Management of Arrhythmias in Cardiac Amyloidosis

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.

Substrate Characterization and Outcomes of Ventricular Tachycardia Ablation in Amyloid Cardiomyopathy: A Multicenter Study

BACKGROUND

Sustained ventricular tachycardia (VT) in cardiac amyloidosis is uncommon, and the substrate and outcomes of catheter ablation are not defined.

METHODS

We included 22 consecutive patients (mean age, 68±10 years; male sex, 91%) with cardiac amyloidosis (ATTR [transthyretin], n=16; light chain, n=6) undergoing catheter ablation for VT/ventricular fibrillation (VF) between 2013 and 2023 in a retrospective, observational, international study. The primary efficacy outcome was recurrent VT/VF during follow-up, while the primary safety end point included major procedure-related adverse events.

RESULTS

The indication for ablation was drug-refractory VT in 17 patients (77%), and premature ventricular complex-initiated polymorphic VT/VF in 5 patients (23%). Catheter ablation was performed using endocardial (n=17.77%) or endo-epicardial approaches (n=5.23%). Complete endocardial electroanatomical voltage maps of the left and right ventricles were obtained in 17 (77%) and 10 (45%) patients, respectively. Each patient had evidence of low-voltage areas, most commonly involving the interventricular septum (n=16); late potentials were recorded in 16 patients (73%). A median of 1 (1-2) VT was inducible per patient; 12 of the 26 mappable VTs (46%) originated from the interventricular septum. Complete procedural success was achieved in 16 patients (73%), with 4 (18%) major procedure-related adverse events. After a median follow-up of 32 (14-42) months, sustained VT/VF recurrence was observed in 9 patients (41%); survival free from VT/VF recurrence was 56% (95% CI, 36%-86%) at 36-month follow-up, and most patients remained on antiarrhythmic drugs. A significant reduction in per patient implantable cardioverter defibrillator therapies was noted in the 6-month period after ablation (before: 6 [4-9] versus after: 0 [0-0]; P<0.001). In multivariable analysis, complete procedural success was associated with reduced risk of recurrent VT/VF (hazard ratio, 0.002; P=0.034).

CONCLUSIONS

Catheter ablation can achieve control of recurrent VT/VF in more than half of patients with cardiac amyloidosis, and the reduction in VT/VF burden post-ablation may be relevant for quality of life. Septal substrate and risk of procedure-related complications challenge successful management of patients with cardiac amyloidosis and VT/VF.

Coronary sinus thrombosis in a patient with amyloidosis, the role of multimodality imaging: a case report

Background

Amyloidosis can affect the heart, causing arrhythmia, thromboembolic events, and sudden cardiac death. Coronary sinus thrombosis is an uncommon though life-threatening condition which requires early identification and management.

Case summary

A 72-year-old Caucasian man, who recovered from out-of-hospital cardiorespiratory arrest, was diagnosed with coronary sinus thrombosis using cardiac imaging techniques. He had no history of invasive procedures and was diagnosed with cardiac amyloidosis based on an extra-cardiac biopsy positive for light chain amyloid, with consistent clinical, echocardiographic, and magnetic resonance criteria.

Discussion

A high frequency of intracardiac thrombosis is seen in amyloidosis. However, coronary sinus thrombosis is an uncommon complication. A multimodality imaging approach appears to be useful for the early diagnosis of coronary sinus thrombosis. The low specificity of the clinical signs, as well as the fast impairment of the patients, could result in fatal complications such as acute myocardial infarction, arrhythmia, and sudden death. Early screening, particularly in high-risk patients, as well as the use of early anticoagulant therapy, could reduce the associated morbidity and mortality.

Monitoring for arrhythmia in transthyretin cardiac amyloidosis with noninvasive ambulatory patch devices

Background

Transthyretin cardiac amyloidosis (ATTR-CA) is associated with an increased incidence of arrhythmias. We hypothesized that 2-week noninvasive ambulatory cardiac rhythm monitoring of patients with ATTR-CA would detect high rates of atrial fibrillation/atrial flutter (AF/AFL) and nonsustained ventricular tachycardia (NSVT).

Objective

The study sought to characterize arrhythmia in patients with ATTR-CA on 2-week, noninvasive cardiac rhythm monitors.

Methods

A total of 38 patients with ATTR-CA who underwent 2-week remote external patch monitoring were included in this single-center retrospective study. An age-matched control group included 38 patients who underwent the same cardiac rhythm monitoring as part of neurological workup.

Results

Of the ATTR-CA cohort, 26.3% had AF/AFL and 81.6% had NSVT. ATTR-CA was associated with higher rates of AF/AFL and NSVT compared with the control group. At a median follow-up of 45 weeks, there was no association between the presence of AF/AFL or NSVT on remote monitor in the ATTR-CA group and a composite of adverse clinical outcome.

Conclusion

ATTR-CA was associated with an elevated rate of AF/AFL and an even higher rate of NSVT on noninvasive ambulatory monitors. While evidence regarding the management of arrhythmias, particularly NSVT/ventricular tachycardia, in ATTR-CA remains limited, 2-week noninvasive cardiac monitoring can be considered to aid in risk stratification for both atrial and ventricular arrhythmias.

Transthyretin amyloid cardiomyopathy: Literature review and red-flag symptom clusters for each cardiology specialty

Wild-type transthyretin amyloid cardiomyopathy (ATTRwt-CM) is a progressive and infiltrative cardiac disorder that may cause fatal consequences if left untreated. The estimated survival time from diagnosis is approximately 3-6 years. Because of the non-specificity of initial symptom manifestation and insufficient awareness among treating physicians, approximately one-third of patients with ATTRwt-CM are initially misdiagnosed with other cardiac diseases. Although heart failure (HF) is the most common initial manifestation of ATTRwt-CM, observed in nearly 70% of affected patients, patients may also present with other cardiologic symptoms, such as atrial fibrillation (AF) and aortic stenosis (AS). This non-specific and diverse nature of the initial ATTRwt-CM presentation indicates that various cardiology subspecialties are involved in patient diagnosis and management. Standard guideline-directed pharmacological treatment for HF is not recommended for patients with ATTRwt-CM because of its limited effectiveness. However, no established algorithms are available regarding HF management in this patient population. This literature review provides an overview of the red flags for ATTRwt-CM and research findings regarding HF management in this patient population. In addition to commonly recognized red flags for ATTRwt-CM (e.g., HF, AF and severe AS), published literature identified potential red flags such as coronary microvascular dysfunction. For HF management in patients with ATTRwt-CM, the use of mineralocorticoid receptor antagonists (MRAs) was reported as a well-tolerated option associated with a low discontinuation rate and reduced mortality. Although there is no concrete evidence for recommendations against sodium-glucose cotransporter 2 inhibitor (SGLT2i) administration, research supporting its use is limited to small-scale studies. Robust evidence is lacking for AF ablation, implantable cardioverter-defibrillators and cardiac resynchronization therapy. Based on the published findings and our clinical experience as Japanese ATTRwt-CM experts, red-flag symptom clusters for each cardiology specialty (HF, arrhythmia and ischaemia/structural heart disease) and a treatment scheme for HF management are presented. As this research area remains at an exploratory stage, our observations would require further discussion among experts worldwide.

Current Therapies and Future Horizons in Cardiac Amyloidosis Treatment

PURPOSE OF REVIEW

Cardiac amyloidosis (CA) is a condition characterized by misfolding and extracellular deposition of proteins, leading to organ dysfunction. While numerous forms of CA exist, two subtypes dominate clinical prevalence: Transthyretin amyloid (ATTR) and immunoglobulin light chain amyloid.

