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.

Left atrial structural and functional remodelling in Fabry disease and cardiac amyloidosis: A comparative analysis

BACKGROUND

Fabry disease (FD) and transthyretin cardiac amyloidosis (TTR CA) are cardiomyopathies with hypertrophic phenotype that share several features, including left atrial (LA) enlargement and dysfunction, but direct comparative data are lacking. Aim of the present study was to perform a comparative analysis of LA remodelling between the two diseases.

METHODS AND RESULTS

In this prospective study, a total of 114 patients (31 FD and 83 TTR CA) were included; all of them had left ventricular hypertrophy (LVH), defined as left ventricular (LV) wall thickness ≥ 12 mm. Despite similar degree of LVH, patients with TTR CA showed worse LV systolic and diastolic function. LA maximal volume index was not significantly different between the two groups (p = 0.084), while patients with TTR CA showed larger LA minimal volume index (p = 0.001). Moreover, all phases of LA mechanics were more impaired in the TTR CA group vs FD (reservoir: 6.9[4.2-15.5] vs 19.0[15.5-29.5], p < 0.001). After excluding patients with atrial fibrillation (AF), these differences remained clearly significant. In multivariable regression analyses, LA reservoir strain showed an independent correlation with TTR CA, controlling for demographic characteristics, AF and LV systolic and diastolic performance (p ≤ 0.001), whereas LV global longitudinal strain did not. Finally, among echocardiographic parameters, LA function demonstrated the highest accuracy in discriminating the two diseases.

CONCLUSIONS

TTR CA is characterized by a more advanced LA structural and functional remodelling in comparison to patients with FD and similar degree of LVH. The association between TTR CA and LA dysfunction remains consistent after adjustment for potential confounders.

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.

Fabry disease in W162C mutation: a case report of two patients and a review of literature

BACKGROUND

Fabry disease is a multisystemic disorder characterized by deposition of globotriaosylceramide (Gb3) and its deacylated form in multiple organs, sometimes localized in specific systems such as the nervous or cardiovascular system. As disease-modifying therapies are now available, early diagnosis is paramount to improving life quality and clinical outcomes. Despite the widespread use of non-invasive techniques for assessing organ damage, such as cardiac magnetic resonance imaging (MRI) for patients with cardiac disease, organ biopsy remains the gold standard to assess organ involvement.

CASE PRESENTATION

The cases of two patients, father and daughter with a W162C mutation, are described. The father presented with late-onset, cardiac Fabry disease, subsequently developing systolic dysfunction and heart failure. His daughter, while asymptomatic and with normal cardiac assessment (except for slightly reduced native T1 values by cardiac MRI), had already initial myocyte Gb3 deposits on the endomyocardial biopsy, allowing her to start therapy precociously and potentially modifying the course of her disease. A review of the literature concerning the W162C mutation is then provided, showing that it is usually associated to classic, multisystemic Fabry disease rather than the cardiac-restricted form as in these two cases.

CONCLUSIONS

Three main points can be concluded from this report. First, the W162C mutation can present with a more variegate phenotype than that predicted on a molecular basis. Second, endomyocardial biopsy was shown in this case to precede non-invasive investigation in determining organ involvement, justifying further studies on this potentially reliable technique, Third, difficulties can arise in the management of asymptomatic female carriers.

Clinical characteristics and outcome of end stage hypertrophic cardiomyopathy: Role of age and heart failure phenotypes

BACKGROUND

A minority of patients with hypertrophic cardiomyopathy (HCM) presents advanced heart failure (HF) during their clinical course, in the context of left ventricular (LV) remodeling with reduced LV ejection fraction (LVEF), or of severe diastolic dysfunction without impaired LVEF. Aim of this study was to describe a multicentric end stage (ES) HCM population and analyze clinical course and outcome among its different phenotypes.

METHODS

Data of all HCM patients from 7 Italian referral centres were retrospectively evaluated. ES was diagnosed in presence of: LVEF <50% (ES-rEF) or NYHA functional class ≥II with severe diastolic dysfunction (ES-pEF). Outcomes were: HCM-related and all-cause mortality; combined arrhythmic events; advanced HF treatments.

RESULTS

Study population included 331 ES patients; 87% presented ES-rEF and 13% ES-pEF. At ES recognition, patients with ES-pEF were more commonly females, had more frequently NYHA III/IV, atrial fibrillation and greater maximal LV wall thickness. Over a median follow-up of 5.6 years, 83 (25%) patients died, 46 (15%) experienced arrhythmic events and (26%) 85 received advanced HF treatments. Incidence of HCM-related and all-cause mortality, and of combined arrhythmic events did not differ in ES-pEF and ES-rEF patients, but ES-pEF patients were less likely to receive advanced HF treatments. Older age at ES recognition was an independent predictor of increased HCM-related mortality (p = 0.01) and reduced access to advanced HF treatments (p < 0.0001).

CONCLUSIONS

Two different HCM-ES phenotypes can be recognized, with ES-pEF showing distinctive features at ES recognition and receiving less frequently advanced HF treatments. Older age at ES recognition has a major impact on outcomes.

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.

Real-world candidacy to mavacamten in a contemporary hypertrophic obstructive cardiomyopathy population

AIMS

In the EXPLORER-HCM trial, mavacamten reduced left ventricular outflow tract obstruction (LVOTO) and improved functional capacity of symptomatic hypertrophic obstructive cardiomyopathy (HOCM) patients. We sought to define the potential use of mavacamten by comparing real-world HOCM patients with those enrolled in EXPLORER-HCM and assessing their eligibility to treatment.

METHODS AND RESULTS

We collected information on HOCM patients followed up at 25 Italian HCM outpatient clinics and with significant LVOTO (i.e. gradient ≥30 mmHg at rest or ≥50 mmHg after Valsalva manoeuvre or exercise) despite pharmacological or non-pharmacological therapy. Pharmacological or non-pharmacological therapy resolved LVOTO in 1044 (61.2%) of the 1706 HOCM patients under active follow-up, whereas 662 patients (38.8%) had persistent LVOTO. Compared to the EXPLORER-HCM trial population, these real-world HOCM patients were older (62.1 ± 14.3 vs. 58.5 ± 12.2 years, p = 0.02), had a lower body mass index (26.8 ± 5.3 vs. 29.7 ± 4.9 kg/m2 , p < 0.0001) and a more frequent history of atrial fibrillation (21.5% vs. 9.8%, p = 0.027). At echocardiography, they had lower left ventricular ejection fraction (LVEF, 66 ± 7% vs. 74 ± 6%, p < 0.0001), higher left ventricular outflow tract gradients at rest (60 ± 27 vs. 52 ± 29 mmHg, p = 0.003), and larger left atrial volume index (49 ± 16 vs. 40 ± 12 ml/m2 , p < 0.0001). Overall, 324 (48.9%) would have been eligible for enrolment in the EXPLORER-HCM trial and 339 (51.2%) for treatment with mavacamten according to European guidelines.

CONCLUSIONS

Real-world HOCM patients differ from the EXPLORER-HCM population for their older age, lower LVEF and larger atrial volume, potentially reflecting a more advanced stage of the disease. About half of real-world HOCM patients were found eligible to mavacamten.

Emery-Dreifuss muscular dystrophy Type 1 is associated with a high risk of malignant ventricular arrhythmias and end-stage heart failure

BACKGROUND AND AIMS

Emery-Dreifuss muscular dystrophy (EDMD) is caused by variants in EMD (EDMD1) and LMNA (EDMD2). Cardiac conduction defects and atrial arrhythmia are common to both, but LMNA variants also cause end-stage heart failure (ESHF) and malignant ventricular arrhythmia (MVA). This study aimed to better characterize the cardiac complications of EMD variants.

METHODS

Consecutively referred EMD variant-carriers were retrospectively recruited from 12 international cardiomyopathy units. MVA and ESHF incidences in male and female variant-carriers were determined. Male EMD variant-carriers with a cardiac phenotype at baseline (EMDCARDIAC) were compared with consecutively recruited male LMNA variant-carriers with a cardiac phenotype at baseline (LMNACARDIAC).

RESULTS

Longitudinal follow-up data were available for 38 male and 21 female EMD variant-carriers [mean (SD) ages 33.4 (13.3) and 43.3 (16.8) years, respectively]. Nine (23.7%) males developed MVA and five (13.2%) developed ESHF during a median (inter-quartile range) follow-up of 65.0 (24.3-109.5) months. No female EMD variant-carrier had MVA or ESHF, but nine (42.8%) developed a cardiac phenotype at a median (inter-quartile range) age of 58.6 (53.2-60.4) years. Incidence rates for MVA were similar for EMDCARDIAC and LMNACARDIAC (4.8 and 6.6 per 100 person-years, respectively; log-rank P = .49). Incidence rates for ESHF were 2.4 and 5.9 per 100 person-years for EMDCARDIAC and LMNACARDIAC, respectively (log-rank P = .09).

CONCLUSIONS

Male EMD variant-carriers have a risk of progressive heart failure and ventricular arrhythmias similar to that of male LMNA variant-carriers. Early implantable cardioverter defibrillator implantation and heart failure drug therapy should be considered in male EMD variant-carriers with cardiac 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.

SCN5A mutation is associated with a higher Shanghai Score in patients with type 1 Brugada ECG pattern

AIMS

Brugada syndrome (BrS) is an inherited arrhythmic disease characterized by a coved ST-segment elevation in the right precordial electrocardiogram leads (type 1 ECG pattern) and is associated with a risk of malignant ventricular arrhythmias and sudden cardiac death. In order to assess the predictive value of the Shanghai Score System for the presence of a SCN5A mutation in clinical practice, we studied a cohort of 125 patients with spontaneous or fever/drug-induced BrS type 1 ECG pattern, variably associated with symptoms and a positive family history.

METHODS

The Shanghai Score System items were collected for each patient and PR and QRS complex intervals were measured. Patients were genotyped through a next-generation sequencing (NGS) custom panel for the presence of SCN5A mutations and the common SCN5A polymorphism (H558R).

