Clinical and Prognostic Implications of Right Ventricular Uptake on Bone Scintigraphy in Transthyretin Amyloid Cardiomyopathy.

BACKGROUND: The extent of myocardial bone tracer uptake with technetium pyrophosphate, hydroxymethylene diphosphonate, and 3,3-diphosphono-1,2-propanodicarboxylate in transthyretin amyloid cardiomyopathy (ATTR-CM) might reflect cardiac amyloid burden and be associated with outcome. METHODS: Consecutive patients with ATTR-CM who underwent diagnostic bone tracer scintigraphy with acquisition of whole-body planar and cardiac single-photon emission computed tomography (SPECT) images from the National Amyloidosis Centre and 4 Italian centers were included. Cardiac uptake was defined according to the Perugini classification: 0=absent cardiac uptake; 1=mild uptake less than bone; 2=moderate uptake equal to bone; and 3=high uptake greater than bone. Extent of right ventricular (RV) uptake was defined as focal (basal segment of the RV free wall only) or diffuse (extending beyond basal segment) on the basis of SPECT imaging. The primary outcome was all-cause mortality. RESULTS: Among 1422 patients with ATTR-CM, RV uptake accompanying left ventricular uptake was identified by SPECT imaging in 100% of cases at diagnosis. Median follow-up in the whole cohort was 34 months (interquartile range, 21 to 50 months), and 494 patients died. By Kaplan-Meier analysis, diffuse RV uptake on SPECT imaging (n=936) was associated with higher all-cause mortality compared with focal (n=486) RV uptake (77.9% versus 22.1%; P<0.001), whereas Perugini grade was not associated with survival (P=0.27 in grade 2 versus grade 3). On multivariable analysis, after adjustment for age at diagnosis (hazard ratio [HR], 1.03 [95% CI, 1.02-1.04]; P<0.001), presence of the p.(V142I) TTR variant (HR, 1.42 [95% CI, 1.20-1.81]; P=0.004), National Amyloidosis Centre stage (each category, P<0.001), stroke volume index (HR, 0.99 [95% CI, 0.97-0.99]; P=0.043), E/e' (HR, 1.02 [95% CI, 1.007-1.03]; P=0.004), right atrial area index (HR, 1.05 [95% CI, 1.02-1.08]; P=0.001), and left ventricular global longitudinal strain (HR, 1.06 [95% CI, 1.03-1.09]; P<0.001), diffuse RV uptake on SPECT imaging (HR, 1.60 [95% CI, 1.26-2.04]; P<0.001) remained an independent predictor of all-cause mortality. The prognostic value of diffuse RV uptake was maintained across each National Amyloidosis Centre stage and in both wild-type and hereditary ATTR-CM (P<0.001 and P=0.02, respectively). CONCLUSIONS: Diffuse RV uptake of bone tracer on SPECT imaging is associated with poor outcomes in patients with ATTR-CM and is an independent prognostic marker at diagnosis.

Tc-99m labelled bone scintigraphy in suspected cardiac amyloidosis.

