Amyloid deposition as a cause of atrial remodelling in persistent valvular atrial fibrillation

Outcomes of patients with cardiac amyloidosis undergoing percutaneous left atrial appendage occlusion

BACKGROUND

There is limited data on the safety and efficacy of left atrial appendage occlusion (LAAO) devices in patients with cardiac amyloidosis. We examined the outcomes of patients with cardiac amyloidosis undergoing LAAO device implantation in a nationally representative cohort of patients.

METHODS

The National Readmissions Database (NRD) was analyzed from 2016 to 2019 to identify patients ≥ 18 years old with atrial fibrillation (AF) undergoing LAAO. Patients were divided into those with cardiac amyloidosis and those without cardiac amyloidosis. A multivariable logistic regression model was utilized to assess the independent association of cardiac amyloidosis with in-hospital, 30-day/90-day/180-day outcomes after adjusting for confounders.

RESULTS

Our cohort included 54,900 LAAO implantation procedures, of which 220 (0.4%) had cardiac amyloidosis. Patients with cardiac amyloidosis had a lower proportion of women and a lower prevalence of comorbidities including anemia, obesity, diabetes, and peripheral vascular disorders but a higher prevalence of stroke, as compared to those without cardiac amyloidosis. On multivariable analysis, cardiac amyloidosis was associated with significantly higher odds of peri-procedural major adverse events (adjusted odds ratio [aOR]: 2.69; 95% confidence interval [CI]: 1.41-5.14; p<0.01) and neurological complications (aOR: 5.48; 95% CI: 2.47-12.8; p<0.01). There was no difference in the odds of other peri-procedural complications, in-hospital mortality, hospital resource utilization, and 30/90/180-day all-cause/bleeding/stroke-related readmissions between both groups.

CONCLUSION

Patients with cardiac amyloidosis undergoing LAAO device implantation have an increased risk of peri-procedural complications without any difference in bleeding/stroke-related readmissions. These hypothesis-generating findings need validation in future prospective studies.

Effect of tafamidis on left atrial function of patients with transthyretin amyloid cardiomyopathy

Transthyretin amyloid cardiomyopathy (ATTR-CM) is characterized by the functional and structural effects of amyloid infiltration, predominantly within the ventricles, causing biventricular wall thickening. Amyloid infiltration can be observed in the left atrium in ATTR-CM patients, but the association of left atrial (LA) myocardial function with cardiovascular events and of changes in LA myocardial function with tafamidis administration have not yet been clarified. Our aim was, therefore, to use speckle-tracking strain for investigating LA myocardial function in patients with ATTR-CM treated with tafamidis. We studied 55 patients with biopsy-proven ATTR-CM who had been treated with tafamidis (age: 76 ± 2 years, male: 93%). For speckle-tracking analysis of LA myocardial function, the systolic LA strain (LA reservoir function) was defined for this study as LA myocardial function from the apical 4-chamber view. The primary endpoint was defined as a composite comprising cardiovascular death and/or heart failure hospitalization after tafamidis administration over a median follow-up period of 28 ± 4 months. Patients with baseline LA strain < 8.6% (median value) experienced significantly more cardiovascular events than those without (log-rank P = 0.002). Moreover, LA strain in 26 patients worsened after tafamidis administration, and multivariate logistic regression analysis showed age, global longitudinal strain and relative apical longitudinal strain index were identified as independent determinants of deterioration of LA strain after tafamidis administration. In conclusion, baseline LA reservoir function is closely associated with cardiovascular events after tafamidis administration, and could be an additional parameter for the management of patients with ATTR-CM.

Electrocardiographic features and rhythm disorders in cardiac amyloidosis

Cardiac amyloidosis (CA) is an infiltrative cardiomyopathy caused by extracellular deposition of amyloid fibrils, mainly derived from transthyretin, either wild-type or hereditary variants, or immunoglobulin light chains misfolding. It is characterized by an increased left ventricular (LV) mass and diastolic dysfunction, which can lead to heart failure with preserved ejection fraction and/or conduction disturbances. The diagnosis is based on invasive pathology demonstration of amyloid deposits, or non-invasive criteria using advanced cardiovascular imaging techniques. Nevertheless, 12-lead electrocardiogram (ECG) remains of crucial importance in the assessment of patients with CA, since they can manifest peculiar features such as low QRS voltages, in discordance with the LV hypertrophy, but also pseudo-infarction patterns, sinus node dysfunction, atrioventricular blocks, premature supraventricular and ventricular beats, which support the presence of a myocardial disease. Great awareness of these common ECG characteristics of CA is needed to increase diagnostic performance and improve patient's outcome. In the present review, we discuss the current role of the ECG in the diagnosis and management of CA, focusing on the most common ECG abnormalities and rhythm disorders.

2024 European Heart Rhythm Association/Heart Rhythm Society/Asia Pacific Heart Rhythm Society/Latin American Heart Rhythm Society expert consensus statement on catheter and surgical ablation of atrial fibrillation

In the last three decades, ablation of atrial fibrillation (AF) has become an evidence-based safe and efficacious treatment for managing the most common cardiac arrhythmia. In 2007, the first joint expert consensus document was issued, guiding healthcare professionals involved in catheter or surgical AF ablation. Mounting research evidence and technological advances have resulted in a rapidly changing landscape in the field of catheter and surgical AF ablation, thus stressing the need for regularly updated versions of this partnership which were issued in 2012 and 2017. Seven years after the last consensus, an updated document was considered necessary to define a contemporary framework for selection and management of patients considered for or undergoing catheter or surgical AF ablation. This consensus is a joint effort from collaborating cardiac electrophysiology societies, namely the European Heart Rhythm Association, the Heart Rhythm Society (HRS), the Asia Pacific HRS, and the Latin American HRS.

Atrial fibrillation in the setting of cardiac amyloidosis - A review of the literature

Cardiac amyloidosis (CA) is related to the aggregation of insoluble fibrous deposits of misfolded proteins within the myocardium. Transthyretin amyloidosis (ATTR) and immunoglobulin light-chain amyloidosis are the main forms of CA. Atrial fibrillation (AF) is a common arrhythmia in CA patients, especially in those with ATTR amyloidosis. Increased atrial preload and afterload, atrial enlargement, enhanced atrial wall stress, and autonomic dysfunction are the main mechanisms of AF in CA patients. CA is associated with the formation of endocardial thrombi and systemic embolism. The promoters of thrombogenesis include endomyocardial damage, blood stasis, and hypercoagulability. The prevalence of thrombi in patients with AF remains elevated despite long-term anticoagulation. Consequently, transesophageal ultrasound examinations before cardioversion should be performed to exclude endocardiac thrombi despite anticoagulation. Furthermore, the CHA2DS2-VASc score should not be used to assess the thromboembolic risk in CA patients with AF. Rate control is challenging in patients with CA, while rhythm control is the preferred treatment option, especially in the early stages of the disease process. Although catheter ablation is an effective treatment option, more data are needed to explore the role of the procedure in CA patients.

2024 European Heart Rhythm Association/Heart Rhythm Society/Asia Pacific Heart Rhythm Society/Latin American Heart Rhythm Society expert consensus statement on catheter and surgical ablation of atrial fibrillation

In the last three decades, ablation of atrial fibrillation (AF) has become an evidence-based safe and efficacious treatment for managing the most common cardiac arrhythmia. In 2007, the first joint expert consensus document was issued, guiding healthcare professionals involved in catheter or surgical AF ablation. Mounting research evidence and technological advances have resulted in a rapidly changing landscape in the field of catheter and surgical AF ablation, thus stressing the need for regularly updated versions of this partnership which were issued in 2012 and 2017. Seven years after the last consensus, an updated document was considered necessary to define a contemporary framework for selection and management of patients considered for or undergoing catheter or surgical AF ablation. This consensus is a joint effort from collaborating cardiac electrophysiology societies, namely the European Heart Rhythm Association, the Heart Rhythm Society, the Asia Pacific Heart Rhythm Society, and the Latin American Heart Rhythm Society .

