Diagnostic and prognostic value of low QRS voltages in cardiac AL amyloidosis

The value of the electrocardiogram in the recognition of cardiac amyloidosis: a systematic meta-analysis

OBJECTIVE

We conducted a systematic review and meta-analysis to assess the diagnostic value of the electrocardiogram (ECG) method in detecting cardiac amyloidosis (CA) to indicate its clinical application.

METHODS

We searched PubMed, Web of Science, OVID Medline, and Cochrane Library databases for clinical trials assessing the diagnostic performance of ECG in detecting CA. We employed the risk ratio and 95% confidence interval (CI) to explicit estimates. QUADAS-2 was applied to evaluate the bias risk and the clinical applicability of the included studies. Reviewer Manager (RevMan) 5.3 and Stata 16.0 were employed to complete all statistical analyses.

RESULTS

This meta-analysis included ten studies (N = 6353 patients). Overall, the findings of the study exposed that, for CA patients in whom the ECG method was used, the sensitivity and specificity were 0.49 and 0.91, respectively. The positive likelihood ratio (LR) and negative LR were 5.17 and 0.57, respectively. The diagnostic odds ratio (DOR) and diagnostic score of the ECG in detecting CA were 9.11 and 2.21. The area under the curve (AUC) was 0.83(95% CI = 0.79-0.86). The hierarchical summary receiver operating characteristic (HSROC) curve further confirmed the diagnostic accuracy of the ECG, demonstrating a high prediction and confidence interval for the pooled estimate. No significant publication bias was detected, as confirmed by funnel plot analysis. Sensitivity analysis confirmed that the pooled estimates for ECG remained stable after the exclusion of individual studies, underscoring the robustness of the findings. The combined DOR and diagnostic score were 9.11 and 2.21, respectively.

CONCLUSIONS

ECM has low sensitivity and high specificity in the diagnosis of CA. AUC > 0.5, indicating that ECM has accuracy and diagnostic value in the diagnosis of CA to some extent.

Prevalence and clinical significance of low QRS voltages in healthy individuals, athletes, and patients with cardiomyopathy: implications for sports pre-participation cardiovascular screening

Low QRS voltages (LQRSV), defined as a QRS amplitude from peak to nadir < 0.5 mV in all limb leads, are an emerging diagnostic finding on the electrocardiogram (ECG). In healthy individuals and athletes, LQRSV are rare (2.2-4% of elite athletes, 0.5% of recreational athletes, and 0.3% of sedentary individuals). LQRSV athletes commonly show ventricular arrhythmias (VAs) on exercise, and up to 40% of those with LQRSV and VAs have late gadolinium enhancement (LGE) on cardiac magnetic resonance (CMR). The prevalence of LQRSV in arrhythmogenic cardiomyopathy ranges from 17-40%, predicts left ventricular (LV) involvement, and is correlated with more extensive LGE replacement on CMR. In hypertrophic cardiomyopathy (HCM), LQRSV ranges from 0.7-11%. LQRSV-HCM patients have more segments with LGE, despite relatively smaller LV mass, suggesting a more advanced clinical stage and a worse prognosis. In dilated cardiomyopathy (DCM), LQRSV range from 6-7%, but may be higher (36%) in certain genetic forms of DCM. On a follow-up, LQRSV are independently associated with incident cardiac events, such as sudden death, sustained ventricular arrhythmia, or appropriate internal cardioverter defibrillator discharge. In cardiac amyloid, LQRSV range from 34-66% and demonstrate a negative prognostic value, with worse clinical outcomes regardless of underlying biologic, genetic, and clinical variables. In conclusion, LQRSV deserve careful consideration for exclusion of arrhythmogenic substrates in healthy individuals, athletes, and patients. While additional research is needed, it is reasonable that LQRSV should trigger clinical investigation to exclude underlying diseases at risk of life-threatening arrhythmias.

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.

ECG/echo indexes in the diagnostic approach to amyloid cardiomyopathy: A head-to-head comparison from the AC-TIVE study

BACKGROUND AND AIMS

The discordance between QRS voltages on electrocardiogram (ECG) and left ventricle (LV) wall thickness (LVWT) on echocardiogram (echo) is a recognized red flag (RF) of amyloid cardiomyopathy (AC) and can be measured by specific indexes. No head-to-head comparison of different ECG/echo indexes among subjects with echocardiographic suspicion of AC has yet been undertaken. The study aimed at evaluating the performance and the incremental diagnostic value of different ECG/echo indexes in this subset of patients.

METHODS

Electrocardiograms of subjects with LV hypertrophy, preserved ejection fraction and ≥ 1 echocardiographic RF of AC participating in the AC-TIVE study, an Italian prospective multicenter study, were independently analyzed by two cardiologists. Low QRS voltages and 8 different ECG/echo indexes were evaluated. Cohort specific cut-offs were computed.

RESULTS

Among 170 patients, 55 (32 %) were diagnosed with AC. Combination of low QRS voltages with interventricular septum ≥ 1,6 cm was the most specific (specificity 100 %, positive predictive value 100 %) ECG/echo index, while the ratio between the sum of all QRS voltages and LVWT <7,8 was the most sensitive and accurate (sensitivity 94 %, negative predictive value 97 %, accuracy 82 %). When the latter index was added to a model using easily-accessible clinical variables, the diagnostic accuracy for AC greatly increased (AUC from 0,84 to 0,95; p = 0,007).

CONCLUSIONS

Among patients with non-dilated hypertrophic ventricles with normal ejection fraction and echocardiographic RF of AC, easily-measurable ECG/echo indexes, mainly when added to few clinical variables, can help the physician orient second level investigations. External validation of the results is warranted.

Electrocardiographic heterogeneity of patients with variant transthyretin amyloid cardiomyopathy: Genotype-phenotype correlations

BACKGORUND

Hereditary transthyretin(vATTR) cardiac amyloidosis has extremely different features according to the type of transthyretin(TTR) mutation. Data about electrocardiographic findings(ECG) in vATTR are limited and not informative of genotype correlation. Aim of this study is to analyze ECG characteristics and their correlation to clinical and echocardiographic aspects in patients with vATTR, focusing on different TTR mutations.

METHODS AND RESULTS

This is a multicentric, retrospective, observational study performed in six Italian referral centres. We divided patients in two groups, according to the previously described phenotypic manifestations of the TTR mutation. Of 64 patients with vATTR, 23(36%) had prevalent cardiac(PC) TTR mutations and 41(64%) patients had a prevalent neurological(PN) TTR mutations. Patients with PC mutations were more frequently males and older, with advanced NAC staging. At baseline ECG, atrial fibrillation was more common in patients with PC, while pacemaker induced rhythm in PN mutations. PQ and QRS durations were longer and voltage to mass ratio was lower in PC mutations. Different TTR mutations tend to have distinctive ECG features.

CONCLUSIONS

ECG in vATTR is extremely heterogeneous and the specific mutations are associated with distinct instrumental and clinical features. The differences between PN and PC vATTR are only partially explained by the different degree of cardiac infiltration.