AIMS: To perform evaluation of widely embraced bone scintigraphy-based non-biopsy diagnostic criteria (NBDC) for ATTR amyloid cardiomyopathy (ATTR-CM) in clinical practice, and to refine serum free light chain (sFLC) ratio cut-offs that reliably exclude monoclonal gammopathy (MG) in chronic kidney disease. METHODS AND RESULTS: A multi-national retrospective study of 3354 patients with suspected or histologically proven cardiac amyloidosis (CA) referred to specialist centres from 2015 to 2021; evaluations included radionuclide bone scintigraphy, serum and urine immunofixation, sFLC assay, eGFR measurement and echocardiography. Seventy-nine percent (1636/2080) of patients with Perugini grade 2 or 3 radionuclide scans fulfilled NBDC for ATTR-CM through absence of a serum or urine monoclonal protein on immunofixation together with a sFLC ratio falling within revised cut-offs incorporating eGFR; 403 of these patients had amyloid on biopsy, all of which were ATTR type, and their survival was comparable to non-biopsied ATTR-CM patients (p = 0.10). Grade 0 radionuclide scans were present in 1091 patients, of whom 284 (26%) had CA, confirmed as AL type (AL-CA) in 276 (97%) and as ATTR-CM in only one case with an extremely rare TTR variant. Among 183 patients with grade 1 radionuclide scans, 122 had MG of whom 106 (87%) had AL-CA; 60/61 (98%) without MG had ATTR-CM. CONCLUSION: The NBDC for ATTR-CM are highly specific [97% (95% CI 0.91-0.99)] in clinical setting, and diagnostic performance was further refined here using new cut-offs for sFLC ratio in patients with CKD. A grade 0 radionuclide scan all but excludes ATTR-CM but occurs in most patients with AL-CA. Grade 1 scans in patients with CA and no MG are strongly suggestive of early ATTR-type, but require urgent histologic corroboration.

Advanced Heart Failure in a Special Population: Heart Failure with Preserved Ejection Fraction.

Heart failure with preserved ejection fraction (HFpEF) is a complex clinical syndrome that has become a global health issue, with mortality ranging from 53% to 74% at 5 years. It is defined as the presence of signs and symptoms of heart failure associated with left ventricular ejection fraction greater than or equal to 50%. The definition and diagnosis of HFpEF in patients with unexplained dyspnea remain a clinical challenge in the absence of a unique diagnostic algorithm universally recognized. Clinical trials conducted so far did not show a significant improvement of prognosis, but forthcoming therapies could provide innovative solutions.

Left ventricular structure and function in transthyretin-related versus light-chain cardiac amyloidosis.

BACKGROUND: Immunoglobulin amyloid light-chain (AL)-related cardiac amyloidosis (CA) has a worse prognosis than either wild-type (ATTRwt) or mutant (ATTRm) transthyretin (TTR) CA. Detailed echocardiographic studies have been performed in AL amyloidosis but not in TTR amyloidosis and might give insight into this difference. We assessed cardiac structure and function and outcome in a large population of patients with CA and compared findings in TTR and AL-related disease. METHODS AND RESULTS: We analyzed 172 patients with CA (AL amyloidosis, n=80; ATTRm, n=36; ATTRwt, n=56) by standard echocardiography and 2-dimensional speckle-tracking imaging-derived left ventricular (LV) longitudinal (LS), radial, and circumferential strains. Despite a preserved LV ejection fraction (55±12%), LS was severely impaired in CA. Standard measures of LV function and speckle-tracking imaging worsened as wall thickness increased, whereas apical LS was preserved regardless of the pathogenesis of CA and the degree of wall thickening. Compared with ATTRm and AL amyloidosis, ATTRwt was characterized by greater LV wall thickness and lower ejection fraction. LS was more depressed in both ATTRwt and AL amyloidosis (-11±3% and -12±4%, respectively, P=0.54) than in ATTRm (-15±4%, P<0.01 versus AL amyloidosis and ATTRwt). TTR-related causes were favorable predictors of survival, whereas LS and advanced New York Heart Association class were negative predictors. CONCLUSIONS: In patients with CA, worsening LV function correlated with increasing wall thickness regardless of pathogenesis. Patients with ATTRwt had a statistically greater wall thickness but lesser mortality than those with AL amyloidosis, despite very similar degrees of LS impairment. This paradox suggests an additional mechanism for LV dysfunction in AL amyloidosis, such as previously demonstrated light-chain toxicity.

Cardiac amyloidosis: the great pretender.

