Prophylactic implantation of cardioverter-defibrillator in patients with severe cardiac amyloidosis and high risk for sudden cardiac death

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

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

Management of systemic AL amyloidosis: recommendations of the Myeloma Foundation of Australia Medical and Scientific Advisory Group

Systemic AL amyloidosis is a plasma cell dyscrasia with a characteristic clinical phenotype caused by multi-organ deposition of an amyloidogenic monoclonal protein. This condition poses a unique management challenge due to the complexity of the clinical presentation and the narrow therapeutic window of available therapies. Improved appreciation of the need for risk stratification, standardised use of sensitive laboratory testing for monitoring disease response, vigilant supportive care and the availability of newer agents with more favourable toxicity profiles have contributed to the improvement in treatment-related mortality and overall survival seen over the past decade. Nonetheless, with respect to the optimal management approach, there is a paucity of high-level clinical evidence due to the rarity of the disease, and enrollment in clinical trials is still the preferred approach where available. This review will summarise the Clinical Practice Guidelines on the Management of Systemic Light Chain (AL) Amyloidosis recently prepared by the Medical Scientific Advisory Group of the Myeloma Foundation of Australia. It is hoped that these guidelines will assist clinicians in better understanding and optimising the management of this difficult disease.

Immunoglobulin Light Chain Systemic Amyloidosis

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

Natural history and therapy of TTR-cardiac amyloidosis: emerging disease-modifying therapies from organ transplantation to stabilizer and silencer drugs

Transthyretin-cardiac amyloidoses (ATTR-CA) are an underdiagnosed but increasingly recognized cause of heart failure. Extracellular deposition of fibrillary proteins into tissues due to a variety of inherited transthyretin mutations in ATTRm or due to advanced age in ATTRwt eventually leads to organ failure. In the heart, amyloid deposition causes diastolic dysfunction, restrictive cardiomyopathy with progressive loss of systolic function, arrhythmias, and heart failure. While traditional treatments have consisted of conventional heart failure management and supportive care for systemic symptoms, numerous disease-modifying therapies have emerged over the past decade. From organ transplantation to transthyretin stabilizers (diflunisal, tafamidis, AG-1), TTR silencers (ALN-ATTR02, ISIS-TTR(Rx)), and degraders of amyloid fibrils (doxycycline/TUDCA), the potential for effective transthyretin amyloid therapy is greater now than ever before. In light of these multiple agents under investigation in human clinical trials, clinicians should be familiar with the systemic cardiac amyloidoses, their differing pathophysiology, natural histories, and unique treatment strategies.

Novel strategies for the diagnosis and treatment of cardiac amyloidosis

Systemic amyloidoses are rare, complex diseases caused by misfolding of autologous protein. The presence of heart involvement is the most important prognostic determinant. The diagnosis of amyloid cardiac involvement relies on echocardiography and magnetic resonance imaging, while scintigraphy with bone tracers is helpful in differentiating light chain amyloidosis from other types of amyloidosis involving the heart. Although these diseases are fatal, effective treatments exist that can alter their natural history, provided that they are started before irreversible cardiac damage has occurred. Refined diagnostic techniques, accurate patients' stratification based on biomarkers of cardiac dysfunction, the availability of novel, more powerful drugs, and ultimately, the unveiling of the cellular mechanisms of cardiac damage created a favorable environment for a dramatic improvement in the treatment of this disease that we expect in the next few years.

