Canadian Cardiovascular Society/Canadian Heart Failure Society Joint Position Statement on the Evaluation and Management of Patients With Cardiac Amyloidosis

Current Challenges of Cardiac Amyloidosis Awareness among Romanian Cardiologists

Cardiac amyloidosis (CA) is a restrictive cardiomyopathy characterized by deposition of amyloid in the myocardium and recent studies revealed it is more frequently seen than we thought. Advances in diagnosis and treatment have been made over the last few years that make it desirable to diagnose CA without delay, and that may require extra education. An online survey was conducted among cardiologists from Romania, representing the first assessment of the knowledge of CA among them, with 195 cardiologists answering the questionnaire. There was a wide variation in their knowledge regarding CA. Our participants had limited experience with CA and reported a significant delay between first cardiac symptoms and diagnosis. We address the gaps in knowledge that were identified as educational opportunities in the main identified areas: prevalence and treatment of wild type transthyretin amyloidosis (ATTRwt), prevalence of variant transthyretin amyloidosis (ATTRv) in Romania, diagnosis of CA, the delay in CA diagnosis and available treatment options. Awareness among cardiologists is the most important challenge in diagnosing CA. Romanian cardiologists are partially aware of this topic, but there are still gaps in their knowledge. Educational programs can improve screening of patients with a high suspicion for this progressive condition the prognosis of which has been dramatically changed by the new treatment options.

National Trends of Gender Disparity in Canadian Cardiovascular Society Guideline Authors, 2001-2020

Background

The level of representation of women in cardiology remains low compared to that of men, particularly in leadership positions. We evaluated gender disparity in the authorship of Canadian Cardiovascular Society (CCS) guidelines.

Methods

All CCS guidelines from 2001-2020 were identified. Gender was assessed based on pronoun use in the biographies and social media of the authors. Only primary panel authors were included in our analysis. Stratified analyses were performed based on subspecialties.

Results

A total of 76 guidelines were identified, with 1172 authors (26% women, 74% men, P < 0.0001), with no significant change in percentage of women authors over 2 decades, (37.1% in 2001, 36.3% in 2020, P = 0.34). Inclusion of women as authors occurred less frequently than inclusion of men in general cardiology guidelines (20.1% vs 79.9%, P < 0.0001) and all subspecialties—heart failure (36.4% vs 63.6%, P < 0.0001), interventional cardiology (12.6% vs 87.4%, P < 0.0001), electrophysiology (20.2% vs 79.8%, P < 0.0001), and pediatric cardiology (41.7% vs 58.3%, P = 0.02). It was less likely for women to be a chair or cochair of a guideline writing committee, compared with men (20.1% vs 79.8%, P < 0.0001). There were 609 unique authors (25.6% women, 74.4% men, P < 0.0001), 542 unique medical doctorate (MD) authors (20.7% women, 79.3% men, P < 0.0001), and 67 unique non-MD authors (65.7% women, 34.3% men, P = 0.0003).

Conclusions

There is a persistent shortfall in the inclusion of women authors for CCS guidelines, which has not changed over time. Further efforts are required to promote women's inclusion in leadership roles, which may lead to authorship of the guidelines.

The State of the Heart Biopsy: A Clinical Review

Endomyocardial biopsy (EMB) is an invaluable and underused diagnostic tool for myocardial disease. The primary indications are surveillance of cardiac allograft rejection and the diagnosis of inflammatory and infiltrative cardiomyopathies. EMB is typically performed by sampling the right ventricular septum via the right internal jugular vein using fluoroscopic guidance. The diagnostic yield of EMB is improved by sampling both ventricles and with the use of guidance from imaging or electroanatomic mapping. The risk of major cardiac complications is operator dependent and < 1% in experienced centres. EMB is the gold standard and most common form of cardiac allograft rejection surveillance, whereas advanced cardiac imaging and donor-specific antibody quantification provide complementary information. Gene expression profiling is an alternative surveillance strategy to EMB for low-risk patients. EMB is recommended for myocarditis and can guide therapy for giant-cell myocarditis, necrotizing eosinophilic myocarditis, sarcoidosis, and immune checkpoint inhibitor myocarditis. There is growing interest in using EMB to guide therapy for viral myocarditis, although the uptake of this approach is limited to specialized centres. EMB has been replaced as a first-line test for infiltrative cardiomyopathy by nonbiopsy diagnostic techniques, but is still useful to clarify the diagnosis or disease subtype. The miniaturization of bioptomes and advances in laboratory techniques such as microarrays promises to improve the safety and yield of EMB. We review the contemporary use of EMB for cardiac allograft rejection, inflammatory cardiomyopathy, and infiltrative cardiomyopathy.