RESULTS

The total Shanghai Score was higher in SCN5A+ patients than in SCN5A- patients. The 81% of SCN5A+ patients and the 100% of patients with a SCN5A truncating variant exhibit a spontaneous type 1 ECG pattern. A significant increase in PR (P = 0.006) and QRS (P = 0.02) was detected in the SCN5A+ group. The presence of the common H558R polymorphism did not significantly correlate with any of the items of the Shanghai Score, nor with the total score of the system.

CONCLUSION

Data from our study suggest the usefulness of Shanghai Score collection in clinical practice in order to maximize genetic test appropriateness. Our data further highlight SCN5A mutations as a cause of conduction impairment in BrS patients.

Impact of GLA Variant Classification on the Estimated Prevalence of Fabry Disease: A Systematic Review and Meta-Analysis of Screening Studies

BACKGROUND

The diagnosis of Fabry disease (FD) has relevant implications related to the management. Thus, a clear assignment of GLA variant pathogenicity is crucial. This systematic review and meta-analysis aimed to investigate the prevalence of FD in high-risk populations and newborns and evaluate the impact of different GLA variant classifications on the estimated prevalence of FD.

METHODS

We searched the EMBASE and PubMed databases on February 21, 2023. Observational studies evaluating the prevalence of FD and reporting the identified GLA variants were included. GLA variants were re-evaluated for their pathogenicity significance using the American College of Medical Genetics and Genomics criteria and the ClinVar database. The pooled prevalence of FD among different settings was calculated. The study was registered on PROSPERO (CRD42023401663) and followed the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines.

RESULTS

Of the 3941 studies identified, 110 met the inclusion criteria. The pooled prevalence of FD was significantly different according to the clinical setting and criteria used for the pathogenicity assessment. Using the American College of Medical Genetics and Genomics criteria, the pooled prevalence was 1.2% in patients with left ventricular hypertrophy/hypertrophic cardiomyopathy (26 studies; 10 080 patients screened), 0.3% in end-stage renal disease/chronic kidney disease (38 studies; 62 050 patients screened), 0.7% in stroke (25 studies; 15 295 patients screened), 0.7% in cardiac conduction disturbance requiring pacemaker (3 studies; 1033 patients screened), 1.0% in small-fiber neuropathy (3 studies; 904 patients screened), and 0.01% in newborns (15 studies; 11 108 793 newborns screened). The pooled prevalence was different if the GLA variants were assessed using the ClinVar database, and most patients with a discrepancy in the pathogenicity assignment carried 1 of the following variants: p.A143T, p.D313Y, and p.E66Q.

CONCLUSIONS

This systematic review and meta-analysis describe the prevalence of FD among newborns and high-risk populations, highlighting the need for a periodic reassessment of the GLA variants in the context of recent clinical, biochemical, and histological data.

REGISTRATION

URL: https://crd.york.ac.uk/PROSPERO/; Unique identifier: CRD42023401663.

Fabry Disease Nephropathy: Histological Changes With Nonclassical Mutations and Genetic Variants of Unknown Significance

RATIONALE & OBJECTIVE

Fabry disease (FD) is an X-linked genetic disorder that causes lysosomal storage of glycosphingolipids, primarily globotriaosylceramide (Gb3) and its derivative globotriaosylsphingosine (lyso-Gb3), with multiorgan dysfunction including chronic kidney disease. Affected individuals may be carriers of gene variants that are of uncertain significance (GVUS). We describe kidney pathology at the early stages of FD-related kidney disease to gain insights into its association with GVUS and sex.

STUDY DESIGN

Single-center, case series.

SETTING & PARTICIPANTS

Thirty-five consecutively biopsied patients (aged 48.1±15.4 years, 22 females) from among 64 patients with genetically diagnosed FD. Biopsies were retrospectively screened using the International Study Group of Fabry Nephropathy Scoring System.

OBSERVATIONS

Genetic mutation type, p.N215S and D313Y, sex, age, estimated glomerular filtration rate (eGFR), plasma lyso-Gb3 (pLyso-Gb3) levels, and histological parameters, including Gb3 deposits were recorded. Genetic analyses showed mostly missense mutations, p.N215S variant in 15, and the "benign polymorphism" D313Y in 4 of the biopsied patients. Morphological lesions were similar for men and women except for interstitial fibrosis and arteriolar hyalinosis being more common in men. Early in their clinical course, patients with normal/mild albuminuria had podocyte, tubular, and peritubular capillary vacuoles/inclusions, and evidence of chronicity, i.e., glomerulosclerosis, interstitial fibrosis, tubular atrophy. These findings appeared to be associated with pLyso-Gb3, eGFR, and age.

LIMITATIONS

Retrospective design and inclusion of outpatients partially based on family pedigree.

CONCLUSIONS

In early stages of kidney disease in the setting of FD, numerous histological abnormalities are present. These observations suggest that kidney biopsies early in FD may reveal activity of kidney involvement that may inform clinical management.

Prognostic Implications of the Extent of Cardiac Damage in Patients With Fabry Disease

BACKGROUND

There is limited evidence on the risk stratification of cardiovascular outcomes in patients with Fabry disease (FD).

OBJECTIVES

This study sought to classify FD patients into disease stages, based on the extent of the cardiac damage evaluated by echocardiography, and to assess their prognostic impact in a multicenter cohort.

METHODS

Patients with FD from 5 Italian referral centers were categorized into 4 stages: stage 0, no cardiac involvement; stage 1, left ventricular (LV) hypertrophy (LV maximal wall thickness >12 mm); stage 2, left atrium (LA) enlargement (LA volume index >34 mL/m2); stage 3, ventricular impairment (LV ejection fraction <50% or E/e' ≥15 or TAPSE <17 mm). The study endpoint was the composite of all-cause death, hospitalization for heart failure, new-onset atrial fibrillation, major bradyarrhythmias or tachyarrhythmias, and ischemic stroke.

RESULTS

A total of 314 patients were included. Among them, 174 (56%) were classified as stage 0, 41 (13%) as stage 1, 57 (18%) as stage 2 and 42 (13%) as stage 3. A progressive increase in the composite event rate at 8 years was observed with worsening stages of cardiac damage (log-rank P < 0.001). On multivariable Cox regression analysis, the staging was independently associated with the risk of cardiovascular events (HR: 2.086 per 1-stage increase; 95% CI: 1.487-2.927; P < 0.001). Notably, cardiac staging demonstrated a stronger and additive prognostic value, as compared with the degree of LV hypertrophy.

CONCLUSIONS

In FD patients, a novel staging classification of cardiac damage, evaluated by echocardiography, is strongly associated with cardiovascular outcomes and may be helpful to refine risk stratification.

Diagnostic delay in arrhythmogenic cardiomyopathy

AIMS

Diagnosis of arrhythmogenic cardiomyopathy (ACM) may be challenging, as it comprises diverse phenotypes (right dominant, biventricular, and left dominant), and each may overlap with other clinical entities. The issue of differential diagnosis with conditions mimicking ACM has been previously highlighted; however, a systematic analysis of ACM diagnostic delay, and of its clinical implications, is lacking.

METHODS AND RESULTS

Data of all ACM patients from three Italian Cardiomyopathy Referral Centres were reviewed to assess the time from first medical contact to definitive ACM diagnosis; a significant diagnostic delay was defined as a time to ACM diagnosis ≥2 years. Baseline characteristics and clinical course of patients with and without diagnostic delay were compared. Of 174 ACM patients, 31% experienced diagnostic delay, with a median time to diagnosis of 8 years (20% in right-dominant ACM, 33% in left-dominant ACM, and 39% in biventricular). Patients with diagnostic delay, when compared with those without, more frequently exhibited an ACM phenotype with left ventricular (LV) involvement (74 vs. 57%, P = 0.04) and a specific genetic background (none had plakophilin-2 variants). The most common initial (mis)diagnoses were dilated cardiomyopathy (51%), myocarditis (21%), and idiopathic ventricular arrhythmia (9%). At follow-up, all-cause mortality was greater in those with diagnostic delay (P = 0.03).

CONCLUSION

Diagnostic delay is common in patients with ACM, particularly in the presence of LV involvement, and is associated with greater mortality at follow-up. Clinical suspicion and increasing use of tissue characterization by cardiac magnetic resonance in specific clinical settings are of key importance for the timely identification of ACM.

Cross-cultural adaptation and test-retest reliability of the Italian version of the Pediatric Balance Scale in children with typical and atypical development

BACKGROUND

Balance disorders in children are complex and disabling. The pediatric balance scale assesses functional balance in the contest of everyday tasks. It is recommended for balance assessment in children. The cross-cultural validation of an assessment instrument allows to assess individuals in the appropriate cultural context. We designed our study with the aim of translating and cross-cultural adapting the Pediatric Balance Scale into Italian, and investigating the reliability of the translated version.

METHODS

Two forward translation of the Pediatric Balance Scale were conducted. Two blind backward translations were subsequently performed. A multidisciplinary group compared the content of the translations with those of the original Pediatric Balance Scale. Ambiguities and discrepancies were amended. To assess conceptual equivalence of the translation, we conducted cognitive debriefing involving physiotherapists, parents, and children. Suggestions for rewording were sought and considered for eventual modification. The Italian Pediatric Balance Scale was administered to 18 children with typical development (age 4.7-7.9 years, female 61.1%, scores 51-56), and to 18 children with atypical development (age 4.9-15.0 years, female 44.4%, scores 38-56). Test-retest reliability (i.e., intrarater and interrater reliability, and agreement between raters) of the scale was assessed by mean of single-rating, absolute-agreement, two-way mixed effects model intra-class correlation coefficients (ICC3,1) and the Bland-Altman method. The standard error of measurement and the minimal detectable change were subsequently computed.