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

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

The transthyretin amyloidoses: advances in therapy

There are two forms of transthyretin (TTR) amyloidosis: non-hereditary and hereditary. The non-hereditary form (ATTRwt) is caused by native or wild-type TTR and was previously referred to as senile systemic amyloidosis. The hereditary form (ATTRm) is caused by variant TTR which results from a genetic mutation of TTR. The predominant effect of ATTRwt amyloidosis is on the heart, with patients having a greater left ventricular wall thickness at presentation than the devastating form which is light chain (AL) amyloidosis. ATTRm amyloidosis is broadly split into two categories: a type that predominantly affects the nervous system (often called familial amyloid polyneuropathy (FAP)) and one with a predilection for the heart (often called familial amyloid cardiomyopathy (FAC)). Approximately half of all TTR mutations known to express a clinical phenotype cause a cardiomyopathy. Since the introduction of orthotopic liver transplantation for ATTRm amyloidosis in 1991, several additional therapies have been developed. These therapies aim to provide a reduction or elimination of TTR from the plasma (through genetic approaches), stabilisation of the TTR molecule (to prevent deposition) and dissolution of the amyloid matrix. We describe the latest developments in these approaches to management, many of which are also applicable to wild-type amyloidosis.

A study of implanted cardiac rhythm recorders in advanced cardiac AL amyloidosis

AIMS

AL amyloidosis may respond to chemotherapy but two-thirds of patients with severe cardiac involvement die within a year of diagnosis, purportedly from tachyarrhythmias or electromechanical dissociation. We sought to characterize the nature of cardiac arrhythmias in severe cardiac AL amyloidosis using implanted cardiac rhythm recorders.

METHODS AND RESULTS

Implantable loop recorders (ILRs) were inserted within 24 h of baseline evaluation at the UK National Amyloidosis Centre, into 20 consecutive patients with newly diagnosed severe cardiac AL amyloidosis and symptoms of syncope or pre-syncope. Weekly ILR recordings and additional recordings at the time of symptoms were obtained. Median (range) follow-up from baseline was 308 (10-399) days. Thirteen patients died, and median survival in the whole cohort was 61 days from device insertion. In each of eight evaluable cases, death was heralded by bradycardia, usually associated with complete atrioventricular block (CAVB), followed shortly thereafter by pulseless electrical activity. Four patients received pacemakers, a median (range) of 7 (3-38) h after development of symptomatic CAVB, but these did not prevent rapid cardiac decompensation and death in three cases. Despite 272 loop recordings, there was only one episode of non-sustained ventricular tachycardia, which was preceded by severe bradycardia. Patients who died had significantly worse global left ventricular strain on echocardiography (P = 0.029) and reduced 6 min walk distance (P = 0.048) at baseline compared with survivors.

CONCLUSIONS

The discovery that bradyarrhythmias heralded terminal cardiac decompensation in most patients with severe cardiac AL amyloidosis supports a study of prophylactic pacemaker insertion in this patient population.

Life-saving implantable cardioverter defibrillator therapy in cardiac AL amyloidosis

Cardiac involvement is the main determinant of prognosis in systemic monoclonal immunoglobulin light chain (AL) amyloidosis. Ventricular arrhythmias and sudden cardiac death are not uncommon. The electrical events that precede sudden death, and their potential to be treated effectively, remain undefined. There are no European guidelines for the use of implantable cardioverter defibrillator (ICD) in amyloidosis. ICDs in general are not usually offered to patients with a life expectancy of less than 1 year. We describe a patient who presented with cardiac AL amyloidosis who underwent prophylactic ICD implantation for the prevention of sudden cardiac death during treatment with chemotherapy, in whom life-threatening ventricular arrhythmia was successfully terminated over a 3-year period.

Recent advances in the diagnosis and management of cardiac amyloidosis

The heart is commonly involved in various forms of amyloidosis and cardiomyopathy is a major cause of morbidity and mortality in these patients. Diagnosis of cardiac amyloidosis is often delayed due to nonspecific presenting symptoms and failure to recognize early signs of amyloid heart disease on routine cardiac imaging. Treatment of cardiac amyloidosis depends upon the type of amyloid protein. Systemic chemotherapy with or without stem cell transplantation is used to treat immunoglobulin-related amyloidosis and liver transplantation is used for familial transthyretin amyloidosis in select patients. Clinical trials with siRNA for the treatment of transthyretin amyloid cardiomyopathies and amyloid protein stabilizers are ongoing. Prognosis depends on the type of amyloid protein with poorer outcomes noted in immunoglobulin light-chain amyloidosis. Supportive care forms the cornerstone of management and advancements in cardiac imaging and proteomics are expected to positively impact our ability to diagnose, prognosticate and treat cardiac amyloidosis.