Transthyretin Amyloid Cardiomyopathy-Current and Future Therapies

OBJECTIVE

To describe the clinical presentation of transthyretin amyloid cardiomyopathy (ATTR-CM) and discuss current treatments and investigational products and their effect on patient outcomes.

DATA SOURCES

A literature search was performed in PubMed (September 2018 to December 2020) using the following keywords: transthyretin amyloidosis, cardiomyopathy, polyneuropathy and transthyretin amyloid cardiomyopathy, monoclonal light-chain, tafamidis, cardiac amyloidosis, ATTR cardiomyopathy, green tea and inhibition of cardiac amyloidosis, AG10, tolcapone, tolcapone and leptomeningeal ATTR, PRX004, NI006, patisiran, inotersen, vutrisiran, AKCEA-TTR-LRx, and NTLA-2001.

STUDY SELECTION AND DATA EXTRACTION

Clinical trials were evaluated for evidence supporting pharmacology, safety, efficacy, and measured outcomes.

DATA SYNTHESIS

Until 2019, there were no approved treatments for ATTR-CM. Treatment consisted of symptom management and organ transplant. Nonpharmacological and pharmacological treatments focused on the symptoms of heart failure (HF) associated with ATTR-CM. However, there are several emerging therapies recently approved or in development to address the underlying pathophysiology. Treatment classes for ATTR-CM include transthyretin stabilizers, human monoclonal antibodies, gene silencers, and CRISPR/Cas9 gene editing.

RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE

ATTR-CM is a complex disease in which amyloidosis causes cardiomyopathy. Underdiagnosis is attributed to the clinical presentation being heterogeneous, indistinguishable from HF caused by other etiologies, and the need for invasive testing modalities, including endomyocardial biopsy. Improved diagnostic approaches along with targeted therapies can slow disease progression and enhance patient quality of life.

CONCLUSION

Diagnostic modalities along with biomarker and genetic testing could detect disease earlier and target therapy more accurately. Novel therapies demonstrate potential treatment benefits and can help shape the standard of care for these patients.

Canadian Guidelines for Hereditary Transthyretin Amyloidosis Polyneuropathy Management

Hereditary transthyretin-mediated (hATTR) amyloidosis is a progressive disease caused by mutations in the TTR gene leading to multisystem organ dysfunction. Pathogenic TTR aggregation, misfolding, and fibrillization lead to deposition of amyloid in multiple body organs and frequently involve the peripheral nerve system and the heart. Common neurologic manifestations include: sensorimotor polyneuropathy (PN), autonomic neuropathy, small-fiber PN, and carpal tunnel syndrome. Many patients have significant progression due to diagnostic delays as hATTR PN is not considered within the differential diagnosis. Recently, two effective novel disease-modifying therapies, inotersen and patisiran, were approved by Health Canada for the treatment of hATTR PN. Early diagnosis is crucial for the timely introduction of these disease-modifying treatments that reduce impairments, improve quality of life, and extend survival. In this guideline, we aim to improve awareness and outcomes of hATTR PN by making recommendations directed to the diagnosis, monitoring, and treatment in Canada.

Establishing a Cardiac Amyloidosis Clinic: A Practical Primer for Cardiologists

Cardiac amyloidosis is an emerging and important cause of heart failure, arrhythmia, and other cardiovascular disease in Canada. In this context, many centres have expressed interest in the development of effective care pathways for screening, evaluating, and treating this rapidly growing patient population. In October 2019, a group of Canadian stakeholders met, including specialists in cardiac amyloidosis, experts in heart failure and chronic disease management, and academic and community-based cardiologists at various stages of cardiac amyloidosis clinic development. Objectives of the meetings included discussion of existing care pathways, consideration of barriers to program development, and achieving a consensus on essential and desirable components of a best-practice cardiac amyloidosis program. Topics discussed included optimal settings for cardiac amyloidosis clinics and integration with other specialty clinics, funding limitations that act as barriers to program development and potential solutions to these barriers, the roles of the multidisciplinary team and specialist physicians in amyloidosis care, and diagnostic pathways and strategies for the identification of patients with cardiac amyloidosis. In this report, we summarize the discussion points and key recommendations for the development of a cardiac amyloidosis clinic that emerged from this meeting, focused on program integration and care coordination, human resource elements, access to care, and quality improvement and outcome measures in cardiac amyloidosis.

