Carpal tunnel syndrome in cardiac amyloidosis: implications for early diagnosis and prognostic role across the spectrum of aetiologies

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.

Epidemiology, diagnosis, and management of cardiac amyloidosis

Cardiac amyloidosis (CA) is an infiltrative restrictive cardiomyopathy caused by the deposition of amyloid fibrils in the myocardium. It manifests in two primary subtypes: transthyretin cardiac amyloidosis (ATTR) and immunoglobulin light chain cardiac amyloidosis (AL). ATTR is further classified into wild-type and hereditary based on transthyretin gene mutation. Advances in diagnostics and therapeutics have transformed CA from a rare and untreatable condition to a more prevalent and manageable disease. Noninvasive diagnostic tools such as electrocardiography, echocardiography, and cardiac magnetic resonance can raise suspicion for CA; bone scintigraphy can non-invasively confirm ATTR, while AL necessitates histological confirmation. The severity of ATTR and AL can be assessed through serum biomarker-based staging. Treatment approaches differ, ranging from silencing or stabilizing transthyretin and degrading amyloid fibrils in ATTR to employing anti-plasma cell therapies and autologous stem cell transplantation in AL.

Prevalence of transthyretin amyloidosis in patients undergoing carpal tunnel surgery: a prospective cohort study and risk factor analysis

Transthyretin amyloidosis is a frequent cause of heart failure, resulting from an accumulation of abnormal proteins in the myocardium. Recent research has highlighted the importance of early diagnosis to enhance the effectiveness of specific treatments. Extra-cardiac symptoms may precede several years before cardiac complications, with carpal tunnel syndrome often considered a red flag. The aim of this prospective, observational cohort study was to determine the incidence rate of positive synovial biopsies for transthyretin amyloidosis in patients aged 60-80 years undergoing carpal tunnel decompression, and to identify risk factors. The diagnosis of transthyretin amyloidosis was confirmed through the analysis of synovial tissue biopsies using Congo Red and immunohistochemical staining. The study included 254 patients, with an 18.5% prevalence of transthyretin amyloidosis. Risk factors for positive test results were identified as male sex, trigger finger, hearing disorders and valve disease. A predictive analysis using logistic regression yielded a probability model for individuals belonging to the positive group.Level of evidence III.

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.

Prevalence and characteristics of transthyretin amyloid cardiomyopathy in hypertrophic cardiomyopathy

AIMS

Recognition of transthyretin amyloid cardiomyopathy is increasing due to advances in cardiac imaging and diagnostic strategies, but questions remain regarding disease frequency and characteristics. We examined the prevalence and characteristics of transthyretin amyloid cardiomyopathy in older patients with hypertrophic cardiomyopathy of unascertained aetiology.

METHODS AND RESULTS

TTRACK was a multicentre, non-interventional, cross-sectional epidemiologic study funded by Pfizer and conducted in 20 hospitals and medical centres in 11 countries (NCT03842163). Eligible patients were aged ≥50 years, had hypertrophic cardiomyopathy (maximal end-diastolic left ventricular wall thickness ≥15 mm on echocardiogram) without an identified genetic or alternative origin at study enrolment, and underwent 99mTechnetium bone scintigraphy, with or without single photon emission computed tomography (SPECT). Cardiac-versus-bone uptake on scans was visually scored from 0 to 3 (Perugini scoring). Patients with grades 1-3 underwent monoclonal protein and laboratory testing and transthyretin (TTR) gene sequencing. Of 766 eligible patients, 691 (90.2%) had scintigraphy alone and 75 (9.8%) scintigraphy plus SPECT. Two hundred and eight patients (27.2%) had grade 2 or 3 cardiac uptake on scintigraphy; 144 (18.8%) had grade 2 or 3 cardiac uptake and no evidence of plasma cell dyscrasia and were diagnosed with transthyretin amyloid cardiomyopathy. Of patients with transthyretin amyloid cardiomyopathy, 11 (7.6%) had a pathogenic TTR gene variant and 34 (23.8%), 74 (51.7%), and 35 (24.5%) had New York Heart Association class I, II, and III/IV heart failure (HF) symptoms, respectively. Clinical and laboratory diagnostic characteristics were observed in ≥90% of patients with transthyretin amyloid cardiomyopathy. The characteristics most strongly associated with transthyretin amyloid cardiomyopathy on multivariable analysis were carpal tunnel syndrome (odds ratio [OR] 54.3; P < 0.0001) and male sex (OR 7.9; P < 0.0001).

CONCLUSIONS

In the TTRACK study, almost one in five patients ≥50 years of age with hypertrophic cardiomyopathy had transthyretin amyloid cardiomyopathy. Greater awareness of the frequency and characteristics of transthyretin amyloid cardiomyopathy in older patients with hypertrophic cardiomyopathy are needed to help improve early detection of this debilitating but treatable disease.

Distinctive Deposition Patterns of Sporadic Transthyretin-Derived Amyloidosis in the Atria: A Forensic Autopsy-Based Study

Left-to-right differences in the histopathologic patterns of transthyretin-derived amyloid (ATTR) deposition in the atria of older adults have not yet been investigated. Hence, this study evaluated heart specimens from 325 serial autopsy subjects. The amount of ATTR deposits in the seven cardiac regions, including both sides of atria and atrial appendages, was evaluated semiquantitatively. Using digital pathology, we quantitatively evaluated the immunohistochemical deposition burden of ATTR in the myocardium. We identified 20 sporadic ATTR cardiac amyloidosis cases (nine males). All patients had ATTR deposition in the left atrial regions of the myocardium. In the semiquantitative analysis, 14 of the 20 cases showed more severe ATTR deposition on the left atrial regions than on the right side, with statistically significant differences in the pathology grading (p < 0.01 for both the atrium and atrial appendage). Quantitative analysis further supported the difference. Moreover, six had ATTR deposition in the epineurium and/or neural fibers of the atria. Cluster analysis revealed that ATTR deposition in the myocardium was significantly more severe in males than in females. The heterogeneous distribution of amyloid deposits between atria revealed in this study may impair the orderly transmission of the cardiac conduction system and induce arrhythmias, which may be further aggravated by additional neuropathy in the advanced phase. This impairment could be more severe among males. These findings emphasize that atrial evaluation is important for individuals with sporadic ATTR cardiac amyloidosis, particularly for early detection.

Early Diagnosis of Amyloidosis and Cardiac Involvement through Carpal Tunnel Surgery and Predictive Factors

Background/Objectives: To determine the prevalence of amyloidosis through the analysis of synovial tissue and transverse carpal ligament (TCL) in patients undergoing surgery for carpal tunnel syndrome (CTS), detect predictive factors for the presence of amyloid, and assess cardiac involvement degree. Methods: A prospective study with longitudinal cohort follow-up at a teaching hospital. Patients undergoing CTS surgery from 1 January 2019 to 31 May 2021 were included. Samples from synovial and TCL tissues were examined for amyloid presence. Multivariate analysis was used to detect predictive factors of the presence of amyloid. Patients with amyloid underwent echocardiography, laboratory analyses, and scintigraphy. Results: Two hundred and forty-six patients were included. The prevalence of amyloid was 11.4% in TCL and 12.6% in synovial tissues. Age (p = 0.035; OR 1.123), bilateral CTS symptoms (p = 0.022; OR 3.647), and trigger finger (p < 0.001; OR 3.537) were predictors of the presence of amyloid. Seventeen patients were diagnosed with transthyretin amyloidosis (ATTR) located in the carpus (no scintigraphic cardiac uptake or grade 0), one with light chain amyloidosis, eight with ATTR with cardiac involvement (grades 2-3), and five with ATTR in the carpus and scintigraphic uptake grade 1 (with normal echocardiogram and blood and urine tests). Conclusions: We detected amyloid in 12.6% of unselected consecutive patients who underwent CTS surgery. Biopsy in patients with CTS for amyloid detection, especially in elderly patients with bilateral symptoms and trigger finger, may be useful for the early diagnosis of amyloidosis, primarily due to transthyretin.