RECENT FINDINGS

The current scientific landscape reflects the urgency to advance therapeutic interventions with over 100 ongoing clinical trials. Heart failure treatment is affected by CA phenotype with poor tolerance of otherwise frequently used medications. Treating comorbidities including atrial fibrillation and valvular disease remains a challenge in CA, driven by technical difficulties and uncertain outcomes. Tafamidis is the first ATTR-stabilizer approved with a rapidly growing rate of clinical use. In parallel, various new therapeutic classes are in late-stage clinical trials including silencers, antibodies and genetic therapy. Managing CA is a critical challenge for future heart failure care. This review delineates the current standard-of-care and scientific landscape of CA therapy.

In-hospital outcomes among amyloidosis patients with atrial fibrillation: A propensity score-matched analysis

Background

The impact of atrial fibrillation (AF) among patients with amyloidosis on in-hospital outcomes is not well-established. We aimed to examine in-hospital outcomes among patients admitted with a primary diagnosis of AF with and without amyloidosis.

Methods and Results

We queried the Nationwide Readmissions Database to compare the in-hospital outcomes among AF patients with and without amyloidosis. Our study demonstrated that in-hospital all-cause mortality, adverse events, and 30-day readmission were comparable between the two groups.

Conclusions

Patients with AF and concurrent amyloidosis did not have worse in-hospital outcomes than those with AF alone.

Cerebrovascular Involvement in Transthyretin Amyloid Cardiomyopathy

Background: Intracardiac thrombosis is common in transthyretin amyloid cardiomyopathy (ATTR-CM), and patients are at risk for thromboembolic events. However, silent cerebral infarcts and the extent of cerebral small vessel disease in patients with cardiac amyloidosis are unknown. Methods: Thirty-two consecutively selected ATTR-CM patients were prospectively studied by cerebral magnetic resonance imaging (cMRI) and compared with 43 CHA2DS2-VASc-matched controls (Co). Structural clinical standard cMRI sequences and features of cerebral vessel involvement were included and quantified by two board certified neuroradiologists in consensus blinded to clinical status. Group differences were estimated using generalized (logistic) linear regression models adjusting for vascular risk factors based on the CHA2DS2-VASc score. Results: The median CHA2DS2-VASc score was 4 for ATTR-CM and Co (p = 0.905). There were no differences between groups in the frequency of current or former smokers (p = 0.755), body-mass-index > 30 (p = 0.106), and hyperlipidemia (p = 0.869). The number of territorial infarcts (4 vs. 0, p = 0.018) was higher in ATTR-CM compared to Co, as was the mean number of cerebral microbleeds (1.4 vs. 0.3, p ≤ 0.001) and the number of Virchow-Robin spaces (43.8 vs. 20.6, p ≤ 0.001). Lacunar lesion presence was higher in ATTR-CM (6 vs. 2, p = 0.054). CHA2DS2-VASc score, atrial fibrillation, anticoagulation, and the interaction term of CHA2DS2-VASc score and atrial fibrillation did not affect the probability of a territorial ischemic lesion or lacunar lesion in logistic regression modeling. Conclusions: In patients with ATTR-CM free from clinically apparent neurological symptoms, cMRI revealed unreported significant small cerebral vessel disease and territorial ischemia. Our findings may support low thresholds for anticoagulation and cMRI in patients with ATTR-CM.

Effect of beta-blockade on mortality in patients with cardiac amyloidosis: A systematic review and meta-analysis

AIMS

The efficacy of beta-blockers in cardiac amyloidosis (CA) is unclear, and concerns persist that neurohormonal blockade could worsen symptoms of heart failure. We aimed to assess whether beta-blocker therapy is associated with improved survival in patients with CA.

METHODS AND RESULTS

We conducted a systematic review and meta-analysis to examine the impact of beta-blocker therapy on mortality in patients with CA. A search of MEDLINE and EMBASE was performed in August 2023. Data were extracted from observational studies and synthesized with pooling and random effects meta-analysis. Thirteen studies including 4215 patients with CA were incorporated in this review (3688 transthyretin amyloid cardiomyopathy (ATTR-CM), 502 light chain amyloid cardiomyopathy (AL-CM), 25 not specified; age 74.8 ± 5.5 years, 76% male). Over half of the cohort (52%) received beta-blockers and the rate of beta-blocker withdrawal was 28%. All-cause mortality was 33% (range: 13-51%) after a median follow-up ranging from 13 to 36 months. There was an inverse association between the pooled risk of mortality and the use of beta-blocker therapy at any time point (RR 0.48, 95% CI 0.29-0.80, I2 = 83%, P = 0.005, seven studies). There was no association between mortality and beta-blocker use (RR 0.65, 95% CI 0.29-1.47, I2 = 88%, P = 0.30) in the three studies that only included patients with ATTR-CM. The three studies that included patients with both ATTR-CM and AL demonstrated an association of beta-blocker use with reduced mortality (OR 0.43, 95% CI 0.29-0.63, I2 = 4%, P < 0.001). The only study that solely included 53 patients with AL-CM, demonstrated improved survival among the 53% who were able to tolerate beta-blocker therapy (RR 0.26, 95% CI 0.08-0.79, P = 0.02). The absence of information on staging of CA is an important limitation of this study.

CONCLUSIONS

Treatment with beta-blockers may be associated with a survival benefit in patients with CA, but these findings are subject to selection and survivor biases. Definitive prospective randomized trials of conventional heart failure therapies are needed in CA.

Best anticoagulation strategy with and without appendage occlusion for stroke-prophylaxis in postablation atrial fibrillation patients with cardiac amyloidosis

INTRODUCTION

Both atrial fibrillation (AF) and amyloidosis increase stroke risk. We evaluated the best anticoagulation strategy in AF patients with coexistent amyloidosis.

METHODS

Consecutive AF patients with concomitant amyloidosis were divided into two groups based on the postablation stroke-prophylaxis approach; group 1: left atrial appendage occlusion (LAAO) in eligible patients and group 2: oral anticoagulation (OAC). Group 1 patients were further divided into Gr. 1A: LAAO + half-does NOAC (HD-NOAC) for 6 months followed by aspirin 81 mg/day and Gr. 1B: LAAO + HD-NOAC. In group 1 patients, with complete occlusion at the 45-day transesophageal echocardiogram, patients were switched to aspirin, 81 mg/day at 6 months. In case of leak, or dense "smoke" in the left atrium (LA) or enlarged LA, they were placed on long-term half-dose (HD) NOAC. Group 2 patients remained on full-dose NOAC during the whole study period.

RESULTS

A total of 92 patients were included in the analysis; group 1: 56 and group 2: 36. After the 45-day TEE, 31 patients from group 1 remained on baby-aspirin and 25 on HD NOAC. At 1-year follow-up, four stroke, one TIA and six device-thrombus were reported in group 1A, compared to none in patients in group 1B (5/31 vs. 0/25, p = .03). No bleeding events were reported in group 1, whereas group 2 had five bleeding events (one subdural hematoma, one retinal hemorrhage, and four GI bleedings). Additionally, one stroke was reported in group 2 that happened during brief discontinuation of OAC.

CONCLUSION

In patients with coexistent AF and amyloidosis, half-dose NOAC following LAAO was observed to be the safest stroke-prophylaxis strategy.