Cardiac amyloidosis: evolving pathogenesis, multimodal diagnostics, and principles of treatment

Amyloidosis is a protein deposition disorder in which insoluble fibril structures accumulate in the bodily tissues damaging the organ function. Cardiac amyloidosis is a severe but under-reported medical condition characterized by the accumulation of amyloid in the extracellular area of the myocardium, which results in thickening and stiffening of ventricular walls. Cardiac amyloidosis has recently gained much attention with its slowly surging incidence. With this study, we seek to comprehensively compile the pathophysiology and clinical picture of cardiac amyloidosis subtypes, extending a clinically oriented, up-to-date clinical approach to diagnosis and therapy. Cardiac amyloidosis can be caused by rare genetic mutations which may be inherited or acquired. The growing incidence can be attributed to advancements in imaging methods and other diagnostic modalities. Most occurrences of cardiac amyloidosis result from two forms of precursor protein: transthyretin [TTR] amyloid and immunoglobulin-derived light-chain amyloid. Prompt identification of cardiac amyloidosis can facilitate the implementation of evolving therapeutic interventions to enhance the outcomes. The modalities for the management of CA have evolved significantly in the last ten years. Apart from therapies for modifying disease and heart failure, a myriad of novel therapeutic approaches that target specific aspects of the disease, including gene therapies, are being researched. These aim at impeding its progression and improving clinical outcomes. See also Figure 1(Fig. 1).

The value of the 12-lead electrocardiogram in the prediction of sudden cardiac death

Sudden cardiac death (SCD) can be caused by several clinical conditions, overt or misconceived, which recognize different pathophysiologies determining the development of fatal arrhythmic events. In the various forms of structural heart disease such as ischaemic heart disease, cardiomyopathies (e.g. hypertrophic cardiomyopathy, dilated cardiomyopathy, and arrhythmogenic cardiomyopathy), channelopathies (e.g. long-QT syndrome, congenital short QT, Brugada syndrome, early repolarization (ER) syndrome, and idiopathic ventricular fibrillation) but also in the apparently healthy subject, the 12-lead electrocardiogram (ECG) has proved, over the years, to be a reliable and readily available method for stratifying the risk of adverse arrhythmic events and consequently SCD. Several electrocardiographic markers have been shown to be associated with adverse outcomes in different types of patients. Although with different sensitivity and specificity in each clinical condition, depolarization abnormalities, such as QRS fragmentation, Q waves, QRS duration, left posterior fascicular block, low QRS voltage, and left ventricular hypertrophy and similarly repolarization abnormalities as ER pattern, T wave alternans, QT interval, and QT dispersion, have shown significant efficacy in predicting SCD. Despite the advancement of techniques especially in the field of imaging, the correct interpretation of the 12-lead ECG remains, therefore, an effective tool for assessing the possible prognostic outcome in terms of arrhythmic risk and SCD in different types of patients.

Echocardiographic phenotype for refined risk stratification and treatment selection in light chain amyloidosis with heart failure

AIMS

Light chain amyloidosis (AL) patients with heart failure (HF) are usually with revised Mayo (rMayo) stage III/IV disease and have a poor prognosis. We sought to investigate whether and what echocardiographic phenotype provides value for further risk stratification and guiding optimal risk-adapted treatment in this subgroup of AL patients.

METHODS AND RESULTS

95 AL patients who presented with HF and were on rMayo stage III/IV were retrospectively included. Of them, 51 patients (53.7%) were with stage III, 44 (46.3%) were with stage IV, and 44 (46.3%) underwent chemotherapy. Laboratory and echocardiographic measurements were acquired before the initiation of chemotherapy. The relevance of different variables with survival was assessed in the entire cohort, chemotherapy, and non-chemotherapy group. By Multivariate Cox regression analysis, right ventricular wall thickness (RVT) [HR 1.145, 95% confidence interval (CI) 1.026-1.279, P = 0.016], relative wall thickness (RWT) (HR 6.709, 95% CI 1.101-40.877, P = 0.039), and left ventricular ejection fraction (LVEF) < 50% (HR 1.939, 95% CI 1.048-3.590, P = 0.035) were found to be independently associated with survival in the entire cohort, RWT (HR 15.488, 95% CI 2.045-117.292, P = 0.008) in the non-chemotherapy group, and RVT (HR 1.331, 95% CI 1.054-1.681, P = 0.016) in the chemotherapy group, respectively. Kaplan-Meier survival analysis revealed that survival was significantly reduced in the presence of RVT ≥ 6.5 mm or LVEF < 50% in the entire cohort, and the significance of RVT ≥ 6.5 mm was irrespective of rMayo stages. In the chemotherapy group, survival was decreased if RVT ≥ 6.5 mm alone or together with RWT ≥ 0.67 were present, particularly in patients on rMayo stage IV.

CONCLUSIONS

Echocardiographic phenotype provides incremental value beyond rMayo staging for predicting survival and could further guide treatment in advanced AL with HF. Those with high-risk echocardiographic phenotypes as higher RVT and RWT and lower LVEF had a worse prognosis.

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.

[Current role of imaging techniques in cardiac amyloidosis]

Cardiac amyloidosis (CA) is an underdiagnosed disease and, if left untreated, rapidly fatal. Emerging therapies for CA increase the urgency of developing non-invasive diagnostic methods for its early detection and for monitoring therapeutic response. Classic imaging features on echocardiography and cardiac magnetic resonance, although typical for cardiac amyloidosis, are not specific enough to distinguish light chain amyloidosis from transthyretin. Myocardial bone-avid radiotracer uptake is highly specific for transthyretin cardiac amyloidosis when plasma cell dyscrasia has been excluded; it is now replacing the need for biopsy in many patients. Detection of early cardiac amyloidosis, quantitation of its burden, and assessment of response to therapy are important next steps for imaging to advance the evaluation and management of cardiac amyloidosis.

Bad players in AL amyloidosis in the current era of treatment

INTRODUCTION

Systemic AL amyloidosis (ALA) is a clonal plasma cell (PC) disease characterized by deposition of amyloid fibrils in different organs and tissues. Traditionally, the prognosis of ALA is poor and is primarily defined by cardiac involvement. The modern prognostic models are based on cardiac markers and free light chain difference (dFLC). Cardiac biomarkers have low specificity and are dependent on renal function, volume status, and cardiac diseases other than ALA. New therapies significantly improved the prognosis of the disease. The advancements in technologies - cardiac echocardiography (ECHO) and cardiac MRI (CMR), as well as new biological markers, relying on cardiac injury, inflammation, endothelial damage, and clonal and non-clonal PC markers are promising.

AREAS COVERED

An update on the prognostic significance of cardiac ALA, number of involved organs, response to treatment, including minimal residual disease (MRD), ECHO, MRI, and new biological markers will be discussed. The literature search was done in PubMed and Google Scholar, and the most recent and relevant data are included.

EXPERT OPINION

Prospective multicenter trials, evaluating multiple clinical and laboratory parameters, should be done to improve the risk assessment models in ALA in the modern era of therapy.

An echo score raises the suspicion of cardiac amyloidosis in Chinese with heart failure with preserved ejection fraction

AIMS

Transthyretin cardiac amyloidosis (ATTR-CA) has been realized as an important cause of heart failure with preserved ejection fraction (HFpEF). We aim to provide insights into its prevalence in Chinese HFpEF patients, which is not known to date, using increased wall thickness (IWT) score by echocardiography.