RESULTS

The forward and backward translations showed no substantial differences in content; wording discrepancies were resolved by consensus. The multidisciplinary group proposed some minor changes. Twenty-three physiotherapists, 36 parents, and 36 children participated in cognitive interviewing and further changes were made. Perfect agreement was observed in test-retest reliability assessment of the Italian pediatric balance scale in children with typical development. High reliability (intrarater: ICC3,1 0.998, 95% CI 0.994 to 0.999; interrater: ICC3,1 0.994, 95% CI 0.984 to 0.998) and agreement among raters (Bland-Altman plots: 89%, 95% CI 67% to 97%, of the data within the 95% CI limits of the bias estimate) were found assessing children with atypical development. Very small standard error of measurement and the minimal detectable change values were observed (intrarater: 0.212 and 0.588; interrater: 0.368 and 1.019).

CONCLUSIONS

The present study provides a translated and cross-culturally adapted Italian version of the Pediatric Balance Scale. The full cross-cultural validity of the tool requires further steps to complete the psychometric testing.

A cost-effectiveness analysis of hypertrophic cardiomyopathy sudden cardiac death risk algorithms for implantable cardioverter defibrillator decision-making

AIMS

To conduct a contemporary cost-effectiveness analysis examining the use of implantable cardioverter defibrillators (ICD) for primary prevention in patients with hypertrophic cardiomyopathy (HCM).

METHODS

A discrete-time Markov model was used to determine the cost-effectiveness of different ICD decision-making rules for implantation. Several scenarios were investigated including the reference scenario of implantation rates according to observed real world practice. A 12-year time horizon with an annual cycle length was used. Transition probabilities used in the model were obtained using Bayesian analysis. The study has been reported according to the Consolidated Health Economic Evaluation Reporting Standards (CHEERS) checklist.

RESULTS

Using a 5-year SCD risk threshold of 6% was cheaper than current practice and has marginally better total quality adjusted life years (QALYs). This is the most cost-effective of the options considered, with an incremental cost effectiveness ratio of £834 per QALY. Sensitivity analyses highlighted that this decision is largely driven by what health related quality of life (HRQL) is attributed to ICD patients and time horizon.

CONCLUSION

We present a timely new perspective on HCM ICD cost-effectiveness, using methods reflecting real-world practice. While we have shown that a 6% 5-year SCD risk cut-off provides the best cohort stratification to aid ICD decision-making, this will also be influenced by the particular values of costs and HRQL for subgroups or at a local level. The process of explicitly demonstrating the main factors which drive conclusions from such an analysis will help to inform shared decision-making in this complex area for all stakeholders concerned.

Clinical course of hypertrophic cardiomyopathy patients implanted with a transvenous or subcutaneous defibrillator

AIMS

The implantable cardioverter-defibrillator (ICD) is a life-saving therapy in patients with hypertrophic cardiomyopathy (HCM) at risk of sudden cardiac death. Implantable cardioverter-defibrillator complications are of concern. The subcutaneous ICD (S-ICD) does not use transvenous leads and is expected to reduce complications. However, it does not provide bradycardia and anti-tachycardia pacing (ATP). The aim of this study was to compare appropriate and inappropriate ICD interventions, complications, disease-related adverse events and mortality between HCM patients implanted with a S- or transvenous (TV)-ICD.

METHODS AND RESULTS

Consecutive HCM patients implanted with a S- (n = 216) or TV-ICD (n = 211) were enrolled. Propensity-adjusted cumulative Kaplan-Meier curves and multivariate Cox proportional hazard ratios were used to compare 5-year event-free survival and the risk of events. The S-ICD patients had lower 5-year risk of appropriate (HR: 0.32; 95%CI: 0.15-0.65; P = 0.002) and inappropriate (HR: 0.44; 95%CI: 0.20-0.95; P = 0.038) ICD interventions, driven by a high incidence of ATP therapy in the TV-ICD group. The S- and TV-ICD patients experienced similar 5-year rate of device-related complications, albeit the risk of major lead-related complications was lower in S-ICD patients (HR: 0.17; 95%CI: 0.038-0.79; P = 0.023). The TV- and S-ICD patients displayed similar risk of disease-related complications (HR: 0.64; 95%CI: 0.27-1.52; P = 0.309) and mortality (HR: 0.74; 95%CI: 0.29-1.87; P = 0.521).

CONCLUSION

Hypertrophic cardiomyopathy patients implanted with a S-ICD had lower 5-year risk of appropriate and inappropriate ICD therapies as well as of major lead-related complications as compared to those implanted with a TV-ICD. Long-term comparative follow-up studies will clarify whether the lower incidence of major lead-related complications will translate into a morbidity or survival benefit.

Electrocardiogram analysis in Anderson-Fabry disease: a valuable tool for progressive phenotypic expression tracking

Background

Electrocardiogram (ECG) has proven to be useful for early detection of cardiac involvement in Anderson-Fabry disease (AFD); however, little evidence is available on the association between ECG alterations and the progression of the disease.

Aim and Methods

To perform a cross sectional comparison of ECG abnormalities throughout different left ventricular hypertrophy (LVH) severity subgroups, providing ECG patterns specific of the progressive AFD stages. 189 AFD patients from a multicenter cohort underwent comprehensive ECG analysis, echocardiography, and clinical evaluation.

Results

The study cohort (39% males, median age 47 years, 68% classical AFD) was divided into 4 groups according to different degree of left ventricular (LV) thickness: group A ≤ 9 mm (n = 52, 28%); group B 10-14 mm (n = 76, 40%); group C 15-19 mm (n = 46, 24%); group D ≥ 20 mm (n = 15, 8%). The most frequent conduction delay was right bundle branch block (RBBB), incomplete in groups B and C (20%,22%) and complete RBBB in group D (54%, p < 0.001); none of the patients had left bundle branch block (LBBB). Left anterior fascicular block, LVH criteria, negative T waves, ST depression were more common in the advanced stages of the disease (p < 0.001). Summarizing our results, we suggested ECG patterns representative of the different AFD stages as assessed by the increases in LV thickness over time (Central Figure). Patients from group A showed mostly a normal ECG (77%) or minor anomalies like LVH criteria (8%) and delta wave/slurred QR onset + borderline PR (8%). Differently, patients from groups B and C exhibited more heterogeneous ECG patterns: LVH (17%; 7% respectively); LVH + LV strain (9%; 17%); incomplete RBBB + repolarization abnormalities (8%; 9%), more frequently associated with LVH criteria in group C than B (8%; 15%). Finally, patients from group D showed very peculiar ECG patterns, represented by complete RBBB + LVH and repolarization abnormalities (40%), sometimes associated with QRS fragmentation (13%).

Conclusions

ECG is a sensitive tool for early identification and long-term monitoring of cardiac involvement in patients with AFD, providing "instantaneous pictures" along the natural history of AFD. Whether ECG changes may be associated with clinical events remains to be determined.

From the phenotype to precision medicine: an update on the cardiomyopathies diagnostic workflow

Cardiomyopathies are disease of the cardiac muscle largely due to genetic alterations of proteins with 'structural' or 'functional' roles within the cardiomyocyte, going from the regulation of contraction-relaxation, metabolic and energetic processes to ionic fluxes. Modifications occurring to these proteins are responsible, in the vast majority of cases, for the phenotypic manifestations of the disease, including hypertrophic, dilated, arrhythmogenic and restrictive cardiomyopathies. Secondary nonhereditary causes to be excluded include infections, toxicity from drugs or alcohol or medications, hormonal imbalance and so on. Obtaining a phenotypic definition and an etiological diagnosis is becoming increasingly relevant and feasible, thanks to the availability of new tailored treatments and the diagnostic advancements made particularly in the field of genetics. This is, for example, the case for transthyretin cardiac amyloidosis, Fabry disease or dilated cardiomyopathies due to laminopathies. For these diseases, specific medications have been developed, and a more tailored arrhythmic risk stratification guides the implantation of a defibrillator. In addition, new medications directly targeting the altered protein responsible for the phenotype are becoming available (including the myosin inhibitors mavacantem and aficamten, monoclonal antibodies against Ras-MAPK, genetic therapies for sarcoglycanopathies), thus making a precision medicine approach less unrealistic even in the field of cardiomyopathies. For these reasons, a contemporary approach to cardiomyopathies must consider diagnostic algorithms founded on the clinical suspicion of the disease and developed towards a more precise phenotypic definition and etiological diagnosis, based on a multidisciplinary methodology putting together specialists from different disciplines, facilities for advanced imaging testing and genetic and anatomopathological competencies.

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.

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.

[Rationale and significance of the Italian Network for Cardiac Amyloidosis]

The perspective on amyloidosis has changed deeply over the last 10 years following major advances in diagnosis and treatment options, especially in cardiac amyloidosis. This intrinsically heterogeneous disease exposes to the risk of fragmentation of knowledge and requires the interaction among experts of different specialties and subspecialties. Suspicion of disease, timely recognition and confirmation of final diagnosis, prognostic stratification, clinical management and therapeutic strategies represent essential steps to be taken. Missing or delaying the diagnosis may have dramatic impact on patient outcome, as in the case of chemotherapy in unrecognized light-chain amyloidosis. Therefore, there is an urgent need for the foundation of an Italian Amyloidosis Network to deal with the challenges of this condition and orient clinical management at national and local levels. The present consensus document aims to provide the rationale and scopes of the Italian Amyloidosis Network, which has been conceived as an organizational framework for professionals managing patients with amyloidosis.

Echocardiographic Markers in the Diagnosis of Cardiac Masses

BACKGROUND

The echocardiographic parameters required for a comprehensive assessment of cardiac masses (CMs) are still largely unknown. The aim of this study was to identify and integrate the echocardiographic features of CMs that can accurately predict malignancy.

