Transthyretin cardiac amyloidosis

Long-Term Clinical Outcomes in Patients With Transthyretin Cardiac Amyloidosis Versus Non-Ischemic Cardiomyopathy

Background

We sought to compare the long-term outcomes in patients with transthyretin cardiac amyloidosis (CA) compared to those with non-ischemic cardiomyopathy (NICM) from a large healthcare system database.

Methods

Patients with CA or NICM were identified from SSM Healthcare System's data warehouse using ICD codes. Inclusion criteria included at least 6 months of follow-up. Outcomes studied were heart failure hospitalization (HFH), ventricular tachyarrhythmias (VTA), implantable cardiac defibrillator (ICD) and pacemaker (PM) placement. Multivariate logistic analysis and Kaplan-Meier survival curves were constructed.

Results

We identified 231 patients with CA and 462 with NICM, matched for age, race, and gender. CA patients had higher incidence of peripheral vascular disease (48.5% vs. 35.5%) and coronary artery disease (10.4% vs. 6.1%). Mean follow-up was 48.1 ± 33.1 months. CA patients had a higher rate of HFH (57.6% vs. 46.1%) and a lower rate of ICD (1.7% vs. 5.9%). In the multivariate model, CA patients had significantly higher odds for HFH (odds ratio: 1.86; 95% confidence interval: 1.29 - 2.68). Kaplan-Meier survival curves showed a trend toward earlier HFH and later PM or ICD implantation in CA patients.

Conclusions

In this retrospective study from a large healthcare system database, compared to NICM, transthyretin CA patients had significantly higher rates of HFH, similar odds of VTA, and a lower likelihood of receiving an intracardiac device.

Advances and challenges in echocardiographic diagnosis and management of cardiac amyloidosis

Cardiac amyloidosis is an infiltrative cardiomyopathy characterized by the abnormal accumulation of amyloid proteins within the heart muscle. It is recognized as a rare yet significant cardiac disease that is often overlooked as a potential cause of heart failure and cardiac arrhythmias, particularly in older individuals with rates escalating from 8 to 17 cases per 100,000 individuals. Cardiac amyloidosis primarily manifests as two predominant subtypes: light-chain and transthyretin amyloidosis, collectively accounting for over 95% of clinical cases. Early diagnosis of these conditions is often hindered by overlapping symptoms with other cardiac pathologies, resulting in diagnostic delays and suboptimal patient outcomes. Echocardiography, a non-invasive imaging technique, has become indispensable for diagnosing cardiac amyloidosis, uncovering crucial echocardiographic signs such as thickening of the left ventricular wall, diastolic dysfunction, and a granular appearance of the myocardium. Recent advancements in echocardiography have significantly enhanced the diagnostic accuracy of cardiac amyloidosis and improved patient management. Advanced echocardiographic techniques, including strain imaging, 3D echocardiography, and contrast echocardiography, have significantly enhanced diagnostic accuracy and prognostication. Future directions in echocardiography encompass the integration of artificial intelligence, the development of novel contrast agents, and the refinement of 4D echocardiography to further optimize patient care. This study explores the pivotal role of echocardiography in both diagnosing and managing cardiac amyloidosis, delving into the disease's underlying mechanisms, distinctive imaging characteristics, the significance of regular echocardiographic assessments, and discusses the challenges associated with differentiating between various types of amyloidosis without supplemental imaging or biopsy methods.

Disease-modifying therapies for amyloid transthyretin cardiomyopathy: Current and emerging medications

Transthyretin amyloidosis (ATTR) is a rare disease that results in amyloid fibril misfolding and deposition in multiple organs, including the heart, leading to the development of ATTR cardiomyopathy (ATTR-CM), which is associated with poor outcomes. In the last decade, several disease-modifying medications are in advanced stages of clinical development or have been approved to treat ATTR-CM. The purpose of this review is to critically evaluate clinical trial data investigating the use of approved and investigational medications for the treatment of ATTR-CM. We performed a comprehensive literature search via PubMed and EMBASE to identify randomized controlled trials evaluating medications for the treatment of ATTR-CM published through August 2024. This narrative review describes the pathophysiology of ATTR-CM, highlights important screening and diagnostic work-up, and summarizes the existing clinical evidence resulting from our literature search. Several classes of disease-modifying medications are in development for ATTR-CM. The tetramer stabilizers and transthyretin silencers have proven to be the most effective therapies to date. Tafamidis and acoramidis are currently approved for ATTR-CM while vutrisiran approval for ATTR-CM may be forthcoming. Other disease-modifying medication classes in development include antisense oligonucleotides, gene editing therapies, and monoclonal antibodies. However, several unmet needs exist including the lack of cost-effectiveness due to the extremely high acquisition costs of these medications. Disease-modifying medications approved and in development to treat ATTR-CM offer hope for patients with this disease, but their lack of affordability is the biggest barrier to their use.

Serum Biomarkers in Transthyretin Amyloidosis: An Overview of Neurofilaments, Cardiac, Renal, and Gastrointestinal Involvement

Hereditary transthyretin amyloidosis (ATTRv, v for variant) is a genetic disorder characterized by the deposition of misfolded transthyretin (TTR) protein in tissues, resulting in progressive dysfunction of multiple organs, including the nervous system, heart, kidneys, and gastrointestinal (GI) tract. Noninvasive serum biomarkers have become key tools for diagnosing and monitoring ATTRv. This review examines the role of available biomarkers for neurological, cardiac, renal, gastrointestinal, and multisystemic involvement in ATTRv. A thorough understanding of these biomarkers is essential for effective disease management and therapeutic monitoring.

Sodium-glucose cotransporter 2 inhibitors and outcomes in transthyretin amyloid cardiomyopathy: Systematic review and meta-analysis

BACKGROUND

Transthyretin amyloid cardiomyopathy (ATTR-CM) commonly leads to heart failure but has traditionally been an exclusion criterion in randomized clinical trials (RCTs) of sodium-glucose cotransporter 2 inhibitors (SGLT2i); therefore, the effects of these drugs in this population remain undocumented. In light of recent studies, this meta-analysis aimed to investigate the effect of SGLT2i on the prognosis of patients with ATTR-CM.

METHODS

A comprehensive search of Medline, Scopus, and the Cochrane Library was conducted up to November 17, 2024. Study selection, data extraction and quality assessment were carried out independently by two investigators. Associations of SGLT2i with outcomes were pooled using random-effects meta-analyses.

RESULTS

A total of five studies (9766 participants, 4 propensity score-matched) were included. The use of SGLT2i was associated with significant reductions in all-cause mortality [hazard ratio (HR) .54, 95% confidence interval (CI) .44-.66], cardiovascular mortality (HR .39, 95% CI .23-.65), major adverse cardiovascular events (HR .71, 95% CI .61-.83), and heart failure hospitalizations (HFHs) (HR .63, 95% CI .52-.77) compared to non-use. The odds of cardiac arrhythmias were significantly lower among SGLT2i users compared to non-users [odds ratio (OR) .73, 95% CI .65-.83]. Specifically, SGLT2i use was associated with significant reductions in the odds of atrial fibrillation (AF) (OR .75, 95% CI .62-.91), ventricular tachycardia (OR .72, 95% CI .59-.88), and sudden cardiac arrest (OR .71, 95% CI .50-.99).

CONCLUSIONS

The use of SGLT2is may be associated with a more favourable prognosis in patients with ATTR-CM. Adequately powered, long-term RCTs are required to validate the available observational evidence.

Clinical Phenotype and Prognosis of Asymptomatic Patients With Transthyretin Cardiac Amyloid Infiltration

Importance

Patients with transthyretin (ATTR) cardiac amyloid infiltration are increasingly diagnosed at earlier disease stages with no heart failure (HF) symptoms and a wide range of cardiac amyloid infiltration.

Objective

To characterize the clinical phenotype and natural history of asymptomatic patients with ATTR cardiac amyloid infiltration.

Design, Setting, and Participants

This cohort study analyzed data of all patients at 12 international centers for amyloidosis from January 1, 2008, through December 31, 2023. Inclusion criteria were asymptomatic ATTR cardiac amyloid infiltration, defined as an absence of HF history, HF signs and symptoms, diuretic therapy, and plasma cell dyscrasia with evidence of myocardial uptake on bone scintigraphy. If plasma cell dyscrasia was present, histologic confirmation of ATTR amyloid was required.