Cardiac amyloidosis (CA) is often misdiagnosed because of both physician-related and disease-related reasons including: fragmented knowledge among different specialties and subspecialties, shortage of centres and specialists dedicated to disease management, erroneous belief it is an incurable disease, rarity of the condition, intrinsic phenotypic heterogeneity, genotypic heterogeneity in transthyretin-related forms and the necessity of target organ tissue histological diagnosis in the vast majority of cases. Pitfalls, incorrect beliefs and deceits challenge not only the path to the diagnosis of CA but also the precise identification of aetiological subtype. The awareness of this condition is the most important prerequisite for the management of the risk of underdiagnoses and misdiagnosis. Almost all clinical, imaging and laboratory tests can be misinterpreted, but fortunately each of these diagnostic steps can also offer diagnostic "red flags" (i.e. highly suggestive findings that can foster the correct diagnostic suspicion and facilitate early, timely diagnosis). This is especially important because outcomes in CA are largely driven by the severity of cardiac dysfunction and emerging therapies are aimed at preventing further amyloid deposition.

Nuclear imaging for cardiac amyloidosis.

Histological analysis of endomyocardial tissue is still the gold standard for the diagnosis of cardiac amyloidosis, but has its limitations. Accordingly, there is a need for non-invasive modalities to diagnose cardiac amyloidosis. Echocardiography and ultrasound and magnetic resonance imaging can show characteristics which may not be very specific for cardiac amyloid. Nuclear medicine has gained a precise role in this context: several imaging modalities have become available for the diagnosis and prognostic stratification of cardiac amyloidosis during the last two decades. The different classes of radiopharmaceuticals have the potential to bind different constituents of the amyloidotic infiltrates, with some relevant differences among the various aetiologic types of amyloidosis and the different organs and tissues involved. This review focuses on the background of the commonly used modalities, their present clinical applications, and future clinical perspectives in imaging patients with (suspected) cardiac amyloidosis. The main focus is on conventional nuclear medicine (bone scintigraphy, cardiac sympathetic innervation) and positron emission tomography.

Disease profile and differential diagnosis of hereditary transthyretin-related amyloidosis with exclusively cardiac phenotype: an Italian perspective.

AIMS: Hereditary transthyretin (TTR)-related amyloidosis (ATTR) is mainly considered a neurologic disease. We assessed the phenotypic and genotypic spectra of ATTR in a Caucasian area and evaluated the prevalence, genetic background, and disease profile of cases with an exclusively cardiac phenotype, highlighting possible hints for the differential diagnosis with hypertrophic cardiomyopathy (HCM) and senile systemic amyloidosis (SSA). METHODS AND RESULTS: In this Italian multicentre study, 186 patients with ATTR were characterized at presentation. Thirty patients with SSA and 30 age-gender-matched HCM patients were used for comparison. Phenotype was classified as exclusively cardiac (n = 31, 17%), exclusively neurologic (n = 46, 25%), and mixed cardiac/neurologic (n = 109, 58%). Among the eight different mutations responsible for an exclusively cardiac phenotype, Ile68Leu was the most frequent. Five patients with an exclusively cardiac phenotype developed mild abnormalities at neurological examination, but no symptoms during a 36-month follow-up (range: 14-50). Exclusively cardiac phenotype was characterized by male gender, age >65 years, heart failure symptoms, symmetric left ventricular (LV) 'hypertrophy', and moderately depressed LV ejection fraction. This profile was similar to SSA, but relatively distinct from HCM. Compared with patients with a mixed phenotype, patients with an exclusively cardiac phenotype showed a more pronounced cardiac involvement on both echocardiogram and electrocardiogram (ECG). CONCLUSION: A clinically relevant subset of Caucasian ATTR patients present with an exclusively cardiac phenotype, mimicking HCM or SSA. Echocardiographic and ECG findings are useful to differentiate ATTR from HCM but not from SSA. The role of liver transplantation in these patients should be reconsidered.

[Cardiac amyloidosis and aortic stenosis: what do we know?] / Amiloidosi cardiaca e stenosi valvolare aortica: quale legame?