Cardiac Amyloidosis: A Comprehensive Review of Pathophysiology, Diagnostic Approach, Applications of Artificial Intelligence, and Management Strategies

Cardiac amyloidosis (CA) is a serious and often fatal condition caused by the accumulation of amyloid fibrils in the heart, leading to progressive heart failure. It involves the misfolding of normally soluble proteins into insoluble amyloid fibrils, with transthyretin and light-chain amyloidosis being the most common forms affecting the heart. Advances in diagnostics, especially cardiac magnetic resonance imaging and non-invasive techniques, have improved early detection and disease management. Artificial intelligence has emerged as a diagnostic tool for cardiac amyloidosis, improving accuracy and enabling earlier intervention through advanced imaging analysis and pattern recognition. Management strategies include volume control, specific pharmacotherapies like tafamidis, and addressing arrhythmias and advanced heart failure. However, further research is needed for novel therapeutic approaches, the long-term effectiveness of emerging treatments, and the optimization of artificial intelligence applications in clinical practice for better patient outcomes. The article aims to provide an overview of CA, outlining its pathophysiology, diagnostic advancements, the role of artificial intelligence, management strategies, and the need for further research.

Amyloidosis and Amyloidogenesis: One Name, Many Diseases

Amyloidosis is a heterogenous group of disorders, caused by the deposition of insoluble fibrils derived from misfolded proteins in the extracellular space of various organs. These proteins have an unstable structure that causes them to misfold, aggregate, and deposit as amyloid fibrils with the pathognomonic histologic property of green birefringence when viewed under cross-polarized light after staining with Congo red. Amyloid fibrils are insoluble and degradation-resistant; resistance to catabolism results in progressive tissue amyloid accumulation. The outcome of this process is organ disfunction independently from the type of deposited protein, however there can be organ that are specifically targeted from certain proteins.

Challenges associated with managing treatment complications in an older patient with cardiac amyloidosis

BACKGROUND

Amyloidosis, particularly wild-type transthyretin amyloidosis (ATTRwt), is an increasingly recognized cause of heart failure with preserved ejection fraction in the aging population. The complexity of managing ATTRwt in older patients underscores the necessity for individualized treatment approaches, yet clinical guidelines are lacking. This case report contributes to the understanding of ATTRwt management in the elderly, emphasizing the intricacies of medication tolerance and therapeutic decision-making.

CASE PRESENTATION

An 83-year-old Korean man with a history of hypertension presented with dyspnea and peripheral edema. Investigations including electrocardiography, transthoracic echocardiography, cardiac magnetic resonance, and Technetium pyrophosphate scintigraphy led to a diagnosis of ATTRwt cardiac amyloidosis. Initial management with heart failure medications, including an angiotensin-converting enzyme inhibitor, diuretic, and mineralocorticoid receptor antagonist, was modified due to evolving clinical presentations, such as hypotension and onset of atrial fibrillation. Challenges included intolerance to beta-blockers and bleeding complications from direct oral anticoagulant therapy. The patient's treatment journey highlighted the need for personalized management strategies in older ATTRwt patients.

CONCLUSIONS

This case illustrates the challenges in diagnosing and managing ATTRwt amyloidosis in the elderly, particularly the complexities in medication management due to the patient's age, comorbid conditions, and side effects. It underscores the importance of a tailored approach in managing ATTRwt in older populations and highlights the need for ongoing research and development of treatment strategies tailored to this demographic.

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.

Management of Arrhythmias and Conduction Disorders in Amyloid Cardiomyopathy

Cardiac amyloidosis, a condition characterized by abnormal protein deposition in the heart, leads to restrictive cardiomyopathy and is notably associated with an increased risk of arrhythmias and conduction disorders. This article reviews the current understanding and management strategies for these cardiac complications, with a focus on recent advancements and clinical challenges. The prevalence and impact of atrial arrhythmias, particularly atrial fibrillation, are examined, along with considerations for stroke risk and anticoagulation therapy. The article also addresses the complexities of managing rate and rhythm control, outlining the utility and limitations of pharmacological agents and interventions such as catheter ablation. Furthermore, it reviews the challenges in the treatment of ventricular arrhythmias, including the contentious use of implantable cardioverter-defibrillators for primary and secondary prevention. Individualized approaches, considering the unique characteristics of cardiac amyloidosis, are paramount. Continuous research and clinical exploration are essential to refine treatment strategies and improve outcomes in this challenging patient population.

Cardiac amyloidosis at a glance

Amyloidosis can affect any organ in the body by deposition of amyloid fibrils. When these aggregate in the heart, it leads to cardiac amyloidosis a life-threatening and progressive disease. Although considered a rare condition, advances in imaging techniques and raised awareness have shown that it might be more frequent than has been historically estimated. Cardiac amyloidosis can be hereditary or occur as a consequence of the ageing process but, regardless of type, patients experience a heavy symptomatic burden. This article provides an overview of its pathophysiology, signs and symptoms and how any nurse can look for the main red flags in clinical practice. Early referral for specialist care can have a significant impact on disease progression and patient quality of life.

Breakthrough advances enhancing care in ATTR amyloid cardiomyopathy

Transthyretin amyloid cardiomyopathy (ATTR-CM) has been traditionally considered a rare and inexorably fatal condition. ATTR-CM now is an increasingly recognized cause of heart failure (HF) and mortality worldwide with effective pharmacological treatments. Advances in non-invasive diagnosis, coupled with the development of effective treatments, have transformed the diagnosis of ATTR-CM, which is now possible without recourse to endomyocardial biopsy in ≈70 % of cases. Many patients are now diagnosed at an earlier stage. Echocardiography and cardiac magnetic resonance have enabled identification of patients with possible ATTR-CM and more accurate prognostic stratification. Although radionuclide scintigraphy with 'bone' tracers has an established diagnostic value, the diagnostic performance of the bone tracers validated for non-invasive confirmation of ATTR-CM may not be equal. Characterising the wider clinical phenotype of patients with ATTR-CM has enabled identification of features with potential for earlier diagnosis such as carpal tunnel syndrome. Therapies able to slow or halt ATTR-CM progression and increase survival are now available and there is also evidence that patients may benefit from specific conventional HF medications. Cutting-edge research in the field of antibody-mediated removal of ATTR deposits compellingly suggest that ATTR-CM is a truly reversible disorder, bringing hope for patients even with advanced disease. A wide horizon of possibilities is unfolding and awaits discovery.

Tolerability and effectiveness of beta-blockers in patients with cardiac amyloidosis: A systematic review and meta-analysis

OBJECTIVE

This systematic review aimed to assess the tolerability of patients with cardiac amyloidosis (CA) to beta-blockers (BBs) and evaluate its association with adverse outcomes.

METHODS

We performed a comprehensive search from January 1, 2000 to October 20, 2023. Studies examining BB use and tolerance or the relationship between BB use and outcomes in patients with CA were included. Pooled adjusted hazard ratios (aHRs) for all-cause mortality were calculated using random- and fixed-effects models.

RESULTS

Eight observational studies involving 4002 patients with CA (87.5% with transthyretin CA [ATTR-CA] and 12.5% with immunoglobulin light chain CA [AL-CA]) were assessed. BBs were used by 52.5% of the patients. However, 26.3% of the patients discontinued BBs because of hypotension, bradycardia, or fatigue. Regarding the association between BB use and all-cause death, four studies were identified that included 2874 patients with ATTR-CA and 16 patients with AL-CA. The meta-analysis revealed no apparent relationship between BB use and all-cause mortality (pooled aHR = 0.78, 95% confidence interval (CI) = 0.40-1.51). Two studies on patients with ATTR-CA found no impact of BB use on all-cause mortality in the subgroup with left ventricular ejection fraction (LVEF) > 40%, but conflicting results exist for those with LVEF ≤40% (pooled aHR = 0.78, 95% CI = 0.40-1.54).