Immunoglobulin light chain amyloidosis

Primary light chain amyloidosis is the most common form of systemic amyloidosis and is caused by misfolded light chains that cause proteotoxicity and rapid decline of vital organ function. Early diagnosis is essential in order to deliver effective therapy and prevent irreversible organ damage. Accurate diagnosis requires clinical skills and advanced technologies. The disease can be halted and the function of target organs preserved by the prompt reduction and elimination of the plasma cell clone producing the toxic light chains in the bone marrow. Heart damage is the major determinant of survival, and staging with cardiac biomarkers guides treatment. Two-thirds of patients can benefit from treatment with improved quality of life and extended survival. Future efforts should be directed at early diagnosis, improving the tolerability and efficacy of anti-plasma cell therapy, accelerating recovery of organ function via promoting resorption of amyloid deposits, and developing novel approaches to counter light chain proteotoxicity.

Systemic amyloidoses: what an internist should know

Systemic amyloidoses are rare, complex diseases caused by misfolding of autologous proteins. Although these diseases are fatal, effective treatments exist that can alter their natural history, provided that they are started before irreversible organ damage has occurred. The cornerstones of the management of systemic amyloidoses are early diagnosis, accurate typing, appropriate risk-adapted therapy, tight follow-up, and effective supportive treatment. Internists play a key role in suspecting the disease, thus allowing early diagnosis, starting the diagnostic workup and selecting patients that should be referred to specialized centers, judiciously titrating supportive measures, and following patients throughout the course of the disease. Here we review the pathogenesis, diagnosis and treatment of the most common forms of systemic amyloidoses.

Ventricular fibrillation after bortezomib therapy in a patient with systemic amyloidosis

A 64-year-old female was diagnosed with systemic amyloidosis associated with multiple myeloma. Bortezomib and dexamethasone-therapy was initiated; however, she developed lethal ventricular fibrillation (VF) and cardiac arrest after 84 hours of therapy. Cardiopulmonary resuscitation using direct current shocks with epinephrine and amiodarone was initiated but failed to receive cardiac function. Although her arterial pulsations recovered immediately after the injection of vasopressin, she died of heart failure 8 hours after the onset of VF. Cardiac amyloidosis was verified by autopsy. Although the direct association of bortezomib with lethal VF remained to be clarified in our patient, the current report emphasizes on bortezomib as a substantial risk factor for cardiomyocyte damage. The potential risk of lethal events associated with cardiac amyloidosis should be carefully considered during bortezomib treatment for patients with AL amyloidosis.

Pathophysiology and treatment of systemic amyloidosis

Amyloid is an abnormal extracellular fibrillar protein deposit in the tissues. In humans, more than 25 different proteins can adopt a fibrillar conformation in vivo that results in the pathognomonic tinctorial property of amyloid (that is, green birefringence when an affected tissue specimen is stained with Congo red dye and viewed by microscopy under cross-polarized light). Amyloid deposition is associated with disturbance of organ function and causes a wide variety of clinical syndromes that are classified according to the respective fibril protein precursor. Systemic amyloidosis, in which amyloid deposits are widespread and typically accumulate gradually, continues to be fatal and is responsible for about one in 1,500 deaths per year in the UK. Advances in our understanding of the pathogenesis of systemic amyloidosis have resulted in the identification of new therapeutic targets, and several drugs with novel mechanisms of action are currently under development. Meanwhile, an increased awareness of amyloidosis coupled with enhancements to existing diagnostic techniques and therapeutic strategies have already resulted in better outcomes for patients with the disease.