METHODS

An observational cohort study was conducted among 286 consecutive patients who underwent standard echocardiographic assessment for suspected CM at Bologna University Hospital between 2004 and 2022. A definitive diagnosis was achieved by histologic examination or, in the case of cardiac thrombi, with radiologic evidence of thrombus resolution after appropriate anticoagulant treatment. Logistic and multivariable regression analysis was performed to confirm the ability of six echocardiographic parameters to discriminate malignant from benign masses. The unweighted count of these parameters was used as a numeric score, ranging from 0 to 6, with a cutoff of ≥3 balancing sensitivity and specificity with respect to the histologic diagnosis of malignancy. Classification tree analysis was used to determine the ability of echocardiographic parameters to discriminate subgroups of patients with differential risk for malignancy.

RESULTS

Benign masses were more frequently pedunculated, mobile, and adherent to the interatrial septum (P < .001). Malignant masses showed a greater diameter and exhibited a higher frequency of irregular margins, an inhomogeneous appearance, sessile implantation, polylobate shape, and pericardial effusion (P < .001). Infiltration, moderate to severe pericardial effusion, nonleft localization, sessile implantation, polylobate shape, and inhomogeneity were confirmed to be independent predictors of malignancy in both univariate and multivariable models. The predictive ability of the unweighted score of ≥3 was very high (>0.90) and similar to that of the previously published weighted score. Classification tree analysis generated an algorithm in which infiltration was the best discriminator of malignancy, followed by nonleft localization and sessile implantation. The percentage correctly classified by classification tree analysis as malignant was 87.5%. Agreement between observer readings and CM histology ranged between 85.1% and 91.5%. The presence of at least three echocardiographic parameters was associated with lower survival.

CONCLUSIONS

In the approach to CMs, some echocardiographic parameters can serve as markers to accurately predict malignancy, thereby informing the need for second-level investigations and minimizing the diagnostic delay in such a complex clinical scenario.

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.

Clinical application of CMR in cardiomyopathies: evolving concepts and techniques : A position paper of myocardial and pericardial diseases and cardiac magnetic resonance working groups of Italian society of cardiology

Cardiac magnetic resonance (CMR) has become an essential tool for the evaluation of patients affected or at risk of developing cardiomyopathies (CMPs). In fact, CMR not only provides precise data on cardiac volumes, wall thickness, mass and systolic function but it also a non-invasive characterization of myocardial tissue, thus helping the early diagnosis and the precise phenotyping of the different CMPs, which is essential for early and individualized treatment of patients. Furthermore, several CMR characteristics, such as the presence of extensive LGE or abnormal mapping values, are emerging as prognostic markers, therefore helping to define patients' risk. Lastly new experimental CMR techniques are under investigation and might contribute to widen our knowledge in the field of CMPs. In this perspective, CMR appears an essential tool to be systematically applied in the diagnostic and prognostic work-up of CMPs in clinical practice. This review provides a deep overview of clinical applicability of standard and emerging CMR techniques in the management of CMPs.

310 CLINICAL COURSE AND CHARACTERISTICS OF ADVANCED HEART FAILURE ASSOCIATED WITH ARRHYTHMOGENIC CARDIOMYOPATHY

Background

The prevalence and course of heart failure (HF) in arrhythmogenic cardiomyopathy (ACM) is unresolved, and previous studies have mostly focused on the right-dominant variant of the disease, less prone to HF. Conversely, ACM variants with left ventricular (LV) involvement are now increasingly recognized, often initially ‘mis-diagnosed’ as dilated cardiomyopathy. Aim of this study was therefore to describe the prevalence and clinical course of advance HF in the full clinical spectrum of ACM.

Methods

We retrospectively reviewed records of all ACM patients diagnosed before 2021 from 3 Italian Cardiomyopathy Referral Centres (Azienda Ospedaliero Universitaria Careggi; Policlinico Sant’Orsola; Azienda Ospedaliero Universitaria Sant’Andrea). LV involvement was diagnosed in the presence of subepicardial late gadolinium enhancement (LGE) in at least 3 contiguous segments in the same short-axis slice at cardiac magnetic resonance, independent of whether it fulfilled the 2010 Task Force criteria for right-dominant ACM (biventricular ACM) or not (left-dominant ACM); in this latter case, diagnosis was reached after careful exclusion of other differential diagnosis, and only when at least one of the following features was present: likely pathogenic/pathogenic genetic variant associated with ACM; familial history of ACM; electrocardiographic abnormalities suggestive of ACM with LV involvement. Advanced HF was defined as NYHA functional class III/IV and/or referral for heart transplantation. Median follow-up was 6 years.

Results

Forty-four out of 174 ACM patients (25%) developed advanced HF: 10 right-dominant ACM and 34 with LV involvement. Twenty ACM patients were initially diagnosed with dilated cardiomyopathy; as such, development of advanced HF in 17 cases preceded the diagnosis of ACM. Five patients were diagnosed with ACM after heart transplantation, by histological examination. In the other 22, median time from ACM diagnosis to advanced HF development was 4 years. As compared to those without, advanced HF patients were more likely to present LV involvement. During clinical course, 20 (46%) advanced HF patients received at least one appropriate ICD intervention, with 13 experiencing an electrical storm. Twenty-six (59%) patients required HF-related hospitalization, and 32 (72%) were referred for heart transplantation with 25 ultimately receiving it. ACM patients with advanced HF, compared to those without, experienced a higher rate of mortality (36% vs. 6%; OR 3.5 [95%CI: 1.4-8.7], p=0.01) and ventricular arrhythmic events (41% vs. 11%; OR 2.4 [95%CI: 1.1-5.0], p=0.02).

Conclusions

Advanced HF progression in ACM is not rare, and occurs more frequently in variants with LV involvement. Advanced HF is associated with increased mortality and arrhythmic risk.

710 NEW PROSPECTIVES IN THE USE OF ELECTROCARDIOGRAM IN ANDERSON-FABRY DISEASE ON AND OFF SPECIFIC DISEASE THERAPY: EARLY DIAGNOSIS AND RESPONSE TO THERAPY

Background

Anderson Fabry disease (AFD) is a rare X-linked lysosomal storage disorder caused by deficient activity of α-galactosidase A bringing to intracellular accumulation of globotriaosylceramide (Gb3) in affected tissues, including heart. Progressive cardiac involvement has shown to cause electrocardiographic modifications in these patients. Treatment with enzyme replacement therapy (ERT) or chaperone therapy has demonstrated to decrease Gb3 levels in the heart, but little is known about its influence on ECG evolution.

Purpose

to gain new insights about ECG evolution in AFD patients on and off specific disease therapy and to assess its potential role in the diagnosis and the follow-up of these patients.

Methods

we analysed the ECG evolution of a multicentre study cohort of 170 patients with a diagnosis of AFD (64 males 38%, median age 46±15 years) for a median follow-up of 64±48 months, dividing them into patients off (group A, N=63) and on (group B, N= 107) specific therapy.

Results

the two groups did not differ as regard age at baseline (47±14 vs 44±12 years; p=0,171) but patients off specific disease therapy (group A) showed lower prevalence of male sex [13(21%) vs 51(48%); p=&lt;0,001], classic phenotype [36(57%) vs 82(77%); p&lt;0,001)] and lower values of maximal wall thickness [11±3 vs 13±4 mm; p=&lt;0,0001]. At baseline group A presented more frequently a normal ECG [44(70%) vs 41(38%), p=0,0001] showing lower prevalence of repolarization anomalies [16(25%) vs 51(48%), p=0,005] and left ventricular hypertrophy [14(22%) vs 51(48%), p=0,001]. During follow-up we observed ECG progression in 9 patients in group A (14%), characterized by the development of repolarization anomalies (N=5; 8%), incomplete right bundle branch block (N=4; 6%), shortening of PR interval (N=2; 3%), left ventricular hypertrophy (N=2; 3%), left atrial enlargement (N=2; 3%) and complete right bundle branch block (N=1; 2%). Differently, in group B an ECG evolution was observed in 31 patients (29%) characterized by the development of repolarization anomalies (N=19; 18%), left atrial enlargement (N=12; 12%), complete right bundle branch block (N=8; 8%), left anterior fascicular hemiblock (N=4; 4%) and left ventricular hypertrophy (N=3; 3%).We observed an improvement in ECG features with a regression of repolarization anomalies only in 1 patient off therapy, which could be explained by the presence of transient overload anomalies. We didn't detect any left bundle brunch block among the patients of the two groups.

Conclusion

We observed ECG progression despite specific disease therapy in 29% of patients of group B showing a potential role of ECG as a marker of cardiac specific response to therapy in these patients. Differently we detected ECG progression in 14% of patients off specific therapy, which is consistent with their less advanced cardiac involvement (lower prevalence of male sex, classic phenotype and lower maximum wall thickness), suggesting that ECG could be an important tool to detect an initial cardiac involvement in these patients even in absence of hypertrophy. The absence of left bundle branch blocks in the two groups compared with a significant prevalence of complete and incomplete right conduction delay could suggest a prevalent involvement of the right bundle branch in these patients and could represent a red flag for the diagnosis of AFD.

826 NEW THERAPEUTIC PERSPECTIVES IN CARDIAC AMYLOIDOSIS

Man, 72 years old, smoker, hypertensive and dyslipidemic, came to our clinic suspected of heart disease with a hypertrophic phenotype. In anamnesis there was a recent hospitalization for heart failure in the course of undated atrial fibrillation. During hospitalization because of the presence of antero-septal and lateral QS complexes, a coronary disease was excluded by coronary angiography while the echocardiogram showed a left ventricle with moderate concentric wall thickening, LVEF 38% with a restrictive transmitral pattern. The patient was discharged on therapy with ramipril, bisoprolol, canrenone, furosemide and rivaroxaban with an electrical cardioversion program which had been subsequently ineffective.

At the time of the first evaluation the patient was symptomatic of dyspnea in functional class NYHA III, he also reported in anamnesis a progressive reduction of exercise tolerance for about two years and a previous surgery for bilateral carpal tunnel syndrome 5 years earlier.

The echocardiogram showed concentric parietal thickening in the presence of granular sparkling, apical sparing, thickening of the valvular apparatus and reduced GLS (- 12%) which led to a suspect of cardiac amyloidosis.

