Heart transplantation in cardiac amyloidosis

Cardiac transplantation in transthyretin amyloid cardiomyopathy: Outcomes from three decades of tertiary center experience

Aims

Transthyretin cardiac amyloidosis (ATTR-CM) is a progressive and fatal cardiomyopathy. Treatment options in patients with advanced ATTR-CM are limited to cardiac transplantation (CT). Despite case series demonstrating comparable outcomes with CT between patients with ATTR-CM and non-amyloid cardiomyopathies, ATTR-CM is considered to be a contraindication to CT in some centers, partly due to a perceived risk of amyloid recurrence in the allograft. We report long-term outcomes of CT in ATTR-CM at two tertiary centers.

Materials and methods and Results

We retrospectively evaluated ATTR-CM patients across two tertiary centers who underwent transplantation between 1990 and 2020. Pre-transplantation characteristics were determined and outcomes were compared with a cohort of non-transplanted ATTR-CM patients. Fourteen (12 male, 2 female) patients with ATTR-CM underwent CT including 11 with wild-type ATTR-CM and 3 with variant ATTR-CM (ATTRv). Median age at CT was 62 years and median follow up post-CT was 66 months. One, three, and five-year survival was 100, 92, and 90%, respectively and the longest surviving patient was Censored > 19 years post CT. No patients had recurrence of amyloid in the cardiac allograft. Four patients died, including one with ATTRv-CM from complications of leptomeningeal amyloidosis. Survival among the cohort of patients who underwent CT was significantly prolonged compared to UK patients with ATTR-CM generally (p < 0.001) including those diagnosed under age 65 years (p = 0.008) or with early stage cardiomyopathy (p < 0.001).

Conclusion

CT is well-tolerated, restores functional capacity and improves prognosis in ATTR-CM. The risk of amyloid recurrence in the cardiac allograft appears to be low.

Outcomes in patients with cardiac amyloidosis undergoing heart transplantation: the eurotransplant experience

BACKGROUND

When advanced heart failure occurs in cardiac amyloidosis, prognosis is poor. In this setting heart transplantation (HTX) is a treatment option for selected patients. We here present the results of post-transplantation outcomes in cardiac amyloidosis within the Eurotransplant area, investigating possible predictors of survival.

METHODS

Of 115 patients undergoing HTX due to cardiac amyloidosis in the Eurotransplant region between November 1987 and May 2020, detailed assessment prior to transplantation was available in 85 patients. The present study was conducted in a retrospective approach. Primary endpoint was mortality after HTX. Baseline variables were entered in a Cox proportional hazards model with the primary endpoint as a dependent variable.

RESULTS

Median overall survival following HTX was 6.3 years in the overall collective and the subgroup. Univariate Cox proportional hazards model revealed a significant relationship between overall survival and the transplantation period (2008 to 2020 vs 1987 to 2007; median survival 9.7 years vs 1.8 years, hazard ratio 0.45, p = 0.01). Further predictors were albumin concentration (hazard ratio 0.92, p < 0.001), and systolic blood pressure (hazard ratio 0.96, p < 0.001). The transplant period as well as albumin concentration remained significant independent predictors in the AL sub cohort in a multivariate Cox proportional hazards model.

CONCLUSIONS

HTX is a viable treatment option for patients at an advanced stage of cardiac amyloidosis as overall survival after transplantation has improved in the modern age. Patients at a very advanced stage of the disease, indicated by low serum albumin and blood pressure, show worse outcomes following HTX. Optimal timing and careful patient selection may therefore be particularly important to further improve post-HTX survival in amyloidosis patients.

Cardiac amyloidosis: a review of the literature

Cardiac amyloidosis is a rare disease associated with severe morbidity and mortality. There are three main types of amyloidosis associated with cardiac involvement: light chain (AL), familial or senile (ATTR) and secondary amyloidosis (AA). Cardiac amyloidosis often results in heart failure with preserved left ventricular ejection fraction, may display echocardiographic features of restrictive cardiomyopathy associated with left ventricular hypertrophy or mimic hypertrophic obstructive cardiomyopathy. However, left ventricular systolic dysfunction and normal wall thickness can sometimes be encountered. Imaging studies (echocardiography, bone scintigraphy, cardiac magnetic resonance) and blood and urine analysis are usually the main tools for the diagnosis. Sometimes, a tissue biopsy may be necessary. Treatment, which is constantly improving, will be carried out on two fronts: treatment of the symptoms and complications that the disease already caused and prevention of additional amyloid deposits while managing the concomitant complications. The purpose of this article is to review the management of cardiac amyloidosis.

