Characteristics of patients with autonomic dysfunction in the Transthyretin Amyloidosis Outcomes Survey (THAOS)

Early cardiovascular autonomic failure in ATTRv predicts poor prognosis and may respond to disease-modifying therapy

BACKGROUND

Hereditary transthyretin amyloidosis (ATTRv) is a life-threatening, but treatable disease presenting with autonomic dysfunction. This study investigates the progression of autonomic failure, response to treatment, and the impact of autonomic failure in ATTRv.

METHODS

Clinical features and autonomic function test (AFT) results were evaluated in 126 patients (40 had treatment) and 12 asymptomatic TTR variant carriers. A subgroup had follow-up (FU) AFT. Kaplan-Meier estimates compared survival time between participants with and without neurogenic orthostatic hypotension (nOH), and logistic regression assessed its impact on mortality.

RESULTS

Patients treated early with disease modifying therapies (DMT) had slower progression and did not develop nOH. In 59 individuals with repeat AFT, autonomic dysfunction worsened, with a decline in the Valsalva ratio (p = 0.002), even in early-stage disease (p = 0.019; median disease duration at FU 4 years). nOH at first assessment predicted worse outcome (mean survival time in individuals with nOH 7.0 vs. 14.9 years without nOH, p < 0.001) and death (OR = 5.27; 95%CI: 1.94 - 14.31; p = 0.001).

CONCLUSIONS

The early development of autonomic dysfunction and nOH is an independent predictive factor for shorter survival in ATTRv. Autonomic testing is a valuable biomarker to capture disease progression. Prospective studies need to confirm the benefit of DMT on autonomic dysfunction.

Underestimated vascular dysfunction is a critical feature of the impaired cardiovascular profile in patients with transthyretin amyloidosis

Amyloidosis is a systemic disease initiated by deposition of misfolded proteins in the extracellular space, which affects multiple organs concomitantly. Cardiac amyloidosis is, however, the major cause of morbidity and mortality in this population due to infiltrative/restrictive cardiomyopathy. The two most common forms of cardiac amyloidosis are immunoglobulin light-chain (AL) and transthyretin amyloidosis (ATTR). Whereas cardiac involvement determines the prognosis in both AL and ATTR, vascular involvement is common and may contribute to the impaired cardiovascular profile in these patients. Several works in the literature suggest that the vascular mechanisms that control circulatory function are impaired in patients with ATTR. Here, we provide an overview of the pathophysiological mechanisms involved in vascular dysfunction in patients with ATTR. We also discuss the complex interplay of these mechanisms, including characteristics of the haemodynamic profile of heart vessels and pulmonary and peripheral arteries. Vascular dysfunction features, including stiffness and endothelium-dependent vasodilation, are discussed along with the impact of regulation of systemic ATTR on microcirculation blood flow. The specific role of the metaboreflex is also depicted. Finally, we discuss the potential clinical impact of therapies on vascular dysfunction associated with systemic ATTR. A specific focus is made on the beneficial effect of training in patients with systemic ATTR. Overall, this review aims to highlight the critical role of vascular dysfunction in patients with systemic ATTR.

Guideline-Directed Medical Therapy for Heart Failure in Transthyretin Amyloid Cardiomyopathy

Cardiac amyloidosis is an underdiagnosed cause of infiltrative cardiomyopathy, leading to heart failure across the spectrum of ejection fractions. Although there are approved disease-modulating therapies for the transthyretin subtype (transthyretin amyloid cardiomyopathy [ATTR-CM]), the role of heart failure medications remains uncertain and challenging in clinical practice. Their effects on clinical outcomes, such as mortality and hospitalization, are unknown for ATTR-CM. This review aims to explore the use of these medications in ATTR-CM, considering the disease's stage and patient-specific issues, such as fluid homeostasis, autonomic dysfunction, conduction disorders, low and fixed stroke volumes, and decreased functional capacity. As our understanding of this condition deepens, it is important to reassess the impact of contemporary heart failure medication in ATTR-CM. Finally, the relevance of guideline recommendations for heart failure drugs based on left ventricular ejection fraction should be reconsidered in the context of ATTR-CM.

Sudoscan in ATTRv Amyloidosis: A Potential Marker of Disease Progression?