Including hemoglobin levels and female sex provide the additional predictive value of the APPLE score for atrial fibrillation recurrence post-catheter ablation

OBJECTIVE

We probed whether the addition of hemoglobin (HGB) or the female sex (SEX) as variables would provide additional prognostic value to the APPLE score.

METHODS

An optimized APPLE score was used to evaluate the AF recurrence risk in the consecutive populations with AF post-catheter ablation including the development (n = 562) and validation (n = 239) cohorts.

RESULTS

In the populations of AF recurrence, most patients were female sex (103/164, 62.8%), and had the lower HGB levels. After adjusting for the APPLE score, HGB level (Odds Ratio [OR], 0.828; 95% Confidence Interval [CI], 0.749-0.915; P < 0.001) and female sex (OR, 1.596; 95% CI, 1.140-2.235; P = 0.006) independently predicted AF recurrence. Adjusting the APPLE score by HGB variable improved its predictive ability for AF recurrence (C-statistic value from 0.675 to 0.711, P = 0.010), which also increased the C-indexes in the external validation (from 0.653 to 0.725, p = 0.023). The female sex variable also enhanced the C-statistic value of the APPLE score for AF recurrence at both development and external validation (C-indices from 0.675 to 0.691, P = 0.004; C-indices from 0.653 to 0.704, p = 0.037, respectively). Decision curve analysis showed that the HGB plus APPLE score was better than the SEX plus APPLE score in predicting AF recurrence in two following AF populations.

CONCLUSION

The inclusion of HGB level and female sex variables improved the predictability and clinical usefulness of adjusted APPLE score. Adjustment of the APPLE score by HGB levels may provide better predictive value than inclusion of the female sex variable.

Transthyretin derived amyloid deposits in the atrium and the aortic valve: insights from multimodality evaluations and mid-term follow up

BACKGROUND

Recent studies have reported atrial involvement and coexistence of aortic stenosis in transthyretin (ATTR) cardiac amyloidosis (CA). However, pathological reports of extraventricular ATTR amyloid deposits in atrial structures or heart valves are limited, and the clinical implications of ATTR amyloid deposits outside the ventricles are not fully elucidated.

CASE PRESENTATION

We report 3 cases of extraventricular ATTR amyloid deposits confirmed in surgically resected aortic valves and left atrial structures, all of which were unlikely to have significant ATTR amyloidosis infiltrating the ventricles as determined by multimodality evaluation including ^99mtechnetium-pyrophosphate scintigraphy, cardiac magnetic resonance, endomyocardial biopsy and their mid-term clinical course up to 5 years. These findings suggested that these were extraventricular ATTR amyloid deposits localized in the aortic valve and the left atrium.

CONCLUSIONS

While long-term observation is required to fully clarify whether these extraventricular ATTR amyloid deposits are truly localized outside the ventricles or are early stages of ATTR-CA infiltrating the ventricles, our 3 cases with multimodality evaluations and mid-term follow up suggest the existence of extraventricular ATTR amyloid deposits localized in the aortic valve and left atrial structures.

Sinus node dysfunction and atrial fibrillation-Relationships, clinical phenotypes, new mechanisms, and treatment approaches

Although the anatomical basis of the pathogenesis of sinus node dysfunction (SND) and atrial fibrillation (AF) is located primarily in the left and right atria, increasing evidence suggests a strong correlation between SND and AF, in terms of both clinical presentation and formation mechanisms. However, the exact mechanisms underlying this association are unclear. The relationship between SND and AF may not be causal, but is likely to involve common factors and mechanisms, including ion channel remodeling, gap junction abnormalities, structural remodeling, genetic mutations, neuromodulation abnormalities, the effects of adenosine on cardiomyocytes, oxidative stress, and viral infections. Ion channel remodeling manifests primarily as alterations in the "funny" current (I_f) and Ca²⁺ clock associated with cardiomyocyte autoregulation, and gap junction abnormalities are manifested primarily as decreased expression of connexins (Cxs) mediating electrical impulse propagation in cardiomyocytes. Structural remodeling refers primarily to fibrosis and cardiac amyloidosis (CA). Some genetic mutations can also cause arrhythmias, such as SCN5A, HCN4, EMD, and PITX2. The intrinsic cardiac autonomic nervous system (ICANS), a regulator of the heart's physiological functions, triggers arrhythmias.In addition, we discuss arrhythmias caused by viral infections, notably Coronavirus Disease 2019 (COVID-19). Similarly to upstream treatments for atrial cardiomyopathy such as alleviating CA, ganglionated plexus (GP) ablation acts on the common mechanisms between SND and AF, thus achieving a dual therapeutic effect.

Atrial Fibrillation, Thromboembolic Risk, and Anticoagulation in Cardiac Amyloidosis: A Review

Cardiac amyloidosis (CA) is caused by extracellular myocardial deposition of amyloid fibrils that are primary derived either from misfolding of transthyretin (ATTR) or light-chain (AL) proteins. CA is associated with atrial fibrillation, potentiated by electromechanical changes as a result of amyloid infiltration in the myocardium. CA also predisposes to thromboembolism and could potentially simultaneously elevate bleeding risk. In this review, we aim to explore and compare the prevalence and pathophysiological mechanisms of atrial fibrillation and thromboembolism in ATTR and AL, examine bleeding risk and factors that promote bleeding, and compare anticoagulation strategies in CA. Finally, we highlight knowledge gaps in the field of thromboembolism in CA to guide future research.

Unravelling the role of sex in the pathophysiology, phenotypic expression and diagnosis of cardiac amyloidosis

Sex-related differences in amyloid transthyretin (ATTR) amyloidosis.

Atrial amyloidosis: mechanisms and clinical manifestations

Cardiac amyloidosis (CA) is now recognized as an important cause of heart failure. Increased wall thickness and diastolic dysfunction of the left ventricle are the most easily detectable manifestations of CA, but amyloid accumulates in all cardiac structures. Involvement of the left and right atria may be due to the haemodynamic effects of ventricular diastolic dysfunction, the effects of amyloid infiltration into the atrial wall, and the cardiotoxic damage of atrial cardiomyocytes by amyloid precursors. Atrial amyloidosis is an early manifestation of CA, and is associated with an increased risk of atrial fibrillation and thromboembolic events. Furthermore, atrial amyloidosis can be found even in the absence of systemic disease and ventricular involvement. This condition is named isolated atrial amyloidosis and is due to a local overproduction of atrial natriuretic peptide. In this review we summarize the evidence on the mechanisms and clinical relevance of atrial amyloidosis.

Right atrial appendage firing in atrial fibrillation

Background

The role of atrial fibrillation (AF) drivers located at the left atrium, superior vena cava, crista terminalis and coronary sinus (CS) is well established. While these regions are classically targeted during catheter ablation, the role of right atrial appendage (RAA) drivers has been incompletely investigated.

Objective

To determine the prevalence and electrophysiological characteristics of AF driver’s arising from the RAA.

