Prevalence of transthyretin amyloidosis in patients with heart failure and no left ventricular hypertrophy

A multicenter study of clinical predictors of positive pyrophosphate scintigraphy findings in the diagnosis of transthyretin amyloidosis

BACKGROUND

The prevalence of wild-type transthyretin (ATTR) amyloidosis is increasing with advancements in diagnostic techniques and growing awareness of the disease worldwide. 99mTc-labeled pyrophosphate (99mTc-PYP) scintigraphy exhibits high performance in diagnosing ATTR cardiac amyloidosis. This study aimed to validate the characteristics of patients with positive 99mTc-PYP scintigraphy results in a multicenter setting to provide more accurate case selection criteria.

METHODS AND RESULTS

In total, 180 patients with suspected ATTR amyloidosis underwent 99mTc-PYP scintigraphy in participating institutions in Japan between January 2018 and July 2022. Of 135 patients included in the analysis, 62 were 99mTc-PYP-positive. Logistic regression analysis was performed, and the following five factors were adopted to create a scoring system, with each weighted according to its odds ratio value; 1 point was scored for the absence of hypertension, existence of peripheral entrapment neuropathy (carpal tunnel syndrome or spinal canal stenosis), conduction disturbance (the presence of QRS complex ≥120 ms, first-degree atrioventricular block, higher degree of atrioventricular block, or presence of pacemaker implantation), and left ventricular hypertrophy and 2 points for troponin I/T ≥ 0.06 ng/mL. 99mTc-PYP scintigraphy positivity rate in the 0-point group was 0 %, whereas that in the 6-point group was 100 %. The area under the curve of the criteria was 0.820 (95 % confidence interval, 0.752-0.888; P < 0.001).

CONCLUSIONS

The combination of clinical information, which is easily available in local clinics, can provide accurate pretest prediction of positive 99mTc-PYP scintigraphy results. This will help clinicians to make an early diagnosis of ATTR amyloidosis.

Transthyretin amyloidosis prevalence and characteristics in Korean patients with heart failure with preserved or mildly reduced ejection fractions

The diagnosis and awareness of transthyretin amyloidosis cardiomyopathy (ATTR-CM) in heart failure with left ventricular ejection fraction (LVEF) > 40% remains under-recognized. This study aimed to investigate the prevalence and characteristics of ATTR-CM in patients with heart failure with LVEF > 40%. Patients with LVEF > 40% and maximal left ventricular wall thickness (MWT) > 10 mm who underwent bone scintigraphy were retrospectively investigated. Patients with a definite cause of heart failure were excluded. ATTR-CM was diagnosed when grade 2 or 3 myocardial uptake was observed on scintigraphy. Among 97 patients (male, 62.5%; median age, 69 years), 13 (13.4%) were diagnosed with ATTR-CM (wild type, 69.2%; hereditary type, 30.8%). Age or biomarker levels did not differ significantly; however, all patients with ATTR-CM were male. The ATTR-CM group had a significantly higher prevalence of polyneuropathy or carpal tunnel syndrome than the non-ATTR-CM group, accompanied by a longer PR interval, thicker MWT, larger left atrial volume index, and higher E/e'. Accordingly, ATTR was present in a substantial number, particularly among men. Clinicians should suspect ATTR when a male patient exhibits neurologic symptoms, diastolic dysfunction, and a long PR interval.