Diagnostic Modalities in the Detection of Cardiac Amyloidosis

Cardiac amyloidosis (CA) results mainly from the infiltration of the myocardium by either immunoglobulin light-chain fibrils (AL) or transthyretin fibrils (ATTR), causing restrictive cardiomyopathy and eventually death if untreated. AL derives from monoclonal immunoglobulin light chains produced by plasma cell clones in the bone marrow, while ATTR is the misfolded form of hepatically derived transthyretin (TTR) protein and can be hereditary (ATTRv) or wild-type (ATTRwt). Over the last decade, improvements in diagnostic imaging and better clinical awareness have unleashed a notable presence of CA in the community, especially ATTR in the elderly population. These multimodality imaging modalities include echocardiography, cardiac magnetic resonance, and radionuclide scintigraphy with bone-avid tracers. There has been remarkable progress in the therapeutic landscape as well, and there are disease-modifying therapies available now that can alter the course of the disease and improve survival if initiated at an early stage of the disease. There remains an unmet need for detecting this disease accurately and early so that these patients can benefit the most from newly emerging therapies.

Results of Implementation of Amyloidosis Screening for Patients Undergoing Carpal Tunnel Release

PURPOSE

Many patients with amyloidosis undergo carpal tunnel release (CTR) before amyloidosis diagnosis and before developing cardiac or other serious disease manifestations. The purposes of this study were to examine if our patient population had a similar prevalence of positive amyloidosis diagnoses to that in prior studies and to describe the results of implementing a screening program for amyloidosis.

METHODS

We retrospectively reviewed the biopsy results and subsequent interventions for all patients who underwent screening tenosynovial biopsy during CTR from March 2020 through December 2021. Amyloid screening was offered to patients who met the criteria for increased risk of disease using an appropriateness screening algorithm.

RESULTS

Seventy-five (48%) of 156 patients who underwent CTR met the eligibility criteria for amyloidosis testing. Of the 62 patients who agreed to undergo tenosynovial biopsy, 14 had amyloid-positive biopsy specimens (10 men and 4 women). All patients with positive tenosynovial biopsies had bilateral carpal tunnel syndrome and wild-type transthyretin amyloid subtype. One patient was diagnosed and started treatment for otherwise asymptomatic cardiac amyloidosis.

CONCLUSIONS

The incidence of amyloid-positive tenosynovial biopsy results from CTR was 22.5% in patients using the criteria from an appropriateness screening algorithm, which was higher than previously reported. Implementation of a screening program for patients undergoing CTR requires a multidisciplinary approach and may result in early diagnosis and lifesaving interventions for patients with amyloidosis.

TYPE OF STUDY/LEVEL OF EVIDENCE

Differential diagnosis/symptom prevalence study, II.

Carpal Tunnel Syndrome and Transthyretin Amyloidosis in the All of Us Research Program

OBJECTIVE

To evaluate the association of carpal tunnel syndrome (CTS) with incident heart failure and incident amyloidosis and to assess the risk of CTS in pathogenic TTR genetic variant carriers.

METHODS

This prospective cohort study included multiethnic US adults 18 years of age and older without prevalent heart failure and amyloidosis with available genotypic data from the All of Us Research Program. The primary outcomes were incident heart failure and incident amyloidosis. The association of incident heart failure and incident amyloidosis with CTS was assessed using multivariable adjusted Cox models accounting for age, sex, race and ethnicity, obesity, hypertension, diabetes, statin use, and smoking status.

RESULTS

Of the 166,987 individuals included, the median age was 54 (38 to 66) years; 105,279 (63.0%) were female, and 92,780 (55.6%) were non-Hispanic White individuals; CTS was identified in 12,407 (7.4%) individuals. Compared with individuals without CTS, the adjusted hazard ratio for incident heart failure was 1.13 (95% CI, 1.02 to 1.26) in individuals with CTS. The risk of amyloidosis was ∼3-fold higher (adjusted hazard ratio, 2.86; 95% CI, 1.71 to 4.77) in individuals with CTS compared with those without CTS. Individuals carrying a pathogenic TTR variant had an approximately 40% higher risk (adjusted hazard ratio, 1.38; 95% CI, 1.16 to 1.65) for development of CTS compared with noncarriers.

CONCLUSION

Cardiac amyloidosis screening programs may use CTS as a sentinel event and use genetic testing to identify individuals at a higher risk of TTR amyloidosis.

Characterization and natural history of different phenotypes in hereditary transthyretin amyloidosis: 40-year experience at a single Italian referral centre

AIMS

Hereditary transthyretin amyloidosis (ATTRv) is one of the leading aetiologies of systemic amyloidosis with more than 135 mutations described and a broad spectrum of clinical manifestations. We aimed to provide a systematic description of a population of individuals carrying pathogenic mutations of transthyretin (TTR) gene and to investigate the major clinical events during follow-up.

METHODS AND RESULTS

This was an observational, retrospective, cohort study including consecutive patients with mutations of TTR gene, admitted to a tertiary referral centre in Bologna, Italy, between 1984 and 2022. Three hundred twenty-five patients were included: 106 asymptomatic carriers, 49 cardiac phenotype, 49 neurological phenotype, and 121 mixed phenotype. Twenty-two different mutations were found, with Ile68Leu (41.8%), Val30Met (19%), and Glu89Gln (10%) being the most common. After a median follow-up of 51 months, 111 patients (38.3%) died and 9 (11.5%) of the 78 asymptomatic carriers developed ATTRv. Carriers had a prognosis comparable with healthy population, while no significant differences were seen among the three phenotypes adjusted by age. Age at diagnosis, New York Heart Association class III, left ventricular ejection fraction, modified polyneuropathy disability score IV, and disease-modifying therapy were independently associated with survival.

CONCLUSION

This study offers a wide and comprehensive overview of ATTRv from the point of view of a tertiary referral centre in Italy. Three main phenotypes can be identified (cardiac, neurological, and mixed) with specific clinical and instrumental features. Family screening programmes are essential to identify paucisymptomatic affected patients or unaffected carriers of the mutation, to be followed through the years. Lastly, disease-modifying therapy represents an evolving cornerstone of the management of ATTRv, with a great impact on mortality.

Clinical suspicion, diagnosis and management of cardiac amyloidosis: update document and executive summary

In recent years, the interest in cardiac amyloidosis has grown exponentially. However, there is a need to improve our understanding of amyloidosis in order to optimise early detection systems. Therefore, it is crucial to incorporate solutions to improve the suspicion, diagnosis and follow-up of cardiac amyloidosis. In this sense, we designed a tool following the different phases to reach the diagnosis of cardiac amyloidosis, as well as an optimal follow-up: a) clinical suspicion, where the importance of the "red flags" to suspect it and activate the diagnostic process is highlighted; 2) diagnosis, where the diagnostic algorithm is mainly outlined; and 3) follow-up of confirmed patients. This is a practical resource that will be of great use to all professionals caring for patients with suspected or confirmed cardiac amyloidosis, to improve its early detection, as well as to optimise its accurate diagnosis and optimal follow-up.