CONCLUSION

The limited number of observational studies that predominantly enrolled patients with ATTR-CA showed that BBs were used in almost half of the patients with CA, with varying tolerability. However, no significant association was observed between BB use and all-cause mortality.

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.

Catheter ablation of atrial arrhythmias in cardiac amyloidosis: Impact on heart failure and mortality

BACKGROUND

Atrial arrhythmias (AA) commonly affect patients with cardiac amyloidosis (CA) and are a contributing risk factor for the development of heart failure (HF). This study sought to investigate the long-term efficacy and impact of catheter ablation on HF progression in patients with CA and AA.

METHODS

Thirty-one patients with CA and AA undergoing catheter ablation were retrospectively included (transthyretin-ATTR CA 61% and light chain-AL CA 39%). AA subtypes included atrial fibrillation (AFib) in 22 (paroxysmal in 10 and persistent in 12), atrial flutter (AFl) in 17 and atrial tachycardia (AT) in 11 patients. Long-term AA recurrence rates were evaluated along with the impact of sinus rhythm (SR) maintenance on HF and mortality.

RESULTS

AA recurrence was observed in 14 patients (45%) at a median of 3.5 months (AFib n = 8, AT n = 6, AFl = 0). Post-cardioversion, medical therapy or catheter ablation, 10 patients (32%) remained in permanent AA. Over a median follow-up of 19 months, all-cause mortality was 39% (n = 12): 3 with end-stage HF, 5 due to late complications of CA, 1 sudden cardiac death, 1 stroke, 1 COVID 19 (and one unknown). With maintenance of SR following catheter ablation, significant reductions in serum creatinine and natriuretic peptide levels were observed with improvements in NYHA class. Two patients required hospitalization for HF in the SR maintenance cohort compared to 5 patients in the AA recurrence cohort (p = 0.1). All 3 patients with deaths secondary to HF had AA recurrence compared to 11 out of the 28 patients whom were long-term survivors or deaths not related to HF (p = 0.04). All-cause mortality was not associated with AA recurrence.

CONCLUSION

This study demonstrates moderate long-term efficacy of SR maintenance with catheter ablation for AA in patients with CA. Improvements in clinical and biological status with positive trends in HF mortality are observed if SR can be maintained.

Elevation of end-tidal CO2 during exercise is attenuated in patients with cardiac amyloidosis

Reduced exercise tolerance is one of the hallmarks of patients with cardiac amyloidosis (CA), but detailed biological responses during exercise were not investigated. The purpose of this study was to compare the cardiopulmonary exercise test (CPX) parameters between CA patients and propensity-matched heart failure patients. This was a single-center, retrospective, observational study of patients diagnosed with CA. The control group was extracted by propensity score matching from patients who underwent CPX for chronic heart failure during the same period. Clinical data including assessment of biological responses during CPX were compared between the patients with CA (CA group, n = 16) and the control group (non-CA group, n = 16). Echocardiography suggested more impaired diastolic function in the CA group than in the non-CA group. There was no significant difference between groups in the fraction of end-tidal carbon dioxide (FETCO2) at rest. However, the difference between the FETCO2 at rest and the FETCO2 at the respiratory compensation point (ΔFETCO2) was significantly smaller in the CA group than in the non-CA group (0.40% ± 0.37% vs. 0.82% ± 0.33%; p = 0.002). Only in the CA group, there was a significant negative correlation between the ΔFETCO2 and the E/e' ratio on echocardiography (r = - 0.521; p = 0.039) and the serum high-sensitivity troponin T concentration (r = - 0.501; p = 0.048). In conclusion, patients with CA may find it difficult to increase cardiac output during exercise due to severe diastolic dysfunction.

2024 Australia-New Zealand Expert Consensus Statement on Cardiac Amyloidosis

Over the past 5 years, early diagnosis of and new treatments for cardiac amyloidosis (CA) have emerged that hold promise for early intervention. These include non-invasive diagnostic tests and disease modifying therapies. Recently, CA has been one of the first types of cardiomyopathy to be treated with gene editing techniques. Although these therapies are not yet widely available to patients in Australia and New Zealand, this may change in the near future. Given the rapid pace with which this field is evolving, it is important to view these advances within the Australian and New Zealand context. This Consensus Statement aims to update the Australian and New Zealand general physician and cardiologist with regards to the diagnosis, investigations, and management of CA.

Gender Differences in the Evaluation and Management of New Acute CHF Due to ATTRwt Cardiac Amyloidosis

Cardiac amyloidosis can be grouped into two main categories: immunoglobulin light chain (AL) and transthyretin (hATTR or hereditary and ATTRwt or wild type). Cardiac infiltration of misfolded proteins can lead to significant infiltrative processes and subsequent heart failure. Diagnosis of ATTRwt heavily relies on clinical suspicion, as it typically appears later in life and is limited to the heart. It is routinely reported that ATTRwt significantly affects males more than females; however, older patients diagnosed with ATTRwt and those diagnosed at autopsy are significantly more likely to be female. Earlier, a more precise diagnosis in females could detect disease at an earlier stage and expedite treatment.

Cardiac amyloid deposition and the forensic autopsy - A review and analysis

Although amyloid material in the heart is not infrequently encountered at autopsy it may on occasion be difficult to determine the significance in terms of possible contributions to the terminal mechanisms of death. A review was undertaken of the literature and of autopsy cases at Forensic Science SA over a 20-year-period (2003-2022) for all cases where significant amyloid material had been encountered on microscopy of the heart. Sixteen cases were found consisting of 11 cases where cardiac amyloid was involved in the lethal episode, and five where it was considered an incidental feature. Of the 11 lethal cases, there were three where cardiac amyloidosis was the cause of death, and eight where it was a contributing factor, along with ischaemic heart disease (N = 7) and bronchopneumonia (N = 1). The age range was 47-92 years, average 78.6 years, with a male to female ratio of 10:1. The weights of the hearts ranged from 496 to 1059 g - average 648 g. Of the five cases where it was considered an incidental finding, the causes of death were blunt head trauma (N = 2), small intestinal ischaemia (N = 2) and small intestinal obstruction (N = 1). The weights of the hearts ranged from 299 to 487 g, average 369 g. The most relevant types of amyloidosis in forensic cases tend to be light chain amyloidosis, senile cardiac amyloidosis and familial amyloid cardiomyopathy. Other forms of amyloidosis that affect the heart, which include reactive amyloidosis, haemodialysis-related amyloidosis and isolated atrial amyloidosis, either have minimal or no clinical significance, or are of uncertain significance. While it may be difficult to determine the prognostic significance of amyloid material at autopsy clinicopathological correlation may provide useful supportive information.

Cardiac Amyloidosis Due to Transthyretin Protein: A Review

Importance

Systemic amyloidosis from transthyretin (ATTR) protein is the most common type of amyloidosis that causes cardiomyopathy.