Aortic valve stenosis and cardiac amyloidosis, particularly transthyretin-related, often coexist and share a common clinical and demographic profile. Several pathophysiological hypotheses have been proposed regarding the causes of this association, neither of which fully substantiated in practice. The key to detect the coexistence of cardiac amyloidosis and aortic valve stenosis lies in clinical suspicion. It is possible to hypothesize concurrent cardiac amyloidosis in patients with aortic valve stenosis with the aid of clinical, electrocardiographic, echocardiographic, and extracardiac "red flags". Subsequent non-invasive diagnostic steps are often sufficient to establish a definitive diagnosis. The early diagnosis of this condition is pivotal since the presence of dual pathology worsens patient's prognosis, especially without intervention. Available data on treatment show a better outcome in terms of survival and cardiovascular events in patients undergoing percutaneous correction of valvular heart disease rather than medical therapy alone, regardless of the presence of cardiac amyloidosis. Furthermore, it seems that cardiac amyloidosis does not impact survival after transcatheter aortic valve replacement, even if higher rates of rehospitalizations have been described. Indeed, percutaneous treatment of valvular heart disease is currently considered the primary therapeutic option. Subsequently a disease-modifying treatment for transthyretin amyloidosis may be considered in order to delay disease progression and improve outcomes, even if specific data are still lacking.

Patisiran for the treatment of patients with p.Ile88Leu hereditary transthyretin amyloidosis: an Italian real-life experience.

Objectives: Evidence on the activity of patisiran therapy in specific subgroups of patients with hereditary transthyretin amyloidosis variant (ATTRv) is still scarce. This prospective real-world study was designed to provide the first in-depth clinical data on the effectiveness of patisiran in patients with ATTRv reporting the p.Ile88Leu variant, the most widespread variant in the Emilia-Romagna regional area, which has been less represented in previous clinical trials. Patients and methods: This prospective study evaluated all the patients with genetically proven ATTRv (p.Ile88Leu) and polyneuropathy treated with patisiran in the Emilia-Romagna referral centers for ATTRv (Institute of Neurological Sciences in Bologna and Division of Neurology in Rimini) from March 2021 to April 2023. All subjects underwent clinical and neurological evaluations at baseline and after 9-12 months of treatment. Results: A total of 22 patients were included in the study; the median age was 73 years (IQR: 9), the age at diagnosis was 72 years (IQR: 10), and the disease duration was 1.6 years (IQR: 2.3). We observed stability of all considered neurological and cardiological parameters at 9-12 months after the beginning of patisiran treatment. Conclusion: Our findings support the clinical data regarding the effectiveness of patisiran in stabilizing the disease course and extend this activity to the subset of patients with the p.Ile88Leu variant.

Characterization and natural history of different phenotypes in hereditary transthyretin amyloidosis: 40-year experience at a single Italian referral centre.

AIMS: Hereditary transthyretin amyloidosis (ATTRv) is one of the leading aetiologies of systemic amyloidosis with more than 135 mutations described and a broad spectrum of clinical manifestations. We aimed to provide a systematic description of a population of individuals carrying pathogenic mutations of transthyretin (TTR) gene and to investigate the major clinical events during follow-up. METHODS AND RESULTS: This was an observational, retrospective, cohort study including consecutive patients with mutations of TTR gene, admitted to a tertiary referral centre in Bologna, Italy, between 1984 and 2022. Three hundred twenty-five patients were included: 106 asymptomatic carriers, 49 cardiac phenotype, 49 neurological phenotype, and 121 mixed phenotype. Twenty-two different mutations were found, with Ile68Leu (41.8%), Val30Met (19%), and Glu89Gln (10%) being the most common. After a median follow-up of 51 months, 111 patients (38.3%) died and 9 (11.5%) of the 78 asymptomatic carriers developed ATTRv. Carriers had a prognosis comparable with healthy population, while no significant differences were seen among the three phenotypes adjusted by age. Age at diagnosis, New York Heart Association class III, left ventricular ejection fraction, modified polyneuropathy disability score IV, and disease-modifying therapy were independently associated with survival. CONCLUSION: This study offers a wide and comprehensive overview of ATTRv from the point of view of a tertiary referral centre in Italy. Three main phenotypes can be identified (cardiac, neurological, and mixed) with specific clinical and instrumental features. Family screening programmes are essential to identify paucisymptomatic affected patients or unaffected carriers of the mutation, to be followed through the years. Lastly, disease-modifying therapy represents an evolving cornerstone of the management of ATTRv, with a great impact on mortality.