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.

Concomitant amyloidosis is the primary cause of endothelial and coronary microvascular dysfunction in carpal tunnel syndrome

Study objectives

Patients with carpal tunnel syndrome (CTS) show manifestations of arterial abnormalities, including carotid intimal thickening and increased vascular stiffness. As carpal tunnel syndrome is associated with amyloidosis, we hypothesized that previously observed abnormalities can largely be related with concomitant amyloidosis rather than CTS itself.

Design

Prospective observational study.

Setting

Medeniyet University Goztepe Hospital.

Participants

61 patients with CTS (of whom 32 had biopsy-proven amyloidosis) and 36 healthy controls.

Interventions

Subjects underwent ultrasound examinations for the measurement of coronary flow velocity reserve (CFVR), flow-mediated vasodilatation (FMD) and carotid intimal-media thickness (CIMT).

Main outcome measures

Comparison of CFVR, FMD and CIMT in CTS patients with or without amyloidosis.

Results

Patients with either CTS or CTS with concomitant amyloidosis (CTS-A) had significantly lower FMD (9.7 % ± 4.0 % in CTS and 10.3 % ± 4.6 % in CTS-A groups, p < 0.05 for both) and CFVR (2.4 (2.1-2.8) in CTS and 1.8 (1.6-2.1) in CTS-A groups, p < 0.001 for both) as compared to controls, while CIMT was only increased in CTS-A group (0.70 (0.60-0.80), p < 0.001). The reduction in CFVR was solely related to an increased basal flow velocity in CTS patients while there was also a reduced hyperemic flow velocity in patients with CTS-A.

Conclusion

Most arterial phenomena in CTS patients could be attributable to concomitant amyloidosis, although endothelial dysfunction was present even in patients with CTS without amyloidosis.

Musculoskeletal co-morbidities in patients with transthyretin amyloid cardiomyopathy: a systematic review

The prevalence of transthyretin-associated amyloidosis cardiomyopathy (ATTR-CM) has grown because of newer non-invasive diagnosis tools. Detecting the presence of extra-cardiac ATTR manifestations such as musculoskeletal pathologies considered 'red flags', when there is minimal or non-cardiac clinical involvement is primordial to carry out an early diagnosis. The aim of this systematic review is to examine the prevalence of musculoskeletal, ATTR-deposition-related co-morbidities in patients already diagnosed with ATTR-CM, specifically carpal tunnel syndrome, ruptured biceps tendon, spinal stenosis, and trigger finger. We performed a systematic review using PRISMA guidelines. Inclusion criteria were all studies in English and Spanish language and participants had to be patients diagnosed with ATTR-CM, by any diagnostic method, with the musculoskeletal co-morbidities subject of this review. The quality of the studies was based on the Risk of Bias Tool. This systematic review included 22 studies for final analysis. Carpal tunnel syndrome is reported in 21 studies, brachial biceps tendon rupture is reported in three, and spinal stenosis in eight studies. No articles that accomplished all the inclusion criteria for trigger finger were found. Regarding to the quality of the studies, all of them were categorized as being of high and moderate quality. The frequent association between ATTR-CM and carpal tunnel syndrome, ruptured biceps tendon, and lumbar spinal is confirmed, and the onset of these co-morbidities usually precedes the diagnosis of by years. This association defines them as red flags that should be search proactively due to the current treatment possibilities and the severity of the presentation of cardiac amyloidosis.

Neuromuscular manifestations of wild type transthyretin amyloidosis: a review and single center's experience

Transthyretin amyloidosis (ATTR) is a condition defined by accumulation of insoluble transthyretin amyloid deposits in multiple organs, especially in the peripheral nerve and heart muscle. ATTR may result from transthyretin mutations (variant ATTR or ATTRv) or may occur with normal transthyretin genotype (wild type ATTR or ATTRwt). ATTRwt was previously known as "senile amyloidosis" and causes cardiomyopathy which may lead to heart failure with a preserved ejection fraction, affecting predominantly elderly men. The exact prevalence of ATTRwt in the general population remains unclear, but its occurrence may be underestimated in women. It was observed that a proportion of ATTRwt cardiomyopathy patients may develop slowly progressing neuropathy that is milder and indolent in comparison with typical progressive neuropathy associated with ATTRv. Furthermore, the causality of neuropathy is often uncertain in patients with ATTRwt. Neuropathy symptoms, including distal sensory loss, unsteadiness and (neuropathic) pain are common in elderly patients with multiple potential causes, and as ATTRwt patients are typically older, relatively high prevalence of peripheral neuropathy is expected with frequent comorbidities. Relatively high prevalence of ATTRwt in elderly population contrasts few documented cases of neuropathy caused by ATTRwt, and there is uncertainty whether ATTRwt neuropathy is an infrequent occurrence or a significant manifestation of multisystemic ATTRwt. We review neurologic and musculoskeletal manifestations of ATTRwt and present clinical features of a single center cohort of ATTRwt patients with suspected peripheral neuropathy.

[Red flags of cardiac amyloidosis in patients with spinal stenosis and yellow ligament hypertrophy]

INTRODUCTION

Studies addressing the prevalence of cardiac amyloidosis (CA) among patients with spinal stenosis (SS) are lacking. The identification of the red flags (RF) of CA could lead to early detection of cases of CA. The primary objective of this study was to address the prevalence of RF of CA among patients with SS.

METHODS

Transversal study including consecutive cases with SS and yellow ligament hypertrophy (YLH). A clinical assessment that included electrocardiogram, echocardiogram and urine and blood test was performed. A clinical suspicion of CA was defined by the presence of left ventricular hypertrophy plus any RF.

RESULTS

One hundred and three patients with SS and YLH were assessed. The prevalence of RF was high: heart failure: 18.4%; aortic stenosis: 1.9%; carpal tunnel syndrome: 7.8%; bicipital tendon rupture: 1.9%; arterial hypotension: 17.4%; polyneuropathy symptoms: 51.5%; pseudoinfarction pattern: 3.9%; low voltages: 15.5%; conduction abnormalities: 15.5%; decreased longitudinal strain: 25.3%; apical sparing pattern: 3.9%. The 57.3% of the cohort met the CA suspicion criteria.

CONCLUSION

The prevalence of RF of CA is high among patients with SS and YLH. A high proportion of patients met the CA suspicion criteria.

Increased Risk of Coronary Artery Disease in People with Diagnosis of Neuromuscular Disorders: A Nationwide Retrospective Population-Based Case-Control Study

The existing literature has explored carpal tunnel syndrome (CTS) and determined that it could be a risk for coronary artery disease (CAD), but there has been little research comparing the relevance of CAD with other neuromuscular disorders (NMDs) to CTS. This case-control study explored the association between CTS, stenosing tenosynovitis (ST), and ulnar side NMDs and CAD. The study utilized data from Taiwan's National Health Insurance Research Database, focusing on health insurance claims. Between January 2000 and December 2011, we employed the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) diagnostic codes to identify 64,025 CAD patients as the case group. The control group consisted of an equal number of individuals without CAD, matched for age, sex, and index year of CAD. Logistic regression analysis was employed to calculate the odds ratios (ORs) and 95% confidence intervals (CIs) for each variable. Multivariate analysis, after adjusting for sociodemographic factors and comorbidities, revealed a significantly higher likelihood of a previous diagnosis of CTS in the CAD group compared to the comparison control group. However, neither ST nor the ulnar side NMDs had any statistical significance. These results indicated that median nerve injury, rather than other NMDs, may uniquely serve as a predisposing factor of CAD.