METHODS

Consecutive patients with HFpEF (EF ≥ 40%) and IWT (≥12 mm) were prospectively screened. Echocardiography was performed, and the IWT score incorporated relative wall thickness, E/e' ratio, longitudinal strains, and tricuspid annular plane systolic excursion, and septal apical-to-base ratio was calculated. ATTR-CA was defined as score ≥8 in the absence of serum and urine free light chain.

RESULTS

Six hundred twenty-four HFpEF patients from January 2019 to December 2021 were enrolled, of which 65.2% were males and the median (interquartile range [IQR]) age was 66 (IQR 57, 73) years. Thirty-three patients (5.3%, 95% CI 3.5-7.0%) were with score ≥8, and 33.3% were females. They were younger (58 vs. 69 years, P < 0.001), had higher NT-proBNP (6525.0 vs. 1741.5 pg/mL, P < 0.001) and troponin I (105.2 vs. 27.7 pg/mL, P = 0.001) level, and lower LVEF (47% vs. 57%, P < 0.001) compared with the patients with score <5. In the internal cohort (82 patients) who had undergone scintigraphy, the IWT score ≥8 was shown to have a sensitivity of 85.7% (95% CI 56.2-97.5%) and a specificity of 92.6% (95% CI 83.0-97.3%) for diagnosing CA, and the IWT score <5 had great accuracy in excluding CA with the negative predictive value of 100%, supporting the clinical usefulness of the IWT score to guide further dedicated testing for ATTR-CA.

CONCLUSIONS

The IWT score by echocardiography was an excellent tool for screening ATTR-CA in HFpEF. In Chinese HFpEF patients associated with a hypertrophic phenotype, the proportion of highly suspected ATTR-CA as detected by IWT score ≥8 was 5.3%, lower than the reported prevalence of ATTR-CA in non-Asian patients with the disease.

Red flags for the diagnosis of cardiac amyloidosis: simple suggestions to raise suspicion and achieve earlier diagnosis

Cardiac amyloidosis is an infiltrative disease characterized by extracellular deposition of insoluble amyloid fibrils in the heart leading to organ dysfunction. Despite recent diagnostic advances, the diagnosis of cardiac amyloidosis is often delayed or even missed. Furthermore, a long diagnostic delay is associated with adverse outcomes, with the early diagnosed patients showing the longest survival. In this narrative review we aimed to summarize the 'red flags' that may facilitate the correct diagnosis. The red flags may be classified as clinical, biohumoral, electrocardiographic, echocardiographic, and cardiac magnetic resonance features and should promptly raise the suspicion of cardiac amyloidosis in order to start a correct diagnostic pathway and targeted treatment strategies that may improve patients' outcomes.

Echocardiography in the Diagnosis of Cardiomyopathies: Current Status and Future Directions

Cardiomyopathies are a challenging pathology and echocardiography is essential for diagnosis and prognosis. The most frequent cardiomyopathies are the dilated cardiomyopathy (DCM) and the hypertrophic cardiomyopathy (HCM), followed by the less frequent restrictive (RCM) and arrhythmogenic right ventricle cardiomyopathies (ARVC). Echocardiography can identify diagnostic features, and guide further testing for a definitive diagnosis. Echographic parameters are involved in risk score computing and prognosis assessment. While the most prevalent hallmark of HCM is the asymmetric left ventricular hypertrophy and systolic anterior motion of the mitral valve with the obstructive phenotype, DCM shows dilated left ventricle with different degrees of systolic dysfunction, and RCM is usually characterized by undilated ventricles associated with atrial enlargement. The aim of this review is to display and compare the most frequent cardiomyopathies encountered in clinical practice and highlight their most characteristic features in a useful way for the practicing clinician.

Cardiac Manifestations of Myotonic Dystrophy in a Pediatric Cohort

Myotonic dystrophy type 1 (DM1) is the most prevalent inherited neuromuscular dystrophy in adults. It is a multisystem disease with cardiac manifestations. Whilst these are well-defined in adults, there are scarce published data in the pediatric population. This study aimed to investigate the yield and progression of cardiac disease in pediatric DM1 patients, focusing on congenital DM1 (cDM1).

Methods

A retrospective observational study of all pediatric DM1 patients referred to our center (December 2000-November 2020) was conducted. Patients were classified into DM1 forms according to age of symptom onset and disease severity. Patients underwent clinical and cardiac evaluation with 12-lead ECG, transthoracic echocardiography and 24-h ECG Holter monitoring.

Results

67 DM1 pediatric patients were included: 56 (83.6%) cDM1 and 11 (16.4%) non-cDM1. Median follow-up time of cDM1 patients was 8.0 [3.25-11.0] years. 49 (87.5%) cDM1 patients had baseline 12-lead ECG and 44 (78.6%) had a follow-up 12-lead-ECG, with a median follow-up time from diagnosis to baseline ECG of 2.8 [1.0-8.5] years and to follow-up ECG of 10.9 [5.7-14.2] years. Overall, 43 (87.8%) presented ECG abnormalities, most commonly in the form of asymptomatic conduction disease (n = 23, 46.9%), of which 21 (42.9%) had first degree atrioventricular block (1st AVB). There was an increase of prevalence from baseline to follow-up ECG in low QRS voltage (16.7%), poor R wave progression (13.9%), abnormal repolarisation (11.9%) and 1st AVB (7.6%). one patient (1.8%) underwent pacemaker implantation for syncope in the context of progressive conduction disease. No patients developed left ventricular systolic dysfunction. 4 (7.1%) cDM1 patients died during follow up, including three who died suddenly with no clear cause of death.

Conclusions

This study is the first to analyse the prevalence and progression of ECG abnormalities in cDM1 pediatric patients. The high prevalence of abnormal findings, progressive changes and number of potentially associated events (1 pacemaker implantation and 3 unexplained sudden deaths) stresses the importance of systematic and continued cardiac evaluation of these patients.

Utility and pitfalls of the electrocardiogram in the evaluation of cardiac amyloidosis

BACKGROUND

Cardiac amyloidosis is a protein misfolding disorder involving deposition of amyloid fibril proteins in the heart. The associated fibrosis of the conduction tissue results in conduction abnormalities and arrhythmias. "Classical" electrocardiogram (ECG) findings in cardiac amyloidosis include that of low voltage complexes with increased left ventricular wall thickness on echocardiography. However, this "classical" finding is neither sensitive nor specific. As cardiac amyloidosis is associated with a generally poor prognosis, the need for early recognition of this disease is important given the availability of new treatment options. In this review, we highlight 3 cases of patients with cardiac amyloidosis. Although presenting with typical clinical signs and symptoms, ECG for all 3 patients was not consistent with the classical findings described. They underwent further diagnostic tests which clinched the diagnosis of cardiac amyloidosis, allowing patients to receive targeted treatment. Through the review of the literature, we will highlight the different ECG patterns in patients with different types of cardiac amyloidosis and clinical scenarios, as well as the pitfalls of using ECG to identify the condition. Lastly, we also emphasize the current paradigms in diagnosing cardiac amyloidosis through the non-invasive methods of echocardiography, cardiac magnetic resonance imaging, and nuclear technetium-pyrophosphate imaging.