Radionuclide Imaging of Cardiac Amyloidosis: An Update and Future Aspects

Cardiac amyloidosis (CA) is caused by the misfolding, accumulation and aggregation of proteins into large fibrils in the extracellular compartment of the myocardium, leading to restrictive cardiomyopathy, heart failure and death. The major forms are transthyretin (ATTR) CA and light-chain (AL) CA, based on the respective precursor protein. Each of them requires early diagnosis for a timely treatment initiation that will improve patient outcomes. For this, radionuclide imaging is essentially used as single-photon emission computed tomography (SPECT) with bone-avid radiotracers or as positron emission tomography (PET) with amyloid-binding radiotracers. Both offer unprecedented specificity for the diagnostic of CA. SPECT has even revolutionized the diagnosis of ATTR-CA by making it non-invasive. Indeed, SPECT has now entered the standard diagnostic pathway to CA and has led to earlier diagnosis of the disease. SPECT also modified the epidemiology of ATTR-CA, highlighting that the disease is much more frequent than previously believed, and showing that ATTR-CA plays a substantial role in HFpEF and aortic stenosis, particularly among elderly patients. In parallel, amyloid-binding radiotracers for PET have accumulated a substantial amount of evidence, but are not approved for clinical use in CA yet. Further studies are needed to refine acquisition protocols and validate results in broader populations. Unlike bone-avid SPECT radiotracers, PET radiotracers have been specifically created to bind to amyloid fibrils. Thus, PET is the only imaging method that is truly specific for amyloid deposits and very sensitive to any amyloid type. Indeed, PET can not only detect ATTR-CA, but also AL-CA and rare hereditary forms. For both SPECT and PET, advances in quantitation of myocardial uptake have generated more granular and reproducible findings, paving the way for progress in earlier diagnosis, risk stratification and therapeutic response monitoring. Encouraging findings have shown that SPECT and PET are sensitive to early CA when other diagnostic methods are negative. Both radionuclide imaging techniques can predict adverse outcomes, but more evidence is needed to determine how to use them in conjunction with usual prognostic staging scores. Studies on follow-up imaging after therapy suggested that SPECT and PET can capture myocardial changes in CA, but again, more data are needed to meaningfully interpret such changes. Based on all these promising results, radionuclide imaging has the potential to further impact the landscape of CA in diagnosis, prognosis and follow-up, but also to substantially contribute to the assessment of novel therapies that will improve the lives of patients with CA.

Effect of Diflunisal in Patients with Transthyretin Cardiomyopathy: A Pilot Study

Background: ATTR-CM is becoming more prevalent, and disease-modifying therapy has been investigated in recent years with promising results. Diflunisal has shown TTR-stabilizing properties assessed by biomarkers and echocardiography, but there are no trials addressing the evolution of morphological changes with CMR. Methods and Results: AMILCA-DIFLU is an exploratory pilot study prospective, single-center, non-randomized, open-label clinical trial. Patients diagnosed with ATTR-CM underwent clinical, functional, biochemical and imaging assessment before and one year after diflunisal therapy initiation. Of the twelve ATTR-CM patients included, only nine patients completed treatment and study protocol in 12 months. To increase the sample size, we included seven real-world patients with one year of diflunisal treatment. Among the group of patients who completed treatment, diflunisal therapy did not show improvement in cardiac disease status as assessed by many cardiac and inflammatory biomarkers, 6MWT and CMR parameters after one year of treatment. However, a non-significant trend towards stabilization of CMR parameters such as LVEF, ECV and T2 at one year was found. When comparing the group of patients who completed diflunisal therapy and those who did not, a significant decrease in the distance performed in the 6MWT was found in the group of patients who completed treatment at one year (-14 ± 81.8 vs. -173 ± 122.2; p = 0.032). Diflunisal was overall well tolerated, showing only a statistically significant worsening in renal function in the group of diflunisal-treatment patients with no clinical relevance or need for treatment discontinuation. Conclusions: In patients with ATTR-CM, treatment with diflunisal was overall well tolerated and tended to stabilize or slow down amyloid cardiac disease progression assessed by CMR parameters, cardiac and inflammatory biomarkers and functional capacity.

Prevalence of transthyretin cardiac amyloidosis in patients with heart failure with preserved ejection fraction: the PRACTICA study

INTRODUCTION AND OBJECTIVES

Transthyretin cardiac amyloidosis (ATTR-CA) is a frequent cause of heart failure with preserved ejection fraction (HFpEF). This study sought to determine the prevalence of ATTR-CA among HFpEF patients in a multicenter nationwide study.

METHODS

Consecutive ambulatory or hospitalized patients aged ≥ 50 years with HFpEF and left ventricle hypertrophy ≥ 12mm were studied at 20 Spanish hospitals. Screening for cardiac amyloidosis was initiated according to the usual clinical practice of each center. Positive scintigraphs were centrally analyzed.

RESULTS

422 patients were included, of whom 387 underwent further screening for cardiac amyloidosis. A total of 65 patients (16.8%) were diagnosed with ATTR-CA, none below 75 years. There was an increase of prevalence with age. Of them, 60% were male, with a mean age of 85.3±5.2 years, mean left ventricle ejection fraction of 60.3±7.6% and a mean maximum left ventricle wall thickness of 17.2 [12-25] mm. Most of the patients were New York Heart Association class II (48.4%) or III (46.8%). Besides being older than non-ATTR-CA patients, ATTR-CA patients had higher median NT-proBNP levels (3801 [2266-7132] vs 2391 [1141-4796] pg/mL; P=.003). There was no statistical difference in the prevalence of ATTR-CA by sex (19.7% for men and 13.8% for women, P=.085). A ∼7% (4/56) of the patients exhibited a genetic variant (ATTRv).