Carpal tunnel syndrome

Median neuropathy at the wrist, commonly referred to as carpal tunnel syndrome (CTS), is the most common entrapment neuropathy. It is caused by chronic compression of the median nerve at the wrist within the space-limited carpal tunnel. Risk factors that contribute to the etiology of compression include female gender, obesity, work-related factors, and underlying medical conditions, such as hypothyroidism, pregnancy, and amyloidosis. The diagnosis is made on clinical grounds, although these can be confounded by anatomical variations. Electrodiagnostic studies, which are specific and sensitive in diagnosing CTS, support the diagnosis; however, a subgroup may present with normal results. The advent of imaging techniques, including ultrasound and MRI, further assists the diagnostic process. The management of CTS is divided into the nonsurgical approaches that include hand therapy, splinting and corticosteroid injection, and surgical decompression of the carpal tunnel. Although several surgical techniques have been developed, no one method is more effective than the other. Each of these management approaches are effective at providing symptom relief and are utilized at different severities of the condition. There is, however, a lack of consensus on standardized diagnostic criteria, as well as when and to whom to refer patients for surgery.

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.

Cardiac amyloidosis in patients with spinal stenosis and yellow ligament hypertrophy

BACKGROUND

Spinal stenosis (SS) is a manifestation associated with cardiac amyloidosis (CA). However, there is a lack of studies assessing the prevalence of CA among patients with SS. We aimed to address the prevalence of CA among patients with SS and YLH.

METHODS

We performed a cross-sectional study of consecutive patients older than 65 years with SS and yellow ligament hypertrophy (YLH). All the patients were assessed with an electrocardiogram, echocardiogram and biohumoral evaluation. Patients with CA red flags was further studied with cardiac magnetic resonance and 99mTc-DPD scintigraphy. A cohort of patients with confirmed CA and SS was used to assess clinical features associated with CA.

RESULTS

105 patients (75.0 ± 6.6 years old; 45.7% males) with SS and YLH [5.5 [5-7] mm] were screened. Prevalence of red flags of CA was high and 58 patients presented clinical suspicion of CA. One patient (0.95%) was finally diagnosed of CA. Patients with confirmed CA presented a more expressive phenotype than the screened population. Patients with suspected CA had greater YLH than patients without suspicion of CA (6.4 ± 1.3 vs. 5.0 ± 0.8 mm; p < 0.001) and patients with confirmed CA presented greater YLH than the screening population (6.7 ± 1.8 vs. 5.7 ± 1.2 mm; p = 0.018).

CONCLUSION

Despite red flags of CA are common among patients with SS, the prevalence of confirmed CA was low in our sample of screened patients.

Standardising Care and Treatment of Transthyretin Amyloid Cardiomyopathy

Transthyretin cardiac amyloidosis (ATTR-CA) has been traditionally considered a rare and inexorably fatal condition. ATTR-CA now is an increasingly recognised cause of heart failure 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-CA, which is now possible without recourse to endomyocardial biopsy in around 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-CA and more accurate prognostic stratification. Therapies able to slow or halt ATTR-CA progression and increase survival are now available and there is also evidence that patients may benefit from specific conventional heart failure medications. A wide horizon of possibilities is unfolding and awaits discovery.

Transthyretin amyloid deposition in ligamentum flavum (LF) is significantly correlated with LF and epidural fat hypertrophy in patients with lumbar spinal stenosis

Lumbar spinal stenosis (LSS) is a degenerative disease characterized by intermittent claudication and numbness in the lower extremities. These symptoms are caused by the compression of nerve tissue in the lumbar spinal canal. Ligamentum flavum (LF) hypertrophy and spinal epidural lipomatosis in the spinal canal are known to contribute to stenosis of the spinal canal: however, detailed mechanisms underlying LSS are still not fully understood. Here, we show that surgically harvested LFs from LSS patients exhibited significantly increased thickness when transthyretin (TTR), the protein responsible for amyloidosis, was deposited in LFs, compared to those without TTR deposition. Multiple regression analysis, which considered age and BMI, revealed a significant association between LF hypertrophy and TTR deposition in LFs. Moreover, TTR deposition in LF was also significantly correlated with epidural fat (EF) thickness based on multiple regression analyses. Mesenchymal cell differentiation into adipocytes was significantly stimulated by TTR in vitro. These results suggest that TTR deposition in LFs is significantly associated with increased LF hypertrophy and EF thickness, and that TTR promotes adipogenesis of mesenchymal cells. Therapeutic agents to prevent TTR deposition in tissues are currently available or under development, and targeting TTR could be a potential therapeutic approach to inhibit LSS development and progression.

Bradyarrhythmias in Cardiac Amyloidosis and Role of Pacemaker

Cardiac amyloidosis (CA) is an underdiagnosed disease that is caused by deposition of misfolded transthyretin (ATTR) or immunoglobulin light chain (AL) fibrils in the myocardium. Bradyarrhythmias are commonly seen in CA, due to disruption of conducting system by amyloid fibrils. Atrioventricular conduction defect is more common than sinus node dysfunction. Bradyarrhythmias are most prevalent in wtATTR, followed by hATTR and AL. Pacemaker implantation, when indicated, can help provide symptomatic relief but does not confer mortality benefit. Progression of conduction system disease is common and often leads to increased right ventricular pacing burden with time. Therefore, cardiac resynchronizing therapy (biventricular therapy) is often considered as a better and safer option in these patients. Finally, the role of prophylactic pacemaker implantation is controversial, and current guidelines do not recommend prophylactic pacemaker insertion in CA patients.

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.

Musculoskeletal manifestations associated with transthyretin-mediated (ATTR) amyloidosis: a systematic review

BACKGROUND

Hereditary and wild-type transthyretin-mediated (ATTRv and ATTRwt) amyloidoses result from the misfolding of transthyretin and aggregation of amyloid plaques in multiple organ systems. Diagnosis of ATTR amyloidosis is often delayed due to its heterogenous and non-specific presentation. This review investigates the association of musculoskeletal (MSK) manifestations with ATTR amyloidosis and the delay from the onset of these manifestations to the diagnosis of ATTR amyloidosis.

METHODS

This systematic review utilized Medline and EMBASE databases. Search criteria were outlined using a pre-specified patient, intervention, comparator, outcome, time, study (PICOTS) criteria and included: amyloidosis, ATTR, and MSK manifestations. Publication quality was assessed utilizing Joanna Briggs Institute (JBI) critical appraisal checklists. The search initially identified 7,139 publications, 164 of which were included. PICOTS criteria led to the inclusion of epidemiology, clinical burden and practice, pathophysiology, and temporality of MSK manifestations associated with ATTR amyloidosis. 163 publications reported on ATTR amyloidosis and MSK manifestations, and 13 publications reported on the delay in ATTR amyloidosis diagnosis following the onset of MSK manifestations.