CONCLUSIONS

Electrocardiogram is often the first investigation used in evaluating many cardiac disorders, including cardiac amyloidosis. However, classical features of cardiac amyloidosis on ECG are often not present. A keen understanding on the ECG features of cardiac amyloidosis and knowledge of the diagnostic workflow is important to diagnose this condition.

New Advanced Imaging Parameters and Biomarkers-A Step Forward in the Diagnosis and Prognosis of TTR Cardiomyopathy

Transthyretin amyloid cardiomyopathy (ATTR-CM) is an infiltrative disorder characterized by extracellular myocardial deposits of amyloid fibrils, with poor outcome, leading to heart failure and death, with significant treatment expenditure. In the era of a novel therapeutic arsenal of disease-modifying agents that target a myriad of pathophysiological mechanisms, timely and accurate diagnosis of ATTR-CM is crucial. Recent advances in therapeutic strategies shown to be most beneficial in the early stages of the disease have determined a paradigm shift in the screening, diagnostic algorithm, and risk classification of patients with ATTR-CM. The aim of this review is to explore the utility of novel specific non-invasive imaging parameters and biomarkers from screening to diagnosis, prognosis, risk stratification, and monitoring of the response to therapy. We will summarize the knowledge of the most recent advances in diagnostic, prognostic, and treatment tailoring parameters for early recognition, prediction of outcome, and better selection of therapeutic candidates in ATTR-CM. Moreover, we will provide input from different potential pathways involved in the pathophysiology of ATTR-CM, on top of the amyloid deposition, such as inflammation, endothelial dysfunction, reduced nitric oxide bioavailability, oxidative stress, and myocardial fibrosis, and their diagnostic, prognostic, and therapeutic implications.

Clinical Clues and Diagnostic Workup of Cardiac Amyloidosis

Cardiac amyloidosis is increasingly recognized as an underlying cause of left ventricular wall thickening, heart failure, and arrhythmia with variable clinical presentation. Due to the subtle cardiac findings in early transthyretin cardiac amyloidosis and the availability of therapies that can modify but not reverse the disease progression, early recognition is vital. In light chain amyloidosis, timely diagnosis and treatment can significantly improve survival. In this manuscript, we review the clinical, imaging, and electrocardiographic clues that should raise suspicion for cardiac amyloidosis and provide a simplified diagnostic workup algorithm that ensures an accurate diagnosis. The evolution of the noninvasive diagnosis of cardiac amyloidosis has significantly influenced our understanding of disease prevalence, presentations, and outcomes. However, clinical recognition of clues and red flags remains the most important factor in advancing the care of patients with cardiac amyloidosis.

A Risk Score to Diagnose Cardiac Involvement and Provide Prognosis Information in Patients at Risk of Cardiac Light-Chain Amyloidosis

Background

Cardiac light-chain amyloidosis (AL CA) portends poor prognosis. Contrast cardiac magnetic resonance (CMR) with late gadolinium enhancement (LGE) imaging is an important tool in recognizing AL CA. But contraindications to contrast CMR would significantly restrict its clinical application value. Our study aims to construct a convenient risk score to help identify cardiac involvement in patients at risk of AL CA. Moreover, we also investigate whether this risk score could provide prognosis information.

Materials and Methods

Sixty-three patients at risk of AL CA were retrospectively included in our study. Basic clinical characters, lab results, 12-lead electrocardiogram data, and cardiac magnetic resonance image data were collected. AL CA was diagnosed according to typical CA LGE pattern. Logistic analysis was used to figure out predictive parameters of AL CA and their β coefficients, further constructing the risk score. Receiver operating characteristics (ROC) curve was used to find the cut-off point best distinguishing AL CA+ from AL CA–patients. Bootstrapping was used for internal validation. All patients were divided into high-risk and low-risk group according to the diagnostic cut-off point, and followed up for survival information. Kaplan-Meier plots and log-rank test were performed to analyze if this score had prognostic value.

Results

The risk score finally consisted of 4 parameters: pericardial effusion (PE) (1 point), low electrocardiographic QRS voltages (LQRSV) (1 point), CMR-derived impaired global radial strain (GRS) (<15.14%) (1 point) and increased left ventricular maximum wall thickness (LVMWT) (>13 mm) (2 points). Total score ranged from 0 to 5 points. A cut-off point of 1.5 showed highest accuracy in diagnosing AL CA with an AUC of 0.961 (95% CI: 0.924–0.997, sensitivity: 90.6%, specificity: 83.9%). Kaplan-Meier plots and log-rank test showed that the high-risk group had significantly poor overall survival rates.

Conclusion

In patients at risk of AL CA, a risk score incorporating the presence of PE, LQRSV, and CMR-derived impaired GRS and increased LVMWT is predictive of a diagnosis of AL CA by LGE criteria. This risk score may be helpful especially when contrast CMR is not available or contraindicated, and further studies should be considered to validate this score.

Prevalence and clinical significance of isolated low QRS voltages in young athletes

AIMS

Low QRS voltages (peak to peak <0.5 mV) in limb leads (LQRSV) on the athlete's electrocardiogram (ECG) may reflect an underlying cardiomyopathy, mostly arrhythmogenic cardiomyopathy (ACM) or non-ischaemic left ventricular scar (NILVS). We studied the prevalence and clinical meaning of isolated LQRSV in a large cohort of competitive athletes.

METHODS AND RESULTS

The index group included 2229 Italian competitive athletes [median age 18 years (16-25), 67% males, 97% Caucasian] without major ECG abnormalities at pre-participation screening. Three control groups included Black athletes (N = 1115), general population (N = 1115), and patients with ACM or NILVS (N = 58). Echocardiogram was performed in all athletes with isolated LQRSV and cardiac magnetic resonance (CMR) in those with ventricular arrhythmias or echocardiographic abnormalities. The isolated LQRSV pattern was found in 1.1% index athletes and was associated with increasing age (median age 28 vs. 18 years; P < 0.001), elite status (71% vs. 34%; P < 0.001), body surface area, and body mass index but not with sex, type of sport, and echocardiographic left ventricular mass. The prevalence of isolated LQRSV was 0.2% in Black athletes and 0.3% in young individuals from the general population. Cardiomyopathy patients had a significantly greater prevalence of isolated LQRSV (12%) than index athletes, Black athletes, and general population. Five index athletes with isolated LQSRV and exercise-induced ventricular arrhythmias underwent CMR showing biventricular ACM in 1 and idiopathic NILVS in 1.

CONCLUSIONS

Unlike cardiomyopathy patients, the ECG pattern of isolated LQRSV was rarely observed in athletes. This ECG sign should prompt clinical work-up for exclusion of an underlying cardiomyopathy.