To complete the diagnosis, the patient underwent: total-body bone scan with 99-Tc-DPD (Perugini score = 2); assay of serum kappa and lambda light chains (negative), serum and urinary immunofixation (negative), NT-proBNP (980 pg / mL) and a determination of troponin I (32 ng / L) which showed a picture of transthyretin cardiac amyloidosis. The genetic sampling confirmed the presence of the Ile68Leu transthyretin mutation and a neurological evaluation with electromyography ruled out a peripheral polyneuropathy.

During follow-up the patient presented a worsening of clinical and instrumental pattern despite the progressive uptitration of diuretic therapy and the addition of metolazone with a simultaneous deterioration of left ventricular dysfunction (LVEF 30%) at echocardiogram.

Therefore, the patient's case and possible therapeutic strategies were discussed collectively as it was not possible to access conventional therapies for cardiac amyloidosis with Tafamidis, Inotersen and Patisiran due to the contextual functional class NYHA&gt; II and the absence of polyneuropathy, not it was possible to undertake biventricular resynchronization in the absence of intraventricular block or to implement therapy for heart failure with reduced ejection fraction due to intolerance. As a last option, implantation of a cardiac contractility modulation device (CCM) was proposed and performed via right subclavicular.

At the successive follow-up after implantation, the patient showed a slight clinical and instrumental improvement and it was possible to reduce the diuretic dose, discontinuing metolazone. The echocardiogram also showed a slight increase in LVEF (35%).

The long-term outpatient evaluation of the patient is currently underway with the aim of undertaking specific therapy with Tafamidis if the prescription criteria are met. Family screening has started.

Conclusion

the present clinical case represents an example of the application of alternative and potentially effective therapeutic strategies in patients with cardiac amyloidosis not susceptible to conventional pharmacological treatments.

172 CLINICAL AND PROGNOSTIC IMPLICATIONS OF RV UPTAKE WITH RADIONUCLIDE SCINTIGRAPHY IN TRANSTHYRETIN CARDIAC AMYLOIDOSIS

Aims

The prognostic role of bone tracer uptake in transthyretin cardiac amyloidosis (ATTR-CA) is controversial. The study investigated the potential prognostic significance of biventricular (BiV) uptake in ATTR-CA.

Methods

Consecutive ATTR-CA patients who had cardiac scintigraphy with acquisition of planar and single-photon emission computed tomography (SPECT) images from the National Amyloidosis Centre (NAC) and four Italian centres were included. Planar BiV uptake was defined in presence of right ventricle (RV) uptake and graded in combination with SPECT imaging. The primary outcome was all-cause mortality.

Results

Among 1422 patients with ATTR-CA, BiV uptake was found in 85% of cases on planar scintigraphy and in 100% of cases on SPECT images. During a median follow-up of 39 months, BiV uptake at planar scintigraphy was associated with a higher all-cause mortality compared to isolated LV uptake (40.5% vs 10.7%, p&lt;0.001), whereas the Perugini scale was not (p=0.27 in grade 2 vs 3). At multivariable analysis, RV uptake at planar scintigraphy leading to BiV uptake (HR 2.80, p=0.001), together with higher age at diagnosis (HR 1.03, p=0.001), V122I TTR variant (HR 1.60, p=0.001), NAC ATTR Stage (HR 1.29, p=0.003), E/e’ (HR 1.02, p=0.044), right atrium area index (HR 1.04, p=0.018) and GLS (HR 1.05, p=0.003) were independently associated with all-cause death. At time-dependent ROC curve analysis, the addition of planar BiV uptake to the NAC stage resulted in improved accuracy of the model for prediction of all-cause death (from AUC 0.74 to 0.79; p&lt;0.001).

Conclusions

Planar RV uptake leading to BiV uptake identified ATTR-CA patients with worse outcome, potentially serving as a novel prognostic marker.

486 ELECTROCARDIOGRAPHIC EVOLUTION IN ANDERSON-FABRY PATIENTS ON DISEASE SPECIFIC THERAPY

Background

Anderson-Fabry disease (AFD) is an X-linked lysosomal storage disorder that have gained attention due to the availability of therapeutic options. Disease specific therapy (DST), either by enzyme replacement therapy or oral pharmacological chaperone, is the mainstay for AFD treatment. Although its widespread use, few data are available on the electrocardiographic variations associated with DST.

Purpose

To evaluate ECG findings and variations in AFD according to time duration of DST, comparing patients under long-term therapy with naïve patients starting therapy during follow-up.

Methods

One-hundred-seventy-nine AFD patients, ≥18 years old, with 2 readable ECGs, were recruited in the present multicentre study cohort. Two patients were excluded due to pacemaker (PM) implantation. Only patients on DST (n=107) were considered for final cohort and divided into 2 groups according to therapy duration: Group A (n=42) included patients treated for ≥12 months at the time of first evaluation, whereas Group B patients (n=65) started therapy during follow-up.

Results

Group A and Group B had not significant difference in terms of age at presentation (48[39-60] vs 48[36-56]years; p=0.856) and maximal wall thickness (13[11-15] vs 13[11-18]mm; p=0.090) whereas they differed for male prevalence (61% vs 38%; p=0.029) and classic phenotype (86% vs 29%; p&lt;0.0001). At baseline, more than half of both groups had ECG abnormalities (61% vs 61%; p=1.000). The prevalence among Group A and Group B of atrial fibrillation (AF 5% vs 6%; p=1.000), first degree atrioventricular block (AVB, 7% vs 5%; p=0.677), right bundle branch block (RBBB, complete 7% vs 8%; p=1.000; incomplete RBBB 14% vs 12%; p=0.776), left anterior fascicular block (LAFB, 10% vs 9%;p=1.000) and repolarization abnormalities (48% vs 38%; p=0.423) was not significantly different. Conversely, left ventricular hypertrophy (LVH) was more prevalent in Group A (64% vs 37%; p=0.010).

During the follow-up (57[60-28] months for Group A vs 70[37-85] months for Group B; p=0.152), both groups developed electrocardiographic alterations (38% vs 23%; p=0.127). Specifically, in GroupA, 4 (10%) patients presented AF, 1 (2%) AVB, 7 (17%) complete or incomplete RBBB, 4 (10%) LAFB, 1 (2%) LVH and 8 (19%) repolarization abnormalities. In Group B, 2 (3%) developed AF, 1 (2%) AVB, 7 (11%) complete or incomplete RBBB, 2(3%) LVH and 11(17%) repolarization abnormalities; none developed LAFB.

Conclusions

In this AFD cohort, both patients on chronic DST (Group A) and patients who started treatment during follow-up (Group B) developed ECG alterations. Treatment status didn't affect considerably the developing of ECG abnormalities and DST did not prevent ECG changes. ECG alterations during the follow-up were more frequent in Group A (38% vs 23%), mainly composed by classic phenotype and male patients, thus supporting a prompt start of therapy at an early stage.

Changes in Right Ventricular-to-Pulmonary Artery Coupling After Transcatheter Edge-to-Edge Repair in Secondary Mitral Regurgitation

BACKGROUND

Preprocedural right ventricular-to-pulmonary artery (RV-PA) coupling is a major predictor of outcome in patients with secondary mitral regurgitation (SMR) undergoing transcatheter edge-to-edge mitral valve repair (M-TEER). However, clinical significance of changes in RV-PA coupling after M-TEER is unknown.

OBJECTIVES

The aim of this study was to evaluate changes in RV-PA coupling after M-TEER, their prognostic value, and predictors of improvement.

METHODS

This was a retrospective observational study, including patients undergoing successful M-TEER (residual mitral regurgitation ≤2+ at discharge) for SMR at 13 European centers and with complete echocardiographic data at baseline and short-term follow-up (30-180 days). RV-PA coupling was assessed with the use of echocardiography as the ratio of tricuspid annular plane systolic excursion to pulmonary artery systolic pressure (TAPSE/PASP). All-cause death was assessed at the longest available follow-up starting from the time of the echocardiographic reassessment.

RESULTS

Among 501 patients included, 331 (66%) improved their TAPSE/PASP after M-TEER (responders) at short-term follow-up (median: 89 days; IQR: 43-159 days), whereas 170 (34%) did not (nonresponders). Lack of previous cardiac surgery, low postprocedural mitral mean gradient, low baseline TAPSE, high baseline PASP, and baseline tricuspid regurgitation were independently associated with TAPSE/PASP improvement after M-TEER. Compared with nonresponders, responders had lower New York Heart Association functional class and less heart failure hospitalizations at short-term follow-up. Improvement in TAPSE/PASP was independently associated with reduced risk of mortality at long-term follow-up (584 days; IQR: 191-1,243 days) (HR: 0.65 [95% CI: 0.42-0.92]; P = 0.017).

CONCLUSIONS

In patients with SMR, improvement in TAPSE/PASP after successful M-TEER is predicted by baseline clinical and echocardiographic variables and postprocedural mitral gradient, and is associated with a better outcome.

Evolution of tricuspid regurgitation after transcatheter edge-to-edge mitral valve repair for secondary mitral regurgitation and its impact on mortality

AIM

To evaluate short-term changes in tricuspid regurgitation (TR) after transcatheter edge-to-edge mitral valve repair (M-TEER) in secondary mitral regurgitation (SMR), their predictors and impact on mortality.

METHODS AND RESULTS

This is a retrospective analysis of SMR patients undergoing successful M-TEER (post-procedural mitral regurgitation ≤2+) at 13 European centres. Among 503 patients evaluated 79 (interquartile range [IQR] 40-152) days after M-TEER, 173 (35%) showed ≥1 degree of TR improvement, 97 (19%) had worsening of TR, and 233 (46%) remained unchanged. Smaller baseline left atrial diameter and residual mitral regurgitation 0/1+ were independent predictors of TR ≤2+ after M-TEER. There was a significant association between TR changes and New York Heart Association class and pulmonary artery systolic pressure decrease at echocardiographic re-assessment. At a median follow-up of 590 (IQR 209-1103) days from short-term echocardiographic re-assessment, all-cause mortality was lower in patients with improved compared to those with unchanged/worsened TR (29.6% vs. 42.3% at 3 years; log-rank p = 0.034). Baseline TR severity was not associated with mortality, whereas TR 0/1+ and 2+ at short-term follow-up was associated with lower all-cause mortality compared to TR 3/4+ (30.6% and 35.6% vs. 55.6% at 3 years; p < 0.001). A TR ≤2+ after M-TEER was independently associated with a 42% decreased risk of mortality (p = 0.011).