CONCLUSIONS

This multicenter nationwide study found a prevalence of 16.8%, confirming that ATTR-CA is a significant contributor to HFpEF in male and female patients with left ventricle hypertrophy and more than 75 years.

Assessment of incidental cardiac uptake in bone scintigraphy across Spain: The ECCINGO study

AIM

Myocardial uptake on bone scintigraphy has become useful for the detection of transthyretin cardiac amyloidosis (ATTR-CA). This study aimed to assess the prevalence of myocardial uptake in patients over 18 years of age with no clinical suspicion of cardiac amyloidosis (CA) who had undergone bone scintigraphy.

METHODS AND RESULTS

This was an observational, retrospective, multicenter study across 21 Spanish hospitals (September-November 2019). Of the 9864 scans analyzed (locally and centrally), incidental cardiac uptake was observed in 71 patients (0.72%), a prevalence that increased with age. A previous diagnosis of heart failure was found in 16.9% of patients with positive uptake, with >50% in NYHA II. ATTR-CA was diagnosed in 10 patients, with a mean delay of 10.4 months (95% CI: 5.1-15.7). All were >70 years old, primarily male, and had greater left ventricular hypertrophy than patients without a confirmed diagnosis (p<0.0001). ATTR-CA patients had higher rates of orthostatic hypotension (30.0% vs. 3.8% in non-ATTR-CA; p=0.025).

CONCLUSIONS

This is the first retrospective, national, multicenter study evaluating the prevalence of incidental cardiac uptake in bone scintigraphy performed for non-cardiac reasons, showing a prevalence of 0.72% in this population. Referral of these patients may facilitate early diagnosis of CA with a resulting benefit for patients.

Towards etiological treatments in cardiomyopathies

This review proposes to look at the evolution of cardiomyopathy treatments in the light of advances in diagnostic techniques, which have enabled to move from a mechanistic to a phenotypic and then etiological approach. The article goes beyond the ejection fraction approach, and look at new therapies that target the pathophysiological pathways of cardiomyopathies, either by targeting the phenotype, or by targeting the etiology. The evolution of HCM treatments is detailed, culminating in the latest etiological treatments such as mavacamten in sarcomeric HCM, tafamidis in transthyretin cardiac amyloidosis and migalastat in Fabry disease. Myosin stimulators are reviewed in the treatment of DCM, before opening perspectives for gene therapy, which proposes direct treatment of the culprit mutation.

Arrhythmias and Device Therapies in Cardiac Amyloidosis

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

Development and Validation of a Prediction Model and Score for Transthyretin Cardiac Amyloidosis Diagnosis: T-Amylo

BACKGROUND

Although transthyretin cardiac amyloidosis (ATTR-CA) is often underdiagnosed, clinical suspicion is essential for early diagnosis.

OBJECTIVES

The aim of this study was to develop and validate a feasible prediction model and score to facilitate the diagnosis of ATTR-CA.

METHODS

This retrospective multicenter study enrolled consecutive patients who underwent 99mTc-DPD scintigraphy for suspected ATTR-CA. ATTR-CA was diagnosed if Grade 2 or 3 cardiac uptake was evidenced on 99mTc-DPD scintigraphy in the absence of a detectable monoclonal component or by demonstration of amyloid by biopsy. A prediction model for ATTR-CA diagnosis was developed in a derivation sample of 227 patients from 2 centers using multivariable logistic regression with clinical, electrocardiography, analytical, and transthoracic echocardiography variables. A simplified score was also created. Both of them were validated in an external cohort (n = 895) from 11 centers.

RESULTS

The obtained prediction model combined age, gender, carpal tunnel syndrome, interventricular septum in diastole thickness, and low QRS interval voltages, with an area under the curve (AUC) of 0.92. The score had an AUC of 0.86. Both the T-Amylo prediction model and the score showed a good performance in the validation sample (ie, AUC: 0.84 and 0.82, respectively). They were tested in 3 clinical scenarios of the validation cohort: 1) hypertensive cardiomyopathy (n = 327); 2) severe aortic stenosis (n = 105); and 3) heart failure with preserved ejection fraction (n = 604), all with good diagnostic accuracy.

CONCLUSIONS

The T-Amylo is a simple prediction model that improves the prediction of ATTR-CA diagnosis in patients with suspected ATTR-CA.

