Outcome and incidence of appropriate implantable cardioverter-defibrillator therapy in patients with cardiac amyloidosis

Recurrent ventricular tachycardia in a patient with A19D mutation-associated hereditary transthyretin amyloidosis: a case report

Background

Previous literature suggests that patients with transthyretin amyloidosis (ATTR) experience a high burden of ventricular arrhythmias. Despite this evidence, optimal strategies for arrhythmia prevention and treatment remain subject to debate.

Case summary

We report the case of a patient with hereditary ATTR cardiomyopathy who developed recurrent ventricular tachycardia prior to a decline in his left ventricular ejection fraction (LVEF). Although he ultimately received an intracardiac device (ICD) for secondary prevention of ventricular tachycardia, his clinical course begets the question of whether more aggressive arrhythmia prevention upfront could have prevented his global functional decline.

Discussion

Given the advent of new disease-modifying therapies for ATTR, it is imperative to reconsider antiarrhythmic strategies in these patients. New decision tools are needed to decide what additional parameters (beyond LVEF ≤ 35%) may warrant ICD placement for primary prevention of ventricular arrhythmias in these patients.

Management of Arrhythmias and Conduction Disorders in Amyloid Cardiomyopathy

Cardiac amyloidosis, a condition characterized by abnormal protein deposition in the heart, leads to restrictive cardiomyopathy and is notably associated with an increased risk of arrhythmias and conduction disorders. This article reviews the current understanding and management strategies for these cardiac complications, with a focus on recent advancements and clinical challenges. The prevalence and impact of atrial arrhythmias, particularly atrial fibrillation, are examined, along with considerations for stroke risk and anticoagulation therapy. The article also addresses the complexities of managing rate and rhythm control, outlining the utility and limitations of pharmacological agents and interventions such as catheter ablation. Furthermore, it reviews the challenges in the treatment of ventricular arrhythmias, including the contentious use of implantable cardioverter-defibrillators for primary and secondary prevention. Individualized approaches, considering the unique characteristics of cardiac amyloidosis, are paramount. Continuous research and clinical exploration are essential to refine treatment strategies and improve outcomes in this challenging patient population.

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.

Prognostic implications of premature ventricular contractions and non-sustained ventricular tachycardia in light-chain cardiac amyloidosis

AIMS

Premature ventricular contractions (PVC) and non-sustained ventricular tachycardia (NSVT) are commonly observed in light chain cardiac amyloidosis (AL-CA), but their association with prognosis is still unclear. We aimed to evaluate the prognostic value of PVCs and NSVT in patients with moderate-to-advanced AL-CA.

METHODS AND RESULTS

We retrospectively included patients with AL-CA at modified 2004 Mayo stages II-IIIb between February 2014 and December 2020. Twenty-four-hour Holter recordings were assessed on admission. The outcomes included (i) new onset of adverse ventricular arrhythmia (VA) or sudden cardiac death (SCD) and (ii) cardiac death during follow-up. Of the 143 patients studied (60.41 ± 11.06 years, male 64.34%), 132 (92.31%) had presence of PVC, and 50 (34.97%) had NSVT on Holter. Twelve (8.4%) patients died in hospital and 131 patients were followed up (median 24.4 months), among whom 71 patients had cardiac death, and 15 underwent adverse VA/SCD. NSVT [hazard ratio (HR): 13.57, 95% confidence interval (CI): 3.06-60.18, P < 0.001], log-transformed PVC counts (HR: 1.46, 95%CI: 1.15-1.86, P = 0.002) and PVC burden (HR: 1.43 95%CI:1.14-1.80, P = 0.002) were predictive of new onset of adverse VA/SCD. The highest tertile of PVC counts (HR: 2.33, 95%CI: 1.27-4.28, P = 0.006) and PVC burden (HR: 2.58, 95%CI: 1.42-4.69, P = 0.002), rather than NSVT (HR: 1.16, 95%CI: 0.67-1.98, P = 0.603), was associated with cardiac death. Higher PVC counts/burden provided incremental value on modified 2004 Mayo stage in predicting cardiac death, with C index increasing from 0.681 to 0.712 and 0.717, respectively (P values <0.05).

CONCLUSION

PVC count, burden, and NSVT significantly correlated with adverse VA/SCD during follow-up in patients with AL-CA. Higher PVC counts/burdens added incremental value for predicting cardiac death.

Arrhythmias and Device Therapies in Cardiac Amyloidosis

Cardiac amyloidosis is caused by amyloid fibrils that deposit in the myocardial interstitium, causing restrictive cardiomyopathy and eventually death. The electromechanical, inflammatory, and autonomic changes due to amyloid deposition result in arrhythmias. Atrial fibrillation is by far the most common arrhythmia. The rate control strategy is generally poorly tolerated due to restrictive filling physiology and heart rate dependance, favoring adoption of the rhythm control strategy. Anticoagulation for stroke prophylaxis is warranted, irrespective of CHA2DS2-VASc score in patients with a favorable bleeding profile; data on left appendage closure devices are still insufficient. Ventricular arrhythmias are also not uncommon, and the role of implantable cardioverter-defibrillator in cardiac amyloidosis is controversial. There is no evidence of improvement in outcomes when used for primary prevention in these patients. Bradyarrhythmia is most commonly associated with sudden cardiac death in cardiac amyloidosis. Pacemaker implantation can help provide symptomatic relief but does not confer mortality benefit.

Perioperative implications of amyloidosis and amyloid cardiomyopathy: A review for anesthesiologists

It is well recognized that amyloid protein can infiltrate many regions of the body. This can include the peripheral nerves, the liver, kidney, spleen, the gastrointestinal tract, and most importantly the myocardium. The amyloid proteins that cause cardiomyopathy may come from genetically altered liver genes (transthyretin amyloid, ATTR) or from the bone marrow with malignant plasma cells (light chain amyloid, AL) generating the aberrant protein. These two types of amyloidosis cause significant damaging effects on both the myocardial cells as well as the conduction system of the heart. The resultant changes can produce dyspnea and exercise intolerance which is thought to be secondary to diastolic dysfunction and reduced stroke volume. This subclinical decompensation poses a significant problem for members of a care team as it often goes unrecognized. In the operating room patients are exposed to dramatic hemodynamic changes and may have difficult airways, autonomic dysfunction, and conduction abnormalities. Although the topic of amyloidosis is well described in cardiology literature, it is underdiagnosed. The purpose of this review is to describe some of the pathophysiology behind the principle proteins that cause cardiac amyloidosis and to comprehensively describe perioperative considerations for anesthesia providers.