Materials and methods

We conducted a retrospective analysis of clinical and procedural data of 317 consecutive patients who underwent an AF ablation procedure after bi-atrial mapping (multipolar catheter). We selected patients who presented with a per-procedural RAA firing (RAAF). RAAF was defined as the recording of a sustained RAA EGM with a cycle length shorter than 120 ms or 120 &lt; RAAF CL ≤ 130 ms and ratio RAA CL/CS CL ≤ 0.75.

Results

Right atrial/atrium appendage firing was found in 22 patients. The prevalence was estimated at 7% (95% CI, 4–10). These patients were mostly men (72%), median age: 66 yo ± 8 without structural heart disease (77%). RAAFs were predominantly found in paroxysmal AF patients (63%, 32%, and 5% for paroxysmal, short standing and long-standing AF, respectively, p &gt; 0.05). RAAF median cycle length was 117 ms ± 7 while CS cycle length was 180 ms ± 10 (p &lt; 0.01).

Conclusion

In 317 consecutive AF ablation patients (22 patients, 7%) the presence of a high-voltage short-cycle-length right atrial appendage driver (RAAF) may conclusively be associated with AF termination. This case series exemplifies the not-so-uncommon role of the RAA in the perpetuation of AF.

[Cardiac arrhythmias and amyloidosis]

Cardiac amyloidosis (CA) is a form of cardiomyopathy characterized by the extracellular deposit of protein fibers in the myocardium, leading to the development of heart failure, arrhythmias, and electrical conduction system alterations. It is known that most cardiomyopathies have a close relationship with heart rhythm abnormalities, however, CA is specially related to different kinds of arrhythmias even in pre-diagnosis stages. Arrhythmias like atrial fibrillation are present in up to 70% of patients with CA associated with a high risk of cardioembolic complications independent of the risk stratification. Ventricular arrhythmias are frequent, but the use of implantable cardioverter defibrillator has not been demonstrated to improve survival. The Atrial-Ventricular node disease is also common, and is frequently associated with the implantation of a pacemaker, even in asymptomatic patients. In this review, we clarify the recommendations of the most current guidelines, summarize historical and contemporaneous data and describe evidence-based strategies for the management of arrhythmias and their complications in CA.

Natriuretic Peptide Oligomers Cause Proarrhythmic Metabolic and Electrophysiological Effects in Atrial Myocytes

BACKGROUND

With aging, the human atrium invariably develops amyloid composed of ANP (atrial natriuretic peptide) and BNP (B-type natriuretic peptide). Preamyloid oligomers are the primary cytotoxic species in amyloidosis, and they accumulate in the atrium during human hypertension and a murine hypertensive model of atrial fibrillation susceptibility. We tested the hypothesis that preamyloid oligomers derived from natriuretic peptides cause cytotoxic and electrophysiological effects in atrial cells that promote arrhythmia susceptibility and that oligomer formation is enhanced for a mutant form of ANP linked to familial atrial fibrillation.

METHODS

Oligomerization was assessed by Western blot analysis. Bioenergic profiling was performed using the Seahorse platform. Mitochondrial dynamics were investigated with immunostaining and gene expression quantitated using quantitative reverse transcription polymerase chain reaction. Action potentials and ionic currents were recorded using patch-clamp methods and intracellular calcium measured using Fura-2.

RESULTS

Oligomer formation was markedly accelerated for mutant ANP (mutANP) compared with WT (wild type) ANP. Oligomers derived from ANP, BNP, and mutANP suppressed mitochondrial function in atrial HL-1 cardiomyocytes, associated with increased superoxide generation and reduced biogenesis, while monomers had no effects. In hypertensive mice, atrial cardiomyocytes displayed reduced action potential duration and maximal dV/dT of phase 0, with an elevated resting membrane potential, compared with normotensive mice. Similar changes were observed when atrial cells were exposed to oligomers. mutANP monomers produced similar electrophysiological effects as mutANP oligomers, likely due to accelerated oligomer formation, while ANP and BNP monomers did not. Oligomers decreased Na⁺ current, inward rectifier K⁺ current, and L-type Ca⁺⁺ current, while increasing sustained and transient outward K⁺ currents, to account for these effects.

CONCLUSIONS

These findings provide compelling evidence that natriuretic peptide oligomers are novel mediators of atrial arrhythmia susceptibility. Moreover, the accelerated oligomerization by mutANP supports a role for these mediators in the pathophysiology of this mutation in atrial fibrillation.

Clinical features and predictors of atrial fibrillation in patients with light-chain or transthyretin cardiac amyloidosis

Aims

The study aimed to investigate the prevalence, phenotypic characteristics, and predictors of atrial fibrillation (AF) in patients presenting with cardiac amyloidosis (CA) of light‐chain (AL) or transthyretin (ATTR) type.

Methods and results

Clinical, biochemical, and echocardiographic data of patients presenting with CA between 2005 and 2020 were retrospectively collected. CA staging was based on established biomarker systems. Binomial logistic regression was run to analyse the effects of clinical variables on the likelihood of AF. The study included 133 patients [53% AL, 41% wild‐type (wt) ATTR‐CA, & 6% hereditary ATTR‐CA]. Mean age was 71 years, and 80% were male patients. AF was diagnosed in 64 (48%) patients (28% in AL‐CA, 80% in wtATTR, 13% in hATTR, P < 0.001). Patients with AF were older (74 vs. 69 years, P < 0.001), more likely to have wtATTR‐CA (67 vs. 16%, P < 0.001), exhibited more often New York Heart Association ≥ III symptoms (66 vs. 45%, P = 0.02) and carried a higher burden of comorbidities. AF patients had lower left ventricular ejection fraction (47 vs. 53%, P < 0.005), higher left atrial volume index (54 vs. 46 mL/m², P = 0.007), higher pulmonary artery pressure (42 vs. 31 mmHg, P = 0.008), and worse tricuspid annular plane systolic excursion values (17 vs. 20 mm, P = 0.01). Mitral regurgitation ≥ Grade 2 was more frequent in AF (56 vs. 25%, P < 0.001). Higher ATTR‐CA stage was associated with higher AF prevalence (47% vs. 74% vs. 94%, P < 0.001, for Stages I, II, & III, respectively). Higher AL‐CA stage was associated with lower AF prevalence (0% vs. 40% vs. 31% vs. 18%, P < 0.001, for Stages I, II, IIIa, & IIIb, respectively). Three independent predictors for AF were identified in a multivariate logistic regression model with 81.5% classification accuracy: AL type [odds ratio (OR) 0.1, confidence interval (CI) 0.01–0.29, P = 0.001], estimated glomerular filtration rate (OR 0.9, CI 0.93–0.99, P = 0.03), and body mass index (OR 1.3, CI 1.07–1.66, P = 0.01). ATTR amyloidosis was associated with a 10‐fold higher risk of AF. During 1 year follow‐up, only one episode of ischaemic stroke was reported.

Conclusions

Atrial fibrillation affects nearly half of all patients with CA. Patients presenting with AF have more severe symptoms and higher burden of comorbidities. ATTR type of amyloidosis is the strongest predictor of AF. Prospective screening for occult AF may be considered in ATTR‐CA.

Age-related amyloidosis outside the brain: A state-of-the-art review

Inside and outside the brain, accumulation of amyloid fibrils plays key roles in the pathogenesis of fatal age-related diseases such as Alzheimer's and Parkinson's diseases and wild-type transthyretin amyloidosis. Although the incidence of all amyloidoses increases with age, for some types of amyloidosis aging is known as the main direct risk factor, and these types are typically diseases of elderly people. More than 10 different precursor proteins are known to cause age-associated amyloidosis; these proteins include amyloid β protein, α-synuclein, transthyretin, islet amyloid polypeptide, atrial natriuretic factor, and the newly discovered epidermal growth factor-containing fibulin-like extracellular matrix protein 1. Except for intracerebral amyloidoses, most age-related amyloidoses have been little studied. Indeed, in view of the increasing life expectancy in our societies, understanding how aging is involved in the process of amyloid fibril accumulation and the effects of amyloid deposits on the aging body is extremely important. In this review, we summarize current knowledge about the nature of amyloid precursor proteins, the prevalence, clinical manifestations, and pathogenesis of amyloidosis, and recent advances in our understanding of age-related amyloidoses outside the brain.