Exposure

Asymptomatic ATTR cardiac amyloid infiltration.

Main Outcomes and Measures

The primary outcomes were all-cause and cardiovascular (CV) mortality. The secondary outcomes were unplanned HF hospitalization, unplanned CV-related hospitalization, and a composite outcome of CV mortality and HF hospitalization.

Results

The study comprised 485 patients with asymptomatic ATTR cardiac amyloid infiltration (mean [SD] age, 74.9 [9.9] years, 85.8% male, 112 [23.1%] with hereditary ATTR amyloidosis), with 369 (76.1%) having grade 2 or 3 and 116 (23.9%) having grade 1 cardiac uptake at baseline. Patients with grade 2 or 3 uptake exhibited significantly more cardiac functional and structural abnormalities vs patients with grade 1 uptake. At 3 years, compared with grade 1 uptake, patients with grade 2 or 3 uptake had greater development of HF (54.3% [95% CI, 47.7%-61.3%] vs 23.1% [95% CI, 14.8%-35.1%]), greater outpatient diuretic initiation and N-terminal pro-B-type natriuretic peptide progression (35.0% [95% CI, 28.0%-43.2%] vs 12.4% [95% CI, 6.3%-23.7%]), and greater HF hospitalization (8.7% [95% CI, 5.9%-12.9%] vs 0%) and unplanned CV hospitalization (20.0% [95% CI, 15.7%-25.3%] vs 4.3% [95% CI, 1.6%-11.3%]). Over a median follow-up of 37 months (IQR, 20-64 months), the all-cause death rate was similar between patients with grade 1 vs 2 and 3 uptake; however, those with grade 2 or 3 compared with grade 1 uptake had a significantly higher risk of CV mortality (unadjusted hazard ratio, 5.30; 95% CI, 1.92-14.65).

Conclusions and Relevance

This study shows that asymptomatic ATTR cardiac amyloid infiltration encompasses a wide spectrum of disease severity, with patients with grade 2 or 3 cardiac uptake experiencing an increased rate of CV events and CV mortality and patients with grade 1 uptake experiencing a lower CV event rate and predominantly non-CV mortality. These findings support the use of disease-modifying treatments in asymptomatic patients with grade 2 or 3 uptake and highlight the need of large-scale studies to assess their role in grade 1 uptake.

Automated extracellular volume fraction measurement for diagnosis and prognostication in patients with light-chain cardiac amyloidosis

AIMS

T1 mapping on cardiac magnetic resonance (CMR) imaging is useful for diagnosis and prognostication in patients with light-chain cardiac amyloidosis (AL-CA). We conducted this study to evaluate the performance of T1 mapping parameters, derived from artificial intelligence (AI)-automated segmentation, for detection of cardiac amyloidosis (CA) in patients with left ventricular hypertrophy (LVH) and their prognostic values in patients with AL-CA.

METHODS AND RESULTS

A total of 300 consecutive patients who underwent CMR for differential diagnosis of LVH were analyzed. CA was confirmed in 50 patients (39 with AL-CA and 11 with transthyretin amyloidosis), hypertrophic cardiomyopathy in 198, hypertensive heart disease in 47, and Fabry disease in 5. A semi-automated deep learning algorithm (Myomics-Q) was used for the analysis of the CMR images. The optimal cutoff extracellular volume fraction (ECV) for the differentiation of CA from other etiologies was 33.6% (diagnostic accuracy 85.6%). The automated ECV measurement showed a significant prognostic value for a composite of cardiovascular death and heart failure hospitalization in patients with AL-CA (revised Mayo stage III or IV) (adjusted hazard ratio 4.247 for ECV ≥40%, 95% confidence interval 1.215-14.851, p-value = 0.024). Incorporation of automated ECV measurement into the revised Mayo staging system resulted in better risk stratification (integrated discrimination index 27.9%, p = 0.013; categorical net reclassification index 13.8%, p = 0.007).

CONCLUSIONS

T1 mapping on CMR imaging, derived from AI-automated segmentation, not only allows for improved diagnosis of CA from other etiologies of LVH, but also provides significant prognostic value in patients with AL-CA.

Cardiovascular Risk Factors and Genetic Risk in Transthyretin V142I Carriers

BACKGROUND

Nearly 3% to 4% of Black individuals in the United States carry the transthyretin V142I variant, which increases their risk of heart failure. However, the role of cardiovascular (CV) risk factors (RFs) in influencing the risk of clinical outcomes among V142I variant carriers is unknown.

OBJECTIVES

This study aimed to assess the impact of CV RFs on the risk of heart failure in V142I carriers.

METHODS

This study included self-identified Black individuals without prevalent heart failure from 6 TOPMed (Trans-Omics for Precision Medicine) cohorts, the REGARDS (Reasons for Geographic And Racial Differences in Stroke) study, and the All of Us Research Program. The cohort was stratified based on the V142I genotype and the number of CV RFs (hypertension, diabetes, obesity, and hypercholesterolemia). Adjusted Cox models were used to assess the association of heart failure with the V142I genotype and CV RF profile, taking noncarriers with a favorable CV RF profile as reference.

RESULTS

The cross-sectional analysis, including 1,625 V142I carriers among 48,365 Black individuals, found that the prevalence of CV RFs did not vary by V142I carrier status. In the longitudinal analysis, there were 587 (3.2%) V142I carriers among 18,407 Black individuals (median age: 60 years [Q1-Q3: 52-68 years], 63.0% female). Among carriers, the heart failure risk was attenuated with a favorable (0 or 1 RF) CV RF profile (adjusted HR: 2.26; 95% CI: 1.58-3.23) compared with an unfavorable (3 or 4 RFs) CV RF profile (adjusted HR: 4.14; 95% CI: 2.79-6.14).

CONCLUSIONS

A favorable CV RF profile lowers but does not abrogate V142I variant-associated heart failure risk. This study highlights the importance of having a favorable CV RF profile among V142I carriers for risk reduction of heart failure.

Biomarkers to Predict Abnormal Technetium-99m Pyrophosphate Scans in Patients With Suspected Transthyretin Amyloidosis

Background

Technetium Tc 99m pyrophosphate scintigraphy (99mTc PYP imaging) is a diagnostic tool for transthyretin amyloid cardiomyopathy (ATTR-CM). Cardiac biomarkers, particularly high-sensitivity cardiac troponin (hs-cTn) and N-terminal pro-B-type natriuretic peptide (NT-proBNP), may help identify patients at low or high risk for ATTR-CM.

Objectives

The authors sought to evaluate the predictive value of hs-cTnT and NT-proBNP in patients undergoing 99mTc PYP imaging for suspected ATTR-CM in a large U.S. cohort.

Methods

This was a retrospective study of patients who underwent 99mTc PYP imaging between May 2013 and September 2022, including those with at least 1 hs-cTnT measurement within 6 months of the scan.

Results

ATTR-CM was diagnosed in 427 of 1,442 patients (29.6%). A hs-cTnT level <6 ng/L (n = 50, 3.5%) showed a negative predictive value of 100% (95% CI: 93%-100%) and sensitivity of 100% (95% CI: 99%-100%) for ruling out ATTR-CM. As the hs-cTnT threshold increased, the number of patients who could be ruled out also increased, but false negatives emerged. The positive predictive value for ruling in ATTR-CM remained low. NT-proBNP showed similar results (n = 1,378). The combination of hs-cTnT <14 ng/L and NT-proBNP <60 ng/L identified 45 patients (3.3%) without ATTR-CM.

Conclusions

In patients undergoing 99mTc PYP imaging for suspected ATTR-CM, very low hs-cTnT levels can effectively rule out the diagnosis, although in a small subset of patients. Higher thresholds increase the risk of false negatives. NT-proBNP and combined biomarker strategies showed similar trends, the utility of hs-cTnT and NT-proBNP for ruling in the disease is limited.