Senile systemic amyloidosis: clinical features at presentation and outcome

BACKGROUND

Cardiac amyloidosis is a fatal disease whose prognosis and treatment rely on identification of the amyloid type. In our aging population transthyretin amyloidosis (ATTRwt) is common and must be differentiated from other amyloid types. We report the clinical presentation, natural history, and prognostic features of ATTRwt compared with cardiac-isolated AL amyloidosis and calculate the probability of disease diagnosis of ATTRwt from baseline factors.

METHODS AND RESULTS

All patients with biopsy-proven ATTRwt (102 cases) and isolated cardiac AL (36 cases) seen from 2002 to 2011 at the UK National Amyloidosis Center were included. Median survival from the onset of symptoms was 6.07 years in the ATTRwt group and 1.7 years in the AL group. Positive troponin, a pacemaker, and increasing New York Heart Association (NYHA) class were associated with worse survival in ATTRwt patients on univariate analysis. All patients with isolated cardiac AL and 24.1% of patients with ATTRwt had evidence of a plasma cell dyscrasia. Older age and lower N-terminal pro-B-type natriuretic peptide (NT pro-BNP) were factors significantly associated with ATTRwt. Patients aged 70 years and younger with an NT pro-BNP <183 pmol/L were more likely to have ATTRwt, as were patients older than 70 years with an NT pro-BNP <1420 pmol/L.

CONCLUSIONS

Factors at baseline associated with a worse outcome in ATTRwt are positive troponin T, a pacemaker, and NYHA class IV symptoms. The age of the patient at diagnosis and NT pro-BNP level can aid in distinguishing ATTRwt from AL amyloidosis.

Cardiac amyloidosis: the heart of the matter

Amyloidosis comprises a unique group of diseases that share in common the extracellular deposition of insoluble fibrillar proteins in organs and tissue including the heart. Cardiac amyloidosis could be primary a part of systemic acquired amyloidosis, or a result of heredofamilial amyloidosis. Although the infiltration of the heart from different types of amyloid results in restrictive cardiomyopathy that manifests with refractory congestive heart failure and conduction abnormalities, unequivocal identification of the deposited amyloidogenic protein is mandatory in order to avoid misdiagnosis and inappropriate treatment. Recent developments in imaging techniques and extracardiac tissue biopsy have minimized the need for invasive endomyocardial biopsy for amyloidosis. Despite advances in treatment, the prognosis of a patient with amyloidosis is still poor and depends upon the underlying disease, and the type and degree of dysfunction of the involved organs. Thus, early diagnosis is mandatory because patients with advanced disease are usually too ill for intensive therapy. This review outlines current approaches to diagnosis, assessment of disease severity, and treatment of cardiac amyloidosis.

Implantable cardioverter defibrillators in patients with cardiac amyloidosis

BACKGROUND

Cardiac amyloidosis (CA) is associated with increased risk of sudden cardiac arrest. Although ICD therapy improves survival in patients with cardiomyopathy due to other etiologies, the benefit of ICD therapy in patients with CA is unclear in large part due to limited data on the precise mechanism of sudden cardiac arrest and selection of patients with cardiac amyloidosis for ICD therapy.

OBJECTIVE

The objective was to determine the benefit of ICD therapy in cardiac amyloidosis.

METHODS

We reviewed all ICD implant indications, procedures, and therapies, of CA patients evaluated at Mayo Clinic between 2000 and 2009.

RESULTS

A total of 53 patients with CA (33 AL, 10 senile, 9 familial, and 1 AA) who underwent ICD implantation were included. Indication for ICD implantation was for primary prevention of sudden cardiac arrest in 41 (77%) patients and secondary prevention in 12 (23%) patients. The rate of appropriate ICD shocks was 32% in the first year and was observed almost exclusively in AL amyloidosis patients, occurring in 15 patients (12 AL amyloidosis, 2 senile, 1 AA). Appropriate ICD shocks were more frequent in patients with prior sudden cardiac arrest or sustained ventricular arrhythmias (secondary prevention indication), and less frequent in patients who presented with decreased ejection fraction or syncope.

