Unfolding Cardiac Amyloidosis –From Pathophysiology to Cure

2019 ◽  
Vol 26 (16) ◽  
pp. 2865-2878 ◽  
Author(s):  
Klemens Ablasser ◽  
Nicolas Verheyen ◽  
Theresa Glantschnig ◽  
Giulio Agnetti ◽  
Peter P. Rainer
Keyword(s):  
Cardiac Disease ◽  
Cardiac Remodeling ◽  
Cardiac Amyloidosis ◽  
Amyloid Fibrils ◽  
Amyloid Deposition ◽  
Transthyretin Amyloidosis ◽  
Cardiac Amyloid ◽  
Amyloidogenic Proteins ◽  
Preclinical Trials ◽  
Current Therapies

Deposition of amyloidogenic proteins leading to the formation of amyloid fibrils in the myocardium causes cardiac amyloidosis. Although any form of systemic amyloidosis can affect the heart, light-chain (AL) or transthyretin amyloidosis (ATTR) account for the majority of diagnosed cardiac amyloid deposition. The extent of cardiac disease independently predicts mortality. Thus, the reversal of arrest of adverse cardiac remodeling is the target of current therapies. Here, we provide a condensed overview on the pathophysiology of AL and ATTR cardiac amyloidoses and describe treatments that are currently used or investigated in clinical or preclinical trials. We also briefly discuss acquired amyloid deposition in cardiovascular disease other than AL or ATTR.

scholarly journals Amyloidosis with Cardiac Involvement: Identification, Characterization, and Management

2021 ◽  
Author(s):  
Faizi Jamal ◽  
Michael Rosenzweig
Keyword(s):  
Cardiac Amyloidosis ◽  
Systemic Disease ◽  
Treatment Options ◽  
Diagnostic Algorithm ◽  
Transthyretin Amyloidosis ◽  
Cardiac Amyloid ◽  
Medical Interventions ◽  
Light Chain Disease ◽  
Organ Response ◽  
New Treatment

Abstract Purpose of Review Amyloidosis is a protein deposition disease whereby a variety of precursor proteins form insoluble fibrils that deposit in tissues, causing organ dysfunction and, many times, death. Accurate characterization of the disease based on the nature of the precursor protein, organ involvement, and extent of disease is paramount to guide management. Cardiac amyloidosis is critical to understand because of its impact on prognosis and new treatment options available. Recent Findings New imaging methods have proven to be considerably valuable in the identification of cardiac amyloid infiltration. For treating clinicians, a diagnostic algorithm for patients with suspected amyloidosis with or without cardiomyopathy is shown to help classify disease and to direct appropriate genetic testing and management. For patients with light chain disease, recently introduced treatments adopted from multiple myeloma therapies have significantly extended progression-free and overall survival as well as organ response. In addition, new medical interventions are now available for those with transthyretin amyloidosis. Summary Although cardiac amyloidosis contributes significantly to the morbidity and mortality associated with systemic disease, new tools are available to assist with diagnosis, prognosis, and management.

scholarly journals Diagnosis of Cardiac Amyloidosis Using Non-Invasive Technics

2021 ◽  
Author(s):  
Eva Strickler ◽  
Ernest Tsiaze ◽  
Gerrit Hellige ◽  
Dominik Zumstein ◽  
Dominik Waldmeier ◽  
...  
Keyword(s):  
Cardiac Amyloidosis ◽  
Al Amyloidosis ◽  
Definite Diagnosis ◽  
Diagnostic Features ◽  
Transthyretin Amyloidosis ◽  
Cardiac Amyloid ◽  
Non Invasive ◽  
Amyloid Accumulation ◽  
Clinically Significant ◽  
Multiorgan Disease

Amyloidosis is a rare multiorgan disease defined by a process of irreversible, extracellular accumulation of fibrillar proteins in the tissues, including the heart. Cardiac involvement is seen in most forms of amyloidosis, but it is frequently present and clinically significant in light chain (AL)-amyloidosis as well as transthyretin amyloidosis (ATTR). Cardiac amyloid accumulation leads to a restrictive filling pattern, which must be differentiated from other forms of restrictive and hypertrophic cardiomyopathies due to consequences for the treatment. Evolving knowledge of the disease has led to a definite diagnosis of the cardiac amyloidosis (CA) using non-invasive and low-risk diagnostic features, such as scintigraphy (gamma scan) and cardiovascular magnetic resonance (CMR) imaging using late gadolinium enhancement (LGE) and T1 mapping technics. The availability and diagnostic accuracy of these technics has reduced the need for cardiac biopsy. In the following chapter, we will describe common types of CA, the basic concepts, and updates of non-invasive diagnostic features.

scholarly journals Characterization of an amyloid fibril protein from senile cardiac amyloid.