From Molecular to Radionuclide and Pharmacological Aspects in Transthyretin Cardiac Amyloidosis

Amyloidosis is a rare pathology characterized by protein deposits in various organs and tissues. Cardiac amyloidosis (CA) can be caused by various protein deposits, but transthyretin amyloidosis (ATTR) and immunoglobulin light chain (AL) are the most frequent pathologies. Protein misfolding can be induced by several factors such as oxidative stress, genetic mutations, aging, chronic inflammation, and neoplastic disorders. In ATTR cardiomyopathy (ATTR-CM), the amyloid fibrils can be found in the myocardium interstitial space and are associated with arrhythmias and heart failure. In pathological situations, the transthyretin (TTR) configuration is destroyed by proteolytic action, leading to monomers that further misfold and aggregate to form the amyloid fibrils. 99mTc-Pyrophosphate (99m-Tc-PYP), 99mTc 3,3-diphosphono-1,2-propanodicarboxylic acid (99m-Tc-DPD) and 99m-Tc hydroxy-methylene-Dyphosphonate (99m-Tc-HMDP) are used to detect myocardium amyloid deposits due to their ability to detect calcium ions that are present in the amyloid fibrils through dystrophic calcification. ATTR-CM therapy acts on different stages of the amyloidogenic process, including liver TTR synthesis, TTR tetramer destabilization, and misfolding of the monomers. The main aim of this narrative review is to present ATTR-CM, starting with molecular changes regarding the protein misfolding process and radionuclide aspects and finishing with pharmacological approaches.

A 68-Year-Old Colombian Man Presenting with Heart Failure and a Diagnosis of Cardiac Transthyretin Amyloidosis

BACKGROUND Amyloidosis is a group of diseases characterized by the pathological deposition of misfolded proteins in various organs, including the heart, leading to structural and functional alterations. The primary types of cardiac amyloidosis are light chain amyloidosis and transthyretin amyloidosis. Early diagnosis is critical for effective management. This report describes the case of a 68-year-old Colombian man presenting with heart failure and a diagnosis of cardiac amyloidosis. CASE REPORT A 68-year-old man presented with heart failure symptoms, biceps tendon rupture, neuropathic pain in the extremities, and an electrocardiogram showing low QRS voltage and a pseudo-infarct pattern. Transthoracic echocardiogram revealed a left ventricular ejection fraction of 30%, severely thickened walls with a speckled appearance, a global longitudinal strain of -6.2% in a bull's eye pattern, and a left ventricular posterior wall thickness of 21.3 mm. Cardiac magnetic resonance imaging showed severe symmetric hypertrophy, moderate global dysfunction, and an elevated native T1 value of 1225 milliseconds. Post-gadolinium T1 mapping revealed a significantly increased extracellular volume of 72%. Perugini grade 3 pyrophosphate scintigraphy, negative hematological tests, and endomyocardial biopsy confirmed the diagnosis of amyloidosis, without monoclonal spikes. Genetic testing identified a heterozygous c.424G>A (p.Val142Ile) variant in the transthyretin gene, consistent with variant transthyretin amyloidosis. CONCLUSIONS Amyloidosis may affect up to 13% of patients with heart failure and preserved ejection fraction. Early recognition of red flags and implementation of a diagnostic algorithm are crucial for timely intervention in this population.

Global longitudinal strain in pre-symptomatic patients with mutation for transthyretin amyloidosis

BACKGROUND

Hereditary transthyretin (ATTRv) amyloidosis is rare, autosomal dominant disease with a fatal outcome if left untreated. Early stages detection is crucial for intervention. We aimed identifying early indexes of cardiac involvement and their eventual correlation with neurological indexes, in pre-symptomatic subjects with TTR gene mutation.

METHODS

Sixteen TTR-mutation carriers (mean age 51 ± 9 years, 6 males, 7 with Val30Met and 9 with Phe64Leu mutation) without left ventricular hypertrophy were studied. Predicted Age of Disease Onset (PADO) and time to PADO (Time-to PADO = PADO-age at evaluation) were computed. Subjects underwent: cardiological and echocardiographic assessment including global longitudinal strain (GLS); tactile and thermal quantitative sensory testing (QST); Perugini score by bone scintigraphy.

RESULTS

Time to PADO was 30 ± 15 years. Nine subjects showed abnormal GLS (> -20%), unrelated to age, LVMi, MWT, E/e', NT-proBNP or Time-to PADO. QST findings were abnormal in most subjects. At a worse cold pain threshold corresponded a worse GLS (r = 0.786, p < 0.001). Perugini score was positive in 1 subject.

CONCLUSIONS

GLS and QST findings support an early involvement of heart and small nerve fibers even many years before PADO. Interestingly, cardiac impairment seems to parallel that of small, nerve fibers, at least in the earliest stage of disease.

Transthyretin cardiac amyloid: Broad heart failure phenotypic spectrum and implications for diagnosis

AIMS

Transthyretin cardiac amyloidosis (ATTR-CA) is most often associated with heart failure with preserved ejection fraction (HFpEF). However, patients may present with impaired systolic function at the time of diagnosis, which has not been widely investigated. We sought to explore the prevalence of various heart failure (HF) phenotypes and their associated clinical characteristics at the time of ATTR-CA diagnosis.

METHODS

We performed a single-centre retrospective cohort study of consecutive patients with ATTR-CA evaluated between February 2016 and December 2022. Data on patient demographics, comorbidities, imaging and laboratory findings were compared across HF phenotypes (age: 78.1 ± 8.6 years, with 91.1% male). A total of 21.6% (n = 46) presented with heart failure with reduced ejection fraction (HFrEF), 17.8% (n = 38) with heart failure with mildly reduced ejection fraction (HFmrEF) and 60.6% (n = 129) with HFpEF at the time of diagnosis with ATTR-CA. Those presenting with HFrEF or HFmrEF were more likely to be African American and had significantly worse New York Heart Association (NYHA) functional class, higher N-terminal pro-brain natriuretic peptide (NT-proBNP) and higher serum creatinine levels as compared with those with HFpEF.

CONCLUSIONS

Although ATTR-CA is traditionally thought to be seen primarily among patients with HFpEF, our data suggest that ATTR-CA has a higher prevalence among patients with HFrEF, which underscores the importance of heightened clinical suspicion regardless of ejection fraction when considering ATTR-CA. Furthermore, although comorbidities are similar, patients with HFmrEF and HFrEF had a worse symptom burden.

Changes of clinical characteristics, distribution of red flags and prognosis in contemporary patients with wild-type transthyretin amyloidosis cardiomyopathy

AIM

Increased diagnostic awareness and specific disease treatments have changed the landscape of transthyretin cardiac amyloidosis (ATTR). Patients with wild-type ATTR (ATTRwt) are increasingly being diagnosed, potentially changing the clinical profile and prognosis compared with existing retrospective data. We aimed to study the clinical characteristics, distribution of red flags and prognosis of contemporary ATTRwt patients.

METHODS

From January 1st 2017, to December 31st 2022, 213 consecutive patients were diagnosed with ATTRwt and prospectively followed up. Data on clinical characteristics, biomarkers, echocardiography findings, hospitalization due to worsening heart failure (WHF) and all-cause mortality were collected.

RESULTS

A 37% increase in newly diagnosed patients from 2017-2019 (n = 90) vs. 2020-2022 (n = 123) was observed. The majority of patients presented with NAC disease stage I in the latter period (49% in 2017-2019 vs. 58% in 2020-2022, p = .16). Red flags were primarily cardiac-related, including elevated NT-proBNP, impaired left ventricular longitudinal systolic strain with an apical sparing pattern, heart failure with increased left ventricular wall thickness and elevated troponins. NAC disease stage I as well as low NT-proBNP levels (<1000 ng/L) were significantly associated with better survival (both p < .001). When compared with NAC disease stage II + III combined, patients with NAC disease stage I had a significantly lower risk of WHF hospitalization or death (log rank test: p = .0001). Independent predictors of the combined endpoint WHF hospitalization or death were NT-proBNP (HR 1.03 [95% CI 1.00-1.07], p < .049) and prior implantation of permanent pacemaker (HR 2.01 [1.30-3.11], p = .002).

CONCLUSION

Increased diagnostic awareness resulted in a 37% increase in newly diagnosed patients in 2020-2022 vs. 2017-2019. As expected all-cause mortality but also the morbidity in terms of risk of hospitalization with WHF were significantly lower in patients with NAC disease stage I, as well as in those with low NT-proBNP levels <1000 ng/L. These findings underline the importance of continuous attention to diagnostic awareness, as early diagnosis is critical for initiating both general and specific ATTR treatment, thus improving prognosis.