CONCLUSIONS

A high rate of appropriate ICD shocks was observed especially in patients with AL-type amyloidosis. However, appropriate ICD therapy did not translate into overall survival benefit, suggesting that selection of patients with CA who might be candidates for ICD is imprecise.

Prevalence and prognostic value of conduction disturbances at the time of diagnosis of cardiac AL amyloidosis

BACKGROUND AND PURPOSE

To evaluate the prevalence and the prognostic implications of conduction delays in a large cohort of cardiac AL patients.

METHODS

Echo Doppler and 12-lead ECG were collected in 344 consecutive patients in whom diagnosis of AL amyloidosis was concluded between 2008 and 2010. Patients were subdivided according to the presence (n = 240) or absence (n = 104) of cardiac involvement.

RESULTS

When compared with patients without myocardial involvement, cardiac AL was associated with prolonged PQ, QRS, QT and QTc intervals (P < 0.05), and with higher prevalence of intraventricular blocks (27.5% vs. 16.5%, P < 0.05), that was associated with higher wall thickness, worse diastolic and regional systolic function, higher NT-proBNP values (all P < 0.05), and higher mortality (P = 0.0001; median follow-up: 402 days).

CONCLUSION

Intraventricular conduction delays have a negative prognostic impact in patients with cardiac AL amyloidosis. Their presence should not be overlooked in the diagnostic workup, prompting a more accurate cardiological support.

Amyloid diseases of the heart: current and future therapies

Amyloid diseases in man are caused by as many as 23 different pre-cursor proteins already described. Cardiologists predominantly encounter three main types of amyloidosis that affect the heart: light chain (AL) amyloidosis, senile systemic amyloidosis (SSA) and hereditary amyloidosis, most commonly caused by a mutant form of transthyretin. In the third world, secondary amyloid (AA) is more prevalent, due to chronic infections and inadequately treated inflammatory conditions. Much less common, are the non-transthyretin variants, including mutations of fibrinogen, the apolipoproteins apoA1 and apoA2 and gelsolin. These rarer types do not usually cause significant cardiac compromise. Occurring worldwide, later in life and of less clinical significance, isolated atrial amyloid (IAA) also involves the heart. Heart involvement by amyloid often has devastating consequences. Clinical outcome depends on amyloid type, the extent of systemic involvement and the treatment options available. An exact determination of amyloid type is critical to appropriate therapy. In this review we describe the different approaches required to treat this spectrum of amyloid cardiomyopathies.

Cardiac involvement in hereditary-transthyretin related amyloidosis

Hereditary transthyretin-related amyloidosis remains a widely underdiagnosed condition, owing to its extreme phenotypic variability: the clinical spectrum of the disease ranges from an almost exclusive neurologic involvement to strictly cardiac manifestations. This heterogeneity is linked to several factors including specific transthyretin mutations, geographic distribution and endemic vs. non-endemic aggregation type. The existence of exclusively or predominantly cardiac phenotypes makes the recognition of the disease very challenging since it can mimic other more common causes of left ventricular "hypertrophy". Assessment of such patients should include an active search for possible red flags that can indicate the correct final diagnosis.

What do I need to know about immunoglobulin light chain (AL) amyloidosis?

Immunoglobulin light chain (AL) amyloidosis is the most common acquired systemic amyloidoses. Its presentation is often insidious and progressive, which may delay diagnosis. The interval between first symptoms and actual diagnosis along the intrinsic heterogeneity of tissue tropism create a wide spectrum of presentations, both in terms of scope and depth of symptoms and signs and functional status of patients. In this review, the authors review the pathogenesis, diagnosis and differential diagnosis of AL amyloidosis along with the prognosis and state-of-the-art management for patients with this affliction.