Revealing the Influences of Sex Hormones and Sex Differences in Atrial Fibrillation and Vascular Cognitive Impairment

The impacts of sex differences on the biology of various organ systems and the influences of sex hormones on modulating health and disease have become increasingly relevant in clinical and biomedical research. A growing body of evidence has recently suggested fundamental sex differences in cardiovascular and cognitive function, including anatomy, pathophysiology, incidence and age of disease onset, symptoms affecting disease diagnosis, disease severity, progression, and treatment responses and outcomes. Atrial fibrillation (AF) is currently recognized as the most prevalent sustained arrhythmia and might contribute to the pathogenesis and progression of vascular cognitive impairment (VCI), including a range of cognitive deficits, from mild cognitive impairment to dementia. In this review, we describe sex-based differences and sex hormone functions in the physiology of the brain and vasculature and the pathophysiology of disorders therein, with special emphasis on AF and VCI. Deciphering how sex hormones and their receptor signaling (estrogen and androgen receptors) potentially impact on sex differences could help to reveal disease links between AF and VCI and identify therapeutic targets that may lead to potentially novel therapeutic interventions early in the disease course of AF and VCI.

Sex-Related Risk of Cardiac Involvement in Hereditary Transthyretin Amyloidosis: Insights From THAOS

OBJECTIVES

Because patients with ATTRv cardiomyopathy are more likely to be male, this analysis aimed to increase information on associations between sex and genotype, phenotype, and degree of myocardial involvement in ATTRv amyloidosis.

BACKGROUND

Transthyretin amyloid cardiomyopathy is a progressive, fatal disease that occurs due to accumulation of wild-type or variant (ATTRv) transthyretin amyloid fibrils in the myocardium.

METHODS

The Transthyretin Amyloidosis Outcomes Survey (THAOS) is an ongoing global longitudinal observational survey of patients with ATTR amyloidosis and asymptomatic carriers with TTR mutations. Data from THAOS (data cutoff: January 6, 2020) were analyzed to determine any sex-based differences in genotype, phenotype, and presence of cardiac and neurological symptoms in patients with ATTRv amyloidosis and in patients with ATTRv amyloidosis and cardiomyopathy.

RESULTS

There were 2,790 patients with ATTRv amyloidosis enrolled in THAOS, with male patients more likely to have symptoms of cardiac involvement and a cardiac phenotype. Male prevalence was greater in patients with more severe cardiac manifestations of disease, as assessed with N-terminal pro-B-type natriuretic peptide, left-ventricular (LV) ejection fraction, mean LV wall thickness divided by height, and LV mass index divided by height. Sex, age at disease onset, and genotype category were identified by multivariate analyses as risk factors for the development of cardiomyopathy (defined as increased LV septum thickness divided by height).

CONCLUSIONS

In this analysis, myocardial involvement was more frequent and pronounced in male patients with ATTRv amyloidosis, suggesting that there may be biological characteristics that inhibit myocardial amyloid infiltration in females or facilitate it in males.

Clinical implications of atrial natriuretic peptide amyloidosis

A 74-year-old woman with a history of diastolic heart failure and refractory atrial fibrillation (AF) presented with unstable angina for coronary artery bypass grafting. Routine pathological analysis of tissue specimens obtained from the left atrial appendage revealed subendocardial and interstitial fibrosis and patchy amyloid deposits with Congo red staining demonstrating filamentous deposits. Mass spectrometry was consistent with isolated atrial amyloidosis (IAA). IAA in this patient was found incidentally on routine postoperative pathology, but likely contributed to significant morbidity. The established relationship between IAA with AF and diastolic heart failure underscores the relevance. Further delineating the pathogenesis has potentially immense implications for the future management of associated conditions. To bridge the gaps in the understanding, a standardised approach to diagnosis is needed to open the door to a large-scale study and further work toward establishing evidence-based management pathways.

The Lancet women and cardiovascular disease Commission: reducing the global burden by 2030

Cardiovascular disease is the leading cause of death in women. Decades of grassroots campaigns have helped to raise awareness about the impact of cardiovascular disease in women, and positive changes affecting women and their health have gained momentum. Despite these efforts, there has been stagnation in the overall reduction of cardiovascular disease burden for women in the past decade. Cardiovascular disease in women remains understudied, under-recognised, underdiagnosed, and undertreated. This Commission summarises existing evidence and identifies knowledge gaps in research, prevention, treatment, and access to care for women. Recommendations from an international team of experts and leaders in the field have been generated with a clear focus to reduce the global burden of cardiovascular disease in women by 2030. This Commission represents the first effort of its kind to connect stakeholders, to ignite global awareness of sex-related and gender-related disparities in cardiovascular disease, and to provide a springboard for future research.

Sex Difference in the Risk of Dementia in Patients with Atrial Fibrillation

Atrial fibrillation (AF) is one of the risk factors for dementia. Female sex is an inconsistent risk factor for dementia after adjusting for age in the general population, and there lacks research on its impact in developing dementia in patients with AF. This paper aims to investigate whether female sex is a risk factor for dementia in AF patients. Data of patients with newly diagnosed AF between 2001–2013 were retrieved from Taiwan’s National Health Insurance Research Database. Exclusion criteria were: patients with incomplete demographic data, age < 20 years, rheumatic heart disease, hyperthyroidism, past valvular heart surgery, and a history of dementia. Propensity score matching (PSM) between sexes was performed, including comorbidities, medications and index date stratified by age. The primary outcome was a new diagnosis of dementia at follow-up. A total of 117,517 men and 156,705 women were eligible for analysis. After 1:1 PSM, both 100,065 men and women (aged 72.5 ± 12.5 years) were included for analysis. Dementia risk varied with age in women compared with men. The difference was negligible for ≤55 years (sub distribution HR (SHR) = 0.89, 95% CI 0.73–1.07), but increased between 56–65 years (SHR = 1.13, 95% CI 1.02–1.25), 66–75 years (SHR = 1.14, 95% CI 1.09–1.20), 75–85 years (SHR = 1.11, 95% CI 1.07–1.15) and >85 years (SHR 1.10, 95% CI 1.04–1.16) for females. This study establishes that female sex increases the risk of developing dementia compared to male sex in AF patients aged >56 years. However, the impact of female sex on dementia in AF patients differs between dementia types.