Heart Transplantation, Either Alone or Combined With Liver and Kidney, a Viable Treatment Option for Selected Patients With Severe Cardiac Amyloidosis

Heart transplantation in cardiac amyloidosis (CA) patients is possible and generally considered for transplantation if other organs are not affected. In this study, we aimed to describe and assess outcome in patients following heart transplantations at our CA referral center.

Methods

We assessed all CA patients that had heart transplantations at our center between 2005 and 2018. Patients with New York Heart Association status 3 out of 4, with poor short-term prognosis due to heart failure, despite treatment, and without multiple myeloma, systemic disease, severe neuropathic/digestive comorbidities, cancer, or worsening infections were eligible for transplantation. Hearts were transplanted by bicaval technique. Standard induction and immunosuppressive therapies were used. Survival outcome of CA patients after transplantation was compared with recipients with nonamyloid pathologies in France.

Results

Between 2005 and 2018, 23 CA patients had heart transplants: 17 (74%) had light chain (light chain amyloidosis [AL]) and 6 (26%) had hereditary transthyretin (hereditary transthyretin amyloidosis [ATTRv]) CA. Also, 13 (57%) were male, and the mean age at diagnosis was 56.5 y (range, 47.7-62.8). Among AL patients, 13 had heart-only and 5 had heart-kidney transplantations. Among ATTRv patients, 1 had heart-only and 5 had heart-liver transplantations. The 1-y survival rate after transplantation was 78%, 70% with AL, and 100% with ATTRv. At 2 y, 74% were alive: 65% with AL and 100% with ATTRv.

Conclusion

After heart transplantation, French CA and nonamyloid patients have similar survival outcomes. Among CA patients, ATTRv patients have better prognosis than those with AL, possibly due to the combined heart-liver transplantation. Selected CA patients should be considered for heart transplantations.

The role of serial 99mTc-DPD scintigraphy in monitoring cardiac transthyretin amyloidosis

PURPOSE

Cardiac transthyretin amyloidosis is a usually fatal form of restrictive cardiomyopathy for which clinical trials of treatments are ongoing. It is anticipated that quantitative nuclear medicine scintigraphy, which is experiencing growing interest, will soon be used to evaluate treatment efficacy. We investigated its utility for monitoring changes in disease load over a significant time period.

METHODS

Sixty-two treatment-naive patients underwent ^99mTc-labelled 3,3-diphosphono-1,2propanodicarboxylic acid (^99mTc-DPD) scintigraphy two to four times each over a five-year period. Quantitation of cardiac ^99mTc-DPD retention was performed according to two established methods: measurement of heart-to-contralateral ratio (H/CL) in the anterior view (planar) and percentage of administered activity in the myocardium (SPECT).

RESULTS

In total 170 datasets were analysed. Increased myocardial retention of ^99mTc-DPD was demonstrable as early as 12 months from baseline. Year-on-year progression across the cohort was observed using SPECT-based quantitation, though on 30 occasions (27.8%) the change in our estimate was negative.

CONCLUSIONS

The spread of our results was notably high compared to the year-on-year increases. If left unaccounted for, variance may draw fallacious conclusions about changes in disease load. We therefore urge caution in drawing conclusions solely from nuclear medicine scintigraphy on a patient-by-patient basis, particularly across a short time period.

[Cardiac amyloidosis and aortic valve stenosis]

Aortic valve stenosis in old age has become a topic of interest for cardiology and cardiac surgery after the development of transvascular and transluminal minimally invasive techniques for aortic valve implantation. The observation of amyloid deposits in surgically excised valvular material led to the diagnostics of amyloidosis of the myocardium, which was discovered in up to 20% of the patients who underwent valve implantation. Clinical signs of cardiac amyloidosis, such as carpal tunnel syndrome and ruptured distal biceps tendon should be taken into account. In addition to the electrocardiogram (ECG), echocardiogram and magnetic resonance imaging, ^99mtechnetium bone scintigraphy plays a key diagnostic role. The simultaneous occurrence of severe aortic valve stenosis and amyloidosis explains the special hemodynamic situation of a low gradient with low blood flow in high-grade valve stenosis. The interventional or surgical valve implantation improves the prognosis for these patients, similarly to aortic valve stenosis alone, followed by a specific pharmaceutical treatment depending on the type of amyloidosis.