Wild-Type Transthyretin Amyloidosis With 99mTc-PYP Uptake in the Extracardiac Soft Tissues But Not in the Myocardium

ABSTRACT

Wild-type transthyretin amyloid (ATTRwt) deposits in most organs, mainly the heart, ligaments, and tenosynovium. Orthopedic diseases due to ATTRwt deposits often precede overt ATTRwt cardiomyopathy. 99mTc-PYP scintigraphy is highly sensitive in detecting myocardial and extracardiac ATTRwt deposits. However, there are few reports of extracardiac ATTRwt deposits before myocardial deposits confirmed by imaging modalities. We report a case of atrial fibrillation-related heart failure in which 99mTc-PYP scintigraphy showed tracer uptake in extracardiac soft tissues but not in the myocardium, and a biopsy of soft tissues with tracer uptake confirmed ATTRwt deposits. 99mTc-PYP scintigraphy can image extracardiac ATTRwt deposits before myocardial deposits.

Pharmacological management of heart failure: a patient-centred approach

INTRODUCTION

Heart failure (HF) is a global health challenge that requires a multidisciplinary approach. Despite recent advances in pharmacological and interventional therapy, morbidity and mortality in these patients remain high. For this reason, and because of its interplay with other cardiovascular and non-cardiovascular diseases, HF represents a major area of research, with new trials being published every year and international guidelines constantly updated.

AREAS COVERED

The authors review the current status and possible future developments in HF pharmacotherapy.

EXPERT OPINION

The treatment of HF has made significant advances in recent years, and the current recommendations are based on large outcome trials. This has led to significant reductions in both mortality and morbidity, but the death rate remains unacceptably high. In this context, a patient-centered approach that considers comorbidities and specific clinical scenarios when dosing HF medication is essential. Prevention of hospital admissions for cardiac decompensation is of utmost importance in patients with HF as is the enablement of activities of daily living, an endpoint which has only recently been incorporated into major HF trials.

Gene editing in common cardiovascular diseases

Cardiovascular diseases are the leading cause of morbidity and mortality worldwide, highlighting the high socioeconomic impact. Current treatment strategies like compound-based drugs or surgeries are often limited. On the one hand, systemic administration of substances is frequently associated with adverse side effects; on the other hand, they typically provide only short-time effects requiring daily intake. Thus, new therapeutic approaches and concepts are urgently needed. The advent of CRISPR-Cas9 genome editing offers great promise for the correction of disease-causing hereditary mutations. As such mutations are often very rare, gene editing strategies to correct them are not broadly applicable to many patients. Notably, there is recent evidence that gene editing technology can also be deployed to disrupt common pathogenic signaling cascades in a targeted, specific, and efficient manner, which offers a more generalizable approach. However, several challenges remain to be addressed ranging from the optimization of the editing strategy itself to a suitable delivery strategy up to potential immune responses to the editing components. This review article discusses important CRISPR-Cas9-based gene editing approaches with their advantages and drawbacks and outlines opportunities in their application for treatment of cardiovascular diseases.

A phenomap of TTR amyloidosis to aid diagnostic screening

Cardiac amyloidosis due to transthyretin (ATTR) remains an underdiagnosed cause of cardiomyopathy. As awareness of the disease grows and referrals for ATTR increase, clinicians are likely to encounter more atypical forms of the condition in clinical practice. Therefore, physicians and treating cardiologists should be aware of the full phenotypic spectrum of ATTR. The phenotypic manifestation of ATTR varies depending on the stage of the disease, the presence and type of TTR mutation and the patient's comorbidities. ATTR findings can be grouped into four major categories: clinical profile and cardiac phenotype, extra-cardiac findings, electrocardiogram and imaging findings, which cumulatively form the full phenomap of ATTR. Results from any diagnostic test for ATTR should be interpreted in light of the pre-test probability for the disease. Findings that suggest negative markers for ATTR can point towards other forms of amyloidosis (such as AL amyloidosis) or alternate causes of left ventricular hypertrophy, including hypertrophic cardiomyopathy or Fabry disease. The rising number of referrals for ATTR cardiomyopathy presents a challenge in daily clinical practice. To prevent an increase in false-positive diagnostic test results, an ATTR phenomap can serve as a valuable tool for guiding diagnostic assessments, interpreting test outcomes and prioritizing appropriate referrals for ATTR screening.

A review of recent clinical trials to evaluate disease-modifying therapies in the treatment of cardiac amyloidosis

Cardiac amyloidosis (CA) is a serious condition that results in infiltrative cardiomyopathy and heart failure with preserved ejection fraction (HFpEF) that is caused by the extracellular deposition of amyloid fibrils within heart tissue. While many important features of CA have been known for years, its prevalence in elderly patients with HF is increasingly being recognized. Plasma cells produce monoclonal immunoglobulin light chains which results in the formation and aggregation of amyloid fibrils that are responsible for AL amyloidosis. CA is classified as originating from either transthyretin (ATTR) or light chain (AL) amyloidosis. ATTR CA may result from a genetic mutation in the TTR gene, which is inherited (ATTRv), or from age-related deposition from wild-type ATTR (ATTRwt). Cardiac involvement in AL amyloidosis is attributed to either of two mechanisms: the extracellular deposition of amyloid fibril in the myocardium, or direct cardiotoxicity from the fibril aggregates. Typing of amyloid fibrils, a critical determinant of therapy, has also improved with wider availability of laser capture and mass spectrometry of histologic specimens. Specific and accurate evaluation of CA is now possible using cardiac magnetic resonance imaging and bone scintigraphy tracers. Survival in CA has improved markedly as novel chemotherapy agents have become available, but challenges remain in advanced disease. Broadening the amyloid-specific therapeutic landscape to include RNA inhibitors, fibril formation stabilizers and inhibitors, and immunotherapeutic targeting of amyloid deposits holds promise and may improve outcomes in systemic and cardiac amyloidoses. Treatment strategies for CA has recently undergone transformative changes, leading to some progress in outcomes for certain patients. Here, we discuss the basic features of CA as well as the emergence of novel, disease-modifying strategies that have been recently evaluated in clinical trials for the treatment of CA.

Histopathological and Immunohistochemical Characteristics of Different Types of Cardiac Amyloidosis

Cardiac involvement is the most important factor determining prognosis in patients with systemic amyloidosis. This retrospective observational study of 98 patients with amyloidosis was undertaken to assess the amyloid types that are most likely to affect the heart, describe histopathological and clinical features of cardiac amyloidosis, and estimate the number of cases not diagnosed clinically prior to death. All cases were divided into two groups based on the method of examination. The first group included 46 patients with cardiac amyloidosis revealed via endomyocardial biopsies (EMBs), and the second group included 52 amyloidosis patients who did not undergo EMBs, in whom cardiac involvement was identified only at autopsy. The EMBs demonstrated that AL amyloidosis was detected in 21 (46%) specimens, ATTR amyloid in 24 cases (52%), and AA amyloid in 1 case (2%). The autopsy reports defined 15 (46%) cases of AL amyloidosis, 21 (40%) of ATTR and 16 (31%) of AA amyloidosis. It should be noted that a clinical diagnosis of ATTR amyloidosis was made only in 9.5% of patients from the autopsy group, suggesting that ATTR may be an underdiagnosed cause of heart failure in elderly patients. The most intense amyloid deposits were determined in biopsy and autopsy specimens of patients with AL kappa amyloidosis, underlying a poorer prognosis.

Safety assessment of Tafamidis: a real-world pharmacovigilance study of FDA adverse event reporting system (FAERS) events

OBJECTIVE

Tafamidis-associated adverse events (AEs) were investigated retrospectively by data mining the US Food and Drug Administration Adverse Event Reporting System (FAERS) to inform clinical safety.

METHODS

Data were gathered from the FAERS database, which spans the second quarter of 2019 to the fourth quarter of 2023. A total number of 8532 reports of Tafamidis-related adverse events were detected after evaluating 8,432,351 data. Disproportionality analyses were used to quantify the signal and assess the significance of Tafamidis-associated AEs using four algorithms, including the reporting odds ratio (ROR), the proportional reporting ratio (PRR), the multi-item gamma Poisson shrinker (MGPS) and the Bayesian confidence propagation neural network (BCPNN).