Impact of Arrhythmias on Hospitalizations in Patients With Cardiac Amyloidosis

Cardiac involvement in amyloidosis is associated with a poor prognosis. Data on the burden of arrhythmias in patients with cardiac amyloidosis (CA) during hospitalization are lacking. We identified the burden of arrhythmias using the National Inpatient Sample (NIS) database from January 2016 to December 2017. We compared patient characteristics, outcomes, and hospitalization costs between CA patients with and without documented arrhythmias. Out of 5,585 hospital admissions for CA, 2,020 (36.1%) had concurrent arrhythmias. Propensity-score matching for age, sex, income, and co-morbidities was performed with 1,405 CA patients with arrhythmias and 1,405 patients without. The primary outcome of all-cause mortality was significantly higher in CA patients with arrhythmia than without(13.9% vs 5.3%, p-value <0.001). Atrial fibrillation (AF) was the most common (72.2%) arrhythmia in CA patients with concurrent arrhythmia. The secondary outcomes of AF-related mortality (11.95% vs 9.16%, p-value = 0.02) and acute and acute on chronic as heart failure (HF) exacerbation (32.38% vs 24.91%, p-value <0.0001) were significantly higher in CA and concurrent arrhythmia compared with CA patients without. The total length of hospital stay (6[3 to 12] vs 5[3 to 10], p-value <0.001) and cost of hospitalization were ($ 15,086[7,813 to 30,373] vs $ 12,219[6,865 to 23,997], p-value = 0.001) were significantly greater among CA with arrhythmia compared with those without. These data suggest that the presence of arrhythmias in CA patients during hospital admission is associated with a poorer prognosis and may reflect patients with a higher risk of HF exacerbation and mortality.

Long-term Electrocardiographic Follow-up in Patients with Light-chain Cardiac Amyloidosis

Amyloid light-chain (AL) cardiac amyloidosis is known to result in restrictive cardiomyopathy, which has a poor prognosis. Although electrocardiography (ECG) is useful for its diagnosis and management, there are few reports on the long-term follow-up of electrocardiographic changes. The patient in the present case was a 62-year-old woman who visited our hospital due to palpitation and lower leg edema. A chest radiograph showed cardiac enlargement, and ECG revealed sinus rhythm, first-degree atrioventricular block, low QRS voltage in the limb leads and a pseudomyocardial infarction pattern in the precordial leads. Echocardiography revealed left ventricular hypertrophy with systolic and diastolic dysfunction. Immunoelectrophoresis demonstrated M-protein (IgGλ), and bone marrow biopsy implied IgGλ-type plasmacytoma. Myocardial biopsy findings were compatible with cardiac amyloidosis. Based on these findings, we diagnosed the patient with AL cardiac amyloidosis. Melphalan-prednisolone (MP) therapy was performed in conjunction with treatment for non-sustained ventricular tachycardia and congestive heart failure. Two years and four months later, the sinus rhythm converted to atrial tachycardia. At a follow-up examination at four years and eight months, right branch block appeared. Then degree of intraventricular conduction was worsened, and the low voltage of the limb leads was not observed. Seven years after the diagnosis, she was eventually hospitalized for the treatment of pneumonia and heart failure with tachycardia. On the seventh day of hospitalization, heart rhythm was changed to atrial stand-still with escaped ventricular rhythm and died of cardiac arrest. These ECG changes may provide valuable information regarding the pathophysiological changes that occur in AL cardiac amyloidosis.

Morpho-functional changes of cardiac telocytes in isolated atrial amyloidosis in patients with atrial fibrillation

Telocytes are interstitial cells with long, thin processes by which they contact each other and form a network in the interstitium. Myocardial remodeling of adult patients with different forms of atrial fibrillation (AF) occurs with an increase in fibrosis, age-related isolated atrial amyloidosis (IAA), cardiomyocyte hypertrophy and myolysis. This study aimed to determine the ultrastructural and immunohistochemical features of cardiac telocytes in patients with AF and AF + IAA. IAA associated with accumulation of atrial natriuretic factor was detected in 4.3-25% biopsies of left (LAA) and 21.7-41.7% of right (RAA) atrial appendage myocardium. Telocytes were identified at ultrastructural level more often in AF + IAA, than in AF group and correlated with AF duration and mitral valve regurgitation. Telocytes had ultrastructural signs of synthetic, proliferative, and phagocytic activity. Telocytes corresponded to CD117+, vimentin+, CD34+, CD44+, CD68+, CD16+, S100-, CD105- immunophenotype. No significant differences in telocytes morphology and immunophenotype were found in patients with various forms of AF. CD68-positive cells were detected more often in AF + IAA than AF group. We assume that in aged AF + IAA patients remodeling of atrial myocardium provoked transformation of telocytes into "transitional forms" combining the morphological and immunohistochemical features with signs of fibroblast-, histiocyte- and endotheliocyte-like cells.

Histopathological changes in the right atrial appendages triggering atrial fibrillation: A tertiary care center study

Background

Atrial fibrillation(AF) is as an abnormal irregular rhythm with chaotic generation of electrical signals in the atria of the heart. Various studies in the West have proved that atrial substrates, like isolated atrial amyloidosis can trigger the development of atrial fibrillation. In India, these structural changes have been analyzed on autopsied hearts.

Aim

To determine the role of Atrial Amyloid as a substrate for Atrial fibrillation in ante mortem hearts.

Methods and Results

Atrial appendages were obtained from seventy five patients undergoing open heart surgery at a tertiary care hospital in south India. They were stained with Hematoxylin &Eosin, Masson's Trichrome and Congo red stains and were examined for myocarditis, fibrosis and amyloidosis, respectively. 30 (40%) patients were in AF. Amyloid deposits were seen in 3 cases. All the three were in AF and had undergone mitral valve replacement (MVR) (P<0.05). 2 out of the 3 amyloid-positive cases showed active myocarditis and severe scarring but there was no statistically significant correlation between these factors.

Conclusion

Amyloid and myocarditis, independently act as an arrythmogenic substrates in the development of atrial fibrillation and are also increasingly associated with female gender and MVR. We hypothesize that the amyloid deposits are due to isolated atrial amyloidosis as they were seen only in young individuals. Some patients in sinus rhythm (SR) had large left atria and myocarditis and probably are at a higher risk for developing AF. Hence, follow-up of these patients is required for prevention of severe organ damage and timely therapeutic intervention.

Heart failure with preserved ejection fraction, atrial fibrillation, and the role of senile amyloidosis

Heart failure with preserved ejection fraction (HFpEF) and atrial fibrillation (AF) are very common conditions, particularly in the elderly. However, the mechanisms underlying the two disorders, including their intricate interaction have not been fully resolved. Here, our aim is to review the evidence on the role of the two types of senile amyloidosis in this connection. Two types of senile amyloidosis can be identified: wild-type transthyretin (TTR)-derived amyloidosis (ATTRwt) and isolated atrial amyloidosis (IAA). ATTRwt is an underlying condition that is being increasingly recognized in patients with HFpEF and often accompanied by AF. IAA is an established cause of AF, adding to the mechanism problem. New diagnostic and therapeutic possibilities have emerged that may facilitate clinical management of (senile) amyloidosis, which in turn may have implications for the management of HFpEF and AF.

Trends, burden, and impact of arrhythmia on cardiac amyloid patients: A 16-year nationwide study from 1999 to 2014

BACKGROUND

Patients with cardiac amyloidosis (CA) have increased mortality, which can be explained in part by an increased risk of arrhythmias. The burden of arrhythmias in CA, their predictors, and impact on in-hospital outcomes remains unclear. The role of implantable cardioverter-defibrillators (ICD) in this population is also uncertain.

METHODS

We queried the National Inpatient Sample (NIS) using ICD-9-CM codes 277.39 and 425.7 to identify CA. Twelve common arrhythmias were extracted using appropriate, validated ICD-9-CM codes. ICD implantation was identified using procedure ICD-9 codes 37.94 to 37.98, 00.51 and 00.54.