[Amyloidosis of the heart]

Amyloidosis is a heterogeneous group of diseases characterized by the pathological deposition of autologous proteins in an antiparallel β-sheet confirmation forming non-branching linear fibrils of indefinite length and an approximate diameter of 10-12 nm. Cardiac amyloidosis is caused by deposits in the heart and may lead to cardiac arrhythmia and low output failure. Following the diagnosis, classification of the amyloid protein and evaluation of further organ involvement is mandatory. Treatment approaches are based on reduction of the production of amyloid precursor proteins. Standard heart failure treatment is usually not well tolerated and the underlying disease remains unaffected. Cardiac amyloidosis, especially of the light chain type, is associated with a poor outcome. The clinical picture is uncharacteristic, therefore correct diagnosis of cardiac amyloidosis is often delayed in many patients. Combination of clinical symptoms of different organ systems should alert the physician to the diagnosis of amyloidosis.

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.

Amyloidosis: pathogenesis and new therapeutic options

The systemic amyloidoses are a group of complex diseases caused by tissue deposition of misfolded proteins that results in progressive organ damage. The most common type, immunoglobulin light chain amyloidosis (AL), is caused by clonal plasma cells that produce misfolded light chains. The purpose of this review is to provide up-to-date information on diagnosis and treatment options for AL amyloidosis. Early, accurate diagnosis is the key to effective therapy, and unequivocal identification of the amyloidogenic protein may require advanced technologies and expertise. Prognosis is dominated by the extent of cardiac involvement, and cardiac staging directs the choice of therapy. Treatment for AL amyloidosis is highly individualized, determined on the basis of age, organ dysfunction, and regimen toxicities, and should be guided by biomarkers of hematologic and cardiac response. Alkylator-based chemotherapy is effective in almost two thirds of patients. Novel agents are also active, and trials are ongoing to establish their optimal use. Treatment algorithms will continue to be refined through controlled trials. Advances in basic research have led to the identification of new drug targets and therapeutic approaches, which will be integrated with chemotherapy in the future.

Transthyretin-related amyloidoses and the heart: a clinical overview

A nonhereditary form of systemic amyloidosis associated with wild-type transthyretin causes heart involvement predominantly in elderly men (systemic senile amyloidosis, or SSA). However, hereditary transthyretin-related amyloidosis (ATTR) is the most frequent form of familial systemic amyloidosis, a group of severe diseases with variable neurological and organ involvement. ATTR remains a challenging and widely underdiagnosed condition, owing to its extreme phenotypic variability: the clinical spectrum of the disease ranges from an almost exclusive neurologic involvement to a strictly cardiac presentation. Such heterogeneity principally results from differential effects of the various reported transthyretin mutations, the geographic region the patient is from and, in the case of the most common mutation, Val30Met, whether or not large foci of cases occur (endemic versus nonendemic aggregation). Genetic or environmental factors (such as age, sex, and amyloid fibril composition) also contribute to the heterogeneity of ATTR, albeit to a lesser extent. The existence of exclusively or predominantly cardiac phenotypes should lead clinicians to consider the possibility of ATTR in all patients who present with an unexplained increase in left ventricular wall thickness at echocardiography. Assessment of such patients should include an active search for possible red flags that can point to the correct final diagnosis.

Staged heart transplantation and chemotherapy as a treatment option in patients with severe cardiac light-chain amyloidosis

AIMS

The prognosis of advanced cardiac light-chain amyloidosis is poor. Heart transplantation might enable causative therapy and ultimately improve prognosis.

METHODS AND RESULTS

Nineteen patients with cardiac amyloidosis but no obvious involvement of other organs were scheduled for heart transplantation. Four to 6 months later, high-dose melphalan chemotherapy and autologous stem cell transplantation (HDM-ASCT) was planned in patients not in complete remission. Seven of nineteen patients died while waiting for heart transplantation. The remaining 12 patients (complete remission, n = 4) underwent surgery. Chemotherapy in patients not in complete remission consisted of HDM-ASCT (n = 5/12; subsequent complete remission, n = 2; partial remission, n = 3) or melphalan-prednisolone (partial remission, n = 1). Two of twelve patients were ineligible for any chemotherapy. Three of twelve patients died [423.5 (105-2131) days] from progressive disease, relapse, or sepsis. The 1- and 3-year survival rates were 83 and 83%, respectively, similar to those of patients undergoing heart transplantation for standard indications. Corresponding survival rates stratified by haematological response were 100 and 100% for complete remission (partial remission, 100 and 100%; progressive disease, 0 and 0%).