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

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

Arrhythmias in Patients with Cardiac Amyloidosis: A Comprehensive Review on Clinical Management and Devices

Cardiac amyloidosis (CA) is a rare but potentially life-threatening disease in which misfolded proteins accumulate in the cardiac wall tissue. Heart rhythm disorders in CA, including supraventricular arrhythmias, conduction system disturbances, or ventricular arrhythmias, play a major role in CA morbidity and mortality, and thus require supplementary management. Among them, AF is the most frequent arrhythmia during CA hospitalizations and is associated with significantly higher mortality, while ventricular arrhythmias are also common and are usually associated with poor prognosis. Early diagnosis of potential arrythmias could be performed through ECG, Holter monitoring, and/or electrophysiology study. Clinical management of these patients is quite significant, and it usually includes initiation of amiodarone and/or digoxin in patients with AF, potential electrical cardioversion, or ablation in specific patients with indication, as well as initiation of anticoagulants in all patients, independent of AF and CHADS-VASc score, for potential intracardiac thrombus. Moreover, identification of patients with conduction disorders that could benefit from prophylactic pacemaker implantation and/or CRT as well as identification of patients with life-threatening ventricular arrythmias that could benefit from ICD could both increase the survival rates of these patients and improve their quality of life.

Clinical, electrocardiographic, and echocardiographic parameters associated with the development of pacing and implantable cardioverter-defibrillator indication in patients with transthyretin amyloid cardiomyopathy

AIMS

This study aimed to identify factors for attention leading to future pacing device implantation (PDI) and reveal the necessity of prophylactic PDI or implantable cardioverter-defibrillator (ICD) implantation in transthyretin amyloid cardiomyopathy (ATTR-CM) patients.

METHODS AND RESULTS

This retrospective single-center observational study included consecutive 114 wild-type ATTR-CM (ATTRwt-CM) and 50 hereditary ATTR-CM (ATTRv-CM) patients, neither implanted with a pacing device nor fulfilling indications for PDI at diagnosis. As a study outcome, patient backgrounds were compared with and without future PDI, and the incidence of PDI in each conduction disturbance was examined. Furthermore, appropriate ICD therapies were investigated in all 19 patients with ICD implantation. PR-interval ≥220 msec, interventricular septum (IVS) thickness ≥16.9 mm, and bifascicular block were significantly associated with future PDI in ATTRwt-CM patients, and brain natriuretic peptide ≥35.7 pg/mL, IVS thickness ≥11.3 mm, and bifascicular block in ATTRv-CM patients. The incidence of subsequent PDI in patients with bifascicular block at diagnosis was significantly higher than that of normal atrioventricular (AV) conduction in both ATTRwt-CM [hazard ratio (HR): 13.70, P = 0.019] and ATTRv-CM (HR: 12.94, P = 0.002), whereas that of patients with first-degree AV block was neither (ATTRwt-CM: HR: 2.14, P = 0.511, ATTRv-CM: HR: 1.57, P = 0.701). Regarding ICD, only 2 of 16 ATTRwt-CM and 1 of 3 ATTRv-CM patients received appropriate anti-tachycardia pacing or shock therapy, under the number of intervals to detect for ventricular tachycardia of 16-32.

CONCLUSIONS

According to our retrospective single-center observational study, prophylactic PDI did not require first-degree AV block in both ATTRwt-CM and ATTRv-CM patients, and prophylactic ICD implantation was also controversial in both ATTR-CM. Larger prospective, multi-center studies are necessary to confirm these results.

Strain Imaging and Ventricular Arrhythmia

Ventricular arrhythmia is one of the main causes of sudden cardiac death. Hence, identifying patients at risk of ventricular arrhythmias and sudden cardiac death is important but can be challenging. The indication for an implantable cardioverter defibrillator as a primary preventive strategy relies on the left ventricular ejection fraction as a measure of systolic function. However, ejection fraction is flawed by technical constraints and is an indirect measure of systolic function. There has, therefore, been an incentive to identify other markers to optimize the risk prediction of malignant arrhythmias to select proper candidates who could benefit from an implantable cardioverter defibrillator. Speckle-tracking echocardiography allows for a detailed assessment of cardiac mechanics, and strain imaging has repeatedly been shown to be a sensitive technique to identify systolic dysfunction unrecognized by ejection fraction. Several strain measures, including global longitudinal strain, regional strain, and mechanical dispersion, have consequently been proposed as potential markers of ventricular arrhythmias. In this review, we will provide an overview of the potential use of different strain measures in the context of ventricular arrhythmias.

Arrhythmic Manifestations of Cardiac Amyloidosis: Challenges in Risk Stratification and Clinical Management

Amylodiosis is a systemic disease characterized by extracellular deposits of insoluble amyloid in various tissues and organs. Cardiac amyloidosis is a frequent feature of the disease, causing a progressive, restrictive type of cardiomyopathy, and is associated with adverse clinical outcomes and increased mortality. The typical clinical presentation in patients with cardiac amyloidosis is heart failure (HF) with preserved ejection fraction. Most patients present with typical symptoms and signs of HF, such as exertional dyspnea, pretibial edema, pleural effusions and angina pectoris due to microcirculatory dysfunction. However, patients may also frequently encounter various arrhythmias, such as atrioventricular nodal block, atrial fibrillation and ventricular tachyarrhythmias. The management of arrhythmias in cardiac amyloidosis patients with drugs and devices is often a clinical challenge. Moreover, predictors of life-threatening arrhythmic events are not well defined. This review intends to give a deepened insight into the arrhythmic features of cardiac amyloidosis by discussing the pathogenesis of these arrhythmias, addressing the challenges in risk stratification and strategies for management in these patients.

Risk stratification in transthyretin-related cardiac amyloidosis

Transthyretin related cardiac amyloidosis (TTR-CA) is an infiltrative cardiomyopathy that cause heart failure with preserved ejection fraction, mainly in aging people. Due to the introduction of a non invasive diagnostic algorithm, this disease, previously considered to be rare, is increasingly recognized. The natural history of TTR-CA includes two different stages: a presymptomatic and a symptomatic stage. Due to the availability of new disease-modifying therapies, the need to reach a diagnosis in the first stage has become impelling. While in variant TTR-CA an early identification of the disease may be obtained with a genetic screening in proband's relatives, in the wild-type form it represents a challenging issue. Once the diagnosis has been made, in order to identifying patients with a higher risk of cardiovascular events and death it is necessary to focus on risk stratification. Two prognostic scores have been proposed both based on biomarkers and laboratory findings. However, a multiparametric approach combining information from electrocardiogram, echocardiogram, cardiopulmonary exercise test and cardiac magnetic resonance may be warranted for a more comprehensive risk prediction. In this review, we aim at evaluating a step by step risk stratification, providing a clinical diagnostic and prognostic approach for the management of patients with TTR-CA.