A simple ATTR-CM score to identify transthyretin amyloid cardiomyopathy burden in HFpEF patients

BACKGROUND

Transthyretin amyloid cardiomyopathy (ATTR-CM) is often found in patients with heart failure with preserved ejection fraction (HFpEF). However, the evidence regarding ATTR-CM and prognosis in HFpEF remains scarce. This study sought to determine whether the ATTR-CM burden was associated with clinical outcomes in HFpEF patients.

METHODS

We evaluated the associations of baseline ATTR-CM score with adverse outcomes in HFpEF patients from the TOPCAT trial using the Cox proportional hazards model or the competing risk regression model. The discriminatory ability of the ATTR-CM score was assessed using the area under the time-dependent receiver operating characteristic curve (AUC).

RESULTS

We included 870 HFpEF patients, 18.9% of which had an ATTR-CM score ≥6. Per 1 increment in the ATTR-CM score was significantly associated with an increased risk of the primary outcome (adjusted hazard ratio [HR] 1.19, 95% confidence interval [CI] 1.12-1.27) with an AUC of 0.652 (0.594-0.711), whereas patients with ATTR-CM score ≥6 presented higher risks of the primary outcome (adjusted HR 2.20, 95% CI 1.65-2.95). Similar results were observed toward the secondary outcomes.

CONCLUSIONS

The simple ATTR-CM score identified an 18.9% ATTR-CM burden in HFpEF patients, and a higher ATTR-CM burden might predict adverse outcomes with moderate discriminatory abilities in HFpEF.

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

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

Insight into different phenotypic presentations of heart failure with preserved ejection fraction

Heart failure (HF) with preserved ejection fraction (HFpEF) accounts for half of all HF diagnoses, and its prevalence is increasing at an alarming rate. Lately, it has been recognized as a clinical syndrome due to diverse underlying etiology and pathophysiological mechanisms. The classic echocardiographic features of HFpEF have been well described as preserved ejection fraction (≥50%), left ventricular hypertrophy, and left atrial enlargement. However, echocardiography can play a key role in identifying the principal underlying mechanism responsible for HFpEF in the individual patient. The recognition of different phenotypic presentations of HFpEF (infiltrative, metabolic, genetic, and inflammatory) can assist the clinician in tailoring the appropriate management, and offer prognostic information. The goal of this review is to highlight several key phenotypes of HFpEF and illustrate the classic clinical scenario and echocardiographic features of each phenotype with real patient cases.

Patient phenotype profiling in heart failure with preserved ejection fraction to guide therapeutic decision making. A scientific statement of the Heart Failure Association, the European Heart Rhythm Association of the European Society of Cardiology, and the European Society of Hypertension

Heart failure with preserved ejection fraction (HFpEF) represents a highly heterogeneous clinical syndrome affected in its development and progression by many comorbidities. The left ventricular diastolic dysfunction may be a manifestation of various combinations of cardiovascular, metabolic, pulmonary, renal, and geriatric conditions. Thus, in addition to treatment with sodium-glucose cotransporter 2 inhibitors in all patients, the most effective method of improving clinical outcomes may be therapy tailored to each patient's clinical profile. To better outline a phenotype-based approach for the treatment of HFpEF, in this joint position paper, the Heart Failure Association of the European Society of Cardiology, the European Heart Rhythm Association and the European Hypertension Society, have developed an algorithm to identify the most common HFpEF phenotypes and identify the evidence-based treatment strategy for each, while taking into account the complexities of multiple comorbidities and polypharmacy.

Estimating the Prevalence of Cardiac Amyloidosis in Old Patients with Heart Failure—Barriers and Opportunities for Improvement: The PREVAMIC Study

Background: Cardiac amyloidosis (CA) could be a common cause of heart failure (HF). The objective of the study was to estimate the prevalence of CA in patients with HF. Methods: Observational, prospective, and multicenter study involving 30 Spanish hospitals. A total of 453 patients ≥ 65 years with HF and an interventricular septum or posterior wall thickness > 12 mm were included. All patients underwent a 99mTc-DPD/PYP/HMDP scintigraphy and monoclonal bands were studied, following the current criteria for non-invasive diagnosis. In inconclusive cases, biopsies were performed. Results: The vast majority of CA were diagnosed non-invasively. The prevalence was 20.1%. Most of the CA were transthyretin (ATTR-CM, 84.6%), with a minority of cardiac light-chain amyloidosis (AL-CM, 2.2%). The remaining (13.2%) was untyped. The prevalence was significantly higher in men (60.1% vs 39.9%, p = 0.019). Of the patients with CA, 26.5% had a left ventricular ejection fraction less than 50%. Conclusions: CA was the cause of HF in one out of five patients and should be screened in the elderly with HF and myocardial thickening, regardless of sex and LVEF. Few transthyretin-gene-sequencing studies were performed in older patients. In many patients, it was not possible to determine the amyloid subtype.