1977 ◽  
Vol 146 (2) ◽  
pp. 631-636 ◽  
Author(s):  
P Westermark ◽  
J B Natvig ◽  
B Johansson
Keyword(s):  
Cardiac Amyloidosis ◽  
Amyloid Fibrils ◽  
Amyloid Fibril ◽  
Heart Tissue ◽  
Normal Heart ◽  
Cardiac Amyloid ◽  
Subunit Protein ◽  
Amyloid Fibril Protein

A protein, ASCA, is isolated from amyloid fibrils extracted from heart tissue of five different patients with senile cardiac amyloidosis (SCA). The proteins of all five patients showed immunological identity when reacted with an antiserum raised against one of the proteins. In contrast, no reaction was obtained with antisera against a variety of other amyloid proteins. The antiserum against the subunit protein of senile cardiac amyloid did not react with any other amyloid preparations tested, nor with extracts of normal heart tissue. Thus, the subunit protein appeared to be unique to senile heart amyloid. The protein could form fibrils in vitro, had a mol wt of about 6,000 daltons and the amino acid compositions investigated in two cases showed extensive similarities but were clearly different from that of protein AA of secondary amyloid fibrils.

scholarly journals Cardiac Amyloidosis: Internist and Cardiologist Insight

2020 ◽  
Vol 10 (6) ◽  
pp. 430-457
Author(s):  
E. V. Reznik ◽  
T. L. Nguyen ◽  
E. A. Stepanova ◽  
D. V. Ustyuzhanin ◽  
I. G. Nikitin
Keyword(s):  
Cardiac Amyloidosis ◽  
Left Ventricular ◽  
Amyloid Deposition ◽  
Left Ventricular Wall ◽  
Left Ventricular Ejection ◽  
Wall Thickening ◽  
Ventricular Wall ◽  
Ventricular Ejection Fraction ◽  
Cardiac Amyloid ◽  
Unclear Etiology

Cardiac amyloidosis (amyloid cardiomyopathy) is a disease damage to the heart caused by extracellular amyloid deposition. In some cases, there may be local damage to the structures of the heart, for example, the atria; more often, heart damage is part of a systemic (generalized) pathology. Depending on the amyloid precursor protein, 36 types of amyloidosis are described, among which hereditary and acquired forms are distinguished. Cardiac amyloidosis is diagnosed 1) in the case of the amyloid infiltration in the myocardial bioptates or 2) in the case of non-cardiac amyloid deposition and the left ventricular wall thickening >12 mm without arterial hypertension and other reasons. The heart is most often affected in AL-, ATTR-, AA-, AANF-types of amyloidosis. Cardiac amyloidosis should be considered in patients with a heart failure with an unclear etiology, especially with preserved left ventricular ejection fraction, refractory to treatment, with proteinuria and CKD 4-5, in patients with idiopathic atrial fibrillation and conduction disturbances, in patients with left ventricular wall thickening of unclear etiology, low ECG voltage, unexplained arterial hypotension and pulmonary hypertension. Screening for cardiac amyloidosis should include non-invasive methods such as electrophoresis and immunofixation of blood and urine proteins, the free light lambda and kappa chains of immunoglobulins, 99Tc-DPD scintigraphy, genetic testing (if hereditary variants of amyloidosis are suspected), as well as a histological examination of biopsy samples stained with Congo red and polarizing microscopy.

scholarly journals Plasmin activity promotes amyloid deposition in a transgenic model of human transthyretin amyloidosis

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Ivana Slamova ◽  
Rozita Adib ◽  
Stephan Ellmerich ◽  
Michal R. Golos ◽  
Janet A. Gilbertson ◽  
...  
Keyword(s):  
Amyloid Fibrils ◽  
Amyloid Deposition ◽  
Amyloid Formation ◽  
Plasmin Activity ◽  
Transthyretin Amyloidosis ◽  
In Vivo Models ◽  
Transgenic Expression ◽  
Attr Amyloidosis ◽  
Amyloid Deposits