Diagnostic Tools for Cardiac Amyloidosis: A Pragmatic Comparison of Pathology, Imaging and Laboratories

Cardiac amyloidosis (CA) is a complex disease considered to be the most common underdiagnosed form of restrictive cardiomyopathy. Accumulation of misfolded proteins called amyloid fibrils in the extracellular space results in clinical deterioration and late diagnosis is associated with morbidity and mortality. Both types of this disease, light chain CA and transthyretin-related CA share many cardiac and extracardiac features that compromise multiple organs such as kidneys, musculoskeletal system, autonomic nervous system, and gastrointestinal tract. Early diagnosis and detection of CA are imperative. Clinicians should maintain a high degree of suspicion among patients with unexplained diastolic heart failure to implement different disease-altering therapies at the early stages of the disease. In this article, we provided a comprehensive review of multiple invasive and non-invasive cardiac imaging modalities with their respective degrees of sensitivities and specificity.

Cardiac Amyloidosis: A Review of Current Imaging Techniques

Systemic amyloidosis is a rare, heterogenous group of diseases characterized by extracellular infiltration and deposition of amyloid fibrils. Cardiac amyloidosis (CA) occurs when these fibrils deposit within the myocardium. Untreated, this inevitably leads to progressive heart failure and fatality. Historically, treatment has remained supportive, however, there are now targeted disease-modifying therapeutics available to patients with CA. Advances in echocardiography, cardiac magnetic resonance (CMR) and repurposed bone scintigraphy have led to a surge in diagnoses of CA and diagnosis at an earlier stage of the disease natural history. CMR has inherent advantages in tissue characterization which has allowed us to better understand the pathological disease process behind CA. Combined with specialist assessment and repurposed bone scintigraphy, diagnosis of CA can be made without the need for invasive histology in a significant proportion of patients. With existing targeted therapeutics, and novel agents being developed, understanding these imaging modalities is crucial to achieving early diagnosis for patients with CA. This will allow for early treatment intervention, accurate monitoring of disease course over time, and thereby improve the length and quality of life of patients with a disease that historically had an extremely poor prognosis. In this review, we discuss key radiological features of CA, focusing on the two most common types; immunoglobulin light chain (AL) and transthyretin (ATTR) CA. We highlight recent advances in imaging techniques particularly in respect of their clinical application and utility in diagnosis of CA as well as for tracking disease change over time.

Electrocardiogram Characteristics and Prognostic Value in Light-Chain Amyloidosis: A Comparison With Cardiac Magnetic Resonance Imaging

Background: An electrocardiogram (ECG) is a simple and cheap non-invasive tool that shows various abnormalities and has prognostic value for patients with light-chain amyloidosis (AL). The present study aimed to explore the association between ECG characteristics and cardiac magnetic resonance (CMR)-detected amyloid burden and to investigate the prognostic value of ECG in AL amyloidosis.

Methods: We prospectively enrolled 99 patients with AL amyloidosis (56 male patients; median age, 58 y). Detailed clinical information, 12-lead ECG, and CMR data were collected. All patients were followed up longitudinally, and the endpoint was all-cause mortality. ECG characteristics were analyzed and correlated with the degree of late gadolinium enhancement (LGE) and extracellular volume (ECV) by T1 mapping on CMR. The prognostic value of ECG characteristics was analyzed using Kaplan–Meier survival analysis and multivariate Cox regression.

Results: During a median follow-up period of 33 months, 69 of the 99 patients died. Fragmented Q wave-R wave-S wave (QRS), pathological Q waves, the Sokolow index, QRS duration, and voltages were significantly associated with the extent of LGE, native T1, and ECV by CMR (p < 0.05). Fragmented QRS and Sokolow index showed independent prognostic value in AL amyloidosis (p = 0.001; p = 0.026, respectively). Fragmented QRS remained independent after adjusting for clinical values (hazard ratio: 2.034; 95% confidence interval: 1.148–3.603; p = 0.015). However, no ECG characteristics were independent predictors for prognosis in AL amyloidosis when LGE and ECV were included in the multivariate analysis.

Conclusion: ECG abnormalities showed significant association with CMR indicators of amyloid burden. Fragmented QRS has an independent prognostic value in AL amyloidosis and could be used as an alternative marker when CMR is not available.

A Case Report of Cardiac Amyloidosis Highlighting the Importance of Strain Analysis

Cardiac involvement in light-chain (AL) amyloidosis has a high mortality. Once cardiac symptoms are present, it is important to make a diagnosis as there is an inverse relationship between mortality and time of diagnosis. Echocardiography is usually one of the first tests performed. But strain analysis, which can provide important clues, is not routinely performed. This is a case of AL amyloidosis presenting with heart failure in which echocardiographic strain analysis was vital for its diagnosis.

Electrocardiographic left ventricular strain pattern, ST-segment depression and atrial fibrillation at the time of diagnosis of systemic light chain amyloidosis: Incidence and clinical significance

BACKGROUND

ST/T abnormalities recognized as electrocardiographic (ECG) left ventricular (LV) strain pattern are known as a marker of myocyte death and reduced survival. The purpose of this study was to determine whether ECG LV strain pattern, its components and atrial fibrillation (AF) predict lower survival at the time of diagnosis of systemic light chain (AL) amyloidosis.

METHODS

12‑lead surface electrocardiogram (ECG), standard two-dimensional echocardiography, laboratory analyses were retrospectively evaluated within 2 months of diagnosis in 87 patients with biopsy-proven systemic AL amyloidosis from 2009 to 2017 in a single center. ECG strain pattern was defined as coexistence of ST-segment horizontal or downward sloping depression ≥0.05 mV at its most horizontal section and negative asymmetrical T-wave deeper than 0.1 mV in at least 1 of leads I,aVL,V1-V6. Patients with QRS >120 ms (BBB or major IVCD) were excluded from the analysis.

RESULTS

Kaplan-Meier survival analysis revealed a 1.8-fold shorter overall survival (OS) at 2 years in the ECG strain (21% of participants) group (p = 0.0078), 2.0-fold shorter OS in the ST-segment depression (STd) (isolated and strain related as one group) (34% of participants) group (p < 0.0001), and 3.9-fold shorter OS in AF (23% of participants) group (p < 0.0001) compared with those without. Median survival of patients with STd and AF were and 13.0 (range 1-74) and 9.5 (range 1-74) months respectively. In univariate analysis STd and AF were stronger predictors of inferior OS than relative wall thickness, average E/e' ratio, and LV ejection fraction, but weaker predictors of OS than B-type natriuretic peptide. In multivariate analysis STd and AF lost significance after adjustment for age, gender, number of organs involved and BNP.

CONCLUSIONS

ST-segment depression and AF were not significantly associated with reduced survival in AL amyloidosis at diagnosis.

Cardiac Amyloidosis: Presentations, Diagnostic Work-up and Collaborative Approach for Comprehensive Clinical Management

Cardiac amyloidosis is a systemic disease characterized by continuous deposition of misfolded proteins called amyloid fibrils in the extracellular space which result in restrictive cardiomyopathy. The most common form of cardiac amyloidosis is light chain (AL) cardiac amyloidosis, a result of continuous deposition of misfolded monoclonal immunoglobulin light chains. Transthyretin-related cardiac amyloidosis (ATTR) results from a point mutation in the transthyretin gene in an autosomal dominant fashion and presents phenotypically similar to AL cardiac amyloidosis. Cardiac amyloidosis is being increasingly recognized due to the advancements in diagnostic cardiac imaging and pharmacotherapy. Clinicians should maintain a high index of suspicion among patients with unexplained diastolic heart failure because earlier diagnosis will allow for the implementation of disease-altering therapy. With established targeted drug therapies and further breakthroughs in immunotherapy, the potential impact of diagnostic and therapeutic advancements on morbidity and mortality of patients with cardiac amyloidosis is promising.