A total of 325 consecutive patients harbouring a pathogenic mutation in the TTR gene, admitted to a tertiary referral centre in Bologna, Italy, between 1984 and 2022, were included in the study.These patients exhibited significant clinical diversity: 106 were asymptomatic carriers, 49 presented with a cardiac phenotype, 49 had a neurological phenotype, and 121 had a mixed phenotype.Asymptomatic carriers demonstrated a prognosis comparable with healthy population, but some of them may develop signs and symptoms of the disease during follow-up.Survival curves adjusted by age are similar among the three phenotypes.Age at diagnosis, New York Heart Association class, modified polyneuropathy disability score, left ventricular ejection fraction, and disease-modifying therapy were identified as independent factors associated with prognosis.

SGLT2 Inhibitor Therapy in Patients With Transthyretin Amyloid Cardiomyopathy.

BACKGROUND: Transthyretin cardiomyopathy (ATTR-CM) was an exclusion criterion in randomized clinical trials of sodium-glucose cotransporter 2 inhibitors (SGLT2i). OBJECTIVES: This study sought to assess the effectiveness and tolerability of SGLT2i in patients with ATTR-CM. METHODS: Data of 2,356 consecutive ATTR-CM patients (2014-2022) were analyzed: 260 (11%) received SGLT2i. After comparing the groups according to the treatment, 14 variables were significantly different-age and N-terminal pro-B-type natriuretic peptide were included in the model. A propensity score reflecting the likelihood of being treated with SGLT2i for each patient was determined using 16 variables. RESULTS: The study comprised 220 patients treated with SGLT2i (age 77 ± 2 years; 82.3% wild-type ATTR-CM; left ventricular ejection fraction 45.8% ± 11%) and 220 propensity-matched control individuals. Adequacy of matching was verified (standardized differences: <0.10 between groups). Discontinuation rate for SGLT2i was 4.5%; at 12 months, SGLT2i treatment was associated with less worsening of NYHA functional class, N-terminal pro-B-type natriuretic peptide, estimated glomerular filtration rate, and fewer new initiations of loop diuretic agent therapy. Over 28 months (Q1-Q3: 18-45 months), SGLT2i therapy was associated with lower all-cause mortality (HR: 0.57; 95% CI: 0.37-0.89; P = 0.010), cardiovascular mortality (HR: 0.41; 95% CI: 0.24-0.71; P < 0.001), heart failure (HF) hospitalization (HR: 0.57; 95% CI: 0.36-0.91; P = 0.014), and the composite outcome of cardiovascular mortality and HF hospitalization (HR: 0.57; 95% CI: 0.38-0.84; P = 0.003). CONCLUSIONS: SGLT2i treatment in ATTR-CM patients was well tolerated and associated with favorable effects on HF symptoms, renal function, and diuretic agent requirement over time. SGLT2i treatment was associated with reduced risk of HF hospitalization and cardiovascular and all-cause mortality, regardless of the ejection fraction, despite the effect size being likely overestimated. In the absence of randomized trials, these data may inform clinicians regarding the use of SGLT2i in patients with ATTR-CM.

Stratifying Disease Progression in Patients With Cardiac ATTR Amyloidosis.

