). During the next decade, the value of these therapies, and others, suggested by studies on the basic properties of cells and proteins, will become clear.