Epidemiology of cardiac amyloidosis in Germany: a retrospective analysis from 2009 to 2018

BACKGROUND

Improved imaging modalities contributed to increasing awareness of cardiac amyloidosis. Contemporary data on frequency trends in Germany are lacking.

METHODS

In a retrospective study using health claims data of a German statutory health insurance, patients with diagnostic codes of amyloidosis and concomitant heart failure between 2009 and 2018 were identified.

RESULTS

Prevalence increased from 15.5 to 47.6 per 100,000 person-years, and incidence increased from 4.8 to 11.6 per 100,000 person-years, with a continuous steepening in the slope of incidence trend. In patients with amyloidosis and heart failure age and proportion of men significantly increased, whereas the frequency of myeloma and nephrotic syndrome significantly decreased over time. Median (IQR) survival time after first diagnosis was 2.5 years (0.5-6 years), with a 9% (95% CI 2-15%, p = 0.008) reduced risk of death in the second compared to the first 5 years of observation. In the 2 years prior and 1 year after diagnosis, mean total health care costs were 6568 €, 11,872 € and 21,955 € per person and year.

CONCLUSION

The rise in cardiac amyloidosis has continuously accelerated in the last decade. Considering the adverse outcome and high health care burden, further effort should be put on early detection of the disease to implement available treatment.

Research trends and hotspots evolution of cardiac amyloidosis: a bibliometric analysis from 2000 to 2022

In the new century, cardiac amyloidosis has received more attention from many countries and institutions, leading to innovations in the essence of the pathology, biological markers, noninvasive tests, and staging diagnoses and treatments for this disease. However, few reviews have summarized the research trends and hotspots in cardiac amyloidosis. Bibliometrics analysis is a statistically based approach to research that visualizes the contributions of academic institutions and changes in research hotspots. Therefore, in this paper, we used Citespace and VOSviewer software to conduct co-occurrence analysis and collaborative network analysis on the countries, institutions, and authors in the articles related to cardiac amyloidosis since the new century. And further find out burst keywords and references to obtain the research history, disciplinary development, and new hotspots and topics.

99mTc Bone-Avid Tracer Cardiac Scintigraphy: Role in Noninvasive Diagnosis of Transthyretin Cardiac Amyloidosis

Transthyretin cardiac amyloidosis (ATTR-CA) is an overlooked cause of heart failure, with substantial morbidity and mortality. The emergence of several novel therapies has fueled the interest in early and accurate diagnosis of ATTR-CA so that potentially life-saving pharmacologic therapy can be administered in a timely manner. The most promising imaging modality and biomarker is SPECT imaging with technetium 99m (99mTc)-radiolabeled bone-seeking tracers, which have high specificity in the diagnosis of ATTR-CA, potentially obviating biopsy. In this article, the authors provide a focused review on the use of 99mTc pyrophosphate (PYP), 3,3-diphosphono-1,2-propanodicarboxylic acid (DPD), and hydroxymethylene diphosphonate (HMDP) for diagnosis of ATTR-CA, present a systematic approach to interpretation of the scans, and highlight several common pitfalls to illustrate important diagnostic principles for accurate interpretation of these images. The authors indicate when to use endomyocardial biopsy for the diagnosis of cardiac amyloidosis and conclude with a section on quantitation of 99mTc-PYP/DPD/HMDP imaging.

Redefining the epidemiology of cardiac amyloidosis. A systematic review and meta-analysis of screening studies

AIMS

An algorithm for non-invasive diagnosis of amyloid transthyretin cardiac amyloidosis (ATTR-CA) and novel disease-modifying therapies have prompted an active search for CA. We examined the prevalence of CA in different settings based on literature data.