INTRODUCTION

Hereditary transthyretin amyloidosis (ATTRv amyloidosis) is a severe, autosomal dominant disease resulting from multisystemic extracellular deposition of amyloid fibrils, leading to progressive organ damage and death. Sudoscan is a reproducible tool investigating sweat gland function and, indirectly, small nerve fiber impairment. The aim of this study was to evaluate any changes over time in electrochemical skin conductance (ESC) measured by Sudoscan in a cohort of late-onset patients with ATTRv from a single Italian center. Additionally, we investigated the role of Sudoscan as a marker of disease severity to confirm previous literature data.

METHODS

We enrolled 61 patients with a late-onset ATTRv amyloidosis harboring different TTR variants with at least one clinical and instrumental evaluation including Sudoscan. Correlations with clinical data (including both clinical scales and questionnaires) were investigated to confirm the role of Sudoscan as a marker of disease severity. Moreover, a longitudinal analysis was performed in the subgroup of patients with at least 4 complete yearly evaluations (n = 23) to assess the role of Sudoscan as a marker of disease progression.

RESULTS

At each yearly assessment, ESC values from both feet and hands significantly correlated with disease duration and neuropathy severity, as assessed by common clinical scales and questionnaires. No correlation was found with age at evaluation. Moreover, we observed a statistically significant change over time in ESC values measured at the feet (fESC) but not at the hands (hESC).

CONCLUSIONS

Sudoscan may represent a reliable marker of dysautonomia in ATTRv amyloidosis, displaying a potential role as a marker of both disease severity and progression. It could, therefore, serve as an outcome measure in future clinical trials. In addition, feet ESC seems to be a significant, independent predictor of autonomic dysfunction.

Effects of eplontersen on symptoms of autonomic neuropathy in hereditary transthyretin-mediated amyloidosis: secondary analysis from the NEURO-TTRansform trial

BACKGROUND

The NEURO-TTRansform trial showed that after 66 weeks of treatment, eplontersen significantly reduced neuropathic impairment and improved quality of life (QoL) in patients with hereditary transthyretin-mediated amyloidosis with polyneuropathy (ATTRv-PN). In this secondary analysis from NEURO-TTRansform, autonomic impairment, and the impact of eplontersen on autonomic impairment progression was evaluated through 85 weeks in patients randomised to eplontersen (n = 144) versus external placebo (n = 60; through Week 66 from the NEURO-TTR trial).

METHODS

Change from baseline in modified Neuropathy Impairment Score +7 (mNIS+7) composite score, Norfolk Quality of Life-Diabetic Neuropathy (Norfolk QoL-DN) total score, and the Neuropathy Symptoms and Change (NSC) total score was evaluated. Exploratory assessments were change in autonomic components of these instruments, Composite Autonomic Symptom Score-31 (COMPASS-31) total score, and nutritional status (modified body mass index [mBMI]).

RESULTS

Patients reported profound autonomic dysfunction at baseline. Improvements with eplontersen versus placebo were observed up to Week 66 in autonomic components of mNIS+7, Norfolk QoL-DN, NSC, and mBMI; eplontersen results were sustained up to Week 85, including improvements in COMPASS-31 (Week 81).

CONCLUSIONS

Eplontersen demonstrated benefit across multiple measures of autonomic impairment known to progress rapidly and negatively impact QoL without treatment, without deterioration in nutritional status.

Prevalence and functional impact of chronotropic incompetence in amyloid cardiomyopathy: a multicentre analysis

BACKGROUND

Little evidence is available about heart rate (HR) response to exercise as well as its relationship with functional capacity in amyloid cardiomyopathy. Then, in a multicentre cohort of patients with amyloid cardiomyopathy, we investigated the prevalence of chronotropic incompetence (CI) and its relationships with cardiopulmonary exercise testing (CPET) variables.

METHODS

Data from 172 outpatients with amyloid cardiomyopathy who performed a maximal CPET and who had no significant rhythm disorders were analysed.

RESULTS

The prevalence of CI differed depending on the age-predicted peak HR (pHR%) cut-off value adopted, ranging from 16% to 59%. pHR% correlated non-linearly with peak oxygen uptake (pVO2), either as expressed as a percentage of the maximum predicted or as mL/kg/min (p<0.001). Although to a lesser extent, pHR% correlated inversely with ventilatory efficiency (p<0.001). A pHR%≤75% resulted in the most accurate cut-off value in identifying a moderate-to-severe exercise impairment (sensitivity 72%; specificity 73%; area under the curve 77.2%).