CONCLUSION

More than one third of patients with SMR undergoing successful M-TEER experienced an improvement in TR. Pre-procedural TR was not associated with outcome, but a TR ≤2+ at short-term follow-up was independently associated with long-term mortality. Optimal M-TEER result and a small left atrium were associated with a higher likelihood of TR ≤2+ after M-TEER.

Prognostic implications of biventricular uptake of bone tracers at planar scintigraphy in transthyretin cardiac amyloidosis

Background

The prognostic role of bone tracer uptake in transthyretin cardiac amyloidosis (ATTR-CA) is controversial. A further characterization of cardiac retention measured by Perugini scale with differentiation between biventricular (BiV) and isolated left ventricle (LV) uptake has never been attempted previously.

Purpose

The study investigated the potential prognostic significance of BiV uptake in ATTR-CA.

Methods

In this multicentre, observational study, we analysed data of ATTR-CA patients who underwent bone tracer scintigraphy with acquisition of both planar and single photon emission computed tomography (SPECT) imaging. Cardiac uptake was defined according to the Perugini visual scale. Planar BiV uptake was defined according to right ventricle (RV) uptake: 0= absent, 1= &lt; bone, 2= equal to bone, and 3= &gt; bone and confirmed by SPECT imaging. The primary outcome was a composite of cardiac death or hospitalization for heart failure. The secondary outcome was all-cause mortality.

Results

All 124 ATTR-CA patients enrolled had LV and RV free wall uptake on SPECT images. Of them, 93 (75%) had BiV uptake visible on planar scintigraphy. BiV uptake was found in 14%, 70%, and 92% of Perugini grade 1, 2 and 3 respectively. Compared to those with isolated LV uptake, patients with BiV uptake were older (81 vs 77 years, p=0.006) and more frequently in NYHA≥3 (32% vs 10%, p=0.018). During a median follow-up of 21 months, BiV uptake was associated with a greater occurrence of the primary outcome compared to isolated LV uptake (40% vs 19%, p=0.021), whereas the Perugini scale was not (p=0.2) (Figure 1). At multivariable analysis, NYHA class ≥3 (hazard ratio [HR] 8.1, p=0.007), eGFR &lt;60 ml/min (HR 2.1, p=0.025) and higher degree of RV uptake (HR 1.69, p=0.007) emerged as independent prognostic parameters. In an external cohort of 463 ATTR-CA patients with a median follow-up of 30 months, planar BiV uptake was independently associated with all-cause mortality, with an incremental risk in higher grades of RV uptake (p&lt;0.001) (Figure 1).

Conclusions

The presence of BiV uptake at planar scintigraphy identified ATTR-CA patients with worse cardiovascular and global outcomes (Figure 2), potentially serving as a novel prognostic marker.

Funding Acknowledgement

Type of funding sources: None.

Electrocardiographic findings in Anderson-Fabry patients on disease specific therapy: can treatment prevent ECG changes?

Background

Anderson-Fabry disease (AFD) is an X-linked lysosomal storage disorder that have gained attention due to the availability of therapeutic options. Disease specific therapy (DST), either by enzyme replacement therapy or oral pharmacological chaperone, is the mainstay for AFD treatment. Although its widespread use, few data are available on the electrocardiographic variations associated with DST.

Purpose

To evaluate ECG findings and variations in AFD according to time duration of DST, comparing patients under long-term therapy with naïve patients starting therapy during follow-up.

Methods

One-hundred-seventy-nine AFD patients, ≥18 years old, with 2 readable ECGs, were recruited in the present multicentre study cohort. Two patients were excluded due to pacemaker (PM) implantation. Only patients on DST (n=107) were considered for final cohort and divided into 2 groups according to therapy duration: Group A (n=42) included patients treated for ≥12 months at the time of first evaluation, whereas Group B patients (n=65) started therapy during follow-up.

Results

Group A and Group B had no significant difference in terms of age at presentation (48 [39–60] vs 48 [36–56] years; p=0.856) and maximal wall thickness (13 [11–15] vs 13 [11–18] mm; p=0.090) whereas they differed for male prevalence (61% vs 38%; p=0.029) and classic phenotype (86% vs 29%; p&lt;0.0001). At baseline, more than half of both groups had ECG abnormalities (61% vs 61%; p=1.000). The prevalence among Group A and Group B of atrial fibrillation (AF, 5% vs 6%; p=1.000), first degree atrioventricular block (AVB, 7% vs 5%; p=0.677), right bundle branch block (RBBB, complete 7% vs 8%; p=1.000; incomplete RBBB 14% vs 12%; p=0.776), left anterior fascicular block (LAFB, 10% vs 9%; p=1.000) and repolarization abnormalities (48% vs 38%; p=0.423) was not significantly different. Conversely, left ventricular hypertrophy (LVH) was more prevalent in Group A (64% vs 37%; p=0.010).

During the follow-up period (57 [60–28] months for Group A vs 70 (37–85) months for Group B; p=0.152), both groups developed electrocardiographic alterations (38% vs 23%; p=0.127). In particular, in Group A, 4 (10%) patients presented AF, 1 (2%) AVB, 7 (17%) complete or incomplete RBBB, 4 (10%) LAFB, 1 (2%) LVH and 8 (19%) repolarization abnormalities. In Group B, 2 (3%) developed AF, 1 (2%) AVB, 7 (11%) complete or incomplete RBBB, 2 (3%) LVH and 11 (17%) repolarization abnormalities; none developed LAFB.

Conclusions

In this AFD cohort, both patients on chronic DST (Group A) and patients who started treatment during follow-up (Group B) developed ECG alterations. ECG changes during the follow-up were more frequent in Group A (38% vs 23%), mainly composed by classic phenotype and male patients, suggesting a prompt start of therapy at an early stage.

Funding Acknowledgement

Type of funding sources: None.

Risk stratification in Arrhythmogenic Right Ventricular Cardiomyopathy: the impact of genotype on the 2019 ARVC risk calculator

Introduction

Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC) is associated with sudden cardiac death (SCD). The 2019 ARVC risk model has been proposed as a method to quantify arrhythmic risk, but the impact of genotype its performance has not been addressed.

Purpose

To study arrhythmic outcomes in patients with ARVC and the performance of the 2019 ARVC risk model in predefined genetic subgroups.

Methods

This is an international, retrospective observational cohort study on consecutively evaluated patients with ARVC recruited from 17 centres in 7 countries. Inclusion criteria were: (i) a definite diagnosis of ARVC according to the 2010 Task Force Criteria; (ii) no history of sustained ventricular arrhythmia (VA) prior to first assessment at the participating centre; (iii) a follow up period of ≥1 month; (iv) age of diagnosis ≥14 years. Sustained ventricular arrhythmia (sustained ventricular tachycardia, appropriate implantable cardioverter defibrillator intervention, aborted SCD, or SCD) comprised the primary outcome (VA). Discriminative ability was assessed by Uno's concordance index (c-statistic) and calibration with the calibration plot slope. Fine-Gray regression was used to model the impact of clinical predictors on the arrhythmic outcome, in the context of competing risks (heart transplantation and non-arrhythmic death). The cumulative probability and 95% confidence intervals (95% CI) for the occurrence of an outcome were estimated using the Aalen-Johansen estimate in order to take into account competing risks.

Results

The study cohort comprised 554 ARVC patients. During a median follow-up of 6.0 [3.1,12.5] years, 100 patients (18%) experienced VA (Figure). Risk estimates for VA using the 2019 ARVC risk model showed good discriminative ability (c-statistic 0.75 (95% CI 0.70–0.81)) but with overestimation of risk (slope 0.46 (95% CI 0.33–0.63)). The ARVC risk model was compared in 4 gene groups: PKP2 (n=118, 21%); DSP (n=79, 14%); other desmosomal (n=59, 11%); and gene elusive (n=160, 29%). Discrimination and calibration were highest for PKP2 [c-statistic 0.83 (95% CI 0.75–0.91); calibration slope 0.67 (95% CI 0.40–1.04)] and lowest for the gene elusive group [c-statistic 0.65 (95% CI 0.57–0.74); calibration slope 0.26 (95% CI 0.06–0.49)]. Univariable analyses revealed variable performance of individual clinical risk markers in the different gene groups (see heatmap of hazard ratios and statistical significance in Figure). For example, RV dimensions and systolic function are significant risk markers in PKP2 but not in DSP patients and the opposite is true of LV systolic function (Figure).

Conclusion

The 2019 ARVC risk model performs reasonably well in gene positive ARVC, (particularly for PKP2) but is more limited in gene elusive patients. Genotype specific risk factors should be considered in ARVC patients.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): British Heart Foundation

Diagnostic pathways leading to arrhythmogenic left ventricular cardiomyopathy in a single center cohort

Background

Despite major advances, the recognition of arrhythmogenic left ventricular cardiomyopathy (ALVC) remains challenging, since this clinical entity is often concealed in different clinical settings both in terms of clinical onset and imaging phenotype, resulting in significant delays in diagnosis with prognostic implications.

Purpose

To describe a single Center cohort of ALVC patients, focusing on the spectrum of clinical presentation and diagnostic pathways.

Methods

Patients were retrospectively evaluated between January 2012 and January 2022. Diagnosis was based on 1) ≥3 contiguous segments with subepicardial/midwall LGE in the LV at cardiac magnetic resonance (CMR) plus a likely pathogenic/pathogenic arrhythmogenic cardiomyopathy (ACM) associated genetic mutation and/or familial history of ACM and/or red flags for ALVC (i.e, negative T waves in V4–6/aVL, low voltages in limb leads) or 2) pathology examination of explanted hearts/autoptic cases suffering from sudden cardiac death (SCD). Patients with significant right ventricular involvement were excluded.