METHODS AND RESULTS

We performed a systematic search for screening studies on CA, focusing on the prevalence, sex and age distribution in different clinical settings. The prevalence of CA in different settings was as follows: bone scintigraphy for non-cardiac reasons (n = 5 studies), 1% (95% confidence interval [CI] 0%-1%); heart failure with preserved ejection fraction (n = 6), 12% (95% CI 6%-20%); heart failure with reduced or mildly reduced ejection fraction (n = 2), 10% (95% CI 6%-15%); conduction disorders warranting pacemaker implantation (n = 1), 2% (95% CI 0%-4%); surgery for carpal tunnel syndrome (n = 3), 7% (95% CI 5%-10%); hypertrophic cardiomyopathy phenotype (n = 2), 7% (95% CI 5%-9%); severe aortic stenosis (n = 7), 8% (95% CI 5%-13%); autopsy series of 'unselected' elderly individuals (n = 4), 21% (95% CI 7%-39%). The average age of CA patients in the different settings ranged from 74 to 90 years, and the percentage of men from 50% to 100%. Many patients had ATTR-CA, but the average percentage of patients with amyloid light-chain (AL) CA was up to 18%.

CONCLUSIONS

Searching for CA in specific settings allows to identify a relatively high number of cases who may be eligible for treatment if the diagnosis is unequivocal. ATTR-CA accounts for many cases of CA across the different settings, but AL-CA is not infrequent. Median age at diagnosis falls in the eighth or ninth decades, and many patients diagnosed with CA are women.

Multimodality assessments of wild‐type transthyretin cardiac amyloidosis with no ventricular hypertrophy

While patients with transthyretin cardiac amyloidosis (ATTR-CA) typically present with concentric or asymmetric hypertrophy, a small percentage of ATTR-CA is known to present with 'atypical' cardiac morphologies such as eccentric hypertrophy or even no hypertrophy. However, detailed report of multimodality assessments of ATTR-CA with no ventricular hypertrophy is lacking. Herein, we report detailed multimodality assessments of an 81-year-old Japanese woman with heart failure and history of carpal tunnel syndrome and lumbar canal stenosis, presenting no ventricular hypertrophy and negative ^99m technetium-pyrophosphate scintigraphy, who was eventually diagnosed as having wild-type ATTR-CA. Our case highlights the role of multimodality assessments for early diagnosis of ATTR-CA in patients with atypical cardiac morphologies and also emphasizes the limitations of bone scintigraphy and the importance of considering ATTR-CA in patients with non-cardiac manifestations of ATTR amyloidosis.

Prevalence and Risk Factors of Cardiac Amyloidosis in Heart Failure: A Systematic Review and Meta-Analysis

AIMS

Heart failure (HF) is one of the leading causes of mortality worldwide. Heart failure is also one of the most common presentations of cardiac amyloidosis (CA). Contemporary epidemiological data of CA in HF patients is lacking. Hence, this systematic review and meta-analysis was conducted to determine the prevalence of amyloidosis in HF patients, and to clarify the risk factors of concomitant CA and HF.

METHODS

A systematic review and meta-analysis was performed. Studies were retrieved from Medline, EMBASE, Scopus and Cochrane library. The search was not restricted in time, type or language of publication. The prevalence of CA in HF grouped according to diagnostic techniques and risk factors of CA with HF was analysed.

RESULTS

Eleven (11) studies were included, involving 3,303 patients. The pooled prevalence of CA in HF was 13.7%. The overall prevalence of CA in HF with preserved ejection fraction was 15.1%, and that of HF with reduced ejection fraction was 11.3%. The main factors associated with the diagnosis of CA in HF included older age, males, raised NT pro-BNP, increased interventricular septal thickness in diastole, apical sparing, and reduced left ventricular systolic function.

CONCLUSION

A high index of clinical suspicion is required to identify HF patients with CA. Supportive investigations may be helpful when clinically correlated. A considerable proportion of HF patients have CA and certain risk factors may be helpful in increasing suspicions of CA in HF.

Multimodality Assessments of Wild-Type Transthyretin Amyloid Cardiomyopathy Presenting With Eccentric Hypertrophy and Aortic Regurgitation

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TTR-CA is underdiagnosed in heart failure patients.

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A small percentage of TTR-CA patients present with atypical cardiac morphologies.

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CMR and bone scintigraphy may be useful for diagnosis even in atypical morphology.

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Concomitant TTR-CA should be considered in patients with valvular heart disease.