RESULTS

The MSK manifestation most frequently associated with ATTR amyloidosis was carpal tunnel syndrome (CTS); spinal stenosis (SS) and osteoarthritis (OA), among others, were also identified. The exact prevalence of different MSK manifestations in patients with ATTR amyloidosis remains unclear, as a broad range of prevalence estimates were reported. Moreover, the reported prevalence of MSK manifestations showed no clear trend or distinction in association between ATTRv and ATTRwt amyloidosis. MSK manifestations precede the diagnosis of ATTR amyloidosis by years, and there was substantial variation in the reported delay to ATTR amyloidosis diagnosis. Reports do suggest a longer diagnostic delay in patients with ATTRv amyloidosis, with 2 to 12 years delay in ATTRv versus 1.3 to 1.9 years delay in ATTRwt amyloidosis.

CONCLUSION

These findings suggest that orthopedic surgeons may play a role in the early diagnosis of and treatment referrals for ATTR amyloidosis. Detection of MSK manifestations may enable earlier diagnosis and administration of effective treatments before disease progression occurs.

Characteristics of Carpal Tunnel Syndrome in Wild-Type Transthyretin Amyloidosis

BACKGROUND

Carpal tunnel syndrome (CTS) is one of the most common extra-cardiac manifestations of wild-type transthyretin amyloidosis (wtATTR); however, the characteristics of CTS in this population remain poorly understood.

METHODS

This retrospective cohort study reports findings from a single-centre experience of comprehensive neurological screening at the time of wtATTR diagnosis by nerve conduction studies (NCS) and neurologist assessment.

RESULTS

Seventy-nine patients underwent neurological screening, 73 (92%) males, mean age 79.2 ± 7.5 years. Seventy-four (94%) had electrodiagnostic findings of median neuropathy at the wrist (MNW), 37 (50%) of which had a prior diagnosis of CTS and 37 (50%) had a new diagnosis of MNW. Over half of wtATTR patients (42, 53%) had bilateral MNW on screening. Most with pre-existing CTS had bilateral disease (28, 76%) and underwent bilateral carpal tunnel release (CTR) (23, 62%) prior to screening. Twenty-one (19%) wrists had mild MNW, 43 (38%) moderate and 49 (43%) severe. Twenty-one (28%) wtATTR patients with MNW were asymptomatic, 10 of which (48%) had moderate disease. Nineteen (36%) wtATTR patients with symptomatic MNW had recurrent disease despite previous CTR. As a result of screening, 36 (68%) patients with symptomatic MNW were referred for CTR.

CONCLUSIONS

MNW is exceptionally common at the time of wtATTR diagnosis, affecting 94% of our patients. Most had severe, bilateral MNW on NCS. Some were asymptomatic, despite having moderate disease. The rate of recurrence following CTR was observed to be higher in wtATTR patients than the general population.

Clinical characteristics and prognostic implications of orthopedic ligament disorders in patients with wild-type transthyretin amyloidosis cardiomyopathy

BACKGROUND

Wild-type transthyretin amyloidosis (ATTRwt) is associated with multiple ligament disorders (LD) such as carpal tunnel syndrome (CTS), lumbar spinal stenosis (LSS), and spontaneous tendon rupture (STR). No studies have investigated the prevalence of these LD in the same cohort of ATTRwt patients. Furthermore, the clinical characteristics and prognostic implications of such disorders have not been studied.

METHODS

From 2017 to 2022, 206 consecutive patients with ATTRwt were diagnosed and followed prospectively to the time of death or the censoring date of September 1st, 2022. Patients with and without LD were compared, and the presence of LD was used along with the baseline clinical, biochemical, and echocardiographic characteristics to predict hospitalization with worsening heart failure and death.

RESULTS

CTS surgery was performed in 34 % of the patients, 8 % were treated for LSS, and 10 % had experienced an STR. The median follow-up time was 706 days (312-1067). Hospitalization with worsening heart failure occurred more frequently in patients with LD compared to patients without LD (p = 0.035). Presence of LD or surgery for CTS were found to be independent predictors of worsening heart failure with a hazard ratio of 2.0 (p = 0.01). The mortality was comparable between patients with and without LD (p = 0.10).

CONCLUSION

Orthopedic disorders are prevalent in ATTRwt cardiomyopathy, and presence of LD was an independent predictor of hospitalization with worsening heart failure.

A comparative study on efficacy of modified endoscopic minimally invasive treatment and traditional open surgery for primary carpal tunnel syndrome

BACKGROUND AND OBJECTIVE

Carpal tunnel syndrome (CTS) is the most common type of median nerve entrapment neuropathy. This study aims to comparatively assess the effectiveness and clinical efficacy of modified transforaminal endoscopic minimally invasive incision of transverse carpal ligament against traditional open incision of transverse carpal ligament in the treatment of CTS.

METHOD

The clinical data of 35 patients (57 wrists) with primary CTS treated in Shanxi Bethune Hospital, China, were retrospectively analyzed. The patients were divided into observation group (21 cases, 33 wrists) and control group (14 cases, 24 wrists), respectively, who underwent modified endoscopic minimally invasive incision of transverse carpal ligament and traditional open incision of transverse carpal ligament release. The Boston Carpal Tunnel Questionnaire (BCTQ) was assessed at for points: before the operation; 2 weeks; 1 month; and 3 months after operation. The BCTQ scores of the two groups were compared on all four points. The incidence of intraoperative and postoperative complication was used as the evaluation index. The study variables were comparatively assessed before and postoperation and also between the groups.

RESULTS

The BCTQ scores at 2 weeks, 1 month and 3 months after the operation were significantly lower than preoperative BCTQ scores (P < 0.005) for both the groups. There was no significant difference in BCTQ scores between the two groups at the four assessment points (P > 0.005). The scar size and wound healing time were significantly better with modified transforaminal endoscopic minimally invasive transverse carpal ligament incision.

CONCLUSION

The clinical effects of both modified transforaminal minimally invasive incision of transverse carpal ligament and traditional open incision of transverse carpal ligament are significant, while the treatment efficacy of modified transforaminal minimally invasive transverse carpal ligament incision is better in terms of operation time, wound size, postoperative scar size and incision healing time.

An Integrated Review of Carpal Tunnel Syndrome: New Insights to an Old Problem

Carpal tunnel syndrome (CTS) is a common entrapment neuropathy characterized by pain, numbness, and impaired function of the hand due to compression of the median nerve at the level of the wrist. Although CTS can develop from repetitive strain, injury, or medical conditions, there are also congenital and genetic risk factors that can predispose individuals to the condition. With respect to anatomical factors, some individuals are born with a smaller carpal tunnel, which increases their susceptibility to median nerve compression. Variations in specific genes, such as those encoding proteins involved in extracellular matrix remodeling, inflammation, and nerve function, have also been linked to an increased risk for CTS. CTS is associated with a high cost of health care maintenance and loss of work productivity. Therefore, it is vital that primary care physicians fully understand the anatomy, epidemiology, pathophysiology, etiology, and risk factors of CTS, so they can be proactive in prevention, diagnosing, and guiding proper treatment. This integrated review also provides insights into how biological, genetic, environmental, and occupational factors interact with structural elements to determine who is most likely to acquire and suffer from CTS. Keeping health practitioners abreast of all the factors that could impact CTS should go a long way in decreasing the health care and socioeconomic burden of CTS.