BACKGROUND: Transthyretin cardiac amyloidosis (ATTR-CA) is a progressive cardiomyopathy. The clinical course varies among individuals and there are no established measures to assess disease progression. OBJECTIVES: The goal of this study was to assess the prognostic importance of an increase in N-terminal pro-B-type natriuretic peptide (NT-proBNP) and outpatient diuretic intensification (ODI) as markers of disease progression in a large cohort of patients with ATTR-CA. METHODS: We evaluated landmark survival analysis based on worsening of NT-proBNP and requirement for ODI between time of diagnosis and a 1-year visit, and subsequent mortality in 2,275 patients with ATTR-CA from 7 specialist centers. The variables were developed in the National Amyloidosis Centre (NAC) cohort (n = 1,598) and validated in the external cohort from the remaining centers (n = 677). RESULTS: Between baseline and 1-year visits, 551 (34.5%) NAC patients and 204 (30.1%) patients in the external validation cohort experienced NT-proBNP progression (NT-proBNP increase >700 ng/L and >30%), which was associated with mortality (NAC cohort: HR: 1.82; 95% CI: 1.57-2.10; P < 0.001; validation cohort: HR: 1.75; 95% CI: 1.32-2.33; P < 0.001). At 1 year, 451 (28.2%) NAC patients and 301 (44.5%) patients in the external validation cohort experienced ODI, which was associated with mortality (NAC cohort: HR: 1.88; 95% CI: 1.62-2.18; P < 0.001; validation cohort: HR: 2.05; 95% CI: 1.53-2.74; P < 0.001). When compared with patients with a stable NT-proBNP and stable diuretic dose, a higher risk of mortality was observed in those experiencing either NT-proBNP progression or ODI (NAC cohort: HR: 1.93; 95% CI: 1.65-2.27; P < 0.001; validation cohort: HR: 1.94; 95% CI: 1.36-2.77; P < 0.001), and those experiencing both NT-proBNP progression and ODI (NAC cohort: HR: 2.98; 95% CI: 2.42-3.67; P < 0.001; validation cohort: HR: 3.23; 95% CI: 2.17-4.79; P < 0.001). CONCLUSIONS: NT-proBNP progression and ODI are frequent and consistently associated with an increased risk of mortality. Combining both variables produces a simple, universally applicable model that detects disease progression in ATTR-CA.

Evaluation of the 2021 ESC recommendations for family screening in hereditary transthyretin cardiac amyloidosis.

AIMS: The 2021 European Society of Cardiology (ESC) screening recommendations for individuals carrying a pathogenic transthyretin amyloidosis variant (ATTRv) are based on expert opinion. We aimed to (i) determine the penetrance of ATTRv cardiomyopathy (ATTRv-CM) at baseline; (ii) examine the value of serial evaluation; and (iii) establish the yield of first-line diagnostic tests (i.e. electrocardiogram, echocardiogram, and laboratory tests) as per 2021 ESC position statement. METHODS AND RESULTS: We included 159 relatives (median age 55.6 [43.2-65.9] years, 52% male) at risk for ATTRv-CM from 10 centres. The primary endpoint, ATTRv-CM diagnosis, was defined as the presence of (i) cardiac tracer uptake in bone scintigraphy; or (ii) transthyretin-positive cardiac biopsy. The secondary endpoint was a composite of heart failure (New York Heart Association class ≥II) and pacemaker-requiring conduction disorders. At baseline, 40/159 (25%) relatives were diagnosed with ATTRv-CM. Of those, 20 (50%) met the secondary endpoint. Indication to screen (≤10 years prior to predicted disease onset and absence of extracardiac amyloidosis) had an excellent negative predictive value (97%). Other pre-screening predictors for ATTRv-CM were infrequently identified variants and male sex. Importantly, 13% of relatives with ATTRv-CM did not show any signs of cardiac involvement on first-line diagnostic tests. The yield of serial evaluation (n = 41 relatives; follow-up 3.1 [2.2-5.2] years) at 3-year interval was 9.4%. CONCLUSIONS: Screening according to the 2021 ESC position statement performs well in daily clinical practice. Clinicians should adhere to repeating bone scintigraphy after 3 years, as progressing to ATTRv-CM without signs of ATTRv-CM on first-line diagnostic tests or symptoms is common.