Cardiac Amyloidosis with Normal Wall Thickness: Prevalence, Clinical Characteristics and Outcome in a Retrospective Analysis

Background: Cardiac amyloidosis (CA) is a rare, progressive, infiltrative cardiac disease. Light chain (AL) and transthyretin (ATTR) amyloidosis are in the background in almost all cases. New, easily available diagnostic tools and recently introduced novel therapies for both types of CA put this disease into the field of interest. Increased left ventricular wall thickness (IWT) detected by echocardiography is generally thought to be a necessary part of the diagnosis. We aimed to determine the proportion of CA patients without IWT, and to define the clinical characteristics of this cohort. Methods: In an academic tertiary center for CA, we identified patients diagnosed and treated for CA between January 2009 and February 2022. In a retrospective analysis we defined the proportion of patients with (≥12 mm) and without (<12 mm) IWT, and described their clinical features. Results: We identified 98 patients suitable for the analysis. In total, 70 had AL and 27 ATTR CA; 89 patients had CA with IWT and 9 patients (9%) had CA without IWT. All non-IWT patients had AL type CA. Both group of patients had clinically significant disease, which is supported by the relevant elevation in cardiac biomarker levels. There was no difference between the outcome of the two groups. Conclusion: Patients without IWT form a relevant subgroup among those with CA. Our results suggest that diagnostic algorithms and criteria should take these individuals into consideration, and, therefore, give them access to effective treatments.

Prevalence and Clinical Outcomes of Transthyretin Amyloidosis: A Systematic Review and Meta-analysis

BACKGROUND

Systematic evidence on the prevalence and clinical outcome of transthyretin amyloidosis (ATTR) is missing. We explored: a) the prevalence of cardiac amyloidosis in various patient subgroups, b) survival estimates for ATTR subtypes and c) the effects of novel therapeutics on the natural course of disease.

METHODS

A systematic review of literature published in Medline before 31/12/2021 was performed for the prevalence of cardiac amyloidosis & all-cause mortality of ATTR patients. Extracted data included sample size, age, sex, and all-cause mortality at 1, 2 and 5-years. Subgroup analyses were performed for ATTR subtype i.e., wild type ATTR (wtATTR) vs. hereditary ATTR (htATTR), htATTR genotypes and treatment subgroups.

RESULTS

We identified a total of 62 studies (n=277,882 individuals) reporting the prevalence of cardiac amyloidosis, which was high among patients with a hypertrophic cardiomyopathy phenotype, HFpEF, and elderly with aortic stenosis. Data on ATTR mortality were extracted from 95 studies (n=18,238 ATTR patients). Patients with wtATTR were older (p=7x10^-10 ) and more frequently male (p=5x10^-20 ) vs. htATTR. The 2-year survival of ATTR was 73.3% (95%CI 71.6-76.2); for non-subtyped ATTR 70.4% (95%CI 66.9-73.9), for wtATTR (76.0%, 95%CI: 73.0-78.9) and for htATTR (77.2%, 95%CI: 74.0-80.4); in meta-regression analysis wtATTR was associated with higher survival after adjusting for confounders. There was an interaction between survival and htATTR genotypes (p=10^-15 , Val30Met having the lowest and Val122Ile/Thr60Ala the highest mortality). ATTR 2-year survival was higher on tafamidis/patisiran compared to natural disease course (79.9%, 95%CI: 74.4-85.3 vs. 72.4%, 95%CI 69.8-74.9, p<0.05).

CONCLUSIONS

We report the prevalence of ATTR in various population subgroups and provide survival estimates for the natural course of disease and the effects of novel therapeutics. Important gaps in worldwide epidemiology research in ATTR were identified. This article is protected by copyright. All rights reserved.

A systematic review and meta-analysis of the prevalence of transthyretin amyloidosis in heart failure with preserved ejection fraction

BACKGROUND

Heart failure with preserved ejection fraction is a complex clinical syndrome marked by different phenotypes and related comorbidities. Transthyretin amyloidosis is an underestimated phenotype. We aim to evaluate the prevalence of transthyretin amyloidosis in heart failure with preserved ejection fraction.

METHODS

This meta-analysis was conducted according to PRISMA guidelines. A search strategy was designed to utilize PubMed/Medline, EMBASE, and Google scholar to locate studies whose primary objective was to analyze the prevalence of transthyretin amyloidosis in heart failure preserved ejection fraction.

RESULTS

Of 271 studies initially identified, 5 studies comprising 670 patients were included in the final analysis. The prevalence of transthyretin amyloidosis was 11%. Patients with transthyretin amyloid cardiomyopathy were more likely to be males (RR 1.38; 95% CI 1.09 to 1.75; P<0.01; I²=37%), and more likely to have low voltage criteria on ECG (RR 2.98; 95% CI 1.03 to 8.58; P=0.04; I²=75%) compared with transthyretin negative group. They also have higher SMD of age (SMD 0.73; 95% CI 0.48 to 0.97; P<0.01; I²=0%), and NT-proBNP (SMD 0.48; 95% CI 0.02 to 0.93; P=0.04; I²=36%) compared with transthyretin negative group. On reported echocardiogram, they have higher SMD of mass index (SMD 0.77; 95% CI 0.27 to 1.27; P<0.01; I²=65%), posterior wall thickness (SMD 0.92; 95% CI 0.62 to 1.21; P<0.01; I²=0%), and septal wall thickness (SMD 1.49; 95% CI 0.65 to 2.32; P<0.01; I²=87%) compared with transthyretin negative group.

