Management of complications of cardiac amyloidosis: 10 questions and answers

Anticoagulation in Atrial Fibrillation Associated With Cardiac Amyloidosis: A Narrative Review

Cardiac amyloidosis (CA) involves the abnormal deposition and accumulation of amyloid proteins in the heart muscle. A hallmark of disease progression is declining heart function, which can lead to structural irregularities, arrhythmias, and ultimately heart failure. Atrial fibrillation (AF) is the most common arrhythmia that presents in CA patients, and this arrhythmia is significant because it can moderately increase the risk of patients developing intracardiac thrombi, thereby putting them at risk for thromboembolic events. The management of this complication entails the use of anticoagulants like vitamin K antagonists and direct oral anticoagulants to reduce the risk of thrombus formation. This article seeks to review AF in CA and the use of anticoagulation therapy for the management and reduction of thromboembolic risk. The major conclusions of this review are centered around the need for safe administration of anticoagulant therapy to CA patients, regardless of their CHA2DS2-VASc risk score. This review highlights the importance of taking a multidisciplinary or collaborative approach to CA treatment to ensure that all aspects of this multifaceted disease can be properly managed while minimizing adverse events like bleeding risk and drug-drug interactions.

Hereditary Transthyretin Amyloidosis: How to Differentiate Carriers and Patients Using Speckle-Tracking Echocardiography

BACKGROUND

Hereditary transthyretin amyloidosis is a rare disease caused by transthyretin (TTR) gene mutations. The aim of our study was to identify early signs of cardiac involvement in patients with a TTR gene mutation in order to differentiate carriers from patients with neurological or cardiac disease.

METHODS

A case-control study was carried out on 31 subjects with the TTR mutation. Patients were divided into three groups: 23% with cardiac amyloidosis and polyneuropathy (group A), 42% with only polyneuropathy (group B) and 35% carriers (group C). Speckle-tracking echocardiography (left-ventricular global longitudinal strain-GLS, atrial stiffness) was performed in all patients. The apical/basal longitudinal strain ratio (SAB) and relative apical sparing (RAS) were assessed in all subjects.

RESULTS

Analyzing groups C and B, we only found a significant difference in the SAB (p-value 0.001) and RAS (p-value 0.039). These parameters were significantly more impaired in group A compared to group B (SAB p-value 0.008; RAS p-value 0.002). Also, atrial stiffness was significantly impaired in groups A and B compared to group C.

CONCLUSIONS

Our study suggests the diagnostic role of the SAB and RAS in cardiac amyloidosis. The SAB and RAS showed a gradual increase from carriers to patients with neurological and cardiac diseases. Thus, these parameters, in addition to atrial stiffness, could be used to monitor carriers. More extensive data are needed.

State-of-the-art document on optimal contemporary management of cardiomyopathies

Cardiomyopathies represent significant contributors to cardiovascular morbidity and mortality. Over the past decades, a progress has occurred in characterization of the genetic background and major pathophysiological mechanisms, which has been incorporated into a more nuanced diagnostic approach and risk stratification. Furthermore, medications targeting core disease processes and/or their downstream adverse effects have been introduced for several cardiomyopathies. Combined with standard care and prevention of sudden cardiac death, these novel and emerging targeted therapies offer a possibility of improving the outcomes in several cardiomyopathies. Therefore, the aim of this document is to summarize practical approaches to the treatment of cardiomyopathies, which includes the evidence-based novel therapeutic concepts and established principles of care, tailored to the individual patient aetiology and clinical presentation of the cardiomyopathy. The scope of the document encompasses contemporary treatment of dilated, hypertrophic, restrictive and arrhythmogenic cardiomyopathy. It was based on an expert consensus reached at the Heart Failure Association online Workshop, held on 18 March 2021.

ANMCO position paper on vericiguat use in heart failure: from evidence to place in therapy

In the growing therapeutic armamentarium for heart failure (HF) management, vericiguat represents an innovative therapeutic option. The biological target of this drug is different from that of other drugs for HF. Indeed, vericiguat does not inhibit neuro-hormonal systems overactivated in HF or sodium-glucose co-transporter 2 but stimulates the biological pathway of nitric oxide and cyclic guanosine monophosphate, which is impaired in patients with HF. Vericiguat has recently been approved by international and national regulatory authorities for the treatment of patients with HF and reduced ejection fraction who are symptomatic despite optimal medical therapy and have worsening HF. This ANMCO position paper summarises key aspects of vericiguat mechanism of action and provides a review of available clinical evidence. Furthermore, this document reports use indications based on international guideline recommendations and local regulatory authority approval at the time of writing.

Impaired Extracellular Proteostasis in Patients with Heart Failure

BACKGROUND

Proteostasis impairment and the consequent increase of amyloid burden in the myocardium have been associated with heart failure (HF) development and poor prognosis. A better knowledge of the protein aggregation process in biofluids could assist the development and monitoring of tailored interventions.

AIM

To compare the proteostasis status and protein's secondary structures in plasma samples of patients with HF with preserved ejection fraction (HFpEF), patients with HF with reduced ejection fraction (HFrEF), and age-matched individuals.

METHODS

A total of 42 participants were enrolled in 3 groups: 14 patients with HFpEF, 14 patients with HFrEF, and 14 age-matched individuals. Proteostasis-related markers were analyzed by immunoblotting techniques. Fourier Transform Infrared (FTIR) Spectroscopy in Attenuated Total Reflectance (ATR) was applied to assess changes in the protein's conformational profile.