A Novel Approach to Medical Management of Heart Failure With Reduced Ejection Fraction

The advent of newly available medical therapies for heart failure with reduced ejection fraction (HFrEF) has resulted in many potential therapeutic combinations, increasing treatment complexity. Publication of expert consensus guidelines and initiatives aimed to improve implementation of treatment has emphasized sequential stepwise initiation and titration of medical therapy, which is labour intensive. Data taken from heart failure registries show suboptimal use of medications, prolonged titration times, and consequently little change in dose intensity, all of which indicate therapeutic inertia. Recently published evidence indicates that 4 medication classes-renin-angiotensin-neprilysin inhibitors, β-blockers, mineralocorticoid antagonists, and sodium-glucose cotransporter inhibitors-which we refer to as Foundational Therapy, confer rapid and robust reduction in both morbidity and mortality in most patients with HFrEF and that they work in additive fashion. Additional morbidity and mortality may be observed following addition of several personalized therapies in specific subgroups of patients. In this review, we discuss mechanisms of action of these therapies and propose a framework for their implementation, based on several principles. These include the critical importance of rapid initiation of all 4 Foundational Therapies followed by their titration to target doses, emphasis on multiple simultaneous drug changes with each patient encounter, attention to patient-specific factors in choice of medication class, leveraging inpatient care, use of the entire health care team, and alternative (ie, virtual visits) modes of care. We have incorporated these principles into a Cluster Scheme designed to facilitate timely and optimal medical treatment for patients with HFrEF.

Metabonomics Analysis of Myocardial Metabolic Dysfunction in Patients with Cardiac Natriuretic Peptide Resistance

Brain natriuretic peptide (BNP) is an important biological marker and regulator of cardiac function. BNP resistance is characterized by high concentrations of less functionally effective BNP and common in heart failure (HF) patients. However, the roles and consequences of BNP resistance remain poorly understood. Investigate the effects of cardiac BNP resistance and identify potential metabolic biomarkers for screening and diagnosis. Thirty patients and thirty healthy subjects were enrolled in this study. Cardiac functions were evaluated by echocardiography. The plasma levels of cyclic guanosine monophosphate (cGMP) and BNP were measured by enzyme-linked immunosorbent assay (ELISA) and the cGMP/BNP ratio is calculated to determine cardiac natriuretic peptide resistance. Liquid chromatograph tandem mass spectrometry (LC-MS) based untargeted metabolomics analysis was applied to screen metabolic changes. The cGMP/BNP ratio was markedly lower in HF patients than controls. The cGMP/BNP ratio and ejection fraction (EF) were strongly correlated (R² = 0.676, P < 0.05). Importantly, metabolic profiles were substantially different between HF patients and healthy controls. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis demonstrated that the differentially expressed metabolites are involved in signaling pathways that regulate cardiac functions. In HF patients, BNP resistance develops in association with a reduction in heart function and metabolic remodeling. It suggests possible functional roles of BNP resistance in the regulation of cardiac metabolism.

Cardiovascular Autonomic Disturbances in Heart Failure With Preserved Ejection Fraction

In heart failure with reduced ejection fraction (HFrEF), diminished tonic and reflex vagal heart rate modulation and exaggerated sympathetic outflow and neural norepinephrine release are evident from disease inception. Each of these disturbances of autonomic regulation has been independently associated with shortened survival, and β-adrenoceptor antagonism and therapeutic autonomic modulation by other means have been demonstrated, in clinical trials, to lessen symptoms and prolong survival. In contrast, data concerning the autonomic status of patients with heart failure with preserved ejection fraction (HFpEF) are comparatively sparse. Little is known concerning the prognostic consequences of autonomic dysregulation in such individuals, and therapies applied with success in HFrEF have in most trials failed to improve symptoms or survival of those with HFpEF. A recent HFpEF Expert Scientific Panel report emphasised that without a deeper understanding of the pathophysiology of HFpEF, establishing effective treatment will be challenging. One aspect of such pathology may be cardiovascular autonomic disequilibrium, often worsened by acute exercise or routine daily activity. This review aims to summarise existing knowledge concerning parasympathetic and sympathetic function of patients with HFpEF, consider potential mechanisms and specific consequences of autonomic disturbances that have been identified, and propose hypotheses for future investigation.