RESULTS

Among the 8532 reports of AEs with Tafamidis as the primary suspected drug, Tafamidis-induced AEs were identified as occurring in 27 system organ classes (SOC). A total of 207 Tafamidis-induced AEs were detected which simultaneously complied with the four algorithms. Our analysis also identified new adverse reactions including Hypoacusis, Deafness, and Essential hypertension. The median onset of adverse reactions associated with Tafamidis was 180 days (interquartile range [IQR] 51-419 days).

CONCLUSION

Tafamidis is a drug that has shown favorable safety and tolerability results in clinical trials. However, a number of adverse reactions associated with Tafamidis have been identified through analysis of the FAERS database. In clinical applications, it is recommended to closely monitor patients' hearing while using Tafamidis. In addition, it is hoped that further experimental and clinical studies will be conducted in the future to understand the mechanism of occurrence between Tafamidis and adverse reactions such as primary hypertension, hyperlipidemia, and height reduction.

Analysis and insights of cardiac amyloidosis: novel perception of rare diseases in cardiology

BACKGROUND

Amyloidosis is a rare systemic disease, while cardiac amyloidosis (CA) is nothing more than a chronic disease that causes fatal damage to the structure and function of the heart. The pathogenesis of CA is elusive, the clinical manifestations are diverse and lack of specificity, and the treatment and prognosis of different subtypes vary widely. It is of great practical significance to deepen the understanding of CA.

OBJECTIVE AND METHODS

The clinical data of 39 patients with CA admitted to the First Affiliated Hospital of Gannan Medical University and Fujian Medical University Union Hospital from January 1, 2018 to March 1, 2024 were collected and retrospectively studied, and the clinical features, diagnosis, differentiation, treatment effects and prognosis of CA patients were analyzed. The Kaplan-Meier method was used for survival analysis. Meanwhile, the latest literature from PubMed was retrieved to systematically discuss the research progress in the diagnosis and treatment of CA. This paper is expected to provide novel and valuable references for the clinical and basic research of CA.

RESULTS

A total of 39 patients with CA were included in this study, including 23 males (58.97%) and 16 females (41.03%). The average age at diagnosis was 60.51±10.28 years old. In this study, 24 patients (61.54%) had anemia of different degrees, 19 patients (48.72%) were accompanied by abnormal elevation of cardiac troponin T (cTnT), and all patients (100%) had abnormal elevation of N-terminal pro-brain natriuretic peptide (NT-proBNP), and 28 patients (71.79%) had renal impairment. Typical electrocardiogram (ECG) findings in CA patients in this study show low voltage in limb leads, various types of atrioventricular block, various types of tachycardia, atrial fibrillation and poor R-wave progression. The representative results of ultrasonic cardiogram (UCG) showed: 1. Atrium were enlarged, and ventricular wall motion was weakened. 2. Septum and posterior walls of the ventricle were symmetrically thickened, and the myocardium showed speckled strong echo. 3. Mitral regurgitation (moderate to severe) and tricuspid regurgitation. 4. Widening of the pulmonary artery and pulmonary hypertension. Typical results of cardiac magnetic resonance imaging (MRI) of CA patients in this study showed that delayed gadolinium enhancement of the ventricular wall, with ventricular wall thickening to varying degrees and ventricle or atrium enlargement. The pathological manifestations of CA patients in this study were mostly Congo red staining (+) and deposition of eosinophilic amyloid in the affected organs or tissues. All CA patients included in this study received standardized treatment, the median follow-up time was 29.5 (range, 6.5-71) months, and at the latest follow-up, only 12 cases of 39 patients with CA were still alive, and 27 patients died in our study, all of which were due to uncontrollable progression of the disease and failed treatment. Our study showed that there is no statistical significance in the different age groups of the CA patients (P>0.05), while it was surprising that male CA patients had significantly worse overall survival (OS) than female patients. Correspondingly, patients who received chemotherapy and were accompanied with renal impairment had a worse prognosis than those who did not receive chemotherapy and had normal renal function (all P<0.05).

CONCLUSION

CA is a rare disease caused by systemic amyloidosis, the pivotal points of CA diagnosis and treatment as well as the premise for improving the long-term prognosis of CA patients are clear diagnosis and accurate typing. The treatment of CA also requires targeted individual treatment according to the subtype and etiology of CA patients, so as to maximize the prognosis of CA patients.

Evaluation of the 2021 ESC recommendations for family screening in hereditary transthyretin cardiac amyloidosis

AIMS

The 2021 European Society of Cardiology (ESC) screening recommendations for individuals carrying a pathogenic transthyretin amyloidosis variant (ATTRv) are based on expert opinion. We aimed to (i) determine the penetrance of ATTRv cardiomyopathy (ATTRv-CM) at baseline; (ii) examine the value of serial evaluation; and (iii) establish the yield of first-line diagnostic tests (i.e. electrocardiogram, echocardiogram, and laboratory tests) as per 2021 ESC position statement.

METHODS AND RESULTS

We included 159 relatives (median age 55.6 [43.2-65.9] years, 52% male) at risk for ATTRv-CM from 10 centres. The primary endpoint, ATTRv-CM diagnosis, was defined as the presence of (i) cardiac tracer uptake in bone scintigraphy; or (ii) transthyretin-positive cardiac biopsy. The secondary endpoint was a composite of heart failure (New York Heart Association class ≥II) and pacemaker-requiring conduction disorders. At baseline, 40/159 (25%) relatives were diagnosed with ATTRv-CM. Of those, 20 (50%) met the secondary endpoint. Indication to screen (≤10 years prior to predicted disease onset and absence of extracardiac amyloidosis) had an excellent negative predictive value (97%). Other pre-screening predictors for ATTRv-CM were infrequently identified variants and male sex. Importantly, 13% of relatives with ATTRv-CM did not show any signs of cardiac involvement on first-line diagnostic tests. The yield of serial evaluation (n = 41 relatives; follow-up 3.1 [2.2-5.2] years) at 3-year interval was 9.4%.

CONCLUSIONS

Screening according to the 2021 ESC position statement performs well in daily clinical practice. Clinicians should adhere to repeating bone scintigraphy after 3 years, as progressing to ATTRv-CM without signs of ATTRv-CM on first-line diagnostic tests or symptoms is common.

Epidemiological Changes in Transthyretin Cardiac Amyloidosis: Evidence from In Vivo Data and Autoptic Series

Cardiac amyloidosis is an infiltrative disease that causes progressive myocardial impairment secondary to amyloid fibril deposition in the extracellular space of the myocardium. Many amyloid precursors, including transthyretin protein, are known to determine cardiac damage by aggregating and precipitating in cardiac tissue. Transthyretin cardiac amyloidosis may be either caused by rare genetic mutations of the transthyretin gene in the hereditary variant, or may arise as a consequence of age-related mechanisms in the acquired form. Although it has been labeled as a rare disease, in recent years, transthyretin cardiac amyloidosis has stood out as an emerging cause of aortic stenosis, unexplained left ventricular hypertrophy and heart failure with preserved ejection fraction, particularly in the elderly. Indeed, the integration of data deriving from both in vivo imaging techniques (whose advancement in the last years has allowed to achieve an easier and more accessible non-invasive diagnosis) and forensic studies (showing a prevalence of amyloid deposition in cardiac tissue of elderly patients up to 29%) suggests that cardiac amyloidosis is a more common disease than traditionally considered. Thanks to all the improvements in non-invasive diagnostic techniques, along with the development of efficacious therapies offering improvements in survival rates, transthyretin cardiac amyloidosis has been transformed from an incurable and infrequent condition to a relatively more diffuse and treatable disease, which physicians should take into consideration in the differential diagnostic processes in daily clinical practice.