A Systematic Review of Tafamidis in Patients With Transthyretin Amyloid Cardiomyopathy

Transthyretin amyloid cardiomyopathy disease burden is increasing daily due to advancements in diagnostic and imaging modalities in the modern world. Tafamidis is one of many therapeutic options. The main objective of this review is to study the role of Tafamidis in slowing the progression of transthyretin cardiomyopathy (TTR-CM) by analyzing randomized controlled trials (RCTs) and non-RCTs of Tafamidis. We searched for published papers of Tafamidis in the English language in electronic databases like Google Scholar, PubMed, Cochrane Library, and PubMed Central. We imported the resulting articles from our search to Mendeley software. Four reviewers removed the duplicates and performed title and abstract screening of the articles. The same reviewers obtained the full-text of relevant articles and did full-text screening based on eligibility criteria. Finally, five reviewers performed a quality assessment of RCTs using the Cochrane risk of bias assessment and of non-RCTs by a checklist prepared by Downs and Black. Any disagreements about any process were resolved by a discussion with other authors. One RCT and five non-RCTs of Tafamidis were included in this systematic review. From the non-RCTs, stability was observed in different parameters like echocardiographic findings, cardiac biomarkers, and ECG in patients with transthyretin cardiomyopathy during the study duration with Tafamidis. ATTR-ACT (Tafamidis in Transthyretin Cardiomyopathy Clinical Trial) trial demonstrated reduction of cardiovascular events and all-cause mortality in the Tafamidis group in comparison to placebo. In both RCT and non-RCTs, Tafamidis was established as a safe and tolerable drug for patients with TTR-CM. Our study proved the role of Tafamidis in reducing cardiovascular events, all-cause mortality, and the progression of cardiac disease in TTR-CM patients. In addition to five non-RCTs, current evidence is based on the findings of only one RCT of Tafamidis. Hence, evidence from additional RCTs is required to strongly support the stability of parameters like echocardiographic findings, cardiac biomarkers, and ECG with Tafamidis use.

Improving contemporary outcomes following heart transplantation for cardiac amyloidosis

BACKGROUND

The incidence of systemic amyloidosis is rising, and there is a concomitant rise in heart transplant for an indication of cardiac amyloidosis.

METHODS

We utilized the Organ Procurement and Transplantation Network (OPTN) database to retrospectively assess survival and outcomes in adult patients undergoing heart transplant for cardiac amyloidosis from 1999 to 2019. We also compared survival among four distinct time periods: 1999-2001, 2002-2008, 2008-2015, 2016-2019.

RESULTS

Of 41,103 patients, 425 (1.03%) were transplanted for an indication of restrictive cardiomyopathy due to cardiac amyloidosis (RCM-Amyloidosis). The percent of all transplants occurring for RCM-Amyloidosis increased from 0.25% in the 1999-2001 era to 1.74% in the 2015-2019 era (p < .001). Across eras, Kaplan-Meier survival functions were comparable between RCM-Amyloidosis and non-RCM patients at 1 year (88% vs. 89%, p = .56) and at 5 years (72% vs. 77%, p = .092), but worse for RCM-Amyloidosis patients at 10 years (44% vs. 59%, p = .002). With adjustment for other clinical variables in multivariable Cox regression model, RCM-Amyloidosis was not associated with increased risk of death at 1 year (hazard ratio [HR] = 1.11, p = .56) or at 5 years (HR = 1.20, p = .18), but it was associated with increased risk of death at 10 years (HR = 1.35, p = .01). Cardiac amyloidosis was not associated with any morbidity outcomes following transplant, including graft failure, acute rejection, or hospitalization for infection or rejection.

CONCLUSIONS

Our data suggest a trend of improving survival among RCM-Amyloidosis patients compared with non-RCM patients across transplant eras, with current similarities in 1- and 5-year survival but a persistent, increased risk of mortality at 10 years.

Outcomes in patients with cardiac amyloidosis and implantable cardioverter-defibrillator

AIMS

Cardiac amyloidosis (CA) is associated with increased mortality due to arrhythmias, heart failure, and electromechanical dissociation. However, the role of an implantable cardioverter-defibrillator (ICD) remains unclear. We conducted case-control study to assess survival in CA patients with and without a primary prevention ICD and compared outcomes to an age, sex, and device implant year-matched non-CA group with primary prevention ICD.