Electrocardiogram Criteria to Diagnose Cardiac Amyloidosis in Men With a Bundle Branch Block

Diagnosing cardiac amyloidosis is challenging and requires a high index of suspicion in patients with an increased left ventricular wall thickness (LVWT). Low QRS voltage on electrocardiogram (ECG) has been regarded as the hallmark ECG finding in cardiac amyloidosis; however, the presence of low voltage can range from 20-74% and the voltage/mass ratio carries a greater diagnostic accuracy than QRS voltage alone. Patients with cardiac amyloidosis can have conduction system infiltration and this may result in a BBB. Therefore, the ECG or mass/voltage criteria established for patients with a narrow QRS in the diagnosis of cardiac amyloidosis may not be applicable in patients with a BBB. We sought to identify criteria to aid in the diagnosis of cardiac amyloidosis in patients with increased LVWT on echocardiogram and with a BBB on ECG. We calculated the total QRS score/LVWT, limb lead QRS score/LVWT, R in lead aVL/LVWT, R in lead I/LVWT, and Sokolow index/LVWT. In patients with an increase in LVWT and BBB, total QRS voltage that is indexed to wall thickness can help distinguish between patients with increased wall thickness who have cardiac amyloidosis from those who have LVH related to a pressure overload state. A unique index of Total QRS Score/LVWT is the best predictor of cardiac amyloidosis with a cutoff value of 92.5 mV/cm which is 100% sensitive and 83% specific for the diagnosis of cardiac amyloidosis. This may be a useful screening tool in patients with an increased wall thickness to raise diagnostic suspicion for cardiac amyloidosis.

Hypertrophic Cardiomyopathy and Primary Restrictive Cardiomyopathy: Similarities, Differences and Phenocopies

Hypertrophic cardiomyopathy (HCM) and primary restrictive cardiomyopathy (RCM) have a similar genetic background as they are both caused mainly by variants in sarcomeric genes. These “sarcomeric cardiomyopathies” also share diastolic dysfunction as the prevalent pathophysiological mechanism. Starting from the observation that patients with HCM and primary RCM may coexist in the same family, a characteristic pathophysiological profile of HCM with restrictive physiology has been recently described and supports the hypothesis that familiar forms of primary RCM may represent a part of the phenotypic spectrum of HCM rather than a different genetic cardiomyopathy. To further complicate this scenario some infiltrative (amyloidosis) and storage diseases (Fabry disease and glycogen storage diseases) may show either a hypertrophic or restrictive phenotype according to left ventricular wall thickness and filling pattern. Establishing a correct etiological diagnosis among HCM, primary RCM, and hypertrophic or restrictive phenocopies is of paramount importance for cascade family screening and therapy.

Cardiac Amyloidosis for the Primary Care Provider: A Practical Review to Promote Earlier Recognition of Disease

Cardiac amyloidosis is increasingly recognized as an underdiagnosed cause of heart failure. Diagnostic delays of up to 3 years from symptom onset may occur, and patients may be evaluated by more than 5 specialists prior to receiving the correct diagnosis. Newly available therapies improve clinical outcomes by preventing amyloid fibril deposition and are usually more effective in early stages of disease, making early diagnosis essential. Better awareness among primary care providers of the clinical presentation and modern treatment landscape is essential to improve timely diagnosis and early treatment of this disease. In this review, we provide practical guidance on the epidemiology, clinical manifestations, diagnostic evaluation, and treatment of transthyretin and light chain cardiac amyloidosis to promote earlier disease recognition among primary care providers.

Clinical approach to genetic testing in amyloid cardiomyopathy: from mechanism to effective therapies

PURPOSE OF REVIEW

To highlight the evolving understanding of genetic variants, utility of genetic testing, and the selection of novel therapies for cardiac amyloidosis.

RECENT FINDINGS

The last decade has seen considerable progress in cardiac amyloidosis recognition given the advancement in cardiac imaging techniques and widespread availability of genetic testing. A significant shift in the understanding of a genetic basis for amyloidosis has led to the development of disease-modifying therapeutic strategies that improve survival.

SUMMARY

The systemic amyloidoses are disorders caused by extracellular deposition of misfolded amyloid fibrils in various organs. Immunoglobulin light-chain or transthyretin amyloidosis are the most common types associated with cardiac manifestations. Genetic testing plays a central role in the identification of genotypes that are associated with different clinical phenotypes and influence prognosis. Given the emergence of effective therapies, a systematic approach to the diagnosis of cardiac amyloidosis, with the elucidation of genotype when indicated, is essential to select the appropriate treatment.

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.

Cardiac amyloidosis-A review of current literature for the practicing physician

The amyloidoses are a family of diseases in which misfolded precursor proteins aggregate to form amyloid and deposit in body tissues. A very serious yet underrecognized form of this disease is cardiac amyloidosis, in which amyloid deposits into the extracellular space of the myocardium, resulting in thickening and stiffening of ventricular walls with resultant heart failure and conductive dysfunction. This review provides a discussion of the pathogenesis and clinical presentation of cardiac amyloidosis subtypes, as well as an up-to-date approach to diagnosis and treatment. Significant progress has been made in recent years regarding diagnosis and treatment of this condition, but prognosis remains heavily reliant on early detection of the disease. Two types of precursor protein are responsible for most cardiac amyloidosis cases: transthyretin amyloid, and immunoglobulin-derived light chain amyloid. An early diagnosis of cardiac amyloidosis can allow for novel treatment modalities to be initiated with the potential to improve prognosis.

Keys to early diagnosis of cardiac amyloidosis: red flags from clinical, laboratory and imaging findings

Cardiac involvement in systemic amyloidosis, due either to immunoglobulin light-chain or transthyretin amyloidosis, influences clinical presentation and is a strong predictor of unfavourable outcome. Until recently considered as a rare, incurable disease, cardiac amyloidosis, is still mis/underdiagnosed, although treatments effective in improving patient survival are now available for both subtypes, including chemotherapy regimens for immunoglobulin light-chain amyloidosis and tetramer stabiliser for transthyretin amyloidosis. Achieving a timely diagnosis allows initiating life-saving therapies and requires the early recognition of clinical, laboratory and imaging signs of cardiac involvement, some of them may be apparent well before the disease becomes clinically manifest. Given the systemic nature of amyloidosis, a close interaction among experts in multiple specialties is also required, including cardiologists, nephrologists, haematologists, neurologists, radiologists, nuclear medicine specialists and internists. As an increased awareness about disease presentation is required to ameliorate diagnostic performance, we aim to provide the clinician with a guide to the screening and early diagnosis of cardiac amyloidosis, and to review the clinical, biohumoral and instrumental ‘red flags’ that should raise the suspicion of cardiac amyloidosis.