Prevalence of ventricular arrhythmias and role of implantable cardioverter-defibrillator in cardiac amyloidosis

Cardiac amyloidosis is an underdiagnosed disease that is caused by myocardial deposition of misfolded light chain (AL) or transthyretin (ATTR) amyloid fibrils, leading to restrictive cardiomyopathy and eventually death if untreated. Ventricular arrhythmias are common in cardiac amyloidosis, and the prevalence is higher in AL than ATTR. There are multiple suspected pathogenic mechanisms for ventricular arrhythmia including activation of inflammatory cascade from direct amyloid deposition, and electro-mechanical as well as autonomic dysfunction due to systemic amyloid deposition. Cardiac amyloidosis is associated with an increased risk of sudden cardiac death, and the risk is higher in AL than ATTR. Finally, the role of implantable cardioverter-defibrillators in cardiac amyloidosis is controversial, and while successful termination of life-threatening ventricular arrhythmias has been reported in few studies, there has been no evidence of improvement in outcomes when used for primary prevention in patients with cardiac amyloidosis.

Diffuse myocardial fibrosis associates with incident ventricular arrhythmia in implantable cardioverter defibrillator recipients

Background

Diffuse myocardial fibrosis (DMF) quantified by extracellular volume (ECV) may represent a vulnerable phenotype and associate with life threatening ventricular arrhythmias more than focal myocardial fibrosis. This principle remains important because 1) risk stratification for implantable cardioverter defibrillators (ICD) remains challenging, and 2) DMF may respond to current or emerging medical therapies (reversible substrate).

Objectives

To evaluate the association between quantified by ECV in myocardium without focal fibrosis by late gadolinium enhancement (LGE) with time from ICD implantation to 1) appropriate shock, or 2) shock or anti-tachycardia pacing.

Methods

Among patients referred for cardiovascular magnetic resonance (CMR) without congenital disease, hypertrophic cardiomyopathy, or amyloidosis who received ICDs (n=215), we used Cox regression to associate ECV with incident ICD therapy.

Results

After a median of 2.9 (IQR 1.5-4.2) years, 25 surviving patients experienced ICD shock and 44 experienced shock or anti-tachycardia pacing. ECV ranged from 20.2% to 39.4%. No patient with ECV<25% experienced an ICD shock. ECV associated with both endpoints, e.g., hazard ratio 2.17 (95%CI 1.17-4.00) for every 5% increase in ECV, p=0.014 in a stepwise model for ICD shock adjusting for ICD indication, age, smoking, atrial fibrillation, and myocardial infarction, whereas focal fibrosis by LGE and global longitudinal strain (GLS) did not.

Conclusions

DMF measured by ECV associates with ventricular arrhythmias requiring ICD therapy in a dose-response fashion, even adjusting for potential confounding variables, focal fibrosis by LGE, and GLS. ECV-based risk stratification and DMF representing a therapeutic target to prevent ventricular arrhythmia warrant further investigation.

A Review of Cardiac amyloidosis: Presentation, Diagnosis, and Treatment

Amyloidosis is a group of disorders that can affect almost any organ due to the misfolding of proteins with their subsequent deposition in various tissues, leading to various disease manifestations based on the location. When the heart is involved, amyloidosis can manifest with a multitude of presentations such as heart failure, arrhythmias, orthostatic hypotension, syncope, and pre-syncope. Diagnosis of cardiac amyloidosis can be difficult due to the non-specific nature of symptoms and the relative rarity of the disease. Amyloidosis can remain undiagnosed for years, leading to its high morbidity and mortality due to this delay in diagnosis. Newer imaging modalities, such as cardiac magnetic resonance imaging, advanced echocardiography, and biomarkers, make a timely cardiac amyloidosis diagnosis more feasible. Many treatment options are available, which have provided new hope for this patient population. This manuscript will review the pathology, diagnosis, and treatment options available for cardiac amyloidosis and provide a comprehensive overview of this complicated disease process.

Cardiac Amyloidosis

Amyloid deposits are defined by their tinctorial properties. Under the light microscope amyloid deposits are eosinophilic and amorphous when stained with hematoxylin and eosin. With Congo red staining the deposits are positive and under polarized light will exhibit green birefringence. Sixty years later electron microscopy demonstrated that all deposits were fibrillar. All amyloid deposits are protein derived. The clinical characteristics will be driven by the nature of the protein subunit. In cardiology, the 2 most common subunits accounting for well more than 90% of cardiac amyloidosis are either immunoglobulin light chain, amyloid light-chain (AL) amyloidosis, or transthyretin; transthyretin (TTR) amyloidosis. Although 70% of patients with systemic amyloidosis have cardiac involvement the diagnosis is made by cardiologists only 20% of the time, suggesting significant gaps in knowledge in how to establish a workflow to arrive at a diagnosis in everyday practice.

Describing mode of death in three major cardiac amyloidosis subtypes to improve management and survival

BACKGROUND

The three main cardiac amyloidosis (CA) types have different progression and prognosis. Little is known about the mode of death (MOD) which is commonly attributed to cardiovascular causes in CA. Improving MOD's knowledge could allow to adapt patient care.

OBJECTIVE

This retrospective study describes the MOD that occurred during long-term follow-up in CA patients in light-chain (AL), transthyretin hereditary (ATTRv) or wild-type (ATTRwt).

MATERIAL AND METHODS

Patients referred to and cared for, at the French referral centre for CA, Henri Mondor Hospital, Créteil between 2010 and 2016 were included. Clinical information surrounding patient deaths were investigated and centrally evaluated by two blinded clinical committees which classified MOD as cardiovascular, non-cardiovascular or unknown and sub-classified it depending on its subtype.

RESULTS

From the 566 patients included, 187 had AL, 206 ATTRv and 173 ATTRwt. During the 864 patient-year follow-up, 160 (28%) deaths occurred, with median survival time of 17.3 months (interquartile range 5.1-35.4). The most frequent MOD was cardiovascular (64%) of which worsening heart failure occurred most frequently and for which, 69% were of AL subtype, 79% ATTRv and 76% ATTRwt. Sudden death also occurred more frequently in AL subtype accounting for 29% of AL deaths. Non-cardiovascular MOD occurred in 26% of patients overall. Among these, infection was the most common non-cardiovascular MOD in any type of CA (80%).

CONCLUSIONS

Mortality is high during natural course of CA and differs between subtypes. The main MOD were worsening heart failure, sudden death and infection, opening room to optimise management.

[Cardiac arrhythmias and amyloidosis]

Cardiac amyloidosis (CA) is a form of cardiomyopathy characterized by the extracellular deposit of protein fibers in the myocardium, leading to the development of heart failure, arrhythmias, and electrical conduction system alterations. It is known that most cardiomyopathies have a close relationship with heart rhythm abnormalities, however, CA is specially related to different kinds of arrhythmias even in pre-diagnosis stages. Arrhythmias like atrial fibrillation are present in up to 70% of patients with CA associated with a high risk of cardioembolic complications independent of the risk stratification. Ventricular arrhythmias are frequent, but the use of implantable cardioverter defibrillator has not been demonstrated to improve survival. The Atrial-Ventricular node disease is also common, and is frequently associated with the implantation of a pacemaker, even in asymptomatic patients. In this review, we clarify the recommendations of the most current guidelines, summarize historical and contemporaneous data and describe evidence-based strategies for the management of arrhythmias and their complications in CA.