Cardiac Amyloidosis Imaging, Part 3: Interpretation, Diagnosis, and Treatment

Cardiac amyloidosis was thought to be rare, undiagnosable, and incurable. However, recently it has been discovered to be common, diagnosable, and treatable. This knowledge has led to a resurgence in nuclear imaging with ^99mTc-pyrophosphate-a scan once believed to be extinct-to identify cardiac amyloidosis, particularly in patients with heart failure but preserved ejection fraction. The renewed interest in ^99mTc-pyrophosphate imaging has compelled technologists and physicians to reacquaint themselves with the procedure. Although ^99mTc-pyrophosphate imaging is relatively simple, interpretation and diagnostic accuracy require an in-depth knowledge of amyloidosis etiology, clinical manifestations, disease progression, and treatment. Diagnosing cardiac amyloidosis is complicated because typical signs and symptoms are nonspecific and usually attributed to other cardiac disorders. In addition, physicians must be able to differentiate between monoclonal immunoglobulin light-chain amyloidosis (AL) and transthyretin amyloidosis (ATTR). Several clinical and noninvasive diagnostic imaging (echocardiography and cardiac MRI) red flags have been identified that suggest a patient may have cardiac amyloidosis. The intent of these red flags is to raise physician suspicion of cardiac amyloidosis and guide a series of steps (a diagnostic algorithm) for narrowing down and diagnosing the specific amyloid type. One element in the diagnostic algorithm is to identify monoclonal proteins indicative of AL. Monoclonal proteins are detected by serum or urine immunofixation electrophoresis and serum free light-chain assay. Another element is identifying and grading cardiac amyloid deposition using ^99mTc-pyrophosphate imaging. When monoclonal proteins are present and the ^99mTc-pyrophosphate scan is positive, the patient should be further evaluated for cardiac AL. The absence of monoclonal proteins and a positive ^99mTc-pyrophosphate scan is diagnostic for cardiac ATTR. Patients with cardiac ATTR need to undergo genetic testing to differentiate between wild-type ATTR and variant ATTR. This article is the third in a 3-part series in this issue of the Journal of Nuclear Medicine Technology Part 1 reviewed amyloidosis etiology and outlined ^99mTc-pyrophosphate study acquisition. Part 2 described ^99mTc-pyrophosphate image quantification and protocol technical considerations. This article discusses scan interpretation along with cardiac amyloidosis diagnosis and treatment.

Bilateral carpal tunnel syndrome and motor dysfunction caused by gout and type 2 diabetes: A case report

BACKGROUND

Carpal tunnel syndrome (CTS) has been associated with gout and type 2 diabetes mellitus (T2DM). However, due to insufficient clinical understanding of gout-related CTS and reliance on the diagnostic importance of elevated serum uric acid levels, such cases are prone to missed diagnosis, misdiagnosis, and delayed treatment. In addition, the effect of T2DM on gout - induced carpal tunnel syndrome has not been reported.

CASE SUMMARY

Herein, we present an unusual case of CTS and motor dysfunction caused by miliary tophaceous gout and T2DM. The patient presented to the hand and foot clinic with paresthesia of the fingers of both hands, especially at night. The patient was diagnosed with type 2 diabetes a month ago. Ultrasonography revealed bilateral transverse carpal ligament thickening with median nerve compression during hospitalization. The patient was successfully treated with carpal tunnel decompression and tendon release. The postoperative pathological examination revealed typical gout nodules. This case suggests that the presence of T2DM could accelerate tophi formation and worsen CTS symptoms, although no definitive proof in this regard has been described previously.

CONCLUSION

Tophi formation may most likely cause the co-occurrence of CTS and flexor dysfunction in gout and incipient diabetes patients.

Risk stratification in transthyretin-related cardiac amyloidosis

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

Amylo-AFFECT-QOL, a self-reported questionnaire to assess health-related quality of life and to determine the prognosis in cardiac amyloidosis

Background and aims

Self-reported questionnaires are useful for estimating the health-related quality of life (HR-QoL), impact of interventions, and prognosis. To our knowledge, no HR-QoL questionnaire has been developed for cardiac amyloidosis (CA). This study aimed to validate Amylo-AFFECT-QOL questionnaire to assess HR-QoL and its prognostic value in CA.

Methods

A self-reported questionnaire, “Amylo-AFFECT” had been designed and validated for CA symptoms evaluation and screening by physicians. It was adapted here to assess HR-QoL (Amylo-AFFECT-QOL) and its prognostic value in CA. To validate the theoretical model, internal consistency and convergent validity were assessed, particularly correlations between Amylo-AFFECT-QOL and the HR-QoL Minnesota Living Heart Failure (MLHF) questionnaire.

Results

Amylo-AFFECT-QOL was completed by 515 patients, 425 of whom (82.5%) had CA. Wild-type and hereditary transthyretin amyloidosis (ATTRwt and ATTRv) and immunoglobulin light-chain amyloidosis (AL) were diagnosed in 47.8, 14.7, and 18.8% of cases, respectively. The best HR-QoL evaluation was obtained with five dimensions: “Heart failure,” “Vascular dysautonomia,” “Neuropathy,” “Ear, gastrointestinal, and urinary dysautonomia,” and “Skin or mucosal involvement.” The global Amylo-AFFECT-QOL and MLHF scores showed significant positive correlations (rs = 0.72, p &lt; 0.05). Patients with a final diagnosis of CA had a global Amylo-AFFECT-QOL score significantly higher than the control group composed by patients with other diagnoses (22.2 ± 13.6 vs. 16.2 ± 13.8, respectively, p-value &lt; 0.01). According to the Amylo-AFFECT-QOL global results, ATTRv patients’ QoL was more affected than AL patients’ QoL or ATTRwt patients’ QoL. Patients with a higher HR-QoL score had a greater risk of death or heart transplant after 1 year of follow-up (log-rank &lt; 0.01).

Conclusion

Amylo-AFFECT-QOL demonstrates good psychometric properties and is useful for quantifying HR-QoL and estimating CA prognosis. Its use may help to improve overall management of patients with CA.

Screening approaches to cardiac amyloidosis in different clinical settings: Current practice and future perspectives

Cardiac amyloidosis is a serious and progressive infiltrative disease caused by the deposition of amyloid fibrils in the heart. In the last years, a significant increase in the diagnosis rate has been observed owing to a greater awareness of its broad clinical presentation. Cardiac amyloidosis is frequently associated to specific clinical and instrumental features, so called "red flags", and it appears to occur more commonly in particular clinical settings such as multidistrict orthopedic conditions, aortic valve stenosis, heart failure with preserved or mildly reduced ejection fraction, arrhythmias, plasma cell disorders. Multimodality approach and new developed techniques such PET fluorine tracers or artificial intelligence may contribute to strike up extensive screening programs for an early recognition of the disease.