RESULTS

There were a total of 145,920 CA hospitalizations between 1999 and 2014 in the United States and 56,199 (38.5%) of them were associated with arrhythmias. The prevalence of arrhythmias remained relatively constant from 41.5% in 1999 to 40.2% in 2014. The most common arrhythmia was atrial fibrillation (25.4%). In-patient mortality was significantly higher in CA patients with arrhythmias (10.4% vs 6.5%, P < .001). ICD implantation was performed in 1,381 (0.94%) patients with CA and analysis revealed an incremental trend in implantation over the study period (0.48% in 1999 to 0.65% in 2014). In-hospital mortality was significantly lower in patients who underwent ICD implantation (3.7% vs 8%; P = .0078). CA patients with arrhythmias also had an increased cost of hospitalization and length of stay ($65,046 ± 1,079 vs $53,322 ± 687 and 8.3 ± 0.1 vs 7.4 ± 0.1 days, respectively; P < .0001).

CONCLUSION

Cardiac arrhythmias are common in patients with CA and are associated with worse in-hospital outcomes, increased length of stay, and cost of hospitalization.

Highly Reactive Isolevuglandins Promote Atrial Fibrillation Caused by Hypertension

Oxidative damage is implicated in atrial fibrillation (AF), but antioxidants are ineffective therapeutically. The authors tested the hypothesis that highly reactive lipid dicarbonyl metabolites, or isolevuglandins (IsoLGs), are principal drivers of AF during hypertension. In a hypertensive murine model and stretched atriomyocytes, the dicarbonyl scavenger 2-hydroxybenzylamine (2-HOBA) prevented IsoLG adducts and preamyloid oligomers (PAOs), and AF susceptibility, whereas the ineffective analog 4-hydroxybenzylamine (4-HOBA) had minimal effect. Natriuretic peptides generated cytotoxic oligomers, a process accelerated by IsoLGs, contributing to atrial PAO formation. These findings support the concept of pre-emptively scavenging reactive downstream oxidative stress mediators as a potential therapeutic approach to prevent AF.

Amyloidosis in surgically resected atrial appendages: a study of 345 consecutive cases with clinical implications

Histomorphologic parameters of atrial appendages removed during the Cox-Maze procedure have been shown to correlate with recurrence of atrial fibrillation. While amyloid deposition has been noted within atrial appendages, the incidence and significance remains incompletely understood. More accurate amyloid typing methodologies and targeted pharmacotherapeutics have recently been developed, prompting pathologists to provide more detailed information about the type of amyloid identified in such samples. This study sought to fully characterize the morphologic characteristics of atrial amyloid as well as its incidence and clinical significance. Tissue archives were queried for atrial appendages removed during the cardiac surgeries (2010-2014). Patient demographics, imaging features, and salient clinical findings were recorded. Pattern and extent of amyloid deposition were recorded. Typing of the amyloid protein, when present, was performed on a subset of cases by laser capture microdissection with mass spectrometry-based proteomic analysis. A total of 383 atrial appendages from 345 consecutive patients were included in the study (mean age, 69 years; range, 26-92 years). Amyloid was present in 46% of patients. A linear relationship was observed between age and presence of atrial amyloidosis. Women were more likely to have atrial amyloidosis. Two distinct morphologies of amyloid were observed: filamentous and nonfilamentous, and correlated perfectly with amyloid type (filamentous = AANF-type amyloid; nonfilamentous = ATTR-type amyloid). Filamentous deposits were observed in 91% of those with amyloid. Amyloid was more likely to be found in the left atrial appendage than the right. Patients with atrial amyloid, irrespective of type, were more likely to have experienced stroke or TIA and more likely to have atrial arrhythmia preoperatively. Postoperatively, those with atrial amyloid are more likely to experience recurrence of arrhythmia than those who did not have atrial amyloid. Understanding the morphologic characteristics of AANF-type amyloid will allow for identification by the light microscopy and obviates the need for expensive ancillary typing techniques. The finding of nonfilamentous amyloid, should still prompt confirmation of amyloid type so that targeted therapy may be employed.

Advances in the diagnosis and treatment of transthyretin amyloidosis with cardiac involvement

Amyloidosis is caused by extracellular deposition of insoluble abnormal fibrils constituted by misfolded proteins, which can modify tissue anatomy and hinder the function of multiple organs including the heart. Amyloidosis that can affect the heart includes mostly systemic amyloidosis (amyloid light chain, AL) and transthyretin amyloidosis (ATTR). The latter can be acquired in elderly patients (ATTRwt), or be inherited in younger individuals (ATTRm). The diagnosis is demanding given the high phenotypic heterogeneity of the disease. Therefore, "red flags," which are suggestive features giving support to diagnostic suspicion, are extremely valuable. However, the lack of broad awareness among clinicians represents a major obstacle for early diagnosis and treatment of ATTR. Furthermore, recent implementation of noninvasive diagnostic techniques has revisited the need for endomyocardial biopsy (EMB). In fact, unlike AL amyloidosis, which requires tissue confirmation and typing for diagnosis, ATTR can now be diagnosed noninvasively with the combination of bone scintigraphy and the absence of a monoclonal protein. Securing the correct diagnosis is pivotal for the newly available therapeutic options targeting both ATTRm and ATTRwt, and are directed to either stabilization of the abnormal protein or the reduction of the production of transthyretin. The purpose of this article is to review the contemporary aspects of diagnosis and management of transthyretin amyloidosis with cardiac involvement, summarizing also the recent therapeutic advances with tafamidis, patisiran, and inotersen.

Hiding in Plain Sight: Cardiac Amyloidosis, an Emerging Epidemic

Amyloidosis is a term used to describe a group of rare heterogeneous diseases that ultimately result in the deposition and accumulation of misfolded proteins. These misfolded proteins, known as amyloids, are associated with a variety of precursor proteins that have amyloidogenic potential. Ultimately, the specific type of amyloidosis is dependent on multiple factors including genetic variability of precursor proteins and the tissue or organ in which the amyloid accumulates. Several types of amyloid have a predilection for the heart and thus contribute to cardiac amyloidosis, a major cause of restrictive cardiomyopathy. Individuals with cardiac amyloidosis present clinically with heart failure with preserved ejection fraction. Although improved diagnostics and increased awareness of cardiac amyloidosis have led to a relative increase in diagnosis, cardiac amyloidosis remains an underrecognized and underdiagnosed cause of heart failure with preserved ejection fraction. It is essential to properly identify cases of cardiac amyloidosis and determine the pathology responsible for the formation of amyloid to appropriately provide management. This review aims to encourage physician awareness of cardiac amyloidosis by focusing on clinical presentation and the distinctions between types. Furthermore, epidemiology is central to understanding the affected demographics and sometimes hereditary nature of the disease. Improved understanding of cardiac amyloidosis will ideally lead to earlier diagnosis and interventions to improve patient outcomes.

Atrial Fibrillation in the Elderly: The Role of Sub-Clinical Isolated Cardiac Amyloidosis

Amyloid infiltration of the atrium is described in patients with valvular heart disease and is associated with an increased risk for atrial fibrillation(AF) while amyloid deposits in the ventricles is increasingly being diagnosed in patients with HFpEF. The role of amyloid deposits in patients with AF without valvular heart disease, which represents the most common form of AF globally, is undefined. In this study, we sought to assess the prevalence of sub-clinical isolated cardiac amyloidosis (ICA) at autopsy and the odds of AF in these patients. A total of 1083 patients were included in the study and 3.1% of patients were found to have asymptomatic ICA. Patients with ICA were older and had a higher odds of AF independent of age and CHA₂DS₂VASc score. Amongst patients with AF, those with ICA were more likely to have persistent forms of AF and had a lower sinus rhythm P-wave amplitude. Further studies are required to further define this entity, identify imaging modalities to aid in antemortem diagnosis of ICA and to establish the optimal management strategies in these patients.