Ventricular arrhythmia burden and implantable Cardioverter-defibrillator outcomes in transthyretin cardiac amyloidosis

BACKGROUND

As targeted treatments for amyloid transthyretin cardiomyopathy (ATTR-CM) are becoming available, we aim to characterize the rates of ventricular arrhythmias (VAs), implantable cardioverter-defibrillator (ICD) utilization, and their impact on survival.

METHODS

This is a retrospective cohort study of 130 patients with ATTR-CM diagnosed at Emory University's Cardiac Amyloidosis Center between April 2012 and September 2020. VAs were defined as non-sustained or sustained ventricular tachycardia and ventricular fibrillation.

RESULTS

Of 130 patients, 42 had wild-type disease (wtATTR) and 88 had hereditary variants (hATTR), most commonly Val122Ile (89%). At ATTR-CM diagnosis, 80 (62%) patients had EF ≤ 40% consistent with systolic heart failure. Of the 69 (53%) patients with documented VAs significantly higher rates occurred among those with EF ≤ 40% compared with EF > 40% (67% vs 28%, p = 0.001). Thirty-two patients (25 hATTR, 7 wtATTR) had primary prevention ICDs implanted. Eight (25%) of these patients received appropriate ICD therapy while two (6%) experienced inappropriate therapy. Comparing patients with EF ≤ 35% with and without ICDs did not reveal any survival difference (3.3 ± 0.5 vs. 2.8 ± 0.4 years, p = 0.699).

CONCLUSIONS

High rates of VAs and appropriate ICD therapy were found amongst a unique cohort of largely hereditary ATTR-CM patients with a high rate of systolic heart failure. This article is protected by copyright. All rights reserved.

The Arrhythmic Phenotype in Cardiomyopathy

In the wide phenotypic spectrum of cardiomyopathies, sudden cardiac death (SCD) has always been the most visible and devastating disease complication. The introduction of implantable cardioverter-defibrillators for SCD prevention by the late 1980s has moved the question from how to whom we should protect from SCD, leaving clinicians with a measure of uncertainty regarding the most reliable option to guide identification of the highest-risk patients. In this review, we will go through all the available evidence in the field of arrhythmic expression and arrhythmic risk stratification in the different phenotypes of cardiomyopathies to provide practical suggestions in daily clinical management.

ATTR Amyloidosis: Current and Emerging Management Strategies: JACC: CardioOncology State-of-the-Art Review

Transthyretin cardiac amyloidosis (ATTR-CA) is increasingly diagnosed owing to the emergence of noninvasive imaging and improved awareness. Clinical penetrance of pathogenic alleles is not complete and therefore there is a large cohort of asymptomatic transthyretin variant carriers. Screening strategies, monitoring, and treatment of subclinical ATTR-CA requires further study. Perhaps the most important translational triumph has been the development of effective therapies that have emerged from a biological understanding of ATTR-CA pathophysiology. These include recently proven strategies of transthyretin protein stabilization and silencing of transthyretin production. Data on neurohormonal blockade in ATTR-CA are limited, with the primary focus of medical therapy on judicious fluid management. Atrial fibrillation is common and requires anticoagulation owing to the propensity for thrombus formation. Although conduction disease and ventricular arrhythmias frequently occur, little is known regarding optimal management. Finally, aortic stenosis and ATTR-CA frequently coexist, and transcatheter valve replacement is the preferred treatment approach.

Electrophysiological Manifestations of Cardiac Amyloidosis: JACC: CardioOncology State-of-the-Art Review

Cardiac amyloidosis (CA) is an infiltrative cardiomyopathy caused by the extracellular deposition of amyloid fibrils in the myocardium. Although cardiac amyloidosis patients primarily present with heart failure symptoms, arrhythmias and conduction system disease are frequently encountered. Atrial fibrillation (AF) is observed in up to 70% of patients at the time of diagnosis, and patients typically have controlled ventricular rates caused by concomitant conduction system disease. Thromboembolic risk is particularly high in patients with CA and AF, and left atrial thrombi have been observed even in the absence of clinically diagnosed AF. Atrioventricular nodal and infra-Hisian disease are common, and permanent pacemakers are frequently required. The use of implantable cardioverter-defibrillators in this population is controversial. This review summarizes the published data and therapeutic strategies surrounding arrhythmias and conduction system disease with the goal of aiding clinicians managing the clinical complexities of CA.

Cardiovascular outcomes after cardiac resynchronization therapy in cardiac amyloidosis

Aims

Cardiac resynchronization therapy (CRT) is highly effective in dilated cardiomyopathy (DCM) patients with impaired left ventricular ejection fraction (LVEF) and left bundle block branch. In cardiac amyloidosis (CA) patients, left ventricular dysfunction and conduction defects are common, but the potential of CRT to improve cardiac remodelling and survival in this particular setting remains undefined. We investigated cardiovascular outcomes in CA patients after CRT implantation in terms of CRT echocardiographic response and major cardiovascular events (MACEs).

Methods and results

Our retrospective study included 47 CA patients implanted with CRT devices from January 2012 to February 2020, in nine French university hospitals (77 ± 6 years old, baseline LVEF 30 ± 8%) compared with propensity‐matched (1:1 for age, LVEF at implantation, and CRT indication) DCM patients with a CRT device. CA patients had lower rates of CRT response (absolute delta LVEF ≥ 10%) compared with DCM patients (36% vs. 70%, P = 0.002). After multivariate Cox analysis, CA was independently associated with MACE (hospitalization for heart failure/cardiovascular death) [hazard ratio (HR) 3.73, 95% confidence interval (CI) 1.85–7.54, P < 0.001], along with the absence of CRT response (HR 3.01, 95% CI 1.56–5.79, P = 0.001). The presence of echocardiographic CRT response (absolute delta LVEF ≥ 10%) was the only predictive factor of MACE‐free survival in CA patients (HR 0.36, 95% CI 0.15–0.86, P = 0.002).

Conclusion

Compared with a matched cohort of DCM patients, CA patients had a lower rate of CRT response and consequently a worse cardiovascular prognosis after CRT implantation. However, CRT could be beneficial even in CA patients given that CRT response was associated with better cardiac outcomes in this population.