Racial Differences in Atrial Fibrillation Management Between White Patients and Black Patients in Transthyretin Cardiac Amyloid.

Black patients have higher rates of stroke than White patients. Paradoxically, atrial fibrillation (AF) affects twice as many White patients compared with Black patients. Transthyretin cardiac amyloidosis (ATTR-CA) is associated with both AF and strokes. We hypothesized that although Black patients with ATTR-CA have a lower incidence of AF, when diagnosed with AF, they have increased thromboembolic events. Patients with ATTR-CA (n = 558) at 3 international centers were retrospectively identified. We compared baseline characteristics, presence of AF, outcomes of thromboembolism (stroke, transient ischemic attack, and peripheral embolism), major bleed, and mortality by race. Of all patients, 367 of 488 White patients (75%) were diagnosed with AF compared with 39 of 70 Black patients (56%) (p = 0.001). Black patients with AF had a hazard ratio of 5.78 (95% confidence interval 2.30 to 14.50) for time to first thromboembolic event compared with White patients. There were no racial differences in major bleeding. Black patients with AF more often lacked anticoagulation (p = 0.038) and had higher incidence of labile international normalized ratio (p <0.001). In conclusion, these data suggest that although Black patients with ATTR-CA have lower incidence of AF, they have increased thromboembolic events compared with White patients. These findings may be related to treatment discrepancies, time in therapeutic range for warfarin, and disparities in healthcare.

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.

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.

Diagnostic pathways to wild-type transthyretin amyloid cardiomyopathy: a multicentre network study.

AIM: Epidemiology of wild-type transthyretin cardiac amyloidosis (ATTRwt-CA) remains poorly defined. A better characterization of pathways leading to ATTRwt-CA diagnosis is of key importance, and potentially informative of disease course and prognosis. The aim of this study was to describe the characteristics of contemporary pathways leading to ATTRwt-CA diagnosis, and their potential association with survival. METHODS AND RESULTS: This was a retrospective study of patients diagnosed with ATTRwt-CA at 17 Italian referral centres for CA. Patients were categorized into different 'pathways' according to the medical reason that triggered the diagnosis of ATTRwt-CA (hypertrophic cardiomyopathy [HCM] pathway, heart failure [HF] pathway, incidental imaging or incidental clinical pathway). Prognosis was investigated with all-cause mortality as endpoint. Overall, 1281 ATTRwt-CA patients were included in the study. The diagnostic pathway leading to ATTRwt-CA diagnosis was HCM in 7% of patients, HF in 51%, incidental imaging in 23%, incidental clinical in 19%. Patients in the HF pathway, as compared to the others, were older and had a greater prevalence of New York Heart Association (NYHA) class III-IV and chronic kidney disease. Survival was significantly worse in the HF versus other pathways, but similar among the three others. In multivariate model, older age at diagnosis, NYHA class III-IV and some comorbidities but not the HF pathway were independently associated with worse survival. CONCLUSIONS: Half of contemporary ATTRwt-CA diagnoses occur in a HF setting. These patients had worse clinical profile and outcome than those diagnosed either due to suspected HCM or incidentally, although prognosis remained primarily related to age, NYHA functional class and comorbidities rather than the diagnostic pathway itself.

Amyloidosis: What does pathology offer? The evolving field of tissue biopsy.