AbstractCardiac ATTR amyloidosis, a serious but much under-diagnosed form of cardiomyopathy, is caused by deposition of amyloid fibrils derived from the plasma protein transthyretin (TTR), but its pathogenesis is poorly understood and informative in vivo models have proved elusive. Here we report the generation of a mouse model of cardiac ATTR amyloidosis with transgenic expression of human TTRS52P. The model is characterised by substantial ATTR amyloid deposits in the heart and tongue. The amyloid fibrils contain both full-length human TTR protomers and the residue 49-127 cleavage fragment which are present in ATTR amyloidosis patients. Urokinase-type plasminogen activator (uPA) and plasmin are abundant within the cardiac and lingual amyloid deposits, which contain marked serine protease activity; knockout of α2-antiplasmin, the physiological inhibitor of plasmin, enhances amyloid formation. Together, these findings indicate that cardiac ATTR amyloid deposition involves local uPA-mediated generation of plasmin and cleavage of TTR, consistent with the previously described mechano-enzymatic hypothesis for cardiac ATTR amyloid formation. This experimental model of ATTR cardiomyopathy has potential to allow further investigations of the factors that influence human ATTR amyloid deposition and the development of new treatments.

scholarly journals Confirming the Diagnosis of Amyloidosis

2020 ◽  
Vol 143 (4) ◽  
pp. 312-321
Author(s):  
Brendan Wisniowski ◽  
Ashutosh Wechalekar
Keyword(s):  
Amyloid Fibrils ◽  
General Term ◽  
Disease Phenotype ◽  
Transthyretin Amyloidosis ◽  
Amyloidogenic Proteins ◽  
Amyloidogenic Protein ◽  
Precursor Proteins ◽  
Laser Capture ◽  
Disease Specific ◽  
Over Time

Amyloidosis is a general term for diseases characterised by the deposition of insoluble amyloid fibrils in organs or tissues, leading to organ dysfunction and, in many cases, death. Amyloid fibrils are derived from soluble precursor proteins, with the number of known amyloidogenic proteins increasing over time. The identity of the precursor protein often predicts the disease phenotype, although many of the amyloidoses have overlapping clinical features. Most patients with amyloidosis will require biopsy of an involved organ or tissue to confirm the diagnosis. Cardiac transthyretin amyloidosis, however, may be diagnosed without a biopsy provided stringent criteria are met. Where amyloid is confirmed histologically, the identity of the amyloidogenic protein must be determined, given several of the amyloidoses have disease-specific therapies. Laser capture microdissection and tandem mass spectrometry, LCM-MS, has revolutionised amyloid subtyping, being able to identify the amyloidogenic protein more reliably than antibody-based methods such as immunohistochemistry. Here we summarise the biopsy approach to amyloidosis, as well as the non-biopsy diagnosis of cardiac transthyretin amyloidosis. Proteomic and antibody-based methods for amyloid subtyping are reviewed. Finally, an algorithm for confirming the diagnosis of amyloidosis is presented.

scholarly journals A temporal and ultrastructural relationship between heparan sulfate proteoglycans and AA amyloid in experimental amyloidosis.

1991 ◽  
Vol 39 (10) ◽  
pp. 1321-1330 ◽  
Author(s):  
A D Snow ◽  
R Bramson ◽  
H Mar ◽  
T N Wight ◽  
R Kisilevsky
Keyword(s):  
Heparan Sulfate ◽  
Amyloid Fibrils ◽  
Dermatan Sulfate ◽  
Polyclonal Antibodies ◽  
Amyloid Deposition ◽  
Sulfate Proteoglycan ◽  
Aa Amyloidosis ◽  
Experimental Amyloidosis ◽  
Protein Core ◽  
Dermatan Sulfate Proteoglycan