Observations

Transthyretin (TTR) protein transports thyroxine (thyroid hormone) and retinol (vitamin A) and is synthesized predominantly by the liver. When the TTR protein misfolds, it can form amyloid fibrils that deposit in the heart causing heart failure, heart conduction block, or arrhythmia such as atrial fibrillation. The biological processes by which amyloid fibrils form are incompletely understood but are associated with aging and, in some patients, affected by inherited variants in the TTR genetic sequence. ATTR amyloidosis results from misfolded TTR protein deposition. ATTR can occur in association with normal TTR genetic sequence (wild-type ATTR) or with abnormal TTR genetic sequence (variant ATTR). Wild-type ATTR primarily manifests as cardiomyopathy while ATTR due to a genetic variant manifests as cardiomyopathy and/or polyneuropathy. Approximately 50 000 to 150 000 people in the US have heart failure due to ATTR amyloidosis. Without treatment, heart failure due to ATTR amyloidosis is associated with a median survival of approximately 5 years. More than 130 different inherited genetic variants in TTR exist. The most common genetic variant is Val122Ile (pV142I), an allele with an origin in West African countries, that is present in 3.4% of African American individuals in the US or approximately 1.5 million persons. The diagnosis can be made using serum free light chain assay and immunofixation electrophoresis to exclude light chain amyloidosis combined with cardiac nuclear scintigraphy to detect radiotracer uptake in a pattern consistent with amyloidosis. Loop diuretics, such as furosemide, torsemide, and bumetanide, are the primary treatment for fluid overload and symptomatic relief of patients with ATTR heart failure. An ATTR-directed therapy that inhibited misfolding of the TTR protein (tafamidis, a protein stabilizer), compared with placebo, reduced mortality from 42.9% to 29.5%, reduced hospitalizations from 0.7/year to 0.48/year, and was most effective when administered early in disease course.

Conclusions and Relevance

ATTR amyloidosis causes cardiomyopathy in up to approximately 150 000 people in the US and tafamidis is the only currently approved therapy. Tafamidis slowed progression of ATTR amyloidosis and improved survival and prevented hospitalization, compared with placebo, in people with ATTR-associated cardiomyopathy.

Characteristics and Clinical Value of Electroanatomic Voltage Mapping in Cardiac Amyloidosis

BACKGROUND

Cardiac amyloidoses (CAs) are an increasingly recognised group of infiltrative cardiomyopathies associated with high risk of adverse cardiac events. We sought to characterise the characteristics and clinical value of right ventricular (RV) electroanatomic voltage mapping (EVM) in CA.

METHODS

Fifteen consecutive patients undergoing endomyocardial biopsy (EMB) for suspected CA (median age 75 years, 1st-3rd quartiles 64-78 years], 67% male) were enrolled in an observational prospective study. Each patient underwent RV high-density EVM using a multipolar catheter and EMB. The primary outcome was death or heart failure hospitalisation at 1-year follow-up. We recorded electrographic features at EMB sampling sites and electroanatomic data in the overall RV, and explored their correlations with histopathologic findings and primary outcomes events.

RESULTS

A final EMB-proven diagnosis of immunoglobulin light chain or transthyretin CA was formulated in 6 and 9 patients, respectively. Electrogram amplitudes in the bipolar and unipolar configurations averaged 1.55 ± 0.44 mV and 5.14 ± 1.50 mV, respectively, in the overall RV, with lower values in AL CA patients. We found a significant inverse correlation between both bipolar and unipolar electrogram amplitude and amyloid burden according to EMB (P = 0.001 and P = 0.025, respectively). At 1-year follow-up, 7 patients (47%) experienced a primary outcome event; the extent of bipolar dense scar area at RV EVM was an independent predictor of primary outcome events at multivariable analysis (odds ratio 2.40; P = 0.037).

CONCLUSIONS

In CA, electrogram amplitudes are around the lower limit of normal yet disproportionately low compared with the increased wall thickness. Out data suggest that RV electrogram amplitude may be a quantitative marker of amyloid burden, and that RV EVM may have prognostic value.

Direct Oral Anticoagulants in Patients With Cardiac Amyloidosis: A Systematic Review and Meta-Analysis

Background and Objectives

Atrial fibrillation is common in patients with cardiac amyloidosis. However, the optimal anticoagulation strategy to prevent thromboembolic events in patients with cardiac amyloidosis and atrial fibrillation is unknown. This systematic review and meta-analysis compares direct oral anticoagulants (DOACs) vs. vitamin K antagonists (VKAs) in patients with cardiac amyloidosis and atrial fibrillation.

Methods

We performed a systematic literature review to identify clinical studies of anticoagulation therapies for patients with cardiac amyloidosis and atrial fibrillation. The primary outcomes of major bleeding and thrombotic events were reported using random effects risk ratios (RRs) with 95% confidence interval (CI).

Results

Our search yielded 97 potential studies and evaluated 14 full-text articles based on title and abstract. We excluded 10 studies that were review articles or did not compare anticoagulation. We included 4 studies reporting on 1,579 patients. The pooled estimates are likely underpowered due to small sample sizes. There was no difference in bleeding events for patients with cardiac amyloidosis and atrial fibrillation treated with DOACs compared to VKAs with a RR of 0.64 (95% CI, 0.38-1.10; p=0.10). There were decreased thrombotic events for patients with cardiac amyloidosis and atrial fibrillation treated with DOACs compared to VKAs with a RR of 0.50 (95% CI, 0.32-0.79; p=0.003).

Conclusions

This systematic review and meta-analysis suggests that DOACs are as safe and effective as VKAs in patients with cardiac amyloidosis and atrial fibrillation. However, more data are needed to investigate clinical differences in anticoagulation therapy in this patient population.

Electrocardiographic abnormalities in patients with cardiomyopathies

Abnormalities in impulse generation and transmission are among the first signs of cardiac remodeling in cardiomyopathies. Accordingly, 12-lead electrocardiogram (ECG) of patients with cardiomyopathies may show multiple abnormalities. Some findings are suggestive of specific disorders, such as the discrepancy between QRS voltages and left ventricular (LV) mass for cardiac amyloidosis or the inverted T waves in the right precordial leads for arrhythmogenic cardiomyopathy. Other findings are less sensitive and/or specific, but may orient toward a specific diagnosis in a patient with a specific phenotype, such as an increased LV wall thickness or a dilated LV. A "cardiomyopathy-oriented" mindset to ECG reading is important to detect the possible signs of an underlying cardiomyopathy and to interpret correctly the meaning of these alterations, which differs in patients with cardiomyopathies or other conditions.

Iatrogenic intramuscular hematoma of the oblique muscles as a complication of technetium-99m-labeled pyrophosphate imaging-based computed tomography-guided core-needle biopsy in a patient with wild-type transthyretin cardiac amyloidosis

Technetium-99m-labeled pyrophosphate imaging-based computed tomography-guided core-needle biopsy of the internal oblique muscle with tracer uptake is a safe and sensitive extracardiac screening biopsy. It can provide histopathological confirmation of the deposition of amyloid transthyretin in patients with wild-type transthyretin cardiac amyloidosis. This case report presents the case of a 73-year-old man receiving triple anti-thrombotic therapy for atrial flutter and coronary stenting who underwent this biopsy to confirm the diagnosis of transthyretin cardiac amyloidosis. The biopsy needle reached the internal oblique muscle via the external oblique muscle between the skin and the target. A type 1 intramuscular hematoma involving these muscles developed subsequently; however, manual compression hemostasis prevented further increase in size. Since this biopsy often targets elderly patients receiving anti-thrombotic therapy who are at high risk of bleeding owing to multimorbidity and polypharmacy, efforts should be made to reduce the frequency of complications, particularly bleeding, which can lead to the development of intramuscular hematoma.

Predictors and outcomes of pacemaker implantation in patients with cardiac amyloidosis

OBJECTIVE

We sought to investigate prevalence, incidence and prognostic implications of permanent pacemaker (PPM) implantation in patients with cardiac amyloidosis (CA), thereby identifying the predictors of time to PPM implantation.