Progress and challenges in the treatment of cardiac amyloidosis: a review of the literature

Cardiac amyloidosis is a restrictive cardiomyopathy determined by the accumulation of amyloid, which is represented by misfolded protein fragments in the cardiac extracellular space. The main classification of systemic amyloidosis is determined by the amyloid precursor proteins causing a very heterogeneous disease spectrum, but the main types of amyloidosis involving the heart are light chain (AL) and transthyretin amyloidosis (ATTR). AL, in which the amyloid precursor is represented by misfolded immunoglobulin light chains, can involve almost any system carrying the worst prognosis among amyloidosis patients. This has however dramatically improved in the last few years with the increased usage of the novel therapies such as proteasome inhibitors and haematopoietic cell transplantation, in the case of timely diagnosis and initiation of treatment. The treatment for AL is directed by the haematologist working closely with the cardiologist when there is a significant cardiac involvement. Transthyretin (TTR) is a protein that is produced by the liver and is involved in the transportation of thyroid hormones, especially thyroxine and retinol binding protein. ATTR results from the accumulation of transthyretin amyloid in the extracellular space of different organs and systems, especially the heart and the nervous system. Specific therapies for ATTR act at various levels of TTR, from synthesis to deposition: TTR tetramer stabilization, oligomer aggregation inhibition, genetic therapy, amyloid fibre degradation, antiserum amyloid P antibodies, and antiserum TTR antibodies. Treatment of systemic amyloidosis has dramatically evolved over the last few years in both AL and ATTR, improving disease prognosis. Moreover, recent studies revealed that timely treatment can lead to an improvement in clinical status and in a regression of amyloid myocardial infiltration showed by imaging, especially by cardiac magnetic resonance, in both AL and ATTR. However, treating cardiac amyloidosis is a complex task due to the frequent association between systemic congestion and low blood pressure, thrombo-embolic and haemorrhagic risk balance, patient frailty, and generally poor prognosis. The aim of this review is to describe the current state of knowledge regarding cardiac amyloidosis therapy in this constantly evolving field, classified as treatment of the cardiac complications of amyloidosis (heart failure, rhythm and conduction disturbances, and thrombo-embolic risk) and the disease-modifying therapy.

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.

Recent advances in the diagnosis and management of amyloid cardiomyopathy

Amyloidosis is a disorder characterized by misfolded precursor proteins that form depositions of fibrillar aggregates with an abnormal cross-beta-sheet conformation, known as amyloid, in the extracellular space of several tissues. Although there are more than 30 known amyloidogenic proteins, both hereditary and non-hereditary, cardiac amyloidosis (CA) typically arises from either misfolded transthyretin (ATTR amyloidosis) or immunoglobulin light-chain aggregation (AL amyloidosis). Its prevalence is more common than previously thought, especially among patients with heart failure and preserved ejection fraction (HFpEF) and aortic stenosis. If there is a clinical suspicion of CA, focused echocardiography, laboratory screening for the presence of a monoclonal protein (serum and urinary electrophoresis with immunofixation and serum free light-chain ratio), and cardiac scintigraphy with 99mtechnetium-labeled bone-tracers are sensitive and specific initial diagnostic tests. In some cases, more advanced/invasive techniques are necessary and, in the last several years, treatment options for both AL CA and ATTR CA have rapidly expanded. It is important to note that the aims of therapy are different. Systemic AL amyloidosis requires treatment targeted against the abnormal plasma cell clone, whereas therapy for ATTR CA must be targeted to the production and stabilization of the TTR molecule. It is likely that a multistep treatment approach will be optimal for both AL CA and ATTR CA. Additionally, treatment of CA includes the management of restrictive cardiomyopathy with preserved or reduced ejection fraction in addition to treating the amyloid deposition. Future studies are necessary to define optimal management strategies for AL CA and ATTR CA and confirm cardiac response to therapy.

A case of AL amyloidosis presenting with refractory ventricular fibrillation

A 66-year-old male with recent diagnosis of heart failure with reduced ejection fraction was referred to our institution for management of cardiogenic/vasodilatory shock. During his evaluation, he suffered a sudden cardiac arrest from refractory ventricular tachycardia/fibrillation (VT/VF) despite normal electrolytes and no evidence of prior ventricular arrhythmias. He was placed on rescue peripheral veno-arterial extracorporeal membrane oxygenation support (VA-ECMO) for 4 days and was decannulated without end-organ damage. Continued workup revealed Mayo stage IV immunoglobulin light chain (AL) amyloidosis. Unfortunately, he developed acute cerebellar hemorrhage several days later. Autopsy findings were consistent with AL amyloidosis, with extensive cardiac fibrosis and amyloid deposition in the myocardium and vasculature. While the most common cause of cardiac death in patients with amyloidosis is severe bradycardia and pulseless electrical activity, sustained ventricular arrhythmias have been reported. The use of implantable cardioverter defibrillators (ICD) is highly debated in this population given the lack of survival benefit. Our patient also developed refractory VT/VF arrest, and ICD shocks would not have rescued him while causing significant distress. Emergent VA-ECMO cannulation allowed us to make a diagnosis, yet this intervention cannot be routinely recommended given the limited survival of patients with AL amyloidosis.

Sustained Ventricular Tachycardia as a Harbinger of Cardiac Amyloidosis

Patient: Male, 71-year-old

Final Diagnosis: Cardiac amyloidosis

Symptoms: Diaphoresis • presyncope • shortness of breath

Medication: —

Clinical Procedure: Electrical cardioversion

Specialty: Cardiology

Natural history and impact of treatment with tafamidis on major cardiovascular outcome-free survival time in a cohort of patients with transthyretin amyloidosis

AIMS

Hereditary (ATTRv) and wild-type (ATTRwt) transthyretin amyloidosis are severe and fatal systemic diseases, characterised by amyloid fibrillar accumulation principally in the heart or peripheral nerves (or both). Since 2012, tafamidis has been used in France to treat patients with ATTRv with neuropathy (alone or combined with cardiomyopathy). Recently, the Phase III ATTR-ACT trial showed that tafamidis decreased the relative risk of mortality in ATTR amyloidosis with cardiomyopathy. The aims of this study were to assess the clinical characteristics of ATTR amyloidosis in a real-life population in comparison to the population included in the ATTR-ACT trial and to assess the impact of tafamidis treatment on major cardiovascular outcome (MCO)-free survival time without cardiac decompensation, heart transplant, or death.

METHODS AND RESULTS

From June 2008 to November 2018, 648 patients with ATTR amyloidosis (423 ATTRwt and 225 ATTRv) consecutively referred to the French Referral Center for cardiac amyloidosis were included. A total of 467 (72%) patients matched the inclusion criteria of the ATTR-ACT trial. For the 631 patients with cardiomyopathy, tafamidis treatment was associated with a longer median MCO-free survival time (n = 98): 1565 (1010-2400) days vs. 771 (686-895) days without treatment (log-rank P < 0.001). This association was confirmed after considering confounding factors (age at inclusion, N-terminal pro-B-type natriuretic peptide and amyloidosis type) with a propensity score (hazard ratio 0.546; P = 0.0132).