METHODS AND RESULTS

There were 91 subjects with CA [mean age= 71.2 ± 10.2, female 22.0%, 49 AL with Mayo Stage 2.9 ± 1.0, 41 transthyretin amyloidosis (ATTR), 1 other] followed by Vanderbilt Amyloidosis centre. Patients with ICD (n = 23) were compared with those without (n = 68) and a non-amyloid group with ICD (n = 46). All subjects with ICD had implantation for primary prevention. Mean left ventricular ejection fraction was 36.2% ± 14.4% in CA with ICD, 41.0% ± 10.6% in CA without ICD, and 33.5% ± 14.4% in non-CA patients. Over 3.5 ± 3.1 years, 6 (26.1%) CA, and 12 (26.1%) non-CA subjects received ICD therapies (P = 0.71). Patients with CA had a significantly higher mortality (43.9% vs. 17.4%, P = 0.002) compared with the non-CA group. Mean time from device implantation to death was 21.8 months in AL and 22.8 months in ATTR patients. There was no significant difference in mortality between CA patients who did and did not receive an ICD (39.0% vs. 46.0%, P = 0.59).

CONCLUSIONS

Despite comparable event rates patients with CA had a significantly higher mortality and ICDs were not associated with longer survival. With the emergence of effective therapy for AL amyloidosis, further study of ICD is needed in this group.

Cardiac amyloidosis in non-transplant cardiac surgery

Cardiac amyloidosis is a rare infiltrative cardiomyopathy that portends a poor prognosis. There is a growing recognition of co-existent aortic valve stenosis and transthyretin cardiac amyloidosis, with some studies suggesting that dual pathology may be associated increased risk of complication and mortality during surgical intervention. This review aims to evaluate the available literature on non-transplant cardiac surgical interventions in patients with cardiac amyloidosis, with particular focus on diagnosis, high surgical risk and areas of uncertainty that require further research.

Immunoglobulin light chain amyloidosis diagnosis and treatment algorithm 2021

Immunoglobulin light chain amyloidosis (AL) commonly presents with nephrotic range proteinuria, heart failure with preserved ejection fraction, nondiabetic peripheral neuropathy, unexplained hepatomegaly or diarrhea, and should be considered in patients presenting with these symptoms. More importantly, patients being monitored for smoldering multiple myeloma and a monoclonal gammopathy of undetermined significance (MGUS) are at risk for developing AL amyloidosis. MGUS and myeloma patients that have atypical features, including unexplained weight loss; lower extremity edema, early satiety, and dyspnea on exertion should be considered at risk for light chain amyloidosis. Overlooking the diagnosis of light chain amyloidosis leading to therapy delay is common, and it represents an error of diagnostic consideration. Herein we provide a review of established and investigational treatments for patients with AL amyloidosis and provide algorithms for workup and management of these 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.

Drug Discovery and Development in Rare Diseases: Taking a Closer Look at the Tafamidis Story

Rare diseases are increasingly recognized as a global public health priority. Governments worldwide currently provide important incentives to stimulate the discovery and development of orphan drugs for the treatment of these conditions, but substantial scientific, clinical, and regulatory challenges remain. Tafamidis is a first-in-class, disease-modifying transthyretin (TTR) kinetic stabilizer that represents a major breakthrough in the treatment of transthyretin amyloidosis (ATTR amyloidosis). ATTR amyloidosis is a rare, progressive, and fatal systemic disorder caused by aggregation of misfolded TTR and extracellular deposition of amyloid fibrils in various tissues and organs, including the heart and nervous systems. In this review, we present the successful development of tafamidis spanning 3 decades, marked by meticulous laboratory research into disease mechanisms and natural history, and innovative clinical study design and implementation. These efforts established the safety and efficacy profile of tafamidis, leading to its regulatory approval, and enabled post-approval initiatives that further support patients with ATTR amyloidosis.