METHODS

Seven hundred eighty-seven patients with CA (602 men, median age 74 years, 571 transthyretin amyloidosis (ATTR), 216 light-chain amyloidosis (AL)) evaluated at two European referral centres were retrospectively included. Clinical, laboratory and instrumental data were analysed. The associations between PPM implantation and mortality, heart failure (HF) or a composite endpoint of mortality, cardiac transplantation and HF were analysed.

RESULTS

81 (10.3%) patients had a PPM before initial evaluation. Over a median follow-up time of 21.7 months (IQR 9.6-45.2), 81 (10.3%) additional patients (18 with AL (22.2%) and 63 with ATTR (77.8%)) underwent PPM implantation with a median time to implantation of 15.6 months (IQR 4.2-40), complete atrioventricular block was the most common indication (49.4%). Independent predictors of PPM implantation were QRS duration (HR 1.03, 95% CI 1.02 to 1.03, p<0.001) and interventricular septum (IVS) thickness (HR 1.1, 95% CI 1.03 to 1.17, p=0.003). The model to estimate the probability of PPM at 12 months and containing both factors showed a C-statistic of 0.71 and a calibration of slope of 0.98.

CONCLUSIONS

Conduction system disease requiring PPM is a common complication in CA that affects up to 20.6% of patients. QRS duration and IVS thickness are independently associated with PPM implantation. A PPM implantation at 12 months model was devised and validated to identify patients with CA at higher risk of requiring a PPM and who require closer follow-up.

Pathway for the Diagnosis and Management of Cardiac Amyloidosis

The systemic amyloidoses are a broad spectrum of diseases that result from misfolding of proteins that aggregate into amyloid fibrils. In cardiac amyloidosis, amyloid fibrils accumulate in the interstitial space between cardiac myocytes causing cellular injury and impairing compliance. Current data suggest that cardiac amyloidosis is more common than previously thought. Advances in cardiac imaging, diagnostic strategies, and therapies have improved the recognition and treatment of cardiac amyloidosis. A position statement for the diagnosis and treatment of cardiac amyloidosis has been published in 2021 by the European Society of Cardiology and an expert consensus decision pathway was published in 2023 by the American College of Cardiology. These are excellent documents but quite lengthy and complex. For this reason, our team developed a novel and simple pathway to help health care providers diagnose and treat patients with cardiac amyloidosis. Our pathway starts with a section titled "suspicion" in which we provide simple clues or "red flags" that are associated with the cardiac amyloidosis phenotype. It is followed by a section titled "diagnosis," where we present in a simplified 2 × 2 format the laboratory and imaging tests that must be performed for an accurate diagnosis. In the section titled "treatment," we describe the 4 pillars in the management of patients with cardiac amyloidosis, which includes the following: heart failure treatments, management of arrhythmias, treatment of significant aortic stenosis, and appropriate selection of disease modifying therapies. Our algorithm ends with our simplified recommendation for follow-up.

A systematic review and meta-analysis of the prevalence, incidence, and predictors of atrial fibrillation in cardiac sarcoidosis

BACKGROUND

The occurrence of atrial arrhythmias, in particular, atrial fibrillation (AF) in patients with cardiac sarcoidosis (CS) are of growing interest in the field of infiltrative cardiomyopathies. Via a systematic review with meta-analysis, we sought to synthesize data on the prevalence, incidence, and predictors of atrial arrhythmias as well as outcomes in patients with CS.

METHODS

PubMed/Medline, Web of Science, and Scopus were systematically queried from inception until April 26th, 2023. Using the random-effects model, separate plots were generated for each effect size assessed.

RESULTS

From a total of 8 studies comprising 978 patients with CS, the pooled summary estimates for the prevalence of AF was 23% (95% CI: 13%-34%). Paroxysmal AF was the most common subtype of AF (83%; 95% CI: 77%-90%), followed by persistent AF (17%; 95% CI: 10%-23%). In 9 studies involving 545 patients with CS, the pooled incidence of AF was estimated at 5%, 13.1%, and 8.9% at <2 years, 2-4 years, and > 4 years of follow-up respectively, with an overall cumulative incidence of 10.6% (95% CI: 4.9%-17.8%) over a 6-year follow-up period. Increased left atrial size and atrial 18F-fluorodeoxyglucose uptake were identified as strong independent predictors for the development of atrial arrhythmias on qualitative synthesis.

CONCLUSION

The burden of AF and related arrhythmias in CS patients is considerable. This necessitates close follow-up and predictive risk-stratification tools to guide the initiation of appropriate strategies, including therapeutic interventions for prevention of AF-related embolic phenomenon, especially in those with known clinical predictors.

A Case of Infiltrative Cardiomyopathy With Refractory Pericardial Effusion Successfully Treated With Empiric Tafamidis

Transthyretin amyloid cardiomyopathy (ATTR-CM) is a rare but fatal systemic infiltrative disease with a challenging course of both diagnosis and management. Definitive diagnosis of such rare infiltrative diseases is not feasible for most centers around the world, often leading to a delay in treatment in these patients. We present a case of suspected ATTR-CM manifesting with recurrent decompensated heart failure, tachyarrhythmias, and recurrent pericardial effusion refractory to several lines of treatment. Eventually, the patient had an excellent response to tafamidis therapy, which was initiated empirically in the absence of a definitive diagnosis. Our case elucidates the challenges of treating this rare disease and the potential effectiveness of initiating newer agents such as tafamidis sooner rather than later in the clinical course.

Mechanisms, prevalence and management of cardiac arrhythmias in cancer patients: a comprehensive review

Recently, prognosis and survival of cancer patients has improved due to progression and refinement of cancer therapies; however, cardiovascular sequelae in this population augmented and now represent the second cause of death in oncological patients. Initially, the main issue was represented by heart failure and coronary artery disease, but a growing body of evidence has now shed light on the increased arrhythmic risk of this population, atrial fibrillation being the most frequently encountered. Awareness of arrhythmic complications of cancer and its treatments may help oncologists and cardiologists to develop targeted approaches for the management of arrhythmias in this population. In this review, we provide an updated overview of the mechanisms triggering cardiac arrhythmias in cancer patients, their prevalence and management.

World Heart Federation Consensus on Transthyretin Amyloidosis Cardiomyopathy (ATTR-CM)

Transthyretin amyloid cardiomyopathy (ATTR-CM) is a progressive and fatal condition that requires early diagnosis, management, and specific treatment. The availability of new disease-modifying therapies has made successful treatment a reality. Transthyretin amyloid cardiomyopathy can be either age-related (wild-type form) or caused by mutations in the TTR gene (genetic, hereditary forms). It is a systemic disease, and while the genetic forms may exhibit a variety of symptoms, a predominant cardiac phenotype is often present. This document aims to provide an overview of ATTR-CM amyloidosis focusing on cardiac involvement, which is the most critical factor for prognosis. It will discuss the available tools for early diagnosis and patient management, given that specific treatments are more effective in the early stages of the disease, and will highlight the importance of a multidisciplinary approach and of specialized amyloidosis centres. To accomplish these goals, the World Heart Federation assembled a panel of 18 expert clinicians specialized in TTR amyloidosis from 13 countries, along with a representative from the Amyloidosis Alliance, a patient advocacy group. This document is based on a review of published literature, expert opinions, registries data, patients' perspectives, treatment options, and ongoing developments, as well as the progress made possible via the existence of centres of excellence. From the patients' perspective, increasing disease awareness is crucial to achieving an early and accurate diagnosis. Patients also seek to receive care at specialized amyloidosis centres and be fully informed about their treatment and prognosis.