CONCLUSION

In a large cohort of ATTRwt and ATTRv patients, representative of the inclusion criteria of the ATTR-ACT trial, the present results show an association between tafamidis treatment and a lower occurrence of cardiovascular outcomes in a real-life population.

Ventricular Arrhythmias in Cardiac Amyloidosis: A Review of Current Literature

Cardiac Amyloidosis is an infiltrative cardiomyopathy which occurs secondary to deposition of mis-folded protein in the myocardium, with the two most common subtypes being AL amyloidosis and TTR amyloidosis. The pathogenesis of the disease is multifaceted and involves a variety of mechanisms including an inflammatory response cascade, oxidative stress and subsequent separation of myocyte fibrils. Cardiac Amyloidosis frequently results in congestive cardiac failure and arrhythmias, from a disruption in cardiac substrate with subsequent electro-mechanical remodelling. Disease progression is usually demonstrated by development of progressive pump failure, which may be seen with a high arrhythmic burden, usually portending a poor prognosis. There is a paucity of literature on the clinical implications of ventricular arrhythmias in the context of cardiac amyloidosis. The important diagnostic investigations for these patients include transthoracic echocardiography, cardiac magnetic resonance imaging and an electrophysiology study. Whilst there are no robust management guidelines, studies have indicated benefits from contemporary pharmacological therapy and case-by-case catheter ablation. There are novel directed therapies available for TTR amyloidosis that have shown to improve overall survival. The role of ICD therapy in cardiac amyloidosis is controversial, with benefits seen predominantly in early phases of the disease process. The only definitive surgical therapy includes heart transplantation, but is largely indicated for progressive decompensated heart failure (Figure 1). Further large-scale studies are required to better outline management paradigms for treating ventricular arrhythmias in cardiac amyloidosis.

Cardiac Implantable Electronic Devices: A Window Into the Evolution of Conduction Disease in Cardiac Amyloidosis

OBJECTIVES

This study characterized the relationship between conduction disease and cardiac amyloidosis (CA) through longitudinal analysis of cardiac implantable electronic device (CIED) data.

BACKGROUND

Bradyarrhythmias and tachyarrhythmias are commonly reported in CA and may precede a CA diagnosis, although the natural history of conduction disease in CA is not well-described.

METHODS

Patients with CA (transthyretin amyloidosis cardiomyopathy [ATTR-CM] and light-chain amyloidosis [AL-CA]) and a CIED were identified within the Duke University Health System. Patient characteristics at the time of implantation, including demographics and data relevant to CA diagnosis, cardiac imaging, and CIED were recorded. CIED interrogations were analyzed for pacing and atrial fibrillation (AF) burden, activity level, lead parameters, and ventricular arrhythmia incidence and/or therapy.

RESULTS

Thirty-four patients with CA (7 with AL-CA, 27 with ATTR-CM [78% with wild-type]; 82% men) with median age of 75 years and a mean ejection fraction of 42 ± 13% had a CIED implanted for bradycardia (65%) or prevention of sudden cardiac death (35%). CIED implantation preceded CA diagnosis in 14 patients (41%). Over a mean follow-up of 3.1 ± 4.0 years, right ventricular sensing amplitudes decreased but did not result in device malfunction; lead impedances and capture thresholds remained stable. Between post-implantation years 1 and 5, mean ventricular pacing increased from 56 ± 9% to 96 ± 1% (p = 0.003) and AF burden increased from 2 ± 1.3 to 17 ± 3 h/day (p = 0.0002). Ventricular arrhythmias were common (mean episodes per patient per year: 6.7 ± 2.3 [ATTR-CM] and 5.1 ± 3.2 [AL-CA]) but predominately nonsustained; only 1 patient with AL-CA required implantable cardioverter-defibrillator therapy.

CONCLUSIONS

Longitudinal analysis of CIED data in patients with CA revealed progressive conduction disease, with high AF burden and eventual dependence on ventricular pacing, although lead parameters remained stable. Ventricular arrhythmias were common but predominantly nonsustained, particularly in ATTR-CM.

Survival Following Implantable Cardioverter-Defibrillator Implantation in Patients With Amyloid Cardiomyopathy

Background Outcomes data in patients with cardiac amyloidosis after implantable cardioverter-defibrillator (ICD) implantation are limited. We compared outcomes of patients with ICDs implanted for cardiac amyloidosis versus nonischemic cardiomyopathies (NICMs) and evaluated factors associated with mortality among patients with cardiac amyloidosis. Methods and Results Using National Cardiovascular Data Registry's ICD Registry data between April 1, 2010 and December 31, 2015, we created a 1:5 propensity-matched cohort of patients implanted with ICDs with cardiac amyloidosis and NICM. We compared mortality between those with cardiac amyloidosis and matched patients with NICM using Kaplan-Meier survival curves and Cox proportional hazards models. We also evaluated risk factors associated with 1-year mortality in patients with cardiac amyloidosis using multivariable Cox proportional hazards regression models. Among 472 patients with cardiac amyloidosis and 2360 patients with propensity-matched NICMs, 1-year mortality was significantly higher in patients with cardiac amyloidosis compared with patients with NICMs (26.9% versus 11.3%, P<0.001). After adjustment for covariates, cardiac amyloidosis was associated with a significantly higher risk of all-cause mortality (hazard ratio [HR], 1.80; 95% CI, 1.56-2.08). In a multivariable analysis of patients with cardiac amyloidosis, several factors were significantly associated with mortality: syncope (HR, 1.78; 95% CI, 1.22-2.59), ventricular tachycardia (HR, 1.65; 95% CI, 1.15-2.38), cerebrovascular disease (HR, 2.03; 95% CI, 1.28-3.23), diabetes mellitus (HR, 1.55; 95% CI, 1.05-2.27), creatinine = 1.6 to 2.5 g/dL (HR, 1.99; 95% CI, 1.32-3.02), and creatinine >2.5 (HR, 4.34; 95% CI, 2.72-6.93). Conclusions Mortality after ICD implantation is significantly higher in patients with cardiac amyloidosis than in patients with propensity-matched NICMs. Factors associated with death among patients with cardiac amyloidosis include prior syncope, ventricular tachycardia, cerebrovascular disease, diabetes mellitus, and impaired renal function.

Impact of Genetic Testing in Transthyretin (ATTR) Cardiac Amyloidosis

PURPOSE OF REVIEW

The review's main focus centers on the genetics of hereditary cardiac amyloidosis, highlighting the opportunities and challenges posed by the widespread availability of genetic screening and diagnostic cardiac imaging.