Narrative review of pharmacotherapy for transthyretin cardiac amyloid

Treatment of cardiac amyloidosis is determined by the amyloid type and degree of involvement. Two types of amyloid commonly infiltrate the heart: immunoglobulin light-chain amyloid (AL), and transthyretin amyloid (ATTR), that encompasses other two forms, a hereditary form (hATTR), and a sporadic, age-related wild-type (wtATTR). The prevalence is expected to increase with aging population. The natural history of ATTR cardiomyopathy includes progressive heart failure (HF), complicated by arrhythmias and conduction system disease. New therapies options have been approved or are under investigation. We performed a narrative literature review, manually-searched the reference lists of included articles and relevant reviews. Treatment for cardiac ATTR should be directed towards alleviation of HF symptoms and to slow or stop progressive amyloid deposition. Conventional HF medications are poorly tolerated and may not alter the disease progression or symptoms, except perhaps with the administration of diuretics. There are three approaches of therapy for ATTR cardiomyopathy: tetramer stabilizers, inhibition of ATTR protein synthesis and clearance of deposited fibrils. Tafamidis diminishes the progression of cardiomyopathy, functional parameters, improves overall outcome in patients with early disease stages, irrespective of ATTR status and is well tolerated. Diflunisal has shown promising results in early studies, but at the expense of significant side effects. Two new agents, antisense oligonucleotides, patisiran and inotersen are under investigation in cardiac amyloidosis. Patisiran appears to be the most effective treatment for hATTR, although evidence is limited, with a relatively small cardiac subpopulation. Therapies considering clearance of amyloid fibrils from tissue remain experimental. In conclusion, tafamidis is the only approved agent for the treatment of ATTR cardiomyopathy although multiple other agents have shown promising early results and are undergoing clinical trials. Careful consideration of the type of ATTR, comorbidities and disease stage will be key in deciding the optimal therapy for ATTR patients.

A case report of an infiltrative cardiomyopathy in everyday practice: a specific cause that cannot be missed in the elderly

Background 

Transthyretin amyloid cardiomyopathy (ATTR-CM) is a commonly misdiagnosed cardiac condition due to low disease awareness and perceived rarity, which frequently results in incorrect management and poor outcomes. Early and prompt diagnosis has become critical with emerging therapies that improve patient survival.

Case summary 

A 68-year-old woman presented to a tertiary care centre with acute decompensated heart failure following recurrent hospitalizations for the same issue over the past several months. Transthoracic echocardiography revealed severe concentric left ventricular hypertrophy with grade III diastolic dysfunction. However, QRS voltage by 12-lead electrocardiogram (ECG) was discordant with the degree of left ventricular hypertrophy seen by echocardiography, and the patient had recurrent non-sustained ventricular tachycardia that necessitated implantable cardioverter-defibrillator implantation a few months prior. After aggressive diuresis, the patient completed cardiac magnetic resonance imaging that raised concern for cardiac amyloidosis. Subsequent serum and urine protein electrophoresis with associated immunofixation were within normal limits. Finally, ATTR-CM was confirmed by technetium-99m pyrophosphate scintigraphy with plans to initiate tafamidis after genetic testing.

Discussion 

Patients >60 years of age with diastolic heart failure phenotypically similar to hypertrophic cardiomyopathy and/or hypertensive heart disease should always be evaluated for ATTR-CM. Features that increase suspicion include discordance between left ventricular wall thickness and ECG voltage, and signs/symptoms of a primary peripheral and autonomic neuropathy. Useful non-invasive diagnostic testing has also made the diagnosis of ATTR-CM inexpensive and possible without the need for an endomyocardial biopsy. Unfortunately, this patient's diagnosis of ATTR-CM came late in her disease course, which delayed the onset of definitive therapy.

Canadian Cardiovascular Society/Canadian Cardiac Transplant Network Position Statement on Heart Transplantation: Patient Eligibility, Selection, and Post-Transplantation Care

Significant practice-changing developments have occurred in the care of heart transplantation candidates and recipients over the past decade. This Canadian Cardiovascular Society/Canadian Cardiac Transplant Network Position Statement provides evidence-based, expert panel recommendations with values and preferences, and practical tips on: (1) patient selection criteria; (2) selected patient populations; and (3) post transplantation surveillance. The recommendations were developed through systematic review of the literature and using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system. The evolving areas of importance addressed include transplant recipient age, frailty assessment, pulmonary hypertension evaluation, cannabis use, combined heart and other solid organ transplantation, adult congenital heart disease, cardiac amyloidosis, high sensitization, and post-transplantation management of antibodies to human leukocyte antigen, rejection, cardiac allograft vasculopathy, and long-term noncardiac care. Attention is also given to Canadian-specific management strategies including the prioritization of highly sensitized transplant candidates (status 4S) and heart organ allocation algorithms. The focus topics in this position statement highlight the increased complexity of patients who undergo evaluation for heart transplantation as well as improved patient selection, and advances in post-transplantation management and surveillance that have led to better long-term outcomes for heart transplant recipients.

Suspecting Cardiac Amyloidosis in Congestive Heart Failure

Amyloidosis is a rare multisystem disease due to deposition of abnormal protein fragments, and cardiac amyloidosis is progressive and difficult to diagnose due to its subtle and non-specific symptoms unless the physician maintains a high degree of suspicion. This case report focuses on amyloid deposition in the heart of an 84-year-old woman who presented with symptoms of uncompensated heart failure.