Wild-type transthyretin amyloid cardiomyopathy: expect the unexpected-a case report

Background

General interest and incidence are increasing in wild-type transthyretin amyloidosis (ATTRwt) in recent time. As patient population increases, further knowledge of the management of the frequently encountered interacting cardiac comorbidities is requested to improve treatment of ATTRwt patients.

Case summary

A 73-year-old male ATTRwt patient presented to the outpatient clinic (Day 0) with dyspnoea, leg swelling, and palpitations. At diagnosis, 3 years prior to presentation, he exhibited only minor signs of ATTRwt. At Day 0, clinical examination revealed atrial fibrillation and mild peripheral oedema. Anticoagulant and symptomatic treatment with beta-blocker and diuretics was initiated, and the patient was planned for sub-acute direct cardioversion, and the patient was discharged with a Holter monitor to outpatient care. At Day 7, analysis of the monitoring demonstrated spontaneous conversion to sinus rhythm and, unexpectedly, episodes of high-rate self-remittent sustained monomorphic ventricular tachycardia (VT) and frequent ventricular ectopic beats. At Day 8, a sub-acute coronary angiography was performed which revealed a significant proximal left anterior descending artery stenosis which was treated with percutaneous coronary intervention (PCI) and subsequently an internal defibrillator was implanted. Following visits at 1- and 3-month post-PCI at the outpatient clinic revealed no VT and suppression of ventricular ectopic beats.

Discussion

The case illustrates some of the frequently encountered cardiac comorbidities (e.g. atrial fibrillation, ventricular arrhythmia, and ischaemic heart disease) associated with ATTRwt. A high level of suspicion is warranted to identify treatable cardiac conditions [atrial fibrillation, atrioventricular (AV) block, and ischaemic heart disease] and to uncover potentially fatal cardiac conditions in patients with ATTRwt.

Imaging findings of right cardiac amyloidosis: impact on prognosis and clinical course

Cardiac involvement from amyloidosis is of growing interest in the overall literature. Despite cardiac amyloidosis (CA) has been considered for a long time a rare disease, the diagnostic awareness is increasing mainly thanks to the improvement of diagnostic softwares and of imaging techniques such as cardiac magnetic resonance  (CMR). Some authors have observed an increase of prevalence rate of CA; moreover it's often underestimated because clinical manifestations are aspecific. The interstitial infiltration of the left ventricle has been extensively studied, while the involvement of the right ventricle (RV) has been less investigated. Involvement of the RV, even in the absence of pulmonary hypertension or clearly left ventricle infiltration, plays an important role as prognostic factor and is useful to achieve an early diagnosis. Therefore, the use of fast and low-cost diagnostic methods such as ultrasound strain of the right ventricle could be used to recognize cardiac amyloidosis early. Herein the importance of evaluating the right ventricular involvement, which can predict the most severe course of the disease also without overt clinical manifestations. The role of imaging, in particular of echocardiography, CMR, and scintigraphy is here reported.

Arrhythmias in Patients with Cardiac Amyloidosis: A Comprehensive Review on Clinical Management and Devices

Cardiac amyloidosis (CA) is a rare but potentially life-threatening disease in which misfolded proteins accumulate in the cardiac wall tissue. Heart rhythm disorders in CA, including supraventricular arrhythmias, conduction system disturbances, or ventricular arrhythmias, play a major role in CA morbidity and mortality, and thus require supplementary management. Among them, AF is the most frequent arrhythmia during CA hospitalizations and is associated with significantly higher mortality, while ventricular arrhythmias are also common and are usually associated with poor prognosis. Early diagnosis of potential arrythmias could be performed through ECG, Holter monitoring, and/or electrophysiology study. Clinical management of these patients is quite significant, and it usually includes initiation of amiodarone and/or digoxin in patients with AF, potential electrical cardioversion, or ablation in specific patients with indication, as well as initiation of anticoagulants in all patients, independent of AF and CHADS-VASc score, for potential intracardiac thrombus. Moreover, identification of patients with conduction disorders that could benefit from prophylactic pacemaker implantation and/or CRT as well as identification of patients with life-threatening ventricular arrythmias that could benefit from ICD could both increase the survival rates of these patients and improve their quality of life.

Treating amyloid transthyretin cardiomyopathy: lessons learned from clinical trials

An increasing awareness of the disease, new diagnostic tools and novel therapeutic opportunities have dramatically changed the management of patients with amyloid transthyretin cardiomyopathy (ATTR-CM). Supportive therapies have shown limited benefits, mostly related to diuretics for the relief from signs and symptoms of congestion in patients presenting heart failure (HF). On the other hand, huge advances in specific (disease-modifying) treatments occurred in the last years. Therapies targeting the amyloidogenic cascade include several pharmacological agents that inhibit hepatic synthesis of TTR, stabilize the tetramer, or disrupt fibrils. Tafamidis, a TTR stabilizer that demonstrated to prolong survival and improve quality of life in the ATTR-ACT trial, is currently the only approved drug for patients with ATTR-CM. The small interfering RNA (siRNA) patisiran and the antisense oligonucleotide (ASO) inotersen have been approved for the treatment of patients with hereditary ATTR polyneuropathy regardless of the presence of cardiac involvement, with patisiran also showing preliminary benefits on the cardiac phenotype. Ongoing phase III clinical trials are investigating another siRNA, vutrisiran, and a novel ASO formulation, eplontersen, in patients with ATTR-CM. CRISPR-Cas9 represents a promising strategy of genome editing to obtain a highly effective blockade of TTR gene expression.

Paradoxical Left Ventricular Hypertrophy by Echocardiogram and Low Voltage ECG: A Key Clue in the Diagnostic Workup of Two Distinct Presentations of Cardiac AL Amyloidosis

Cardiac amyloidosis remains a rare disease caused by the extracellular deposition of abnormal proteins-amyloids in the myocardium. These protein structures in the myocardium are associated with high morbidity and mortality, with prognosis hinging on early detection and treatment. Three main types of cardiac amyloidosis have been identified: light chain (AL), familial or senile (ATTR), and secondary amyloidosis which is associated with chronic inflammation. Cardiac amyloidosis classically presents as diastolic heart failure with symptoms of volume overload low voltage on electrocardiogram (ECG) and echocardiographic features of diastolic dysfunction and paradoxical left ventricular hypertrophy (paradoxical with respect to low voltage on ECG). Early suspicion should trigger additional laboratory and imaging workup to facilitate early detection. Early detection remains critical to prognosis. Herein, we present two patients admitted to a safety-net hospital within one month of each other with distinct presentations yet important, overlapping characteristics that led to the diagnosis of AL amyloidosis in both patients.

[Systemic forms of amyloidosis with cardiac manifestation]

The term amyloidosis summarizes heterogeneous diseases in which a misfolding of protein structures occurs. These misfolded proteins can fundamentally be deposited anywhere in the body and lead to malfunction of the affected organ. There are preferential sites of deposition depending on which protein is misfolded. Cardiac transthyretin (ATTR) amyloidosis is a rare cause of cardiomyopathy and part of an underdiagnosed systemic disease. For cardiac ATTR amyloidosis, which involves deposition of misfolded tranthyretin either as a wild type (wtATTR) or as a mutated form (mATTR or hATTR), evidence-based treatment options have recently become available with slowing of the progression of the cardiomyopathy and a significant reduction of hospitalization rates. Therefore, it is important to diagnose this severe disease at an early stage and to differentiate it from other forms of amyloidosis. A clinical screening is easily possible by determination of free light chains using imaging examinations (cardiac magnetic resonance imaging or scintigraphic procedures) and immunofixation before the definitive diagnosis is made based on a biopsy and/or genetic tests. An interdisciplinary work-up involving hemato-oncology, nephrology, neurology and other disciplines, is indispensable when cardiac amyloidosis is suspected.