Results

Sixty-six patients were evaluated for suspected ALVC: 8 phenocopies were excluded (6 acute myocarditis and 2 sarcoidosis) after a comprehensive clinical and multi-modality instrumental evaluation. The final study cohort was composed by 56 patients (55% males, median age 45 years), from 36 families. Diagnostic pathways leading to diagnosis were: SCD in 4 (7%), ventricular arrhythmias in 11 (20%), chest pain in 9 (16%), heart failure in 7 (12%), and familial screening in 25 (45%) (Figure 1). An echocardiogram was available for all but 2 patients with SCD: 25 (46%) had normal phenotype, 17 (32%) had a hypokinetic non dilated cardiomyopathy, and 12 (22%) had a dilated cardiomyopathy (DCM). Of the 49 tested patients, 31 (63%) had a pathogenic/likely pathogenic DNA variant: desmoplakin (DSP, N=21), filamin C (FLNC, N=4), SCN5A (N=3) were the most frequently involved genes; 8 patients had a double gene mutation. Twenty-four patients (43%) had previously received a diagnosis other than ALVC: 10 idiopathic DCM, 9 acute myocarditis, 4 post-myocarditis DCM, 2 acute myocardial injury/non-ST elevated myocardial infarction. In 13 patients ALVC was diagnosed with the introduction of CMR in the diagnostic work-up of a DCM, in 2 cases the diagnosis was done with the pathology examination after heart transplantation. The median diagnostic delay was of 8 years, with a maximum of 20 years. It is worth nothing that patients from the same family might have different diagnostic pathways and phenotypes of ALVC (Figure 2).

Conclusions

ALVC is a challenging diagnosis, hidden in different clinical scenarios. Five main clinical pathways leading to ALVC diagnosis may be identified: ventricular arrhythmias, chest pain, heart failure, SCD at first presentation, and clinical/instrumental familial screening.

Funding Acknowledgement

Type of funding sources: None.

Electrocardiographic evolution in Anderson-Fabry disease patients on and off specific therapy: a potential marker to study the therapeutic cardiac goal

Background

Anderson Fabry disease (AFD) is an X-linked lysosomal storage disorder leading to a deficiency in α-galactosidase A and globotriasylceramide (Gb3) deposition in different organs, including the heart. In AFD patients electrocardiogram (ECG) represents an important tool to detect cardiac involvement. AFD specific therapy (enzyme replacement or chaperon therapy) has shown to modify the natural history of the disease and to decrease Gb3 levels, but so far there are no data on its influence on ECG evolution.

Purpose

To assess the progression of ECG features in AFD patients on and off specific disease therapy and to evaluate the potential role of ECG in studying the cardiac specific response to therapy.

Methods

We recruited 170 patients with an established AFD diagnosis, ≥18 years old (64 males 38%, median age 46±15 years) in a multicentre study cohort. We analysed their ECG evolution for a median follow-up of 64±48 months in patients off (group A, N=63) and on (group B, N=107) specific therapy.

Results

AFD patients off specific disease therapy (group A) had similar age at baseline compared to those on therapy (47±14 vs 44±12 years; p=0,171), however significantly differed for males prevalence [13 (21%) vs 51 (48%); p≤0,001], classic phenotype [36 (57%) vs 82 (77%); p&lt;0,001)] and maximal wall thickness [11±3 vs 13±4 mm; p≤0,0001]. As regards ECG features at baseline, group A showed a lower prevalence of repolarization anomalies [16 (25%) vs 51 (48%), p=0,005], left ventricular hypertrophy [14 (22%) vs 51 (48%), p=0,001], pseudo necrosis [4 (6%) vs 18 (17%) vs, p≤0,060] and short PR [2 (3%) vs 12 (11%), p=0.0845]. During the follow-up ECG progression was observed in 9 patients in group A (14%), characterized by the development of repolarization anomalies (N=5; 8%), incomplete right bundle block (N=4; 6%), shortening of PR interval (N=2; 3%), left ventricular hypertrophy (N=2; 3%), left atrial enlargement (N=2; 3%) and complete right bundle block (N=1; 2%). Differently, in group B an ECG evolution was observed in 31 patients (29%) characterized by the development of repolarization anomalies (N=19; 18%), left atrial enlargement (N=12; 12%), complete right bundle block (N=8; 8%), left anterior fascicular hemiblock (N=4; 4%), left bundle block (N=4, 4%) and left ventricular hypertrophy (N=3; 3%). Among patients off therapy we observed an improvement of ECG in 1 patient characterized by regression of repolarization anomalies, which could be explained with the presence of transient overload anomalies.

Conclusion

In AFD patients off and on specific disease therapy, ECG evolution was detected in 14% and 29% respectively, consistently with the more advanced cardiac involvement in patients on therapy (higher prevalence of male sex, classic phenotype and higher maximum wall thickness). The fact that one third of the patients showed ECG changes progression despite being on specific disease therapy could be relevant to better defined the therapeutic cardiac goal.

Funding Acknowledgement

Type of funding sources: None.

ECG as a storytelling of cardiac involvement evolution in Anderson Fabry disease

Background

Cardiac involvement in Anderson-Fabry disease (AFD) is related to a progressive glycosphingolipid storage over time and is characterized by left ventricular hypertrophy (LVH), conduction abnormalities and myocardial fibrosis. ECG is useful for early recognition of AFD, however evidence is limited on the association between ECG alterations and disease stage.

Purpose

To assess the relationship between ECG characteristics and progressive cardiac involvement, from the pre-hypertrophic phase to phenotypes with increasing degree of LVH.

Methods

In a multicenter cohort, 183 AFD patients (40% male, age 47±12 years, 60% affected by “classical AFD”) underwent ECG and transthoracic echocardiography. Patients were divided into 4 groups according to the different degree of LV thickness measured in parasternal short axis view: group A ≤9 mm (N=46, 25%), group B 10–14 mm (N=77, 42%), group C 15–19 mm (N=45, 25%) and group D ≥20 mm (N=15, 8%). Patients with pacemaker and under 18 years of age were excluded.

Results

A normal ECG was present in 89% in group A, 59% in group B, 11% in group C and it was absent in group D. Short PR (&lt;120 ms) was more frequent in group A, whereas with LVH increasing, median PR interval duration significantly prolonged among the 4 groups (136 [125–150]vs 141 [130–160] vs 160 [130–180] vs 170 [130–180] ms, p=0.002 respectively). Median P-wave duration was shorter in group A and B compared to group C and D (80 m vs 100 ms, p&lt;0.001), while both QRS and QTc gradually increased. Median Sokolow-Lyon voltage criteria statistically augmented among the groups (22 [18–26] vs 27 [20–33] vs 32 [25–45] vs 35 [18–40] mm, p&lt;0.001 respectively), along with right ventricular hypertrophy (0%, 1%, 11%, 8%, p=0.02). Right bundle branch block (RBBB) had a higher frequency in advanced stages (0%, 34%, 34%, 40%, p&lt;0.001), with a prevalence of complete RBBB of 46% in group D. Similarly, left anterior fascicular block (0%, 7%, 18%, 46%, p&lt;0.001) and QRS fragmentation (2%, 11%, 25%, 23%, p=0.009) were more common in advanced stages. No differences were found in left bundle branch block (LBBB), in low QRS voltages or in LV pre-excitation prevalence. According with the wall thickness increase, negative T waves were more frequent in lateral (4%, 21%, 70%, 77%, p&lt;0.001) and inferior leads (6%, 15%, 32%, 46%, p 0.001), as well as their association with ST-T depression (4%, 17%, 64%, 46%, p&lt;0.001). Giant negative T waves were present only in group C and D (16% and 31%) mainly representing a LVH distribution toward the apex.

Conclusions

ECG is a very useful tool to stage cardiac involvement evolution in AFD. Peculiar ECG characteristics evolve together with LV wall thickness: incomplete and progressively complete RBBB usually associated (preceding or following) LVH and/or typical repolarization abnormalities in inferior or lateral leads and giant negative T waves in the more advanced stages are the most frequent and typical ECG patterns.

Funding Acknowledgement

Type of funding sources: None.

[Ten questions about transthyretin amyloidosis]

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.

Importance of genotype for risk stratification in arrhythmogenic right ventricular cardiomyopathy using the 2019 ARVC risk calculator

AIMS

To study the impact of genotype on the performance of the 2019 risk model for arrhythmogenic right ventricular cardiomyopathy (ARVC).

METHODS AND RESULTS

The study cohort comprised 554 patients with a definite diagnosis of ARVC and no history of sustained ventricular arrhythmia (VA). During a median follow-up of 6.0 (3.1,12.5) years, 100 patients (18%) experienced the primary VA outcome (sustained ventricular tachycardia, appropriate implantable cardioverter defibrillator intervention, aborted sudden cardiac arrest, or sudden cardiac death) corresponding to an annual event rate of 2.6% [95% confidence interval (CI) 1.9-3.3]. Risk estimates for VA using the 2019 ARVC risk model showed reasonable discriminative ability but with overestimation of risk. The ARVC risk model was compared in four gene groups: PKP2 (n = 118, 21%); desmoplakin (DSP) (n = 79, 14%); other desmosomal (n = 59, 11%); and gene elusive (n = 160, 29%). Discrimination and calibration were highest for PKP2 and lowest for the gene-elusive group. Univariable analyses revealed the variable performance of individual clinical risk markers in the different gene groups, e.g. right ventricular dimensions and systolic function are significant risk markers in PKP2 but not in DSP patients and the opposite is true for left ventricular systolic function.

CONCLUSION

The 2019 ARVC risk model performs reasonably well in gene-positive ARVC (particularly for PKP2) but is more limited in gene-elusive patients. Genotype should be included in future risk models for ARVC.