Advances in pharmacotherapy for cardiac amyloidosis

INTRODUCTION

Amyloidosis is a group of progressive and devastating disorders resulting from extracellular deposition of misfolded proteins into tissues. When deposition of fibrils occurs in cardiac tissues, this systemic disease can lead to a very poor prognosis. Systemic amyloidosis can be acquired [light chain (AL) amyloidosis; AA amyloidosis], or hereditary [transthyretin (ATTR) amyloidosis]. Cardiac disease in amyloidosis is usually secondary to a systemic disease. The diagnosis of cardiac involvement is often delayed and yields an adverse prognosis.

AREAS COVERED

in this review, the authors report current literature on advances in pharmacotherapy for cardiac amyloidosis, mainly focused on AL and ATTR amyloidosis treatment.

EXPERT OPINION

Most pharmacological trials in amyloidosis patients, both AL and TTR, are directed to study the effects of drugs on polyneuropathy. However, since cardiac involvement carries a prominent negative survival impact in amyloidosis patients, future research should be more focused on amyloidosis cardiomyopathy as primary endpoint. Additionally, in AL amyloidosis therapies are mainly derived from experience on multiple myeloma treatment. In this specific setting, possible future research could particularly focus on immunotherapeutic agents able to optimize the standard chemotherapy results and, thus, allowing a larger population of patients to be treated by bone marrow stem cell transplantation.

Poor Yield of Routine Transthyretin Screening in Patients with Idiopathic Neuropathy

Background and objectives:

Transthyretin familial amyloid polyneuropathy (TTR-FAP) is caused by a mutation in the transthyretin (TTR) gene. Although classically described as rapidly progressive and life-threatening, recent studies on TTR-FAP show significant genetic and phenotypic heterogeneity depending on geographic localization. In light of new therapeutic advances and their implication for patient management, the aim of our study was to determine the prevalence of TTR-FAP within patients with idiopathic neuropathy in a North American population.

Methods:

We sequenced the TTR gene in a cohort of patients with idiopathic neuropathy. Genetic screening was performed in 110 patients from two neuromuscular clinics in Montreal, Canada.

Results:

No variants of unknown significance or pathogenic mutations were detected in the TTR gene.

Conclusion:

Our study confirms that TTR-FAP is a rare entity in our patient population, and that diagnostic yield of screening all patients with idiopathic neuropathy is very low.

[Cardiac Amyloidosis: Experience in a National Reference Cardiovascular Institute]

Objectives

To determine the clinical, imaging and laboratory characteristics and one year after diagnosis survival of patients with cardiac amyloidosis in a national reference hospital.

Materials and methods

Case series study. We evaluated the clinical characteristics, complementary examinations and survival of patients with cardiac amyloidosis diagnosed, treated and followed up in the Clinical Cardiology service of the National Cardiovascular Institute - INCOR EsSalud in Lima, Peru.

Results

We found eight patients with diagnosis of cardiac amyloidosis. The median age was 64.5 years and 75% were male. The etiology of cases was unspecified cardiac amyloidosis (25%), transthyretin cardiac amyloidosis (37.5%), and light chain cardiac amyloidosis (37.5%). Symptomatic heart failure (NYHA II-III) was the most common initial presentation symptom (87.5%). The most frequent extracardiac manifestations were: sensory-motor neuropathy (62.5%), musculoskeletal (37.5%), nephropathy (25%), bilateral carpal tunnel syndrome (25%), monoclonal gammopathies (25%) and refractory pleural effusion (25 %). Survival at one year was 75% and the cause of the 2 deaths was sudden death.

Conclusions

In this study of cardiac amyloidosis at a specialized center, the most frequent clinical manifestations were heart failure and sensory-motor neuropathy. Mortality was 25% per year, and in all cases as sudden death.