CONCLUSIONS

CI is prevalent in patients with amyloid cardiomyopathy in sinus rhythm, its percentage varying according to the pHR% cut-off value. A blunted exercise-induced HR response correlated with a poor exercise capacity even in this setting of patients, a pHR%≤75% cut-off value being possibly useful in centres without CPET availability to identify a significant exercise impairment.

Exploring Cardiac Sympathetic Denervation in Transthyretin-Mediated Hereditary Amyloidosis (ATTRv): Insights from 123I-mIBG Scintigraphy

Background/Objectives: Hereditary transthyretin-mediated amyloidosis (ATTRv) is a rare disease characterized by the deposition of amyloid in the heart and peripheral nerves, particularly affecting small fibers. This study aims to evaluate autonomic cardiac involvement in ATTRv. Methods: Twelve patients with ATTRv and twelve sex- and age-matched healthy subjects underwent 123I-mIBG scintigraphy to evaluate the early and late heart-to-mediastinum ratio (eH/M and lH/M), 99mTc-HDP bone scan scintigraphy, and neurophysiological assessments. Data were analyzed in relation to functional cardiac and neurologic scales (NYHA and FAP scales). Results: Patients with ATTRv exhibited significant cardiac denervation, as demonstrated by the reduction in early and late H/M ratios compared to the control group (eH/M: 1.48 ± 0.08 vs. 1.89 ± 0.05, p < 0.001; lH/M: 1.39 ± 0.08 vs. 2.01 ± 0.05, p < 0.001). Values of eH/M and lH/M < 1.6 effectively differentiated patients with ATTRv from the healthy controls. Cardiac denervation correlated with interventricular septal thickness and the Perugini score but was not related to neurophysiological assessments or NYHA and FAP scales. Conclusions: Ultimately, 123I-mIBG scintigraphy is an effective tool for assessing cardiac denervation in patients with ATTRv.

Phenotype variability and therapeutic response to Patisiran in patients with hereditary transthyretin amyloidosis: a Belgian real-world experience

INTRODUCTION

Hereditary transthyretin amyloidosis (hATTRv) is a rare, genetic, adult-onset, multisystemic disorder which can affect diverse organs, including peripheral nerves, heart, kidneys, gastrointestinal tract, liver, skin and eyes. Currently, several disease-modifying treatments for hATTRv are available in Belgium including the TTR stabilizer tafamidis and TTR mRNA silencers patisiran and vutrisiran. Patisiran contains a small interfering RNA encapsulated into a lipid nanoparticle to deliver to hepatocytes, the main source of TTR protein production, thereby reducing TTR production.

METHODS

We report and discuss five cases of hATTRv in different clinical scenarios that were successfully managed with patisiran, highlighting our real-world clinical practice.

RESULTS

These cases illustrate that patisiran is effective to improve mild symptoms and stabilize the moderate ones. The cases also highlight the importance of red flags recognition to allow early diagnosis and treatment to prevent further disease progression.

CONCLUSION

Due to the multisystemic nature of the disease and its heterogeneous clinical presentation, close collaboration between neurologists and cardiologists is highly recommended, ideally within a multidisciplinary amyloidosis team, to provide holistic care in hATTRv patients.

Symptoms of Hereditary Transthyretin Amyloidosis: The Patient and Physician Perspective

This article has been co-authored by a patient living with hereditary transthyretin (ATTRv) amyloidosis and a neurologist. This rare, progressive disease is associated with impairment of multiple organ systems, including the nerves, heart, and the gastrointestinal tract, forcing patients to live with and adapt to a range of debilitating symptoms. Here, the patient and physician discuss how the symptoms of ATTRv amyloidosis profoundly impact day to day life, the difficulties with identifying the disease, and how this effects the diagnosis experience. In recent years, significant advancements have been made in the treatment and management of ATTRv amyloidosis. However, the authors highlight the urgency of increasing awareness of the disease among the wider medical community, as well as in patients who notice the symptoms, to ensure that earlier diagnosis and appropriate treatment are achieved.