Advances in the Diagnosis and Management of Cardiac Amyloidosis: A Literature Review

Cardiac amyloidosis, increasingly recognized for its significant impact on global heart health and patient survival, demands a thorough review to understand its complexity and the urgency of improved management strategies. As a cause of cardiomyopathy and heart failure, particularly in patients with aortic stenosis and atrial fibrillation, this condition also relates to higher incidences of dementia in the affected populations. The objective of this review was to integrate and discuss the latest advancements in diagnostics and therapeutics for cardiac amyloidosis, emphasizing the implications for patient prognosis. We evaluated the latest literature from major medical databases such as PubMed and Scopus, focusing on research from 2020 to 2024, to gather comprehensive insights into the current landscape of this condition. Insights from our review highlight the complex pathophysiology of cardiac amyloidosis and the diagnostic challenges it presents. We detail the effectiveness of emerging treatments, notably gene silencing therapies like patisiran and vutrisiran, which offer transformative potential by targeting the production of amyloidogenic proteins. Additionally, the stabilization therapy acoramidis shows promise in modifying disease progression and improving clinical outcomes. This review underscores the critical need for updated clinical guidelines and further research to expand access to groundbreaking therapies and enhance disease management. Advocating for continued research and policy support, we emphasize the importance of advancing diagnostic precision and treatment effectiveness, which are vital for improving patient outcomes and addressing this debilitating disease globally.

Clinical and genetic profiles of patients with hereditary and wild-type transthyretin amyloidosis: the Transthyretin Cardiac Amyloidosis Registry in the state of São Paulo, Brazil (REACT-SP)

BACKGROUND

Transthyretin amyloidosis (ATTR) is a multisystem disease caused by the deposition of fibrillar protein in organs and tissues. ATTR genotypes and phenotypes are highly heterogeneous. We present data on physical signs and symptoms, cardiac and neurological assessments and genetic profile of patients enrolled in the Transthyretin Cardiac Amyloidosis Registry of the State of São Paulo, Brazil.

RESULTS

Six hundred-forty-four patients were enrolled, 505 with the variant form (ATTRv) and 139 with wild-type (ATTRwt). Eleven different mutations were detected, the most common being Val50Met (47.5%) and V142Ile (39.2%). Overall, more than half of the patients presented cardiac involvement, and the difference in this proportion between the ATTRv and ATTRwt groups was significant (43.9 vs. 89.9%; p < 0.001). The prevalence of the neurological phenotype also differed between ATTRv and ATTRwt (56.8 vs. 31.7%; p < 0.001). The mixed phenotype was found in 25.6% of the population, without a significant difference between ATTRv and ATTRwt groups. A group of patients remained asymptomatic (10.4%), with a lower proportion of asymptomatic ATTRwt patients.

CONCLUSIONS

This study details the clinical and genetic spectrum of patients with ATTR in São Paulo, Brazil. This preliminary analysis highlights the considerable phenotypic heterogeneity of neurological and cardiac manifestations in patients with variant and wild-type ATTR.

Cardiac Amyloidosis: A Comprehensive Review of Pathophysiology, Diagnostic Approach, Applications of Artificial Intelligence, and Management Strategies

Cardiac amyloidosis (CA) is a serious and often fatal condition caused by the accumulation of amyloid fibrils in the heart, leading to progressive heart failure. It involves the misfolding of normally soluble proteins into insoluble amyloid fibrils, with transthyretin and light-chain amyloidosis being the most common forms affecting the heart. Advances in diagnostics, especially cardiac magnetic resonance imaging and non-invasive techniques, have improved early detection and disease management. Artificial intelligence has emerged as a diagnostic tool for cardiac amyloidosis, improving accuracy and enabling earlier intervention through advanced imaging analysis and pattern recognition. Management strategies include volume control, specific pharmacotherapies like tafamidis, and addressing arrhythmias and advanced heart failure. However, further research is needed for novel therapeutic approaches, the long-term effectiveness of emerging treatments, and the optimization of artificial intelligence applications in clinical practice for better patient outcomes. The article aims to provide an overview of CA, outlining its pathophysiology, diagnostic advancements, the role of artificial intelligence, management strategies, and the need for further research.

Pathophysiology of Cardiac Amyloidosis

Amyloidosis refers to a heterogeneous group of disorders sharing common pathophysiological mechanisms characterized by the extracellular accumulation of fibrillar deposits consisting of the aggregation of misfolded proteins. Cardiac amyloidosis (CA), usually caused by deposition of misfolded transthyretin or immunoglobulin light chains, is an increasingly recognized cause of heart failure burdened by a poor prognosis. CA manifests with a restrictive cardiomyopathy which progressively leads to biventricular thickening, diastolic and then systolic dysfunction, arrhythmias, and valvular disease. The pathophysiology of CA is multifactorial and includes increased oxidative stress, mitochondrial damage, apoptosis, impaired metabolism, and modifications of intracellular calcium balance.

Amyloidosis and Amyloidogenesis: One Name, Many Diseases

Amyloidosis is a heterogenous group of disorders, caused by the deposition of insoluble fibrils derived from misfolded proteins in the extracellular space of various organs. These proteins have an unstable structure that causes them to misfold, aggregate, and deposit as amyloid fibrils with the pathognomonic histologic property of green birefringence when viewed under cross-polarized light after staining with Congo red. Amyloid fibrils are insoluble and degradation-resistant; resistance to catabolism results in progressive tissue amyloid accumulation. The outcome of this process is organ disfunction independently from the type of deposited protein, however there can be organ that are specifically targeted from certain proteins.

Specific Therapy in Transthyretin Amyloid Cardiomyopathy: Future Perspectives Beyond Tafamidis

Transthyretin amyloid cardiomyopathy (ATTR-CM) is a relatively prevalent cause of morbidity and mortality. Over the recent years, development of disease-modifying treatments has enabled stabilization of the circulating transthyretin tetramer and suppression of its hepatic production, resulting in a remarkable improvement in survival of patients with ATTR-CM. Second-generation drugs for silencing are currently under investigation in randomized clinical trials. In vivo gene editing of transthyretin has been achieving unanticipated suppression of hepatic production in ATTR-CM. Trials of antibodies inducing the active removal of transthyretin amyloid deposits in the heart are ongoing, and evidence has gathered for exceptional spontaneous regression of ATTR-CM.

Clinical Use of Biomarkers in Cardiac Amyloidosis

Amyloidosis is a systemic condition characterized by multiple organs involvement. A multidisciplinary and multimodal approach in assessing patients is pivotal and recommended by the international scientific societies. Biomarkers represent an essential noninvasive tool to increase the suspicion of disease and orient further workup and clinical management of patients. This review provides an updated contemporary focus on the clinical use of biomarkers in cardiac amyloidosis, emphasizing their role in both the diagnostic and prognostic setting and discussing future perspective of emerging biomarkers.

Evolution of Disease-modifying Therapy for Transthyretin Cardiac Amyloidosis

Transthyretin cardiac amyloidosis (ATTR-CA) represents an inexorably progressive and fatal cardiomyopathy. Increased understanding of the underlying pathogenesis responsible for the misfolding of transthyretin and the subsequent accumulation of amyloid fibrils within the myocardium has led to the development of several disease-modifying therapies that act on different stages of the disease pathway. Tafamidis is the first, and to date remains the only, therapy approved for the treatment of ATTR-CA, which, alongside acoramidis, stabilizes the transthyretin tetramer, preventing disaggregation, misfolding and formation of amyloid fibrils. Gene-silencing agents, such as patisiran, vutrisian and eplontersen, and novel gene-editing therapies, such as NTLA-2001, act to reduce the hepatic synthesis of transthyretin. Anti-amyloid therapies represent another strategy in the treatment of ATTR-CA and are designed to bind amyloid fibril epitopes and stimulate macrophage-mediated removal of amyloid fibrils from the myocardium. Many of these treatments are at an early investigational stage but represent an important area of unmet clinical need and could potentially reverse disease and restore cardiac functions even in patients with advanced disease.

SGLT2 Inhibitor Therapy in Patients With Transthyretin Amyloid Cardiomyopathy

BACKGROUND

Transthyretin cardiomyopathy (ATTR-CM) was an exclusion criterion in randomized clinical trials of sodium-glucose cotransporter 2 inhibitors (SGLT2i).

OBJECTIVES

This study sought to assess the effectiveness and tolerability of SGLT2i in patients with ATTR-CM.

METHODS

Data of 2,356 consecutive ATTR-CM patients (2014-2022) were analyzed: 260 (11%) received SGLT2i. After comparing the groups according to the treatment, 14 variables were significantly different-age and N-terminal pro-B-type natriuretic peptide were included in the model. A propensity score reflecting the likelihood of being treated with SGLT2i for each patient was determined using 16 variables.