Impact of Carpal Tunnel Syndrome Surgery on Early Diagnosis and Treatment of Transthyretin Cardiac Amyloidosis

Background and Objectives: Cardiac amyloidosis is an infiltrative, progressive, and restrictive cardiomyopathy that leads to heart failure, reduces life quality, and causes death. This is a multisystem disorder caused by mutations of the transthyretin protein and is associated not only with cardiac diseases or carpal tunnel syndrome but also with nerve, liver, lung, gastrointestinal tract, kidney, or eye pathologies. Carpal tunnel syndrome is an early red-flag symptom of transthyretin (TTR) cardiac amyloidosis; therefore, screening for unsuspected cardiac amyloidosis can be performed through histological testing of flexor retinaculum specimens gathered during carpal tunnel release surgery. Our case highlights that early detection and accurate diagnosis of a disease are important factors for improving clinical outcomes in patients with TTR amyloidosis. Case Summary: We report the case of a 71-year-old man who presented with bilateral carpal tunnel syndrome. Amyloid deposits were detected after carpal tunnel release surgery through histological testing of the synovial tissue. The patient was sent for a cardiological evaluation. Physical examination, laboratory tests, and the ECG revealed no significant changes. The diagnosis of amyloidosis was confirmed with multimodality imaging in the early stage, which helped to start specific medicamental treatment with the transthyretin stabilizer tafamidis. Conclusions: Our objective is to highlight the early recognition and specific medicamental treatment of cardiac amyloidosis for better patient prognosis and outcomes.

Amyloidosis and Carpal Tunnel Syndrome: Surgical Technique for Extended Carpal Tunnel Release with Tenosynovium and Transverse Carpal Ligament Biopsies

Carpal tunnel syndrome (CTS) is common in patients with transthyretin amyloidosis (ATTR), and many experience residual symptoms and/or develop recurrent disease following routine carpal tunnel release (CTR). An extended CTR with median nerve neurolysis is recommended for thorough nerve decompression. Tissue confirmation of amyloidosis can be performed at the time of CTR with biopsies of the transverse carpal ligament and/or tenosynovium.

METHODS

We describe a retrospective, single-center experience performing an extended CTR technique including unilateral and bilateral cases for 13 consecutive patients (18 wrists) with ATTR and symptomatic median neuropathy at the wrist.

RESULTS

The mean patient age was 83 (range 67-90) years and 11 (85%) were men. Notable intraoperative findings in all cases included thickened tenosynovium and median nerve epineurium, and adherence of the median nerve to the deep surface of transverse carpal ligament. Pathology findings were positive for amyloidosis from both the transverse carpal ligament and the tenosynovium biopsies in all patients.

CONCLUSIONS

Extended CTR with simultaneous wrist tissue biopsy can be safely performed for ATTR patients with CTS. Characteristic intraoperative findings should increase clinical suspicion for undiagnosed ATTR and prompt performance of biopsy for diagnostic confirmation. Volar wrist tenosynovial biopsy is our preferred tissue for confirmation of ATTR, for patients with and without CTS, given its safety profile and 100% pathological yield in our series.

Real-Life Evaluation of an Algorithm for the Diagnosis of Cardiac Amyloidosis

OBJECTIVE

To evaluate the real-life use of a modified Gillmore algorithm with a "one-stop-shop" approach, bone scintigraphy (BS), a monoclonal gammopathy test (GT), a salivary gland biopsy (SGB), and genetic testing performed at the same time for the diagnosis of cardiac amyloidosis at the French National Reference Centre for Cardiac Amyloidosis (Henri Mondor Hospital, Créteil, France).

METHODS

This retrospective cohort study included a total of 1222 patients with suspected amyloidosis who underwent BS and GT between June 2008 and May 2019.

RESULTS

Of 1222 patients, 349 had no cardiac uptake on BS and negative GT (BS-/GT-), 276 were BS-/GT positive (GT+), 420 patients were BS+/GT-, and 177 were BS+/GT+. Our one-stop-shop check-up enabled us to diagnose 892 (72.9%) patients; 330 (27.0%) patients required additional examinations, such as mass spectrometry and/or a cardiac biopsy. This subset notably included 112 patients with amyloid light chain amyloidosis. More than 64% of the patients with transthyretin amyloidosis or another type of amyloidosis were diagnosed during the one-stop shop visit. Sensitivity and specificity of BS for transthyretin amyloidosis diagnosis was 99% and 96%, respectively. For amyloid light chain diagnosis, sensitivity and specificity were 100% and 76%, respectively, for GT and 54% and 100%, respectively, for SGB. Of 910 transthyretin genetic tests, 205 (17%) detected mutations.

CONCLUSION

The results of our real-life cohort study confirmed the ability of a one-stop-shop approach with a modified Gillmore algorithm to diagnose cardiac amyloidosis and the interest of simultaneous testing for earlier diagnosis. The SGB has diagnostic value because it is easy, quick, and less invasive than a cardiac biopsy.

Transthyretin Cardiac Amyloidosis: A Cardio-Orthopedic Disease

Orthopaedic manifestations of wild-type transthyretin amyloidosis are frequent and characteristic, including idiopathic bilateral carpal tunnel syndrome, idiopathic lumbar canal stenosis, atraumatic rupture of the brachial biceps tendon, and, more rarely, finger disease and rotator cuff. These manifestations often coexisting in the same patient, frequently male and aged, steadily precede cardiac involvement inducing a rapidly progressive heart failure with preserved ejection fraction. Although transthyretin cardiac amyloidosis remains a cardiac relevant disease, these extracardiac localisation may increase diagnostic suspicion and allow for early diagnosis assuming the role of useful diagnostic red flags, especially in light of new therapeutic opportunities that can slow or stop the progression of the disease. For the cardiologist, the recognition of these extracardiac red flags is of considerable importance to reinforce an otherwise less emerging diagnostic suspicion. For orthopedists and rheumatologists, the presence in an old patient with or without clinical manifestations of cardiovascular disease, of an unexpected and inexplicable constellation of musculoskeletal symptoms, can represent a fundamental moment for an early diagnosis and treatment is improving a patient's outcome.

Amyloidosis: What does pathology offer? The evolving field of tissue biopsy

Since the mid-nineteenth century pathology has followed the convoluted story of amyloidosis, recognized its morphology in tissues and made identification possible using specific staining. Since then, pathology studies have made a significant contribution and advanced knowledge of the disease, so providing valuable information on the pathophysiology of amyloid aggregation and opening the way to clinical studies and non-invasive diagnostic techniques. As amyloidosis is a heterogeneous disease with various organ and tissue deposition patterns, histology evaluation, far from offering a simple yes/no indication of amyloid presence, can provide a wide spectrum of qualitative and quantitative information related to and changing with the etiology of the disease, the comorbidities and the clinical characteristics of patients. With the exception of cardiac transthyretin related amyloidosis cases, which today can be diagnosed using non-biopsy algorithms when stringent clinical criteria are met, tissue biopsy is still an essential tool for a definitive diagnosis in doubtful cases and also to define etiology by typing amyloid fibrils. This review describes the histologic approach to amyloidosis today and the current role of tissue screening biopsy or targeted organ biopsy protocols in the light of present diagnostic algorithms and various clinical situations, with particular focus on endomyocardial and renal biopsies. Special attention is given to techniques for typing amyloid fibril proteins, necessary for the new therapies available today for cardiac transthyretin related amyloidosis and to avoid patients receiving inappropriate chemotherapy in presence of plasma cell dyscrasia unrelated to amyloidosis. As the disease is still burdened with high mortality, the role of tissue biopsy in early diagnosis to assure prompt treatment is also mentioned.