Diagnosis and Screening of Patients with Hereditary Transthyretin Amyloidosis (hATTR): Current Strategies and Guidelines

The outlook for transthyretin amyloidosis (ATTR) is changing with the availability of new and emerging treatments. ATTR now appears to be more common than previously thought and is no longer viewed as an obscure diagnosis with a grim prognosis. Now more than ever, there is growing emphasis on the need for early diagnosis because the treatments appear to be most effective if started in earlier stages of the disease. Diagnosing ATTR is a challenge as it may initially present with nonspecific symptoms and it is often thought of as a diagnosis of exclusion. Increased awareness is imperative as new treatments offer hope and have the potential to change the disease trajectory. ATTR commonly presents with neurological and cardiac features. Transthyretin (TTR) is a protein produced in the liver which misfolds either due to genetic mutations or due to aging and results in deposition of amyloid fibrils in organs and tissues. Apart from the traditional imaging modalities, newer techniques including echocardiographic strain imaging, magnetic resonance imaging (MRI), and nuclear scintigraphy, as well as the increased availability of genetic testing are aiding in making a timely diagnosis. In this review, we present the current understanding of the ATTR disease process, diagnostic and surveillance approaches, newer treatment modalities, and the future directions.

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.

Advances in the Treatment of Cardiac Amyloidosis

OPINION STATEMENT

Cardiac amyloidosis is associated with a high mortality rate, a long delay between the first signs and the diagnosis but a short interval between diagnosis and death. This scenario has changed recently due to improved disease awareness among doctors and significant progress in diagnosis thanks to multimodal imaging and a multidisciplinary approach. Therefore, during the last few years, we have had access to specific therapies for those patients. Those therapies are quite different depending on the type of amyloidosis, but there has been real progress. Systemic light chain amyloidosis (AL) with cardiac involvement is the most common form of cardiac amyloidosis. The severity of heart disease dictates the prognosis in AL amyloidosis. Advances in chemotherapy and immunotherapy that suppress light chain production have improved the outcomes. These recent improvements in survival rates have enabled therapies such as implanted cardiac defibrillators and heart transplantation that were usually not indicated for patients with advanced light chain amyloid cardiomyopathy to now be applied in selected patients. For transthyretin amyloidosis (ATTR), the second most common form of amyloidosis with cardiac involvement, there is also significant progress in treatment. Until recently, we had no specific therapy for ATTR cardiomyopathy (ATTR-CM), though now disease-modifying therapies are available. Therapies that stabilize transthyretin, such as tafamidis, have been shown to improve outcomes for patients with ATTR-CM. Modern treatments that stop the synthesis of TTR through gene silencing, such as patisiran and inotersen, have shown positive results for patients with TTR amyloidosis. Significant progress has been made in the treatment of amyloid cardiomyopathy, and hopefully, we will see even more progress with the spread of those treatments. We now can be optimistic about patients with this disease.

Transthyretin Amyloid Cardiomyopathy: JACC State-of-the-Art Review

Transthyretin amyloid cardiomyopathy (ATTR-CM) is an under-recognized cause of heart failure (HF) in older adults, resulting from myocardial deposition of misfolded transthyretin (TTR) or pre-albumin. Characteristic patterns of echocardiography and cardiac magnetic resonance can strongly suggest the disease but are not diagnostic. The diagnosis can be made with noninvasive nuclear imaging when there is no evidence of a monoclonal protein. Amyloid fibril formation results from a destabilizing mutation in hereditary ATTR amyloidosis (hATTR) or from an aging-linked process in wild-type ATTR amyloidosis (wtATTR). Recent studies have suggested that up to 10% to 15% of older adults with HF may have unrecognized wtATTR. Associated features, including carpal tunnel syndrome and lumbar spinal stenosis, raise suspicion and may afford a means for early diagnosis. Previously treatable only by organ transplantation, pharmaceutical therapy that slows or halts ATTR-CM progression and favorably affects clinical outcomes is now available. Early recognition remains essential to afford the best treatment efficacy.

Update in recent clinical trials in heart failure

PURPOSE OF REVIEW

Heart failure represents a major growing health problem in developed world. This article aims to review recent heart failure trials that have significantly impacted the management of heart failure.