RESULTS

The study comprised 220 patients treated with SGLT2i (age 77 ± 2 years; 82.3% wild-type ATTR-CM; left ventricular ejection fraction 45.8% ± 11%) and 220 propensity-matched control individuals. Adequacy of matching was verified (standardized differences: <0.10 between groups). Discontinuation rate for SGLT2i was 4.5%; at 12 months, SGLT2i treatment was associated with less worsening of NYHA functional class, N-terminal pro-B-type natriuretic peptide, estimated glomerular filtration rate, and fewer new initiations of loop diuretic agent therapy. Over 28 months (Q1-Q3: 18-45 months), SGLT2i therapy was associated with lower all-cause mortality (HR: 0.57; 95% CI: 0.37-0.89; P = 0.010), cardiovascular mortality (HR: 0.41; 95% CI: 0.24-0.71; P < 0.001), heart failure (HF) hospitalization (HR: 0.57; 95% CI: 0.36-0.91; P = 0.014), and the composite outcome of cardiovascular mortality and HF hospitalization (HR: 0.57; 95% CI: 0.38-0.84; P = 0.003).

CONCLUSIONS

SGLT2i treatment in ATTR-CM patients was well tolerated and associated with favorable effects on HF symptoms, renal function, and diuretic agent requirement over time. SGLT2i treatment was associated with reduced risk of HF hospitalization and cardiovascular and all-cause mortality, regardless of the ejection fraction, despite the effect size being likely overestimated. In the absence of randomized trials, these data may inform clinicians regarding the use of SGLT2i in patients with ATTR-CM.

Management of hypertrophic cardiomyopathy

Hypertrophic cardiomyopathy is an important cause of heart failure and arrhythmias, including sudden death, with a major impact on the healthcare system. Genetic causes and different phenotypes are now increasingly being identified for this condition. In addition, specific medications, such as myosin inhibitors, have been recently shown as potentially able to modify its symptoms, hemodynamic abnormalities and clinical course. Our article aims to provide a comprehensive outline of the epidemiology, diagnosis and treatment of hypertrophic cardiomyopathy in the current era.

Breakthrough advances enhancing care in ATTR amyloid cardiomyopathy

Transthyretin amyloid cardiomyopathy (ATTR-CM) has been traditionally considered a rare and inexorably fatal condition. ATTR-CM now is an increasingly recognized cause of heart failure (HF) and mortality worldwide with effective pharmacological treatments. Advances in non-invasive diagnosis, coupled with the development of effective treatments, have transformed the diagnosis of ATTR-CM, which is now possible without recourse to endomyocardial biopsy in ≈70 % of cases. Many patients are now diagnosed at an earlier stage. Echocardiography and cardiac magnetic resonance have enabled identification of patients with possible ATTR-CM and more accurate prognostic stratification. Although radionuclide scintigraphy with 'bone' tracers has an established diagnostic value, the diagnostic performance of the bone tracers validated for non-invasive confirmation of ATTR-CM may not be equal. Characterising the wider clinical phenotype of patients with ATTR-CM has enabled identification of features with potential for earlier diagnosis such as carpal tunnel syndrome. Therapies able to slow or halt ATTR-CM progression and increase survival are now available and there is also evidence that patients may benefit from specific conventional HF medications. Cutting-edge research in the field of antibody-mediated removal of ATTR deposits compellingly suggest that ATTR-CM is a truly reversible disorder, bringing hope for patients even with advanced disease. A wide horizon of possibilities is unfolding and awaits discovery.

Clinical and Prognostic Implications of Right Ventricular Uptake on Bone Scintigraphy in Transthyretin Amyloid Cardiomyopathy

BACKGROUND

The extent of myocardial bone tracer uptake with technetium pyrophosphate, hydroxymethylene diphosphonate, and 3,3-diphosphono-1,2-propanodicarboxylate in transthyretin amyloid cardiomyopathy (ATTR-CM) might reflect cardiac amyloid burden and be associated with outcome.

METHODS

Consecutive patients with ATTR-CM who underwent diagnostic bone tracer scintigraphy with acquisition of whole-body planar and cardiac single-photon emission computed tomography (SPECT) images from the National Amyloidosis Centre and 4 Italian centers were included. Cardiac uptake was defined according to the Perugini classification: 0=absent cardiac uptake; 1=mild uptake less than bone; 2=moderate uptake equal to bone; and 3=high uptake greater than bone. Extent of right ventricular (RV) uptake was defined as focal (basal segment of the RV free wall only) or diffuse (extending beyond basal segment) on the basis of SPECT imaging. The primary outcome was all-cause mortality.

RESULTS

Among 1422 patients with ATTR-CM, RV uptake accompanying left ventricular uptake was identified by SPECT imaging in 100% of cases at diagnosis. Median follow-up in the whole cohort was 34 months (interquartile range, 21 to 50 months), and 494 patients died. By Kaplan-Meier analysis, diffuse RV uptake on SPECT imaging (n=936) was associated with higher all-cause mortality compared with focal (n=486) RV uptake (77.9% versus 22.1%; P<0.001), whereas Perugini grade was not associated with survival (P=0.27 in grade 2 versus grade 3). On multivariable analysis, after adjustment for age at diagnosis (hazard ratio [HR], 1.03 [95% CI, 1.02-1.04]; P<0.001), presence of the p.(V142I) TTR variant (HR, 1.42 [95% CI, 1.20-1.81]; P=0.004), National Amyloidosis Centre stage (each category, P<0.001), stroke volume index (HR, 0.99 [95% CI, 0.97-0.99]; P=0.043), E/e' (HR, 1.02 [95% CI, 1.007-1.03]; P=0.004), right atrial area index (HR, 1.05 [95% CI, 1.02-1.08]; P=0.001), and left ventricular global longitudinal strain (HR, 1.06 [95% CI, 1.03-1.09]; P<0.001), diffuse RV uptake on SPECT imaging (HR, 1.60 [95% CI, 1.26-2.04]; P<0.001) remained an independent predictor of all-cause mortality. The prognostic value of diffuse RV uptake was maintained across each National Amyloidosis Centre stage and in both wild-type and hereditary ATTR-CM (P<0.001 and P=0.02, respectively).

CONCLUSIONS

Diffuse RV uptake of bone tracer on SPECT imaging is associated with poor outcomes in patients with ATTR-CM and is an independent prognostic marker at diagnosis.

Vutrisiran: a new drug in the treatment landscape of hereditary transthyretin amyloid polyneuropathy

INTRODUCTION

Hereditary transthyretin (ATTRv) amyloidosis is a progressive, fatal disorder caused by mutations in the transthyretin (TTR) gene leading to deposition of the misfolded protein in amyloid fibrils. The main phenotypes are peripheral neuropathy (PN) and cardiomyopathy (CM).

AREAS COVERED

Gene silencing therapy, by dramatically reducing liver production of TTR, has transformed ATTRv-PN patient care in the last decade. In this drug discovery case history, the authors discuss the treatment history of ATTRv-PN and focus on the latest siRNA therapy: vutrisiran. Vutrisiran is chemically enhanced and N-acetylgalactosamin-conjugated, allowing increased stability and specific liver delivery. HELIOS-A, a phase III, multicenter randomized study, tested vutrisiran in ATTRv-PN and showed significant improvement in neuropathy impairment, disability, quality of life (QoL), gait speed, and nutritional status. Tolerance was acceptable, no safety signals were raised.

EXPERT OPINION

Vutrisiran offers a new treatment option for patients with ATTRv-PN. Vutrisian's easier delivery and administration route, at a quarterly frequency, as well as the absence of premedication, are major improvements to reduce patients' disease burden and improve their QoL. Its place in the therapeutic strategy is to be determined, considering affordability.

Hospitalization-based epidemiology of systemic and cardiac amyloidosis in the Veneto Region, Italy

AIM

Defining the epidemiology of systemic and cardiac amyloidosis (CA) is a contemporary challenge. The present study aimed to estimate incidence and time trends in amyloidosis-related hospitalizations (AH) in Veneto Region (5 million inhabitants, Northeastern Italy).

METHODS

International Classification of Diseases (ICD-9) codes were used to identify AH in Veneto from 2010 to 2020. AH were defined as any hospitalization with a discharge summary reporting an ICD-9 code for systemic amyloidosis. Hospitalization for CA was defined as records with ICD-9 code for systemic amyloidosis and ICD-9 code for heart failure,cardiomyopathy or arrhythmia. Hospital/outpatient encounters for carpal tunnel syndrome (CTS) surgeries also were extracted. AH incidence was estimated using a buffer of 5 years.