Since the mid-nineteenth century pathology has followed the convoluted story of amyloidosis, recognized its morphology in tissues and made identification possible using specific staining. Since then, pathology studies have made a significant contribution and advanced knowledge of the disease, so providing valuable information on the pathophysiology of amyloid aggregation and opening the way to clinical studies and non-invasive diagnostic techniques. As amyloidosis is a heterogeneous disease with various organ and tissue deposition patterns, histology evaluation, far from offering a simple yes/no indication of amyloid presence, can provide a wide spectrum of qualitative and quantitative information related to and changing with the etiology of the disease, the comorbidities and the clinical characteristics of patients. With the exception of cardiac transthyretin related amyloidosis cases, which today can be diagnosed using non-biopsy algorithms when stringent clinical criteria are met, tissue biopsy is still an essential tool for a definitive diagnosis in doubtful cases and also to define etiology by typing amyloid fibrils. This review describes the histologic approach to amyloidosis today and the current role of tissue screening biopsy or targeted organ biopsy protocols in the light of present diagnostic algorithms and various clinical situations, with particular focus on endomyocardial and renal biopsies. Special attention is given to techniques for typing amyloid fibril proteins, necessary for the new therapies available today for cardiac transthyretin related amyloidosis and to avoid patients receiving inappropriate chemotherapy in presence of plasma cell dyscrasia unrelated to amyloidosis. As the disease is still burdened with high mortality, the role of tissue biopsy in early diagnosis to assure prompt treatment is also mentioned.

[Ten questions about transthyretin amyloidosis]. / Dieci quesiti in tema di amiloidosi da transtiretina.

Systemic amyloidosis is a hereditary or acquired disease characterized by deposition of amyloid insoluble fibrils into body organs and tissues, causing structural abnormalities and organ dysfunction, i.e. heart failure. This disease is classified according to the precursor protein involved; immunoglobulin light chains, transthyretin and apolipoprotein A1 underlie the cardiac involvement. Amyloid cardiomyopathy is characterized by symmetric biventricular hypertrophy, preserved systolic function, and pronounced diastolic dysfunction. Although transthyretin-related cardiac amyloidosis has always been considered a rare disease, in the last few years it has been found to be one of the most common causes of hypertrophic cardiomyopathy, thanks to better diagnostic algorithms and considerable improvements in cardiac imaging. Achieving an early diagnosis is a challenge for the modern cardiologist since new disease-modifying therapies have been developed in recent years. This article aims to answer to the main questions about transthyretin-related cardiac amyloidosis: when to suspect it, how to diagnose it and how to treat it.

Systemic embolism in amyloid transthyretin cardiomyopathy.

AIMS: Although systemic embolism is a potential complication in transthyretin amyloid cardiomyopathy (ATTR-CM), data about its incidence and prevalence are scarce. We studied the incidence, prevalence and factors associated with embolic events in ATTR-CM. Additionally, we evaluated embolic events according to the type of oral anticoagulation (OAC) and the performance of the CHA2 DS2 -VASc score in this setting. METHODS AND RESULTS: Clinical characteristics, history of atrial fibrillation (AF) and embolic events were retrospectively collected from ATTR-CM patients evaluated at four international amyloid centres. Overall, 1191 ATTR-CM patients (87% men, median age 77.1 years [interquartile range-IQR 71.4-82], 83% ATTRwt) were studied. A total of 162 (13.6%) have had an embolic event before initial evaluation. Over a median follow-up of 19.9 months (IQR 9.9-35.5), 41 additional patients (3.44%) had an embolic event. Incidence rate (per 100 patient-years) was 0 among patients in sinus rhythm with OAC, 1.3 in sinus rhythm without OAC, 1.7 in AF with OAC, and 4.8 in AF without OAC. CHA2 DS2 -VASc did not predict embolic events in patients in sinus rhythm whereas in patients with AF without OAC, only those with a score ≥4 had embolic events. There was no difference in the incidence rate of embolism between patients with AF treated with vitamin K antagonists (VKAs) (n = 322) and those treated with direct oral anticoagulants (DOACs) (n = 239) (p = 0.66). CONCLUSIONS: Embolic events were a frequent complication in ATTR-CM. OAC reduced the risk of systemic embolism. Embolic rates did not differ with VKAs and DOACs. The CHA2 DS2 -VASc score did not correlate well with clinical outcome in ATTR-CM and should not be used to assess thromboembolic risk in this population.