RECENT FINDINGS

Despite advances in heart failure, mortality and morbidity remains elevated amongst patients. Recent clinical trials demonstrate promising treatment strategies that likely impact clinical practice; including heart failure prevention with the use of SGLT2-inhibitors in patients with diabetes and cardiovascular risk, new treatments that may abrogate disease progression in cardiac amyloidosis, intravenous iron therapy in iron deficiency anemia in chronic systolic heart failure, predischarge treatment with angiotensin receptor blocker with neprilysin inhibition (ARNi) in patients hospitalized for acute decompensated heart failure, and newer continuous flow left ventricular assist device with increased durability and efficacy in patients with Stage D heart failure.

SUMMARY

Recent clinical trials with SGLT2 inhibitors, therapies targeting transthyretin cardiac amyloidosis, iron, angiotensin receptor blocker with neprilysin inhibition and newer mechanical circulatory support devices are very promising as practice changing new treatment strategies in prevention and treatment of heart failure. This article presents a summary of important trials and should be of practical value to both clinicians and researchers.

A novel risk score to predict survival in advanced heart failure due to cardiac amyloidosis

BACKGROUND

Cardiac amyloidosis, caused by deposition of immunoglobulin light chains (AL) or transthyretin (ATTR), carries a poor prognosis. Established risk scores for amyloidosis may not predict outcomes in those patients who develop advanced heart failure and who are potential candidates for heart transplantation. Here, we aimed to identify predictive parameters for patients with severe heart failure due to amyloidosis.

METHODS

Out of > 1000 patients with cardiac amyloidosis (AL or ATTR) admitted to our centre between September 1998 and January 2016, a cohort of 120 patients with a complete cardiac assessment at diagnosis, including right heart catheterization, echocardiography and biomarkers, was analysed retrospectively in this study. Primary endpoint was all-cause mortality. We performed univariate and multivariate Cox regression analysis, generated risk scores to predict outcomes in AL and ATTR amyloidosis and compared those to established risk models for amyloidosis.

RESULTS

In the Cox multivariate model, high-sensitivity troponin T (hsTnT; hazard ratio (HR) 1.003; confidence interval (CI) 1.001-1.005; p = 0.009) and mean pulmonary artery pressure (HR 1.061; CI 1.024-1.100; p = 0.001) were found to significantly and independently predict outcomes for AL amyloidosis, whereas QRS duration (HR 1.021; CI 1.004-1.039; p = 0.013), hsTnT (HR 1.021; CI 1.006-1.036; p = 0.006) and N-terminal pro-brain natriuretic peptide (HR 1.0003; CI 1.0001-1.0004; p = 0.002) were the best predictors for ATTR amyloidosis. A simple risk score ("HeiRisk") including these parameters for AL and ATTR allowed a more precise risk stratification in our patient population compared to established risk models.

CONCLUSIONS

Risk stratification for cardiac amyloidosis with the newly developed "HeiRisk" score may be superior to other staging systems for patients with advanced heart failure due to amyloid cardiomyopathy.

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.

Disease-modifying therapy for proteinopathies: Can the exception become the rule?

Disease-modifying therapies for proteinopathies are urgently needed yet clinical trials for the major neurodegenerative diseases, Alzheimer's and Parkinson's, have been failing at an alarming rate leaving patients and caregivers scrambling for any sign of hope. At the same time, for one family of proteinopathies, the rare TTR amyloidoses, disease-modifying therapy has existed for almost 3 decades and two new types of disease-modifying therapy have become available more recently. In this chapter, I discuss those therapies, examine to what extent they can be generalized for other diseases, and consider what we may learn from their relative success.

Hereditary transthyretin amyloidosis: a model of medical progress for a fatal disease

Hereditary amyloidogenic transthyretin (ATTRv) amyloidosis with polyneuropathy (also known as familial amyloid polyneuropathy) is a condition with adult onset caused by mutation of transthyretin (TTR) and characterized by extracellular deposition of amyloid and destruction of the somatic and autonomic PNS, leading to loss of autonomy and death. This disease represents a model of the scientific and medical progress of the past 30 years. ATTRv amyloidosis is a worldwide disease with broad genetic and phenotypic heterogeneity that presents a diagnostic challenge for neurologists. The pathophysiology of the neuropathy is increasingly understood and includes instability and proteolysis of mutant TTR leading to deposition of amyloid with variable lengths of fibrils, microangiopathy and involvement of Schwann cells. Wild-type TTR is amyloidogenic in older individuals. The main symptoms are neuropathic, but the disease is systemic; neurologists should be aware of cardiac, eye and kidney involvement that justify a multidisciplinary approach to management. Infiltrative cardiomyopathy is usually latent but present in half of patients. Disease-modifying therapeutics that have been developed include liver transplantation and TTR stabilizers, both of which can slow progression of the disease and increase survival in the early stages. Most recently, gene-silencing drugs have been used to control disease in the more advanced stages and produce some degree of improvement.