RECENT FINDINGS

Advancements in cardiac imaging, heightened awareness of the ATTR amyloidosis diagnosis, and greater access to genetic testing have all led to an increased appreciation of the prevalence of ATTR cardiac amyloidosis. Elucidation of the TTR molecular structure and effect of mutations on TTR function have allowed for novel TTR therapy development leading to clinical implementation of transthyretin stabilizers and transthyretin gene silencers. The transthyretin amyloidoses are a diverse group of protein misfolding disorders with cardiac and peripheral/autonomic nervous system manifestations due to protein deposition. Genetic screening allows for the early identification of asymptomatic TTR mutation carriers. With the advent of TTR-specific therapeutics, clinical guidance is necessary for the management of individuals with mutations in the TTR gene without evidence of disease.

Primary prevention implantable cardioverter-defibrillators in transthyretin cardiac amyloidosis

BACKGROUND

Due to the poor long-term prognosis of patients with transthyretin cardiac amyloidosis (ATTR-CA), the role of primary prevention implantable cardioverter-defibrillators (ICDs) in this patient population remains controversial. We aimed to study the impact of primary prevention ICDs on survival in patients with ATTR-CA.

METHODS

Among 382 patients diagnosed with ATTR-CA at our institution between 2004 and 2018, 19 had primary prevention ICDs implanted. This cohort was matched in a 1:3 manner on the basis of age, gender, ejection fraction (EF) and ATTR-CA stage with 57 patients without cardiac devices. Patients were followed up for a mean of 23 ± 19 months. Our primary outcome of interest was all-cause mortality.

RESULTS

Mean EF at the time of ICD implantation was 28 ± 8%. No patients had a history of sustained ventricular arrhythmia (VA) at the time of implant. Only a minority of patients were tolerant of optimal medical therapy due to renal impairment, hypotension, or a combination of the two. Death occurred in 43 (75%) patients without primary prevention ICDs and 16 (84%) patients with primary prevention ICDs, P = .26. Of the 19 patients with ICDs, three had inappropriate shocks delivered for atrial fibrillation, and none had therapies for sustained VAs. On Cox proportional hazards analyses, the presence of a primary prevention ICD was not associated with improved survival (HR 0.72, 95% CI 0.4-1.3, P = .27).

CONCLUSION

Primary prevention ICDs do not prolong survival in patients with ATTR-CA and a reduced EF. Our findings are observational and will need to be validated in future prospective studies.

Deleterious effect of right ventricular pacing in patients with cardiac transthyretin amyloidosis: potential clinical benefit of cardiac resynchronization therapy

Background

Cardiac amyloidosis involvement is associated with a detrimental outcome including frequent arrhythmias, heart failure, and conduction disturbances which may need permanent pacing.

Cases summary

We report two cases of patients with transthyretin amyloidosis (ATTR) who developed heart failure and depressed left ventricular ejection fraction (LVEF) following permanent right ventricular (RV) pacing but highly responded to cardiac resynchronization therapy (CRT).

Discussion

The impact of RV pacing and CRT in cardiac amyloidosis is not known. In our cases, the detrimental effect of permanent RV pacing on left ventricular (LV) systolic function and heart failure symptoms was suggested by both permanent RV pacing mediated functional and LV function decline and LV systolic dysfunction reversal following CRT along with QRS width reduction. Whether cardiac resynchronization should be readily recommended in ATTR patients who need ventricular pacing whatever the LVEF deserves further investigation.

Effect of ICD implantation on cardiovascular outcomes in patients with cardiac amyloidosis: A systematic review and meta-anaylsis

INTRODUCTION

Cardiac amyloidosis is associated with a high rate of sudden cardiac death (SCD). Whether implantable cardioverter-defibrillator (ICD) use in such patients prevents SCD is uncertain. This study assesses outcomes of ICD use in patients with cardiac amyloidosis.

METHODS

A systematic review and meta-analysis of data were performed after searching multiple databases and scientific sites pertaining to ICD use and cardiac amyloidosis. Of 8260 citations identified, six studies comprising 194 patients met inclusion criteria.

RESULTS

Mean values and frequencies of patient characteristics were as follows: mean NT-proBNP: 6867.9 pg/mL, mean left ventricular ejection fraction: 48.1%, heart failure: 67%, nonsustained ventricular tachycardia: 51%, syncope: 21%, and secondary prevention: 33%. During the mean follow-up period of 18.21 months, 18% of patients received appropriate ICD treatment and 5% received inappropriate ICD treatment. The mortality rate was 31%. Two studies assessed the difference between patients with appropriate ICD treatment and patients with absence of appropriate ICD treatment. There was no difference between the two groups when stratified on multiple selected third variables except for two subgroups. Male gender was associated with a higher rate of appropriate ICD treatment, whereas New York Heart Association class III or IV heart failure patients was associated with a lower rate of appropriate ICD treatment.

CONCLUSION

The frequency of appropriate ICD treatment in cardiac amyloidosis is low and is not predicted by nonsustained ventricular tachycardia. Male gender is associated with appropriate ICD treatment. New York Heart Association class III or IV heart failure is associated with lower rate of appropriate ICD treatment.

Cardiac Amyloidosis: Evolving Diagnosis and Management: A Scientific Statement From the American Heart Association

Transthyretin amyloid cardiomyopathy (ATTR-CM) results in a restrictive cardiomyopathy caused by extracellular deposition of transthyretin, normally involved in the transportation of the hormone thyroxine and retinol-binding protein, in the myocardium. Enthusiasm about ATTR-CM has grown as a result of 3 simultaneous areas of advancement: Imaging techniques allow accurate noninvasive diagnosis of ATTR-CM without the need for confirmatory endomyocardial biopsies; observational studies indicate that the diagnosis of ATTR-CM may be underrecognized in a significant proportion of patients with heart failure; and on the basis of elucidation of the mechanisms of amyloid formation, therapies are now approved for treatment of ATTR-CM. Because therapy for ATTR-CM may be most effective when administered before significant cardiac dysfunction, early identification of affected individuals with readily available noninvasive tests is essential. This scientific statement is intended to guide clinical practice and to facilitate management conformity by covering current diagnostic and treatment strategies, as well as unmet needs and areas of active investigation in ATTR-CM.

Cardiac Care of Patients with Cardiac Amyloidosis

Cardiac amyloidosis, the majority of cases of which are due to immunoglobulin light chain amyloidosis (AL) and transthyretin amyloidosis (ATTR), affects different aspects of the heart and cardiovascular system. Amyloid-induced cardiomyopathy, clinically manifesting with heart failure and electrophysiological abnormalities, has distinct characteristics compared to non-amyloid cardiomyopathies. Accordingly, specific management strategies are required. This paper will review the cardiovascular manifestations of patients with cardiac amyloidosis and their suggested treatment strategies, emphasizing the importance of multidisciplinary care.