Interpreting Diastolic Dynamics and Evaluation through Echocardiography

In patients with heart failure, evaluating left ventricular (LV) diastolic function is vital, offering crucial insights into hemodynamic impact and prognostic accuracy. Echocardiography remains the primary imaging modality for diastolic function assessment, and using it effectively requires a profound understanding of the underlying pathology. This review covers four main topics: first, the fundamental driving forces behind each phase of normal diastolic dynamics, along with the physiological basis of two widely used echocardiographic assessment parameters, E/e' and mitral annulus early diastolic velocity (e'); second, the intricate functional relationship between the left atrium and LV in patients with varying degrees of LV diastolic dysfunction (LVDD); third, the role of stress echocardiography in diagnosing LVDD and the significance of echocardiographic parameter changes; and fourth, the clinical utility of evaluating diastolic function from echocardiography images across diverse cardiovascular care areas.

Cardiovascular autonomic failure in hereditary transthyretin amyloidosis and TTR carriers is an early and progressive disease marker

BACKGROUND

The cardiomyopathic and neuropathic phenotype of hereditary transthyretin amyloidosis are well recognized. Cardiovascular autonomic dysfunction is less systematically and objectively assessed.

METHODS

Autonomic and clinical features, quantitative cardiovascular autonomic function, and potential autonomic prognostic markers of disease progression were recorded in a cohort of individuals with hereditary transthyretin amyloidosis and in asymptomatic carriers of TTR variants at disease onset (T0) and at the time of the first quantitative autonomic assessment (T1). The severity of peripheral neuropathy and its progression was stratified with the polyneuropathy disability score.

RESULTS

A total of 124 individuals were included (111 with a confirmed diagnosis of hereditary transthyretin amyloidosis, and 13 asymptomatic carriers of TTR variants). Symptoms of autonomic dysfunction were reported by 27% individuals at T0. Disease duration was 4.5 ± 4.0 years [mean ± standard deviation (SD)] at autonomic testing (T1). Symptoms of autonomic dysfunction were reported by 78% individuals at T1. Cardiovascular autonomic failure was detected by functional testing in 75% individuals and in 64% of TTR carriers. Progression rate from polyneuropathy disability stages I/II to III/IV seemed to be shorter for individuals with autonomic symptoms at onset [2.33 ± 0.56 versus 4.00 ± 0.69 years (mean ± SD)].

CONCLUSIONS

Cardiovascular autonomic dysfunction occurs early and frequently in individuals with hereditary transthyretin amyloidosis within 4.5 years from disease onset. Cardiovascular autonomic failure can be subclinical in individuals and asymptomatic carriers, and only detected with autonomic function testing, which should be considered a potential biomarker for early diagnosis and disease progression.

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.

Hereditary transthyretin amyloid neuropathies: advances in pathophysiology, biomarkers, and treatment

Hereditary transthyretin (TTR) amyloid polyneuropathy is an autosomal dominant life-threatening disorder. TTR is produced mainly by the liver but also by the choroid plexus and retinal pigment epithelium. Detailed clinical characterisation, identification of clinical red flags for misdiagnosis, and use of biomarkers enable early diagnosis and treatment. In addition to liver transplantation and TTR stabilisers, three other disease-modifying therapies have regulatory approval: one antisense oligonucleotide (inotersen) and two small interfering RNAs (siRNAs; patisiran and vutrisiran). The siRNAs have been shown to stop progression of neuropathy and improve patients' quality of life. As none of the disease-modifying therapies can cross the blood-brain barrier, TTR deposition in the CNS, which can cause stroke and cognitive impairment, remains an important unaddressed issue. CRISPR-Cas9-based one-time TTR editing therapy is being investigated in a phase 1 clinical study. Identification of the earliest stages of pathogenesis in TTR variant carriers is a major challenge that needs addressing for optimal management.