Cardiac amyloidosis: A case report and review of literature

BACKGROUND

Cardiac amyloidosis, a disease caused by the precipitation of amyloid proteins in the myocardial extracellular matrix has been historically difficult to diagnose due to lack of specific clinical manifestations and necessity of biopsy to demonstrate amyloid deposition. However, advances in cardiovascular imaging techniques have facilitated earlier recognition of this disease. In addition, while once thought of as incurable, treatment strategies are emerging for cardiac amyloidosis, making early diagnosis essential.

CASE SUMMARY

We outline the case of a 73 years old African American female who was admitted with sudden onset shortness of breath and found to be in cardiogenic shock. Cardiac amyloidosis was suspected due to discordance between electrocardiogram and echocardiogram findings and this was subsequently confirmed with the aid of scintigraphy and an endomyocardial biopsy.

CONCLUSION

Our objective is to highlight the diagnostic evaluation and clinical implications of cardiac amyloidosis.

Immunoglobulin light chain amyloidosis diagnosis and treatment algorithm 2018

Immunoglobulin light chain amyloidosis (AL) should be considered in any patient that presents to a cancer care provider with nephrotic range proteinuria, heart failure with preserved ejection fraction, non-diabetic peripheral neuropathy, unexplained hepatomegaly or diarrhea. More importantly, patients being monitored for smoldering multiple myeloma and a monoclonal gammopathy of undetermined significance (MGUS) are at risk for developing AL amyloidosis. MGUS and myeloma patients that have atypical features, including unexplained weight loss; lower extremity edema, early satiety, and dyspnea on exertion should be considered at risk for light chain amyloidosis. Overlooking the diagnosis of light chain amyloidosis leading to therapy delay is common, and it represents an error of diagnostic consideration. Algorithms will be provided on how to evaluate patients with suspected AL amyloid as well as how to manage patients referred from other medical specialties with biopsy-proven amyloid. An organized stepwise approach to the treatment of patients with light chain amyloidosis, including established and investigational therapies, will be reviewed.

Wild-type transthyretin cardiac amyloidosis (ATTRwt-CA), previously known as senile cardiac amyloidosis: clinical presentation, diagnosis, management and emerging therapies

Cardiac amyloidosis is thought to be a rare group of diseases caused by extracellular deposition of misfolded proteins in the extracellular cardiac matrix resulting in heart failure with preserved ejection fraction (HFpEF). This review focuses on the similarities and differences between the pathophysiology, clinical presentation and diagnostic tests of wild-type transthyretin cardiac amyloidosis (ATTRwt-CA) compared to immunoglobulin light chain amyloidosis and hereditary cardiac amyloidosis. We address some obstacles to timely diagnosis and opportunities for management of the clinical symptoms as well as possibility of future novel disease modifying therapies.

Fabrication of scaffold-free tubular cardiac constructs using a Bio-3D printer

A major challenge in cardiac tissue engineering is the host's immune response to artificial materials. To overcome this problem, we established a scaffold-free system for assembling cell constructs using an automated Bio-3D printer. This printer has previously been used to fabricate other three-dimensional (3D) constructs, including liver, blood vessels, and cartilage. In the present study, we tested the function in vivo of scaffold-free cardiac tubular construct fabricated using this system. Cardiomyocytes derived from induced pluripotent stem cells (iCells), endothelial cells, and fibroblasts were combined to make the spheroids. Subsequently, tubular cardiac constructs were fabricated by Bio-3D printer placing the spheroids on a needle array. Notably, the spheroid fusion and beat rate in the constructs were observed while still on the needle array. After removal from the needle array, electrical stimulation was used to test responsiveness of the constructs. An increased beat rate was observed during stimulation. Importantly, the constructs returned to their initial beat rate after stimulation was stopped. In addition, histological analysis shows cellular reorganization occurring in the cardiac constructs, which may mimic that observed during organ transplantation. Taken together, our results indicate that these engineered cardiac tubular constructs, which address both the limited supply of donor tissues as well as the immune-induced transplant rejection, has potential to be used for both clinical and drug testing applications. To our knowledge, this is the first time that cardiac tubular constructs have been produced using optimized Bio-3D printing technique and subsequently tested for their use as cardiac pumps.