CONCLUSION

Transthyretin amyloidosis affects 11% of HFpEF patients. Therefore, screening HFpEF patients at risk of cardiac amyloidosis is warranted.

Aetiological classification and prognosis in patients with heart failure with preserved ejection fraction

AIMS

Heart failure with preserved ejection fraction (HFpEF) is a heterogeneous syndrome with various causes that may influence prognosis.

METHODS AND RESULTS

We extracted the electronic medical records for 2180 consecutive patients hospitalized between 2016 and 2019 for decompensated heart failure. Using a text mining algorithm looking for a left ventricular ejection fraction ≥50% and plasma brain natriuretic peptide level >100 pg/mL, we identified 928 HFpEF patients. We screened for a prevailing cause of HFpEF according to European guidelines and found that 418 (45.0%) patients had secondary HFpEF due to either myocardial (n = 125, 13.5%) or loading condition abnormalities (n = 293, 31.5%), while the remaining 510 (55.0%) patients had idiopathic HFpEF. We assessed the association between the causes of HFpEF and survival collected up to 31 December 2020 using Cox proportional hazards analysis. Even though patients with idiopathic HFpEF were older, frequently female, and had frequent co-morbidities and a higher crude mortality rate compared with secondary HFpEF patients, their prognosis was similar after adjustment for age and sex. Unsupervised clustering analysis revealed three main phenogroups with different distribution of idiopathic vs. secondary HFpEF. The phenogroup with the highest proportion of idiopathic HFpEF (69%) had (i) an excess rate of non-cardiac co-morbidities including chronic obstructive pulmonary disease (31%) or obesity (41%) and (ii) a better prognosis compared with the two other phenogroups enriched with secondary HFpEF.

CONCLUSIONS

Aetiological classification provides clinical and prognostic information and may be useful to better decipher the clinical heterogeneity of HFpEF.

Prevalence of transthyretin amyloidosis in patients with heart failure and no left ventricular hypertrophy

AIMS

As evidenced by scintigraphy imaging, the prevalence of transthyretin (TTR) cardiac amyloidosis in heart failure patients with preserved ejection fraction (HFpEF) and left ventricular hypertrophy (LVH) ranges between 13% and 19%. The natural evolution of cardiac amyloidosis begins with the deposition of amyloid material in the myocardium, with LVH ensuing at later stages. With current imaging modalities, it is possible to detect TTR cardiac amyloidosis before the hypertrophic stage. The aim of this study was to determine the prevalence of TTR cardiac amyloidosis in HFpEF patients without LVH.

METHODS AND RESULTS

The study prospectively enrolled patients admitted for HF with LV ejection fraction (LVEF) ≥ 50% and LV wall thickness <12 mm. TTR cardiac amyloidosis was diagnosed according to accepted criteria, which include positive cardiac 99-Tc-DPD scintigraphy in the absence of monoclonal protein expansion in blood. Transthyretin gene sequencing was performed in positive patients. From July 2017 to January 2020, 329 patients with HFpEF and LV thickness <12 mm were identified. After exclusions, 58 patients completed the study with cardiac scintigraphy (79 years, 54% men; median LVEF 60% and LV wall thickness 10.5 mm). Three patients (5.2%) were positive for TTR cardiac amyloidosis; genetic analysis excluded the presence of hereditary TTR amyloidosis. Positive patients baseline characteristics (84 years, 67% men, LVEF 60%, and LV wall thickness 11 mm) were similar to patients without TTR, except for troponin levels (0.05 vs. 0.02 ng/mL, P = 0.03) and glomerular filtration rate (82 vs. 60 mL/min, P = 0.032), which were higher in TTR patients.

CONCLUSIONS

In a cohort of patients with HFpEF without LVH, the prevalence of TTR cardiac amyloidosis was 5%. Early diagnosis of cardiac involvement in TTR amyloidosis (before manifest LVH) would seem recommendable because newly approved specific treatments can prevent additional deposition of amyloid material.