Diagnostic and prognostic value of low QRS voltages in cardiomyopathies: old but gold

The interpretation of 12-lead resting electrocardiogram (ECG) in patients with a definitive diagnosis or with the suspicion of a cardiomyopathy represents a cornerstone for the diagnostic work up and management of patients. Although low electrocardiographic QRS voltages (LQRSV) detected by 12-lead resting ECG have historically been acknowledged by physicians, in view of recent evidence on the demonstration of myocardial scar by cardiac magnetic resonance and its relevance as a cause of sudden cardiac death even in young individuals, a new interest has been raised about the utility of LQRSV in the clinical practice. Beyond their diagnostic value, LQRSV have also demonstrated a prognostic role in different cardiomyopathies. The present review summarizes the diagnostic and prognostic value of LQRSV in cardiomyopathies, reporting the new evidence, primarily based on advanced imaging studies, supporting the clinical utility of this parameter.

Indexed left ventricular mass to QRS voltage ratio is associated with heart failure hospitalizations in patients with cardiac amyloidosis

In cardiac amyloidosis (CA), amyloid infiltration results in increased left ventricular (LV) mass disproportionate to electrocardiographic (EKG) voltage. We assessed the relationship between LV mass-voltage ratio with subsequent heart failure hospitalization (HHF) and mortality in CA. Patients with confirmed CA and comprehensive cardiovascular magnetic resonance (CMR) and EKG exams were included. CMR-derived LV mass was indexed to body surface area. EKG voltage was assessed using Sokolow, Cornell, and Limb-voltage criteria. The optimal LV mass-voltage ratio for predicting outcomes was determined using receiver operating characteristic curve analysis. The relationship between LV mass-voltage ratio and HHF was assessed using Cox proportional hazards analysis adjusting for significant covariates. A total of 85 patients (mean 69 ± 11 years, 22% female) were included, 42 with transthyretin and 43 with light chain CA. At a median of 3.4-year follow-up, 49% of patients experienced HHF and 60% had died. In unadjusted analysis, Cornell LV mass-voltage ratio was significantly associated with HHF (HR, 1.05; 95% CI 1.02-1.09, p = 0.001) and mortality (HR, 1.05; 95% CI 1.02-1.07, p = 0.001). Using ROC curve analysis, the optimal cutoff value for Cornell LV mass-voltage ratio to predict HHF was 6.7 gm/m2/mV. After adjusting for age, NYHA class, BNP, ECV, and LVEF, a Cornell LV mass-voltage ratio > 6.7 gm/m2/mV was significantly associated with HHF (HR 2.25, 95% CI 1.09-4.61; p = 0.03) but not mortality. Indexed LV mass-voltage ratio is associated with subsequent HHF and may be a useful prognostic marker in cardiac amyloidosis.

Pittsburgh B Compound Positron Emission Tomography in Patients With AL Cardiac Amyloidosis

BACKGROUND

It remains unknown whether the noninvasive evaluation of the degree of amyloid deposition in the myocardium can predict the prognosis of patients with light chain (AL) cardiac amyloidosis.

OBJECTIVES

The purpose of this study was to demonstrate that ¹¹C-Pittsburgh B compound positron emission tomography (¹¹C-PiB PET) is useful for prognostication of AL cardiac amyloidosis by noninvasively imaging the myocardial AL amyloid deposition.

METHODS

This study consecutively enrolled 41 chemotherapy-naïve AL cardiac amyloidosis patients. The amyloid deposit was quantitatively assessed with amyloid P immunohistochemistry in endomyocardial biopsy specimens and was compared with the degree of myocardial ¹¹C-PiB uptake on PET. The primary endpoint was a composite of all-cause death, heart transplantation, and acute decompensated heart failure.

RESULTS

The degree of myocardial ¹¹C-PiB PET uptake was significantly higher in the cardiac amyloidosis patients compared with normal subjects and correlated well with the degree of amyloid deposit on histology (R² = 0.343, p < 0.001). During follow-up (median: 423 days, interquartile range: 93 to 1,222 days), 24 patients experienced the primary endpoint. When the cardiac amyloidosis patients were divided into tertiles by the degree of myocardial ¹¹C-PiB PET uptake, patients with the highest PiB uptake experienced the worst clinical event-free survival (log-rank p = 0.014). The degree of myocardial PiB PET uptake was a significant predictor of clinical outcome on multivariate Cox regression analysis (adjusted hazard ratio: 1.185; 95% confidence interval: 1.054 to 1.332; p = 0.005).

CONCLUSIONS

These proof-of-concept results show that noninvasive evaluation of myocardial amyloid load by ¹¹C-PiB PET reflects the degree of amyloid deposit and is an independent predictor of clinical outcome in AL cardiac amyloidosis patients.

Prognosis and Staging of AL Amyloidosis

The treatment options for systemic light chain amyloidosis (AL) are currently widening in an unprecedented way, brought about by an expanding arsenal of anti-myeloma therapy as well as by novel approaches to target toxic light chains and, most recently, deposited amyloid directly. In this context, accurate estimates of prognosis in AL, which allow for reliable patient advice and for example comparison of different therapies, are particularly important to clinicians. Some biomarkers and especially the genetic background of the underlying clonal disease as evaluated by interphase fluorescence in situ hybridization even have predictive value, enabling an appropriate treatment selection. Derived from the most frequently involved organs in AL, heart and kidney, this review focuses on overall survival and renal survival. A comprehensive overview and summary of reported prognostic factors and biomarkers in AL is given and the most important and validated factors are highlighted. Finally, established staging systems in AL as well as validated and perspective response criteria are presented.

Diagnosis and Treatment of Cardiac Amyloidosis Related to Plasma Cell Dyscrasias

Light chain amyloidosis is a deadly disease in which a monoclonal plasma cell dyscrasia produces misfolded immunoglobulin light chains (AL) that aggregate and form rigid amyloid fibrils. The amyloid deposits infiltrate one or more organs, leading to injury and severe dysfunction. The degree of cardiac involvement is a major driver of morbidity and mortality. Early diagnosis and treatment are crucial to prevent irreversible end-organ damage and improve overall survival. Treatment of AL cardiac amyloidosis involves eliminating the underlying plasma cell dyscrasia with chemotherapy and pursuing supportive heart failure management.

Fundamentals of Light Chain Cardiac Amyloidosis: A Focused Review

The estimated prevalence of AL CA in the US is approximately 8-12 cases per million. Almost 30-50% diagnosed cases of AL amyloid in the US have multisystem involvement, including cardiac involvement. Even with the availability of advanced diagnostic testing and novel therapies, prognosis remains poor. It is overlooked as a cause of heart failure with preserved ejection fraction leading to a delay in diagnosis when management options are limited and associated with poor survival outcomes. Therefore, the education of physicians is needed to ensure that it would be highly considered as a differential diagnosis. The purpose of this manuscript is to review the advances in the diagnosis and management of cardiac amyloidosis with the aim of educating colleagues who provide care in the primary care setting. We have summarized the pathogenesis of amyloidosis, its association with plasma cell dyscrasias, novel diagnostic and surveillance approaches including echocardiography, cardiovascular magnetic resonance imaging, histopathologic techniques, systemic biomarkers, and advanced treatment approaches including supportive symptomatic management and standard of care chemotherapy targeting the amyloid deposits. Given the overall poor prognosis of amyloidosis, we have also discussed the role of palliative and hospice care.