Clinical Features and Natural History of Preadolescent Nonsyndromic Hypertrophic Cardiomyopathy

BACKGROUND

Up to one-half of childhood sarcomeric hypertrophic cardiomyopathy (HCM) presents before the age of 12 years, but this patient group has not been systematically characterized.

OBJECTIVES

The aim of this study was to describe the clinical presentation and natural history of patients presenting with nonsyndromic HCM before the age of 12 years.

METHODS

Data from the International Paediatric Hypertrophic Cardiomyopathy Consortium on 639 children diagnosed with HCM younger than 12 years were collected and compared with those from 568 children diagnosed between 12 and 16 years.

RESULTS

At baseline, 339 patients (53.6%) had family histories of HCM, 132 (20.9%) had heart failure symptoms, and 250 (39.2%) were prescribed cardiac medications. The median maximal left ventricular wall thickness z-score was 8.7 (IQR: 5.3-14.4), and 145 patients (27.2%) had left ventricular outflow tract obstruction. Over a median follow-up period of 5.6 years (IQR: 2.3-10.0 years), 42 patients (6.6%) died, 21 (3.3%) underwent cardiac transplantation, and 69 (10.8%) had life-threatening arrhythmic events. Compared with those presenting after 12 years, a higher proportion of younger patients underwent myectomy (10.5% vs 7.2%; P = 0.045), but fewer received primary prevention implantable cardioverter-defibrillators (18.9% vs 30.1%; P = 0.041). The incidence of mortality or life-threatening arrhythmic events did not differ, but events occurred at a younger age.

CONCLUSIONS

Early-onset childhood HCM is associated with a comparable symptom burden and cardiac phenotype as in patients presenting later in childhood. Long-term outcomes including mortality did not differ by age of presentation, but patients presenting at younger than 12 years experienced adverse events at younger ages.

C64 UNMASKING THE PREVALENCE OF AMYLOID CARDIOMYOPATHY IN THE REAL WORLD: RESULTS FROM PHASE 2 OF AC–TIVE STUDY, AN ITALIAN NATIONWIDE SURVEY

Background

Clinicians need to identify patients with amyloid cardiomyopathy (AC) at an early stage, due to the availability of disease–modifying therapies. Some echocardiographic findings may rise the suspicion of AC, also in patients with mild or no symptoms, addressing second level diagnostic tests.

Aim

To investigate the prevalence of AC in consecutive patients ≥55 years undergoing clinically indicated, routine transthoracic echocardiogram in Italy and presenting echocardiographic signs suggestive of AC.

Methods

This is a prospective multicentric study conducted in Italy. It comprises two phases: 1) a recording phase consisting in a national survey on prevalence of possible echocardiographic red flags of AC in consecutive unselected patients ≥55 years undergoing routine echocardiogram (previously published) and 2) an AC diagnostic phase involving a diagnostic work–up for AC to investigate AC prevalence among patients with at least one echocardiographic red flag (herein presented). Patients that in Phase 1 presented an “AC suggestive” echocardiogram (i.e., at least one red flag of AC in hypertrophic, non–dilated left ventricles with preserved ejection fraction) underwent clinical evaluation, blood and urine tests and scintigraphy with bone tracer. Diagnosis of transthyretin related–AC (ATTR–AC) was made in presence of grade 2–3 Perugini uptake at scintigraphy and absence of monoclonal protein. The study was registered at ClinicalTrials.gov (#NCT04738266).

Results

Of the 5315 screened echocardiograms, 381 exams (7.2%) were classified as “AC suggestive” and proceeded to Phase 2. 217 patients completed Phase 2 investigations. Main reasons for the 164 non–entering patients into Phase 2 were death (n = 49) and refusal to participate (n = 66). A final diagnosis of AC was made in 62 patients with an estimated prevalence of 28,6% (95% CI: 22,5%–34,7%). ATTR–AC was diagnosed in 51 and AL–AC in 11 patients, ascertaining a prevalence of 23,5% (95% CI: 17,8%–29,2%) and 5,1% (95% CI: 2,2%–8,0%), respectively.

Conclusion

Among a cohort of consecutive unselected patients ≥55 years with echocardiographic findings suggestive of AC, the prevalence of AC ranged from 23% up to 35%. Although ATTR–AC was predominant, AL–AC was diagnosed in a significant number of cases. Echocardiography has a fundamental role in screening patients, raising the suspicion of disease and orienting diagnostic work–up for AC.

Relationship Between Maximal Left Ventricular Wall Thickness and Sudden Cardiac Death in Childhood Onset Hypertrophic Cardiomyopathy

BACKGROUND

Maximal left ventricular wall thickness (MLVWT) is a risk factor for sudden cardiac death (SCD) in hypertrophic cardiomyopathy (HCM). In adults, the severity of left ventricular hypertrophy has a nonlinear relationship with SCD, but it is not known whether the same complex relationship is seen in childhood. The aim of this study was to describe the relationship between left ventricular hypertrophy and SCD risk in a large international pediatric HCM cohort.

METHODS

The study cohort comprised 1075 children (mean age, 10.2 years [±4.4]) diagnosed with HCM (1-16 years) from the International Paediatric Hypertrophic Cardiomyopathy Consortium. Anonymized, noninvasive clinical data were collected from baseline evaluation and follow-up, and 5-year estimated SCD risk was calculated (HCM Risk-Kids).

RESULTS

MLVWT Z score was <10 in 598 (58.1%), ≥10 to <20 in 334 (31.1%), and ≥20 in 143 (13.3%). Higher MLVWT Z scores were associated with heart failure symptoms, unexplained syncope, left ventricular outflow tract obstruction, left atrial dilatation, and nonsustained ventricular tachycardia. One hundred twenty-two patients (71.3%) with MLVWT Z score ≥20 had coexisting risk factors for SCD. Over a median follow-up of 4.9 years (interquartile range, 2.3-9.3), 115 (10.7%) had an SCD event. Freedom from SCD event at 5 years for those with MLVWT Z scores <10, ≥10 to <20, and ≥20 was 95.6%, 87.4%, and 86.0, respectively. The estimated SCD risk at 5 years had a nonlinear, inverted U-shaped relationship with MLVWT Z score, peaking at Z score +23. The presence of coexisting risk factors had a summative effect on risk.

CONCLUSIONS

In children with HCM, an inverted U-shaped relationship exists between left ventricular hypertrophy and estimated SCD risk. The presence of additional risk factors has a summative effect on risk. While MLVWT is important for risk stratification, it should not be used either as a binary variable or in isolation to guide implantable cardioverter defibrillator implantation decisions in children with HCM.

Clinical presentations leading to arrhythmogenic left ventricular cardiomyopathy

OBJECTIVES

To describe a cohort of patients with arrhythmogenic left ventricular cardiomyopathy (ALVC), focusing on the spectrum of the clinical presentations.

METHODS

Patients were retrospectively evaluated between January 2012 and June 2020. Diagnosis was based on (1) ≥3 contiguous segments with subepicardial/midwall late gadolinium enhancement in the left ventricle (LV) at cardiac magnetic resonance plus a likely pathogenic/pathogenic arrhythmogenic cardiomyopathy (AC) associated genetic mutation and/or familial history of AC and/or red flags for ALVC (ie, negative T waves in V4-6/aVL, low voltages in limb leads, right bundle branch block like ventricular tachycardia) or (2) pathology examination of explanted hearts or autoptic cases suffering sudden cardiac death (SCD). Significant right ventricular involvement was an exclusion criterion.

RESULTS

Fifty-two patients (63% males, age 45 years (31-53)) composed the study cohort. Twenty-one (41%) had normal echocardiogram, 13 (25%) a hypokinetic non-dilated cardiomyopathy (HNDC) and 17 (33%) a dilated cardiomyopathy (DCM). Of 47 tested patients, 29 (62%) were carriers of a pathogenic/likely pathogenic DNA variant. Clinical contexts leading to diagnosis were SCD in 3 (6%), ventricular arrhythmias in 15 (29%), chest pain in 8 (15%), heart failure in 6 (12%) and familial screening in 20 (38%). Thirty patients (57%) had previously received a diagnosis other than ALVC with a diagnostic delay of 6 years (IQR 1-7).

CONCLUSIONS

ALVC is hidden in different clinical scenarios with a phenotypic spectrum ranging from normal LV to HNDC and DCM. Ventricular arrhythmias, chest pain, heart failure and SCD are the main clinical presentations, being familial screening essential for the affected relatives' identification.

Unmasking the Prevalence of Amyloid Cardiomyopathy in the Real World: Results from Phase 2 of AC-TIVE Study, an Italian Nationwide Survey

AIM

To investigate the prevalence of amyloid cardiomyopathy (AC) and the diagnostic accuracy of echocardiographic red flags of AC among consecutive adult patients undergoing transthoracic echocardiogram for reason other than AC in 13 Italian institutions.

METHODS AND RESULTS

This is an Italian prospective multicentric study, involving a clinical and instrumental work-up to assess AC prevalence among patients ≥ 55 years old with an "AC suggestive" echocardiogram (i.e. at least one echocardiographic red flag of AC in hypertrophic, non-dilated left ventricles with preserved ejection fraction). The study was registered at ClinicalTrials.gov (#NCT04738266). 381 patients with an "AC suggestive" echocardiogram were identified among a cohort of 5315 screened subjects. 217 patients completed the investigations. A final diagnosis of AC was made in 62 patients with an estimated prevalence of 29% (95% CI: 23%-35%). Transthyretin-related AC (ATTR-AC) was diagnosed in 51 and light chain related AC (AL-AC) in 11 patients. Either apical sparing or a combination of ≥ 2 other echocardiographic red flags, excluding interatrial septum thickness, provided a diagnostic accuracy > 70%.

CONCLUSION

In a cohort of consecutive adults with echocardiographic findings suggestive of AC and preserved LVEF, the prevalence of AC (either ATTR or AL) was 29%. Easily available echocardiographic red flags, when combined together, demonstrated good diagnostic accuracy.