Insights From Atrial Fibrillation Genomics: From Bedside to Bench and Back Again

From the bedside of patients contributing samples to large genome-wide association studies for atrial fibrillation (AF), over 100 AF risk loci have been identified. The top locus is near a gene implicated in pulmonary vein formation; the ostia of the pulmonary veins harbor initiating triggers of AF, and isolation of these areas is the cornerstone of ablation therapies for AF. Transcriptomic studies suggest that AF is associated with impaired or overwhelmed responses to cell stress. A dual risk model proposes that in genetically-susceptible individuals, inadequate transcriptional responses to stress predispose to AF in later life. Drugs targeting metabolic, oxidative, or protein handling stress may be novel upstream agents to bring back to the bedside for study in the prevention of AF.

Cardiac amyloidosis: An underdiagnosed/underappreciated disease

Cardiac amyloidosis or amyloid cardiomyopathy (ACM), commonly resulting from extracellular deposition of amyloid fibrils consisted of misfolded immunoglobulin light chain (AL) or transthyretin (TTR) protein, is an underestimated cause of heart failure and cardiac arrhythmias. Among the three types of cardiac amyloidosis (wild-type or familial TTR and light-chain), the wild-type (Wt) TTR-related amyloidosis (ATTR) is an increasingly recognized cause of heart failure with preserved ejection fraction (HFpEF), and amyloidosis should be considered in the differential diagnosis of this heart failure group of patients. Recent advances in the diagnosis and drug treatment of ACM have ushered in a new era in early disease detection and better management of these patients. Certain clues in cardiac and extracardiac manifestations of ACM may heighten clinical suspicion and guide further confirmatory testing. Newer noninvasive imaging methods (strain echocardiography, cardiac magnetic resonance and bone scintigraphy) may obviate the need for endomyocardial biopsy in ATTR patients, while newer targeted therapies may alter the adverse prognosis in these patients. Early recognition of ACM is crucial in halting the disease process before irreversible organ damage occurs. Chemotherapy and stem-cell transplantation combined with immunomodulatory therapy may also favorably affect the course and prognosis of light chain ACM. Finally, in select patients with end-stage disease, heart transplantation may render results comparable to non-ACM patients. All these issues are herein reviewed.

Atrial fibrillation and subtype of atrial fibrillation in cardiac amyloidosis: clinical and echocardiographic features, impact on mortality

Background: Atrial fibrillation (AF) commonly affects patients with cardiac amyloidosis (CA). Amyloid deposition within the left atrium may be responsible for the subtype of AF in either permanent or non-permanent form. The prognostic implications of AF and its clinical subtype according to the type of CA are still controversial in this population. This study sought to investigate the prevalence, incidence and prognostic implications of AF and the clinical subtype of AF (permanent or non-permanent) in patients with CA. Methods: Two hundred and thirty-eight patients with CA and full medical records were retrospectively enrolled in the study: About 115 (48%) with light chain (AL) amyloidosis and 123 (52%) with transthyretin amyloidosis (ATTR). Patient's medical records were reviewed to establish baseline prevalence, incidence and impact on all-cause and cardiovascular mortality during follow-up of AF. Results: One hundred and four (44%) patients had history of AF at the time of diagnosis: 62 (60%) permanent and 42 (40%) non-permanent. There were 30 (26%) and 74 (60%) patients with history of AF among patients with AL and ATTR (including 5 hereditary and 69 wild-type), respectively (p<.0001). During the follow-up, 48 new patients developed AF (29, 12 and 7 among patients with AL, wild-type ATTR and hereditary ATTR). After adjustment for age, survival was similar in patients with or without history of AF (HR 0.87 (95% CI, 0.60 to 1.27; p = .467). AF had no impact on cardiovascular mortality. Among the 152 patients with history of AF included in the whole study, there were 75 (49%) patients with permanent AF. After adjustment for age, survival was similar in patients with permanent and non-permanent AF: HR 1.29 (95% CI, 0.84 to 1.99; p = .251). The results were the same among patients with AL or wild-type amyloidosis. Subtype of AF had no impact on cardiovascular mortality. Conclusions: AF is common in patients with CA. However, AF and clinical subtype of AF have no impact on all-cause mortality, whatever the type of amyloidosis.

Diagnosis of cardiac amyloidosis: a systematic review on the role of imaging and biomarkers

BACKGROUND

Cardiac Amyloidosis (CA) pertains to the cardiac involvement of a group of diseases, in which misfolded proteins deposit in tissues and cause progressive organ damage. The vast majority of CA cases are caused by light chain amyloidosis (AL) and transthyretin amyloidosis (ATTR). The increased awareness of these diseases has led to an increment of newly diagnosed cases each year.

METHODS

We performed multiple searches on MEDLINE, EMBASE and the Cochrane Database of Systematic Reviews. Several search terms were used, such as "cardiac amyloidosis", "diagnostic modalities cardiac amyloidosis" and "staging cardiac amyloidosis". Emphasis was given on original articles describing novel diagnostic and staging approaches to the disease.

RESULTS

Imaging techniques are indispensable to diagnosing CA. Novel ultrasonographic techniques boast high sensitivity and specificity for the disease. Nuclear imaging has repeatedly proved its worth in the diagnostic procedure, with efforts now focusing on standardization and quantification of amyloid load. Because the latter would be invaluable for any staging system, those spearheading research in magnetic resonance imaging of the disease are also trying to come up with accurate tools to quantify amyloid burden. Staging tools are currently being developed and validated for ATTR CA, in the spirit of the acclaimed Mayo Staging System for AL.

CONCLUSION

Cardiac involvement confers significant morbidity and mortality in all types of amyloidosis. Great effort is made to reduce the time to diagnosis, as treatment in the initial stages of the disease is tied to better prognosis. The results of these efforts are highly sensitive and specific diagnostic modalities that are also reasonably cost effective.

Atrial Fibrillation Mechanisms and Implications for Catheter Ablation

AF is a heterogeneous rhythm disorder that is related to a wide spectrum of etiologies and has broad clinical presentations. Mechanisms underlying AF are complex and remain incompletely understood despite extensive research. They associate interactions between triggers, substrate and modulators including ionic and anatomic remodeling, genetic predisposition and neuro-humoral contributors. The pulmonary veins play a key role in the pathogenesis of AF and their isolation is associated to high rates of AF freedom in patients with paroxysmal AF. However, ablation of persistent AF remains less effective, mainly limited by the difficulty to identify the sources sustaining AF. Many theories were advanced to explain the perpetuation of this form of AF, ranging from a single localized focal and reentrant source to diffuse bi-atrial multiple wavelets. Translating these mechanisms to the clinical practice remains challenging and limited by the spatio-temporal resolution of the mapping techniques. AF is driven by focal or reentrant activities that are initially clustered in a relatively limited atrial surface then disseminate everywhere in both atria. Evidence for structural remodeling, mainly represented by atrial fibrosis suggests that reentrant activities using anatomical substrate are the key mechanism sustaining AF. These reentries can be endocardial, epicardial, and intramural which makes them less accessible for mapping and for ablation. Subsequently, early interventions before irreversible remodeling are of major importance. Circumferential pulmonary vein isolation remains the cornerstone of the treatment of AF, regardless of the AF form and of the AF duration. No ablation strategy consistently demonstrated superiority to pulmonary vein isolation in preventing long term recurrences of atrial arrhythmias. Further research that allows accurate identification of the mechanisms underlying AF and efficient ablation should improve the results of PsAF ablation.