CONCLUSION

Heart transplantation in advanced cardiac amyloidosis is a promising approach to interrupting the vicious circle of ineligibility for potential curative chemotherapeutic treatment and extremely poor prognosis of cardiac amyloidosis without chemotherapy. Highly urgent heart transplantation combined with subsequent HDM-ASCT appears to offer a successful treatment option to improve the poor outcome of cardiac amyloidosis. However, it should be restricted to highly selected patients in specialized centres.

Frequencies and types of arrhythmias in patients with systemic light-chain amyloidosis with cardiac involvement undergoing stem cell transplantation on telemetry monitoring

Cardiac patients with systemic light-chain amyloidosis have a high incidence of arrhythmias and arrhythmia-related death. We aimed to describe the arrhythmias, determine patient characteristics associated with the development of ventricular arrhythmias, and the utility of telemetric monitoring in patients with cardiac involvement due to AL amyloidosis undergoing stem cell transplantation (SCT). Arrhythmia events of 24 consecutive cardiac patients with AL who underwent SCT with continuous telemetric monitoring were retrospectively reviewed. The relation between number and severity of ventricular arrhythmias (ventricular tachycardia/ventricular fibrillation [VT/VF]) and baseline clinical, laboratory, and echocardiographic data were determined. Atrial and ventricular arrhythmias were found in all patients. Nonsustained VT was the most frequent event (267 total events). Therapeutic intervention for arrhythmias was required in 20 patients; in 3 patients, life-threatening arrhythmias were detected and treated. There was an inverse relation between VT/VF and cardiac output (r = -0.72, p <0.0001), cardiac index (r = -0.71, p = 0.0001), and stroke volume (r = -0.59, p = 0.0029). There was also a relation between VT/VF and brain natriuretic peptide before SCT (r = 0.47, p = 0.019) and average brain natriuretic peptide levels during admission for SCT (r = 0.62, p = 0.0012), troponin I levels at diagnosis (r = 0.47, p = 0.022), and serum creatinine levels before SCT (r = 0.62, p = 0.001). In conclusion, patients with cardiac amyloidosis undergoing SCT have a high incidence of ventricular and atrial arrhythmias; decreased cardiac output was strongly associated with significant ventricular arrhythmias. Continuous telemetric monitoring contributed to patient safety during SCT.

[Risk stratification and treatment of cardiac amyloidoses]

Cardiac amyloidoses are a heterogeneous group of cardiomyopathies that are resistant to treatment and are associated with a poor outcome. Standard heart failure treatment is usually not well tolerated and the underlying disease remains unaffected. The clinical picture is uncharacteristic. Cardiac amyloidosis is often associated with dysfunction of additional organs. Early cardiac amyloid involvement usually reveals left ventricular hypertrophy, impairment of longitudinal shortening and diastolic ventricular function. Without adequate therapy (bi-)ventricular hypertrophy will progress to severe systolic ventricular function decrease. The combination of low voltage pattern, left ventricular hypertrophy and granular sparkling is characteristic for advanced cardiac amyloid involvement. Cardiac magnetic resonance imaging and scintigraphy yield further information on the pattern and severity of cardiac involvement. In unclear cases (left ventricular) endomyocardial biopsy is necessary. Detection of early cardiac involvement and proper identification of patients at high risk for sudden cardiac death due to rapid progressive amyloidosis is still incompletely defined. Referral to specialized centers is strongly recommended.