RESULTS

Patients with HFrEF showed an elevated concentration of oligomeric proteic species and reduced clusterin levels. ATR-FTIR spectroscopy coupled with multivariate analysis allowed the discrimination of HF patients from age-matched individuals in the protein amide I absorption region (1700-1600 cm^-1), reflecting changes in protein conformation, with a sensitivity of 73 and a specificity of 81%. Further analysis of FTIR spectra showed significantly reduced random coils levels in both HF phenotypes. Also, compared to the age-matched group, the levels of structures related to fibril formation were significantly increased in patients with HFrEF, whereas the β-turns were significantly increased in patients with HFpEF.

CONCLUSION

Both HF phenotypes showed a compromised extracellular proteostasis and different protein conformational changes, suggesting a less efficient protein quality control system.

Therapy of ATTR Cardiac Amyloidosis: Current Indications

Transthyretin cardiac amyloidosis is a restrictive cardiomyopathy caused by extracellular deposition in the heart of amyloid fibrils derived from plasma transthyretin (ATTR), either in its hereditary (ATTRh) or acquired (ATTRwt) forms. Cardiac amyloidosis has a very poor prognosis if therapy is not started promptly. Therefore, it is very important to recognize cardiac amyloidosis early in order to immediately start a treatment capable of modifying the prognosis. Treatment of cardiac amyloidosis is not easy, often requiring a multidisciplinary team. New RNA-interfering drugs (such as patisiran) have been devised and are effective in the treatment of ATTRh amyloidosis. Tafamidis (a stabilizer of the native tetramer structure of TTR) is recommended to treat patients with genetic testing-proven hereditary hTTR-cardiomyopathy or wild-type TTR cardiomyopathy and NYHA Class I or II to reduce symptoms, CV hospitalization and mortality (Class I, level of evidence B). Patisiran should be considered in ATTRh cardiomyopathy with polyneuropathy. Thus, this review is intended to be a simple practical guide for the treatment of ATTR cardiac amyloidosis.

Treatment of Transthyretin Amyloid Cardiomyopathy: The Current Options, the Future, and the Challenges

Transthyretin amyloid cardiomyopathy (ATTR-CM) is a progressively debilitating, rare disease associated with high mortality. ATTR-CM occurs when TTR amyloid protein builds up in the myocardium along with different organs, most commonly the peripheral and the autonomic nervous systems. Managing the cardiac complications with standard heart failure medications is difficult due to the challenge to maintain a balance between the high filling pressure associated with restricted ventricular volume and the low cardiac output. To date, tafamidis is the only agent approved for ATTR-CM treatment. Besides, several agents, including green tea, tolcapone, and diflunisal, are used off-label in ATTR-CM patients. Novel therapies using RNA interference also offer clinical promise. Patisiran and inotersen are currently approved for ATTR-polyneuropathy of hereditary origin and are under investigation for ATTR-CM. Monoclonal antibodies in the early development phases carry hope for amyloid deposit clearance. Despite several drug candidates in the clinical development pipeline, the small ATTR-CM patient population raises several challenges. This review describes current and future therapies for ATTR-CM and sheds light on the clinical development hurdles facing them.

Patients with cardiac amyloidosis have a greater neurohormonal activation than those with non-amyloidotic heart failure

BACKGROUND

Neurohormonal activation has never been investigated in patients with cardiac amyloidosis (CA).

METHODS

Forty-seven patients with amyloid light-chain (AL)-CA and 61 with transthyretin (ATTR)-CA were matched to non-amyloidotic heart failure (HF) patients based on age, sex, left ventricular ejection fraction ranges, renal function and HF therapies. N-terminal pro-B-type natriuretic peptide (NT-proBNP), norepinephrine and renin were dosed. The primary and secondary endpoints were 1-year cardiovascular death or HF hospitalisation, and 5-year cardiovascular death, respectively.

RESULTS

Patients with AL-CA had a 10-fold higher NT-proBNP than HF patients (6548 ng/L [2059-15,097] vs. 692 [243-2241], p < 0.001), and slightly higher norepinephrine (595 ng/L [383-869] vs. 416 [250-693], p = 0.047). Patients with ATTR-CA had higher NT-proBNP (3984 ng/L [2275-9505] vs. 1751 [470-4768], p = 0.006), norepinephrine (552 ng/L [344-855] vs. 441 [323-601], p = 0.020), and renin (14 mU/L [8-80] vs. 10 [4-34], p = 0.017). Patients with AL- or ATTR-CA had more often 2 or 3 neurohormones above the corresponding upper reference limits than matched HF patients. NT-proBNP and aldosterone were univariate predictors of the primary endpoint in patients with ATTR-CA, but not in matched controls. NT-proBNP and renin predicted the secondary endpoint in patients with AL-CA, but not in matched controls.

CONCLUSIONS

Patients with CA display a neurohormonal activation, with some prognostic significance.

Transthyretin amyloid cardiomyopathy: An uncharted territory awaiting discovery

Transthyretin amyloid cardiomyopathy (ATTR-AC) is an under-recognized and underdiagnosed disease. Although traditionally considered a rare condition, the epidemiology of the disease is rapidly changing due to the possibility of non-invasive diagnosis through cardiac scintigraphy with bone tracers and novel disease-modifying treatments providing survival advantages. Nevertheless, many questions and grey areas have to be addressed, such as the natural history of ATTR-AC, the role and implications of genotype-phenotype interactions, the best clinical management, prognostic stratification and the most appropriate treatments, including those already recommended for patients with heart failure. Clinicians have to cope with old beliefs and evolving concepts in ATTR-AC. A wide horizon of possibilities for physicians of many specialties is unfolding and awaits discovery.