Noncardiac Manifestations of Hereditary Amyloidosis

The most common forms of cardiac amyloidosis are progressive, life threatening, and underrecognized. Symptoms affect a variety of organs and overlap with those of more common conditions, complicating and postponing diagnosis. Cardiac disease generally determines mortality, but noncardiac manifestations typically surface before cardiac symptoms, often several years before diagnosis. Familiarity with noncardiac manifestations may lead to early diagnosis, enabling treatment and improving prognosis.

High Prevalence of Cardiac Amyloidosis in Clinically Significant Aortic Stenosis: A Meta-Analysis

Background

There is growing evidence of coexistence of aortic stenosis (AS) and transthyretin cardiac amyloidosis (CA). Not screening AS patients at the time of hospital/clinic visit for CA represents a lost opportunity.

Methods

We surveyed studies that reported the prevalence of CA among AS patients. Studies that compared patients with aortic stenosis with cardiac amyloidosis (AS-CA) and AS alone were further analyzed, and meta-regression was performed.

Results

We identified nine studies with 1,321 patients of AS, of which 131 patients had concomitant CA, with a prevalence of 11%. When compared to AS-alone, the patients with AS-CA were older, more likely to be males, had higher prevalence of carpal tunnel syndrome, right bundle branch block. On echocardiogram, patients with AS-CA had thicker interventricular septum, higher left ventricular mass index (LVMI), lower myocardial contraction fraction, and lower stroke volume index. Classical low-flow low-gradient (LFLG) physiology was more common among patients with AS-CA. Patients with AS-CA had higher all-cause mortality than patients with AS alone (33% vs. 22%, P = 0.02) in a follow-up period of at least 1 year.

Conclusions

CA has a high prevalence in patients with AS and is associated with worse clinical, imaging, and biochemical parameters than patients with AS alone.

Diagnostic Accuracy of Bone Scintigraphy for the Histopathological Diagnosis of Cardiac Transthyretin Amyloidosis-A Retrospective Austrian Multicenter Study

We aimed to ascertain the real-world diagnostic accuracy of bone scintigraphy in combination with free light chain (FLC) assessment for transthyretin (ATTR) cardiac amyloidosis (CA) using the histopathological diagnosis derived from endomyocardial biopsy (EMB) as a reference standard. We retrospectively analyzed 102 patients (22% women) with suspected CA from seven Austrian amyloidosis referral centers. The inclusion criteria comprised the available results of bone scintigraphy, FLC assessment, and EMB with histopathological analysis. ATTR and AL were diagnosed in 60 and 21 patients (59%, 21%), respectively, and concomitant AL and ATTR was identified in one patient. The specificity and positive predictive value (PPV) of Perugini score ≥ 2 for ATTR CA were 95% and 96%. AL was diagnosed in three out of 31 patients (10%) who had evidence of monoclonal proteins and a Perugini score ≥ 2. When excluding all patients with detectable monoclonal proteins (n = 62) from analyses, the PPV of Perugini score ≥ 2 for ATTR CA was 100% and the NPV of Perugini score < 2 for ATTR CA was 79%. Conclusively, ATTR CA can be diagnosed non-invasively in the case of a Perugini score ≥ 2 and an unremarkable FLC assessment. However, tissue biopsy is mandatory in suspected CA in any other constellation of non-invasive diagnostic work-up.

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.

Trends in diagnosis, referral, red flag onset, patient profiles and natural outcome of de novo cardiac amyloidosis and their multidisciplinary implications

BACKGROUND

Cardiac amyloidosis (CA) is often overlooked or misdiagnosed. Effects of growing disease awareness, diagnostic ameliorations and novel treatment options on CA diagnosis and management are scarcely reported.

OBJECTIVE

To report trends in diagnosis, referral routes, clinical presentation, early onset diagnostic red flags and outcome in de novo CA subjects.

METHODS

An unselected cohort of 139 de novo CA patients over an 8-year period in a tertiary referral hospital was recruited.

RESULTS

Transthyretin (ATTR, 82%, n = 114) was the most common CA form; Light-chain (AL, 15%, n = 21) and secondary (AA, 3%, n = 4) are less prevalent. Increased awareness over time led to a marked ATTR diagnostic surge, steep non-invasive diagnostic approach increment and increased nuclear medicine and external cardiologist referrals (all p < 0.001). A total of 41% (n = 57/139) of patients were referred by non-cardiology specialist disciplines. Specific referral to rule out CA (24-36%) and diagnostic time lag from symptom onset (9 ± 12 to 8 ± 14 months), however, did not improve (all p > 0.050). Multiple early red flag events preceded CA diagnose several years in ATTR: Left ventricular hypertrophy (LVH, 60%, 4.9 ± 4.3 y), heart failure (54%, 2.5 ± 3.5 y), atrial fibrillation (47%, 5.9 ± 6.7 y), bilateral carpal tunnel syndrome (43%, 9.5 ± 5.7 y) and spinal stenosis (40%, 7.4 ± 6.5 y). LVH ≥ 12 mm was absent in 11% ATTR (n = 13/114) and 5% AL (n = 1/21) patients. Hypertension was common in both ATTR (n = 70/114, 62%) and AL (n = 10/21, 48%). 56% (n = 78/139) of CA presented with heart failure. Cumulative 1 and 5-year mortality of 10%/66%, 40%/52% and 75%/75% for ATTR, AL, and AA, respectively, remains high.

CONCLUSIONS

Although CA diagnostic uptake and referral improve, specialist-specific disease and diagnostic red flag ignorance result in non-timely diagnosis and unfavourable outcome.

Identification of wild-type transthyretin cardiac amyloidosis in patients with carpal tunnel syndrome surgery (CACTuS)

AIMS

Wild-type transthyretin cardiac amyloidosis (ATTRwt) is an infiltrative cardiomyopathy with a poor prognosis. The condition is associated with carpal tunnel syndrome (CTS), which often precedes the ATTRwt diagnosis by several years. The aim of the study was (i) to screen patients with a recent history of CTS for ATTRwt using red flags, (ii) to determine whether patients with screened ATTRwt had less advanced disease compared with patients with clinical ATTRwt, and (iii) to assess the sensitivity and specificity of known red flags in ATTRwt.

METHODS AND RESULTS

Patients aged ≥60 years at the time of CTS surgery were invited for screening. Red flags were defined as elevated biomarker levels of N-terminal pro-B-type natriuretic peptide (NT-proBNP) or cardiac troponin, an electrocardiogram pattern associated with ATTRwt, left ventricular hypertrophy (LVH), and impaired longitudinal strain with apical sparring. All patients with a red flag were referred for a diagnostic scintigraphy. Patients with ATTRwt diagnosed by screening were compared with patients with clinical ATTRwt (n = 51) matched by age, gender, and CTS surgery. Among the 120 enrolled subjects (mean age 74.5 years, 90% male), the suspicion of ATTR was raised in 67 (55.8%), and 10 (8.3%) were diagnosed with ATTRwt. Patients identified with ATTRwt were predominantly asymptomatic and had mildly elevated NT-proBNP, mildly increased LVH, preserved left ventricular ejection fraction, and systolic longitudinal function, which differed significantly from clinical ATTRwt controls (P < 0.001).

CONCLUSIONS

The study found an ATTRwt prevalence of 8.3% in a population of age and gender-selected patients with a recent history of CTS. The identified patients with ATTRwt had less structural and functional cardiac involvement than clinical ATTRwt controls.