What the Intensivists Need to Know About Critically Ill Myeloma Patients

Multiple myeloma (MM) is a hematological malignancy characterized by an increase in aberrant plasma cells in the bone marrow leading to rising monoclonal protein in serum and urine. With the introduction of novel therapies with manageable side effects, this incurable disease has evolved into a chronic disease with an acceptable quality of life for the majority of patients. Accordingly, management of acute complications is fundamental in reducing the morbidity and mortality in MM. MM emergencies include symptoms and signs related directly to the disease and/or to the treatment; many organs may be involved including, but not limited to, renal, cardiovascular, neurologic, hematologic, and infectious complications. This review will focus on the numerous approaches that are aimed at managing these complications.

Use of Implantable Electronic Devices in Patients With Cardiac Amyloidosis

Arrhythmias are a major cause of morbidity and mortality in the course of cardiac amyloidosis (CA). Less commonly, they may be the initial manifestation that lead to the diagnosis. With improved therapeutic interventions for amyloidosis, it is no longer considered to be a terminal untreatable condition, and there is increasing recognition of the role of implantable electronic devices in CA. The frequency and nature of arrhythmias are largely determined by the type of amyloidosis. Bradyarrhythmias are more common in the transthyretin form of amyloidosis, and risk for ventricular arrhythmias is higher in the light-chain form. Pacemaker implantation is often required and effective for alleviation of symptoms. The role of implantable cardioverter-defibrillators (ICDs) remains controversial, especially for primary prevention of sudden death. Traditional risk stratification tools for sudden death do not appear to be applicable to CA, because decline of left ventricular (LV) systolic dysfunction to the point of the usual indication for an ICD implant in other cardiomyopathies, ie, LV ejection fraction ≤ 35%, usually marks end-stage disease in CA when pump failure becomes the predominant cause of death. The challenge remains the identification of markers for sudden death in early stages of the disease. Included in this review is a general overview of available data on the nature of bradycardia and ventricular arrhythmias, including the role of implantable electronic devices for the treatment of these conditions. Published series of ICD use in CA are summarized and the role of newer pacing techniques, including biventricular pacing, is discussed.

Strategies to improve the quality of life in patients with hereditary transthyretin amyloidosis (hATTR) and autonomic neuropathy

Purpose

Hereditary transthyretin amyloidosis (hATTR) is a severe adult-onset progressive disease mainly involving the peripheral nervous system and the heart, with a prominent impact on the autonomic nervous system. This review summarizes the clinical aspects of autonomic dysfunction in hATTR, and their impact on quality of life as well as potential therapeutic options.

Methods

Literature review.

Results

Autonomic dysfunction, causing neurogenic orthostatic hypotension, gastroparesis, constipation, diarrhea, bladder dysfunction, and erectile dysfunction in males, has a major impact on the quality of life of patients with hATTR. Improvement of qualify of life in patients with hATTR implies periodic symptomatic screening and early management, taking into consideration comorbidities and medication side effects. The specific effect of the disease-modifying treatment on this aspect remains to be unraveled.

Conclusions

Management of autonomic dysfunction in patients with hAATR is feasible and can result in improved qualify of life. Novel disease-modifying treatments for hAATR may contribute to improve autonomic dysfunction, although specific studies are required.

AL Amyloidosis for the Cardiologist and Oncologist: Epidemiology, Diagnosis, and Management

AL amyloidosis results from clonal production of immunoglobulin light chains, most commonly arising from a clonal plasma cell disorder. Once considered a nearly uniformly fatal disease, prognosis has improved markedly over the past 15 years, predominantly because of advances in light chain suppressive therapies. Cardiac deposition of amyloid fibrils is common, and the severity of cardiac involvement remains the primary driver of prognosis. Improvements in chemotherapy/immunotherapy have prompted a reassessment of the role of advanced cardiac therapies previously considered contraindicated in most patients, including the role of implantable cardioverter-defibrillators and cardiac transplantation. This state-of-the-art review highlights the current state of the field, including diagnosis, prognosis, and hematologic- and cardiac-specific therapies.

Cardiac amyloidosis: An underdiagnosed/underappreciated disease

Cardiac amyloidosis or amyloid cardiomyopathy (ACM), commonly resulting from extracellular deposition of amyloid fibrils consisted of misfolded immunoglobulin light chain (AL) or transthyretin (TTR) protein, is an underestimated cause of heart failure and cardiac arrhythmias. Among the three types of cardiac amyloidosis (wild-type or familial TTR and light-chain), the wild-type (Wt) TTR-related amyloidosis (ATTR) is an increasingly recognized cause of heart failure with preserved ejection fraction (HFpEF), and amyloidosis should be considered in the differential diagnosis of this heart failure group of patients. Recent advances in the diagnosis and drug treatment of ACM have ushered in a new era in early disease detection and better management of these patients. Certain clues in cardiac and extracardiac manifestations of ACM may heighten clinical suspicion and guide further confirmatory testing. Newer noninvasive imaging methods (strain echocardiography, cardiac magnetic resonance and bone scintigraphy) may obviate the need for endomyocardial biopsy in ATTR patients, while newer targeted therapies may alter the adverse prognosis in these patients. Early recognition of ACM is crucial in halting the disease process before irreversible organ damage occurs. Chemotherapy and stem-cell transplantation combined with immunomodulatory therapy may also favorably affect the course and prognosis of light chain ACM. Finally, in select patients with end-stage disease, heart transplantation may render results comparable to non-ACM patients. All these issues are herein reviewed.

Prevalence of cardiac amyloidosis among elderly patients with systolic heart failure or conduction disorders

Objective: Cardiac amyloid infiltration can lead to systolic heart failure (HF) or to conduction disorders (CD). Patients with transthyretin (ATTR) amyloidosis are particularly exposed. We sought to determine the prevalence of ATTR and AL among patients >60 years admitted with CD or unexplained systolic HF and increased wall thickness. Materials and Methods: We studied 143 patients (57% males, 79 ± 9 years) with HF (N = 28) or CD requiring pacemaker implantation (N = 115). In total, 139 (97%) patients (28 with HF and 111 with CD) underwent ^99mTc-DPD scintigraphy to detect ATTR, and 105 (73%; 19 HF and 86 CD) underwent AL screening. Results: Five patients (4%; 95%CI:0-7%) exhibited wild-type ATTR (ATTRwt) amyloidosis, 2 (2%; 95%CI:0-4%) had CD and 3 (11%; 95%CI:0-23%) HF. No patient showed AL. The 2 ATTRwt patients with CD were previously asymptomatic, did not show classical ECG signs and exhibited mild LV hypertrophy with preserved LVEF. By contrast, all ATTRwt patients with HF had ECG and echocardiographic signs of amyloid. During a mean follow-up of 18 ± 11 months, 3(60%) patients with ATTRwt amyloidosis (1 CD and 2 HF) and 14(10.4%) without died. Conclusion: Prevalence of ATTRwt amyloidosis in patients with CD requiring pacemaker is low. Although, additional studies are needed, prevalence seems to be higher in elderly patients with systolic HF.