Previous histochemical studies have suggested a close temporal relationship between the deposition of highly sulfated glycosaminoglycans (GAGs) and amyloid during experimental AA amyloidosis. In the present investigation, we extended these initial observations by using specific immunocytochemical probes to analyze the temporal and ultrastructural relationship between heparan sulfate proteoglycan (HSPG) accumulation and amyloid deposition in a mouse model of AA amyloidosis. Antibodies against the basement membrane-derived HSPG (either protein core or GAG chains) demonstrated a virtually concurrent deposition of HSPGs and amyloid in specific tissue sites regardless of the organ involved (spleen or liver) or the induction protocol used (amyloid enhancing factor + silver nitrate, or daily azocasein injections). Polyclonal antibodies to AA amyloid protein and amyloid P component also demonstrated co-localization to sites of HSPG deposition in amyloid sites, whereas no positive immunostaining was observed in these locales with a polyclonal antibody to the protein core of a dermatan sulfate proteoglycan (known as "decorin"). Immunogold labeling of HSPGs (either protein core or GAG chains) in amyloidotic mouse spleen or liver revealed specific localization of HSPGs to amyloid fibrils. In the liver, heparan sulfate GAGs were also immunolocalized to the lysosomal compartment of hepatocytes and/or Kupffer cells adjacent to sites of amyloid deposition, suggesting that these cells are involved in HSPG production and/or degradation. The close temporal and ultrastructural relationship between HSPGs and AA amyloid further implies an important role for HSPGs during the initial stages of AA amyloidosis.

Regression of cardiac amyloid deposits with novel therapeutics: reaching new frontiers in cardiac ATTR amyloidosis

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
L Chacko ◽  
A Martinez-Naharro ◽  
T Kotecha ◽  
R Martone ◽  
D Hutt ◽  
...  
Keyword(s):  
Treatment Group ◽  
Cardiac Amyloidosis ◽  
T1 Mapping ◽  
Group Versus ◽  
Control Group ◽  
Cardiac Amyloid ◽  
Attr Amyloidosis ◽  
Amyloid Load ◽  
The Impact

Abstract Background Cardiac involvement is the main driver of outcome in ATTR amyloidosis. Advances in therapeutics hold potential in transforming the course of the disease but the impact on cardiac amyloid load is unknown. The aim of this study was to evaluate the impact of patisiran, a new double stranded RNA based gene silencing therapy and a stabilizer, diflunisal, on cardiac amyloid load as measured by CMR and T1 mapping, in patients with ATTR amyloidosis. Methods and results Thirty-two patients with hereditary cardiac amyloidosis were studied. Sixteen patients received treatment with patisiran, and sixteen control subjects did not receive any disease modifying treatment. Patients were assessed with echocardiogram, CMR, NT-proBNP and six-minute walk time measurements at baseline and at 1 year (Mean interval 11.45±3.08 months in treatment group, mean interval 12.82±5.06 months in the control group). CMR analysis comprised LV volumes, T1 mapping to measure the extracellular volume (ECV) occupied by amyloid, T2 mapping and late gadolinium enhancement imaging. At 1-year follow-up, there was a substantial reduction in cardiac amyloid burden, in keeping with cardiac amyloid regression in 45% of patients on treatment. Overall the treatment group showed a reduction in ECV at 1 year follow up compared to an increase in ECV at 1 year in the control group (−1.37%, 95% CI: −3.43 to 0.68% versus 5.02%, 95% CI: 2.86% to 7.18% respectively, p<0.001). The treatment group also showed an improvement in change in 6MWT at 1 year follow up compared to 6MWT at 1 year in the control group (−8.12 meters, 95% CI: −50.8 to 34.6 meters in the treatment group versus −132.27 meters, 95% CI: −216 to −48.6 meters in the control group, p=0.002). The treatment group showed a reduction in BNP at 1 year follow up compared to an increase in the control group (−567.87, 95% CI: −1288.90 to 153.15 in the treatment group versus 2004, 95% CI: 12.82 to 3995.45 in the control group, p<0.001). There was no significant difference from baseline and 1-year data between the control and treatment groups for the difference in echocardiographic parameters, native T1, T2. There was a significant reduction in the percentage of injected dose by 99Tc-DPD scintigraphy in treated patients at 1 year compared to baseline. Conclusions These findings provide the first compelling evidence of substantial cardiac amyloid regression in ATTR amyloidosis, as well as the potential for CMR to be used to track response in treated patients with ATTR cardiac amyloidosis. Combination therapy with transthyretin knock down and stabilizing agents may well be synergistic given enhanced stoichiometry of stabilizers in the face of much reduced plasma transthyretin concentration. Funding Acknowledgement Type of funding source: None

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