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

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

Opportunities and drawbacks of the subcutaneous defibrillator across different clinical settings

INTRODUCTION

The subcutaneous implantable cardioverter-defibrillator (S-ICD) is an established therapy for the prevention of sudden cardiac death (SCD) and an alternative to a transvenous implantable cardioverter-defibrillator system in selected patients. Beyond randomized clinical trials, many observational studies have described the clinical performance of S-ICD across different subgroups of patients.

AREAS COVERED

Our review aimed to describe the opportunities and drawbacks of the S-ICD, focusing on their use in special populations and across different clinical settings.

EXPERT OPINION

The choice to implant S-ICD should be based on the patient's tailored approach, which takes into account the adequate S-ICD screening at rest or during stress, the infective risk, the ventricular arrhythmia susceptibility, the progressive nature of the underlying disease, the work or sports activity, and the risk of lead-related complications.

CT Extracellular Volume Fraction versus Myocardium-to-Lumen Signal Ratio for Cardiac Amyloidosis

Background Large studies on the diagnostic performance of CT-derived myocardial extracellular volume fraction (ECV) for detecting cardiac amyloidosis are lacking. A simple and practical index as a surrogate for CT ECV would be clinically useful. Purpose To compare the diagnostic performances between CT-derived myocardial ECV and myocardium-to-lumen signal ratio for the detection of cardiac amyloidosis in a large patient sample. Materials and Methods This retrospective study included patients who underwent CT ECV analysis because of suspected heart failure or cardiomyopathy between January 2018 and July 2021. CT ECV was quantified using routine pre-transcatheter aortic valve replacement planning cardiac CT, pre-atrial fibrillation ablation planning cardiac CT, or coronary CT angiography with the addition of unenhanced and delayed phase cardiac CT scans. The diagnostic performances of CT ECV and myocardium-to-lumen signal ratio in delayed phase cardiac CT (a simplified index not requiring unenhanced CT and hematocrit) for detecting cardiac amyloidosis were evaluated using the area under the receiver operating characteristic curve (AUC), sensitivity, and specificity. Results Of 552 patients (mean age, 69 years ± 14 [SD]; 295 men), 41 had cardiac amyloidosis. The sensitivity of CT ECV for amyloidosis was 90% (37 of 41 patients [95% CI: 77, 97]), with a specificity of 92% (472 of 511 patients [95% CI: 90, 95]) and optimal ECV cutoff value of 37% (AUC, 0.97 [95% CI: 0.96, 0.99]). The sensitivity of myocardium-to-lumen signal ratio was 88% (36 of 41 patients [95% CI: 74, 96]), with a specificity of 92% (469 of 511 patients [95% CI: 89, 94]) and optimal myocardium-to-lumen signal ratio cutoff value of 0.87 (AUC, 0.96 [95% CI: 0.94, 0.97]; P = .27 for comparison with ECV). Conclusion CT-derived myocardial extracellular volume fraction and myocardium-to-lumen signal ratio showed comparable and excellent diagnostic performance in detecting cardiac amyloidosis in a large patient sample. © RSNA, 2022 Online supplemental material is available for this article. See also the editorial by Williams in this issue.

Outcomes of Transcatheter Aortic Valve Replacement in Patients With Coexisiting Amyloidosis: Mortality, Stroke, and Readmission

Background

Cardiac amyloidosis can coexist in patients with severe aortic stenosis. There are limited outcomes data on whether this impacts the risk of transcatheter aortic valve replacement (TAVR).

Objectives

The authors aimed to investigate the effect of amyloidosis on outcomes of TAVR.

Methods

We used the Nationwide Readmissions Database to identify hospitalizations for TAVR between 2016 and 2019. The presence of a diagnosis of amyloidosis was identified. Propensity score-weighted regression analysis was used to identify the association of amyloidosis with in-hospital mortality, acute ischemic stroke, and 30-day readmission rate after TAVR.

Results

We identified 245,020 hospitalizations for TAVR, including 273 in patients with amyloidosis. The mean age was 79.4 ± 8.4 years. There was no difference in in-hospital mortality or 30-day readmission rate in patients with and without amyloidosis (1.8% vs 1.5%, P = 0.622; and 12.9% vs 12.5%, P = 0.858; respectively). However, there was a higher rate of acute ischemic stroke in patients with amyloidosis (6.2% vs 1.8%, P < 0.001). Propensity score-weighted logistic regression analysis showed the presence of amyloidosis was associated with greater odds of acute ischemic stroke (odds ratio: 3.08, 95% CI: 1.41-6.71, P = 0.005), but no difference in mortality (odds ratio: 0.79, 95% CI: 0.28-2.27, P = 0.666) or 30-day readmission rate after TAVR (HR: 0.72, 95% CI: 0.41-1.25, P = 0.241).

Conclusions

This analysis suggests amyloidosis may be associated with a higher thromboembolic risk after TAVR that merits further investigation.

Cardiac Amyloidosis

Amyloidosis is a pathologic and clinical condition resulting from the accumulation of insoluble aggregates of misfolded proteins in tissues. Extracellular deposition of amyloid fibrils in the myocardium leads to cardiac amyloidosis, which is often overlooked as a cause of diastolic heart failure. Although cardiac amyloidosis was previously believed to have a poor prognosis, recent advances in diagnosis and treatment have emphasized the importance of early recognition and changed management of this condition. This article provides an overview of cardiac amyloidosis and summarizes current screening, diagnosis, evaluation, and treatment options.

Prevalence and Impact of Arrhythmia on Outcomes in Restrictive Cardiomyopathy-A Report from the Beijing Municipal Health Commission Information Center (BMHCIC) Database

BACKGROUND

Data on the outcomes of restrictive cardiomyopathy (RCM) are limited, when the condition is complicated with arrhythmia. This study was designed to investigate the prevalence of atrial fibrillation (AF), ventricular tachycardia (VT) and bradycardia (BC) and their impact on adverse outcomes (intra-cardiac thrombus, stroke and systematic embolism [SSE], heart failure and death) of RCM.

METHODS AND RESULTS

The retrospective cohort study used data collected from the Beijing Municipal Health Commission Information Center (BMHCIC) database from 1 January 2010 to 31 December 2020. There were 745 (64.9%) patients with AF, 117 (10.2%) patients with VT and 311 (27.1%) patients with bradycardia. The presence of AF was associated with an increased risk of SSE (adjusted HR:1.37, 95%CI:1.02-1.83, p = 0.04) and heart failure (aHR:1.36, 95%CI:1.17-1.58, p < 0.001). VT was associated with an increased risk of intracardiac thrombus (aHR:2.34, 95%CI:1.36-4.01, p = 0.002) and death (aHR:2.07, 95%CI:1.19-3.59, p = 0.01). Bradycardia did not increase the adverse outcomes in RCM. The results remained consistent and steady when AF, VT and bradycardia were adjusted as competing factors.

CONCLUSIONS

Cardiac arrhythmia are highly prevalent and associated with adverse outcomes in patients with RCM. AF and VT are more likely to be associated with intracardiac thrombosis, and the presence of AF increased the risk of SSE and HF. The presence of VT increased the risk of death.