Sequence variants with large effects on cardiac electrophysiology and disease

Features of the QRS complex of the electrocardiogram, reflecting ventricular depolarisation, associate with various physiologic functions and several pathologic conditions. We test 32.5 million variants for association with ten measures of the QRS complex in 12 leads, using 405,732 electrocardiograms from 81,192 Icelanders. We identify 190 associations at 130 loci, the majority of which have not been reported before, including associations with 21 rare or low-frequency coding variants. Assessment of genes expressed in the heart yields an additional 13 rare QRS coding variants at 12 loci. We find 51 unreported associations between the QRS variants and echocardiographic traits and cardiovascular diseases, including atrial fibrillation, complete AV block, heart failure and supraventricular tachycardia. We demonstrate the advantage of in-depth analysis of the QRS complex in conjunction with other cardiovascular phenotypes to enhance our understanding of the genetic basis of myocardial mass, cardiac conduction and disease.

Aberrant morphology of the QRS complex in an electrocardiogram can be associated with cardiac morbidity and mortality. Here, the authors perform genome-wide association studies for ten measures of the QRS complex in 81,192 individuals and find 86 previously unreported loci that associate with at least one parameter.

Noninvasive Mapping of the Electrophysiological Substrate in Cardiac Amyloidosis and Its Relationship to Structural Abnormalities

Background

The relationship between structural pathology and electrophysiological substrate in cardiac amyloidosis is unclear. Differences between light‐chain (AL) and transthyretin (ATTR) cardiac amyloidosis may have prognostic implications.

Methods and Results

ECG imaging and cardiac magnetic resonance studies were conducted in 21 cardiac amyloidosis patients (11 AL and 10 ATTR). Healthy volunteers were included as controls. With respect to ATTR, AL patients had lower amyloid volume (51.0/37.7 versus 73.7/16.4 mL, P=0.04), lower myocardial cell volume (42.6/19.1 versus 58.5/17.2 mL, P=0.021), and higher T1 (1172/64 versus 1109/80 ms, P=0.022) and T2 (53.4/2.9 versus 50.0/3.1 ms, P=0.003). ECG imaging revealed differences between cardiac amyloidosis and control patients in virtually all conduction‐repolarization parameters. With respect to ATTR, AL patients had lower epicardial signal amplitude (1.07/0.46 versus 1.83/1.26 mV, P=0.026), greater epicardial signal fractionation (P=0.019), and slightly higher dispersion of repolarization (187.6/65 versus 158.3/40 ms, P=0.062). No significant difference between AL and ATTR patients was found using the standard 12‐lead ECG. T1 correlated with epicardial signal amplitude (cc=−0.78), and extracellular volume with epicardial signal fractionation (cc=0.48) and repolarization time (cc=0.43). Univariate models based on single features from both cardiac magnetic resonance and ECG imaging classified AL and ATTR patients with an accuracy of 70% to 80%.

Conclusions

In this exploratory study cardiac amyloidosis was associated with ventricular conduction and repolarization abnormalities, which were more pronounced in AL than in ATTR. Combined ECG imaging–cardiac magnetic resonance analysis supports the hypothesis that additional mechanisms beyond infiltration may contribute to myocardial damage in AL amyloidosis. Further studies are needed to assess the clinical impact of this approach.

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.

Prevalence of cardiac amyloidosis among adult patients referred to tertiary centres with an initial diagnosis of hypertrophic cardiomyopathy

BACKGROUND

Differential diagnosis of genetic causes of left ventricular hypertrophy (LVH) is crucial for disease-specific therapy. We aim to describe the prevalence of Cardiac Amyloidosis (CA) among patients ≥40 years with an initial diagnosis of HCM referred for second opinion to national cardiomyopathy centres.

METHODS

Consecutive patients aged ≥40 years referred with a tentative HCM diagnosis in the period 2014-2017 underwent clinical evaluation and genetic testing for HCM (including trans-thyretin-TTR). Patients with at least one red flag for CA underwent blood/urine tests, abdominal fat biopsy and/or bone-scintigraphy tracing and eventually ApoAI sequencing.

RESULTS

Out of 343 patients (age 60 ± 13 years), 251 (73%) carried a likely/pathogenic gene variant, including 12 (3.5%) in the CA-associated genes TTR (n = 11) and ApoAI (n = 1). Furthermore, 6 (2%) patients had a mutation in GLA. Among the remaining, mutation-negative patients, 26 with ≥1 CA red-flag were investigated further: 3 AL-CA and 17 wild-type-TTR-CA were identified. Ultimately, 32(9%) patients were diagnosed with CA. Prevalence of CA increased with age: 1/75 (1%) at age 40-49, 2/86 (2%) at age 50-59, 8/84 (9%) at age 60-69, 13/61 (21%) at age 70-79, 8/31 (26%) at age ≥80 (p for trend <0.01).

CONCLUSIONS

Among patients referred with and initial diagnosis of HCM, CA was the most common unrecognized mimic (9% prevalence) and increased with age (from 1% at ages 40-49 years to 26% >80 years). Age at diagnosis should be considered one of the most relevant red flags for CA in patients with HCM phenotypes; however, there is no clear age cut-off mandating scintigraphy and other second level investigations in the absence of other features suggestive of CA.

Contemporary Imaging Diagnosis of Cardiac Amyloidosis

Cardiac amyloidosis is a rare disease that frequently presents as ventricular hypertrophy. However, diagnosis is not always easy or straightforward as there are several myocardial disorders that phenocopy cardiac amyloidosis. Here, we present a narrative review of the current modalities that are actively used or being developed for diagnosis and follow-up of cardiac amyloidosis. Although not all of the findings may be present in those with cardiac amyloidosis, there are some clues in each diagnostic step that help lead to confirmatory diagnosis of cardiac amyloidosis; we believe that cardiologists should be familiar with these clues.

Lingual liability: macroglossia and dyspnoea as the harbinger of systemic AL (light-chain) cardiac amyloidosis

A 58-year-old man presented with a chief complaint of tongue indentations and discomfort. Otolaryngology treated him for oral thrush with counselling to avoid tongue biting. In addition, the patient reported dyspnoea described as a decrease in tolerance of his physical activities. Due to continued increase in tongue size and worsening dyspnoea, he underwent a tissue biopsy with findings consistent with amyloidosis. Further evaluation with a bone marrow biopsy revealed underlying multiple myeloma. Echocardiography revealed abnormal ventricular wall thickness, with a reduced left ventricular chamber size, dilated atria and Doppler findings with restrictive filling patterns indicative of cardiac amyloidosis. The patient was initiated on chemotherapy for his multiple myeloma and supportive therapy for his cardiac amyloidosis. Light-chain amyloidosis (AL) is a systemic disease characterised by irreversible deposition of amyloid in tissues throughout the body; when there is cardiac involvement, it can result in heart failure with a poor prognosis. Early diagnosis of cardiac amyloidosis can lead to prolonged survival.