Genomics of Atrial Fibrillation

Atrial fibrillation (AF) is a common clinical arrhythmia that appears to be highly heritable, despite representing a complex interplay of several disease processes that generally do not manifest until later in life. In this manuscript, we will review the genetic basis of this complex trait established through studies of familial AF, linkage and candidate gene studies of common AF, genome wide association studies (GWAS) of common AF, and transcriptomic studies of AF. Since AF is associated with a five-fold increase in the risk of stroke, we also review the intersection of common genetic factors associated with both of these conditions. Similarly, we highlight the intersection of common genetic markers associated with some risk factors for AF, such as hypertension and obesity, and AF. Lastly, we describe a paradigm where genetic factors predispose to the risk of AF, but which may require additional stress and trigger factors in older age to allow for the clinical manifestation of AF.

ScaI atrial natriuretic peptide gene polymorphisms and their possible association with postoperative atrial fibrillation - a preliminary report

INTRODUCTION

Atrial fibrillation (AF) is a frequently encountered complication after coronary artery bypass grafting (CABG), but its underlying mechanisms are still unclear. The natriuretic peptides have been reported as markers for predicting the occurrence of postoperative AF. This study evaluates whether the ScaI ANP gene polymorphisms predict the occurrence of postoperative AF.

MATERIAL AND METHODS

A prospective study of 203 consecutive patients with coronary artery disease undergoing elective CABG was undertaken for atrial natriuretic peptide (ANP) ScaI gene polymorphism. Several perioperative data were analysed. Postoperative AF was defined as lasting for at least 15 min, confirmed by 12-lead ECG and occurring within 6 postoperative days. The ScaI polymorphism of the ANP gene was determined by polymerase chain reaction (PCR). Size-dependent separation of the PCR products on a polyacrylamide gel was followed by staining with ethidium bromide.

RESULTS

The total frequency of AF was 19.7%. The frequencies of ScaI ANP gene polymorphisms were as follows: A1A1 4.90%, A1A2 59.60% and A2A2 35.46%. In order to assess the hypothesis that the A2 allele is a marker of increased risk of postoperative atrial fibrillation, the odds ratio (OR) was calculated: A2 vs. non-A2, OR = 0.98 (0.23-4.1), p = 0.97, which was not significant. The odds ratios for A2A2 and A1A1 were not significant either: A2A2 vs. non-A2A2, OR = 1.11 (0.54-2.29), p = 0.76, and A1A1 vs. non-A1A1, OR = 1.17 (0.23-5.92), p = 0.84.

CONCLUSIONS

ANP genotype did not predispose to the incidence of "new-onset" AF.

Association of Atrial Fibrillation with Morphological and Electrophysiological Changes of the Atrial Myocardium

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia. For long time it was considered as pure functional disorder, but in recent years, there were identified atrial locations, which are involved in the initiation and maintenance of this arrhythmia. These structural changes, so called remodelation, start at electric level and later they affect contractility and morphology. In this study we attempted to find a possible relation between morphological (scarring, amyloidosis, left atrial (LA) enlargement) and electrophysiological (ECG features) changes in patients with AF. We examined grossly and histologically 100 hearts of necropsy patients - 54 with a history of AF and 46 without AF. Premortem ECGs were evaluated. The patients with AF had significantly heavier heart, larger LA, more severely scarred myocardium of the LA and atrial septum, and more severe amyloidosis in both atria. Severity of amyloidosis was higher in LAs vs. right atria (RAs). Distribution of both fibrosis and amyloidosis was irregular. The most affected area was in the LA anterior wall. Patients with a history of AF and with most severe amyloidosis have more often abnormally long P waves. Finding of long P wave may contribute to diagnosis of a hitherto undisclosed atrial fibrillation.

[Morphological features of the myocardium of the atrial appendages in patients with different forms of atrial fibrillation]

AIM

to analyze the morphological features of the myocardium of the atrial appendages in patients with different forms of atrial fibrillation (AF) and to compare the findings with the clinical parameters of patients.

MATERIAL AND METHODS

Light and electron microscopies were used to examine the myocardium of the atrial appendages in adult patients with paroxysmal (PAF), persistent (PrAF), or long-standing persistent atrial fibrillation (LPAF) and in comparison group patients with sinus rhythm without history of AF. A morphometric method was employed to evaluate myocardial fibrosis and to measure the diameter of cardiomyocytes (CMCs); the degree of lipomatosis and amyloidosis was semiquantitatively determined; and the content of CMC myofibrils was estimated. Atrial natriuretic peptide content in the myocytes was measured by immunoconfocal microscopy.

RESULTS

In all groups, the patients with AF were found to have signs of atrial structural remodeling: fibrosis, lipomatosis, isolated atrial amyloidosis, CMC hypertrophy with the phenomena of a partial loss of myofibrils without significant differences between these parameters in different groups. In PAF patients, atrial remodeling was accompanied by hypertrophy of a number of CMCs with their higher myofibrilar mass; the increased CMC size in the left atrial appendage prevented left atrial enlargement; the degree of amyloidosis negatively correlated with the CMC myofibrillar loss that was recorded in the minor CMCs; the degree of CMC myolysis positively correlated with mitral valve insufficiency and left atrial enlargement. In contrast to the clinical and morphological changes that are typical of PAF, in LPAF the increase in CMC sizes was positively correlated with left atrial enlargement and mitral annular dilatation; while the myofibrillar loss phenomenon was noted in the most hypertrophied CMCs; the degree of amyloidosis was positively correlated with CMC myofibrillar loss. In the patients with PrAF, the size of CMCs did not correlate with their myofibril content.

CONCLUSION

The patients with PAF were ascertained to have opposite changes in the ratio of CMC hypertrophy to left atrial enlargement, amyloidosis, and CMC myofibrillar loss, hypertrophy of CMCs and their myofibril content in comparison with these indicators in LPAF.

Cumulative Burden of Myocardial Dysfunction in Cardiac Amyloidosis Assessed Using Four-Chamber Cardiac Strain

BACKGROUND

The aim of this study was to test the hypothesis that prognosis in patients with cardiac amyloidosis is closely coupled with amyloid burden in all four cardiac chambers. The goal was to evaluate longitudinal strain (LS) in each cardiac chamber and to determine whether LS in specific cardiac chambers is preferentially associated with prognosis over conventional two-dimensional echocardiographic parameters in patients with cardiac amyloidosis.

METHODS

Patients with two phenotypes of left ventricular (LV) hypertrophy (cardiac amyloidosis in 55 patients and nonobstructive hypertrophic cardiomyopathy in 40 patients) and 55 healthy subjects were retrospectively enrolled for the simultaneous assessment of LS of all four cardiac chambers in the apical four-chamber view. Patients with cardiac amyloidosis were followed up to record major adverse cardiovascular events, including cardiac death, heart transplantation, nonfatal myocardial infarction, ventricular tachyarrhythmia, and exacerbation of heart failure requiring hospitalization.

RESULTS

LS in each chamber was significantly depressed in patients with both LV hypertrophy phenotypes compared with healthy subjects. Right atrial LS was significantly lower in patients with cardiac amyloidosis than those with nonobstructive hypertrophic cardiomyopathy after adjusting for LV ejection fraction and LV mass index. During a median follow-up period of 10 months, major adverse cardiovascular events developed in 22 patients with cardiac amyloidosis. Four-chamber LS were significantly associated with major adverse cardiovascular events, with incremental value over traditional echocardiographic parameters.

CONCLUSIONS

Cardiac amyloidosis involves all cardiac chambers, and thus, chamber-specific strain analysis may be useful to assess the total cumulative burden of cardiac dysfunction.