RESULTS

In the time range 2015-2020, the incidence rate of AH was 23.5 cases per 106 (95% confidence interval, CI, 21.8; 25.3), mainly affecting patients>65 years (76.2%) and males (63.5%), with a progressively increasing trend (percent annual increase 17%, 95% CI 12; 22%). The 10 year prevalence of AH in 2020 was 124.5 per 106 (95% CI 114.9; 134.8). In 2020, annual hospitalized prevalent cases of CA were about 70% of all cases (159/228), mainly patients >65 years and males. Among patients with multiple CTS surgeries, a subsequent code for cardiac disease was found in 913 after a median of 3.9 years, more frequently in men than in women (463/6.526 7.1% versus 450/11.406 3.9%).

CONCLUSIONS

In Veneto, we recorded a significantly increasing trend in the incidence of AH, with concordant increasing prevalence estimates.

ECG/echo indexes in the diagnostic approach to amyloid cardiomyopathy: A head-to-head comparison from the AC-TIVE study

BACKGROUND AND AIMS

The discordance between QRS voltages on electrocardiogram (ECG) and left ventricle (LV) wall thickness (LVWT) on echocardiogram (echo) is a recognized red flag (RF) of amyloid cardiomyopathy (AC) and can be measured by specific indexes. No head-to-head comparison of different ECG/echo indexes among subjects with echocardiographic suspicion of AC has yet been undertaken. The study aimed at evaluating the performance and the incremental diagnostic value of different ECG/echo indexes in this subset of patients.

METHODS

Electrocardiograms of subjects with LV hypertrophy, preserved ejection fraction and ≥ 1 echocardiographic RF of AC participating in the AC-TIVE study, an Italian prospective multicenter study, were independently analyzed by two cardiologists. Low QRS voltages and 8 different ECG/echo indexes were evaluated. Cohort specific cut-offs were computed.

RESULTS

Among 170 patients, 55 (32 %) were diagnosed with AC. Combination of low QRS voltages with interventricular septum ≥ 1,6 cm was the most specific (specificity 100 %, positive predictive value 100 %) ECG/echo index, while the ratio between the sum of all QRS voltages and LVWT <7,8 was the most sensitive and accurate (sensitivity 94 %, negative predictive value 97 %, accuracy 82 %). When the latter index was added to a model using easily-accessible clinical variables, the diagnostic accuracy for AC greatly increased (AUC from 0,84 to 0,95; p = 0,007).

CONCLUSIONS

Among patients with non-dilated hypertrophic ventricles with normal ejection fraction and echocardiographic RF of AC, easily-measurable ECG/echo indexes, mainly when added to few clinical variables, can help the physician orient second level investigations. External validation of the results is warranted.

Cardiopulmonary Exercise Testing in Evaluating Transthyretin Amyloidosis

Importance

Cardiopulmonary exercise testing (CPET) has an established role in the assessment of patients with heart failure. However, data are lacking in patients with transthyretin (ATTR) amyloidosis.

Objective

To use CPET to characterize the spectrum of functional phenotypes in patients with ATTR amyloidosis and assess their association with the cardiac amyloid burden as well as the association between CPET parameters and prognosis.

Design, Setting and Participants

This single-center study evaluated patients diagnosed with ATTR amyloidosis from May 2019 to September 2022 who underwent CPET at the National Amyloidosis Centre. Of 1045 patients approached, 506 were included and completed the study. Patients were excluded if they had an absolute contraindication to CPET or declined participation. The mean (SD) follow-up period was 22.4 (11.6) months.

Main Outcomes and Measures

Comparison of CPET parameters across disease phenotypes (ATTR with cardiomyopathy [ATTR-CM], polyneuropathy, or both [ATTR-mixed]), differences in CPET parameters based on degree of amyloid infiltration (as measured by cardiovascular magnetic resonance [CMR] with extracellular volume mapping), and association between CPET parameters and prognosis.

Results

Among the 506 patients with ATTR amyloidosis included in this study, the mean (SD) age was 73.5 (10.2) years, and 457 participants (90.3%) were male. Impairment in functional capacity was highly prevalent. Functional impairment in ATTR-CM and ATTR-mixed phenotypes (peak mean [SD] oxygen consumption [VO2], 14.5 [4.3] mL/kg/min and 15.7 [6.2] mL/kg/min, respectively) was observed alongside impairment in the oxygen pulse, with ventilatory efficiency highest in ATTR-CM (mean [SD] ventilatory efficiency/volume of carbon dioxide expired slope, 38.1 [8.6]). Chronotropic incompetence and exercise oscillatory ventilation (EOV) were highly prevalent across all phenotypes, with both the prevalence and severity being higher than in heart failure from different etiologies. Worsening of amyloid burden on CMR was associated with decline in multiple CPET parameters, although chronotropic response and EOV remained abnormal irrespective of amyloid burden. On multivariable Cox regression analysis, peak VO2 and peak systolic blood pressure (SBP) were independently associated with prognosis (peak VO2: hazard ratio, 0.89 [95% CI, 0.81-0.99; P = .03]; peak SBP: hazard ratio, 0.98 [95% CI, 0.97-0.99; P < .001]).

Conclusions and Relevance

In this study, ATTR amyloidosis was characterized by distinct patterns of functional impairment between all disease phenotypes. A high prevalence of chronotropic incompetence, EOV, and ventilatory inefficiency were characteristic of this population. CPET parameters were associated with amyloid burden by CMR and with peak VO2, and SBP, which have been shown to be independent predictors of mortality. These findings suggest that CPET may be useful in characterizing distinct patterns of functional impairment across the spectrum of amyloid infiltration and predicting outcomes, and potentially offers a more comprehensive method of evaluating functional capacity for future prospective studies.

Back to the basics: The need for an etiological classification of chronic heart failure

The left ventricular (LV) ejection fraction (LVEF), despite its severe limitations, has had an epicentral role in heart failure (HF) classification, management, and risk stratification for decades. The major argument favoring the LVEF based HF classification has been that it defines groups of patients in which treatment is effective. However, this reasoning has recently collapsed, since medical treatment with neurohormonal inhibitors, has proved beneficial in most HF patients regardless of the LVEF. In addition, there has been compelling evidence, that the LVEF provides poor guidance for device treatment of chronic HF (implantation of cardioverter defibrillator, cardiac resynchronization therapy) since sudden cardiac death may occur and cardiac dyssynchronization may be disastrous in all HF patients. The same holds true for LV assist device implantation, in which the LVEF has been used as a surrogate for LV size. In this review article we update the evidence questioning the use of LVEF-based HF classification and argue that guidance of chronic HF treatment should transition to more contemporary concepts. Specifically, we propose an etiologic chronic HF classification predominantly based on epidemiological data, which will be foundational for further higher resolution phenotyping in the emerging era of precision medicine.

Molecular mechanisms and emerging therapies in wild-type transthyretin amyloid cardiomyopathy

Wild-type transthyretin amyloid cardiomyopathy (ATTRwt-CM) is an underrecognized cause of heart failure due to misfolded wild-type transthyretin (TTRwt) myocardial deposition. The development of wild-type TTR amyloid fibrils is a complex pathological process linked to the deterioration of homeostatic mechanisms owing to aging, plausibly implicating multiple molecular mechanisms. The components of amyloid transthyretin often include serum amyloid P, proteoglycans, and clusterin, which may play essential roles in the localization and elimination of amyloid fibrils. Oxidative stress, impaired mitochondrial function, and perturbation of intracellular calcium dynamics induced by TTR contribute to cardiac impairment. Recently, tafamidis has been the only drug approved by the U.S. Food and Drug Administration (FDA) for the treatment of ATTRwt-CM. In addition, small interfering RNAs and antisense oligonucleotides for ATTR-CM are promising therapeutic approaches and are currently in phase III clinical trials. Newly emerging therapies, such as antibodies targeting amyloid, inhibitors of seed formation, and CRISPR‒Cas9 technology, are currently in the early stages of research. The development of novel therapies is based on progress in comprehending the molecular events behind amyloid cardiomyopathy. There is still a need to further advance innovative treatments, providing patients with access to alternative and effective therapies, especially for patients diagnosed at a late stage.