[Neurological manifestations of ATTR amyloidosis]

Transthyretin amyloidosis (ATTR) is a rare disease in which the protein transthyretin (TTR) is deposited in the form of amyloid fibrils in various tissues and organs and secondarily leads to functional impairment, especially in peripheral nerves and the heart. A differentiation is made between hereditary and sporadic forms. The hereditary variant is inherited in an autosomal dominant manner and usually occurs in the younger to middle-aged, while the sporadic form occurs in older age and has no known genetic cause. Typical signs of hereditary ATTR amyloidosis (ATTRv, v for variant) include a rapidly progressing sensorimotor and autonomic polyneuropathy (PNP), cardiac dysfunction as well as ocular and gastrointestinal symptoms. A carpal tunnel syndrome often precedes the manifestation. Various options (tafamidis, patisiran, inotersen or vutrisiran) are available for the treatment of patients with ATTRv with PNP in Germany, depending on the severity. In the sporadic variant of wild-type ATTR amyloidosis (ATTRwt), symptoms of progressive cardiomyopathy are usually prominent; however, neurological assessment of these patients often also reveals a concomitant sensory ataxic PNP. The tetramer stabilizer tafamidis can be used for treatment. Because of this complex presentation, the management of patients with ATTR amyloidosis should be performed in interdisciplinary centers specialized in amyloidosis.

Cardiovascular reflex tests detect autonomic dysfunction in symptomatic and pre-symptomatic subjects with hereditary transthyretin amyloidosis

PURPOSE

Autonomic dysfunction is a distinctive but undervalued feature of hereditary transthyretin amyloidosis (ATTRv). It may predate the onset of polyneuropathy and cardiomyopathy, thereby providing crucial prognostic and therapeutic information. The objective of this study was to assess autonomic function by means of the standardized cardiovascular autonomic reflex tests (CRTs) in a cohort of subjects with genetically proven ATTRv from non-endemic areas who were in the symptomatic and pre-symptomatic stages.

METHODS

All subjects enrolled in this cross-sectional study had genetically proven ATTRv. They underwent the head-up tilt test, Valsalva manoeuvre, deep breathing test, cold face test and handgrip test while under continuous blood pressure and heart rate monitoring. Based on the results of the nerve conduction study, the subjects were divided into two groups: those with polyneuropathy (ATTRv-wPN) and those without polyneuropathy (ATTRv-woPN). Age- and sex-matched healthy controls (HC) were used for comparison.

RESULTS

Thirty-seven ATTRv subjects (19 with ATTRv-wPN, 18 with ATTRv-woPN) and 41 HC performed the CRTs. Of these 37 subjects with ATTRv, four (11%) presented neurogenic orthostatic hypotension the during head-up tilt test. Based on the results of the CRTs, autonomic dysfunction characterized by either sympathetic or parasympathetic impairment was detected in 37% and 63% of ATTRv-wPN subjects, respectively. Subjects with ATTRv-woPN presented a significant impairment of autonomic responses to the Valsalva manoeuvre compared to the HC (overshoot p = 0.004; Valsalva ratio p = 0.001).

CONCLUSION

Autonomic dysfunctions are frequent in subjects with ATTRv when investigated by means of standardized CRTs, and are also relevant in the pre-symptomatic stage. Cardiovagal functions are the primary functions affected, among others. This may be crucial in defining the proper diagnostic workout for early diagnosis and improving the likelihood of providing the patient with prompt administration of disease-modifying treatments.

Enlarged cross-sectional area in peripheral nerves in Swedish patients with hereditary V30M transthyretin amyloidosis

INTRODUCTION

In hereditary transthyretin amyloidosis (ATTRv), two different fibrillar forms causing the amyloid deposition, have been identified, displaying substantially cardiac or neuropathic symptoms. Neuropathic symptoms are more frequent in early-onset patients, whereas late-onset patients, besides cardiac symptoms, seem to develop carpal tunnel syndrome, more often. With ultrasonography (US) of peripheral nerves, it is possible to distinguish structural changes, and enlarged cross-sectional area (CSA). The main purpose of this study was, for the first time, to elucidate US of peripheral nerves in Swedish ATTRv patients at an early stage of the disease, and to evaluate possible early enlarged CSA.

MATERIAL AND METHODS

This prospective study included first visit data of 13 patients, aged 30-88 years, of which 11 with late-onset age. All had a positive V30M mutation. Eight men and six women (aged 28-74 years) served as controls.

RESULTS

Significantly enlarged CSA was seen in ATTRv patients for the tibial nerve at the ankle (p = .001), the sural nerve (p < .001), the peroneal nerve at the popliteal fossa (p = .003), and the ulnar nerve at the middle upper arm (p = .007).

CONCLUSION

US of peripheral nerves could be a valuable tool in disease evaluation and could facilitate monitoring of disease progression.