Pediatric Restrictive Cardiomyopathies

Restrictive cardiomyopathy (RCM) is the least frequent phenotype among pediatric heart muscle diseases, representing only 2.5-3% of all cardiomyopathies diagnosed during childhood. Pediatric RCM has a poor prognosis, high incidence of pulmonary hypertension (PH), thromboembolic events, and sudden death, is less amenable to medical or surgical treatment with high mortality rates. In this scenario, heart transplantation remains the only successful therapeutic option. Despite a shared hemodynamic profile, characterized by severe diastolic dysfunction and restrictive ventricular filling, with normal ventricle ejection fraction and wall thickness, RCM recognizes a broad etiological spectrum, consisting of genetic/familial and acquired causes, each of which has a distinct pathophysiology and natural course. Hence, the aim of this review is to cover the causes, clinical presentation, diagnostic evaluation, treatment, and prognosis of pediatric RCM.

Clinical Profile of Cardiac Involvement in Danon Disease: A Multicenter European Registry

BACKGROUND

The X-linked Danon disease manifests by severe cardiomyopathy, myopathy, and neuropsychiatric problems. We designed this registry to generate a comprehensive picture of clinical presentations and outcome of patients with Danon disease in cardiomyopathy centers throughout Europe.

METHODS

Clinical and genetic data were collected in 16 cardiology centers from 8 European countries.

RESULTS

The cohort comprised 30 male and 27 female patients. The age at diagnosis was birth to 42 years in men and 2 to 65 in women. Cardiac involvement was observed in 96%. Extracardiac manifestations were prominent in men but not in women. Left ventricular (LV) hypertrophy was reported in 73% of male and 74% of female patients. LV systolic dysfunction was reported in 40% of men (who had LV ejection fraction, 34±11%) and 59% of women (LV ejection fraction, 28±13%). The risk of arrhythmia and heart failure was comparable among sexes. The age of first heart failure hospitalization was lower in men (18±6 versus 28±17 years; P<0.003). Heart failure was the leading cause of death (10 of 17; 59%), and LV systolic dysfunction predicted an adverse outcome. Eight men and 8 women (28%) underwent heart transplantation or received an LV assist device. Our cohort suggests better prognosis of female compared with male heart transplant recipients.

CONCLUSIONS

Danon disease presents earlier in men than in women and runs a malignant course in both sexes, due to cardiac complications. Cardiomyopathy features, heart failure and arrhythmia, are similar among the sexes. Clinical diagnosis and management is extremely challenging in women due to phenotypic diversity and the absence of extracardiac manifestations.

A clinical and instrumental study of heart failure in amyloidotic cardiomyopathy

Background

Heart failure (HF) is one of the main features of amyloidotic cardiomyopathy (AC) and it is supposed to carry important prognostic implications. Despite the intrinsic etiologic heterogeneity of AC, HF has been mainly attributed to diastolic dysfunction, but the role played by the different amyloid subtypes of AC and by the clinical and hemodynamic factors in the pathophysiology of HF remains unclear.

Objectives

We aimed to assess the hemodynamic profile and outcome of patients with or without advanced HF (defined as NYHA class III-IV) at the time of first evaluation in light-chain (AL), hereditary transthyretin-related (h-ATTR) and non-mutant transthyretin-related (wt-ATTR) AC.

Methods

Among the 411 patients diagnosed with AC (156 AL, 131 h-ATTR, 124 wt-ATTR) at our Centre between 1990–2019, we analyzed central hemodynamic data, echocardiographic, clinical, ECG details and survival of the whole cohort. Cox regression analysis was used to stratify prognosis.

Results

112 (27%) patients presented advanced HF at first evaluation and frequently showed severe symmetric left ventricle wall thickening (higher values in h-ATTR), non-dilated left ventricle, preserved ejection fraction and pathological global longitudinal strain and/or myocardial contraction fraction.

At ECG, a significantly lower QRS voltage was present in advanced HF patients. Hemodynamically, elevated filing pressures on both cardiac sides were present in patients in NYHA III-IV class of the three etiologies. Overall survival at 2 years was 35% for AL, 83% for h-ATTR, 65% for wt-TTR. H-ATTR and wt-TTR were favorable predictors of survival, while reduced cardiac index and elevated filling pressures were indepedently associated with higher mortality.

Conclusions

The characterization of hemodynamic profile plays a central role in predicting the natural history of AC, since reduced stroke volume and elevated filling pressures are the best predictors of mortality, reflecting a physiopathological restrictive model of the disease. Conversely, left ventricular ejection fraction is rarely abnormal and it is not a reliable marker of poor prognosis, especially in the early stages of the disease. AL amyloidosis shows the worst outcome probably due to a combination of the underlying illness and light chains cardiotoxicity.

LVEF and cardiac index in HF

Funding Acknowledgement

Type of funding source: None

Electrocardiographic differences between Anderson-Fabry and sarcomeric hypertrophic cardiomyopathy and correlation with cardiac magnetic resonance

Background

Differential diagnosis between Anderson-Fabry (AF) and sarcomeric hypertrophic cardiomyopathy (HCM) is often very challenging particularly in AF patients with late onset cardiac involvement.

Purpose

To gain new insights from standard electrocardiogram (ECG) in AF disease for differential diagnosis from sarcomeric HCM. Additionally, to better understand ECG features in AF patients, a correlation substudy ECG-cardiac magnetic resonance (CMR) has been performed.

Methods

From 162 patients with definite diagnosis of AF disease, 111 [65 males, median age 57 (51–67) years] with pathologic left ventricular hypertrophy (LVH) (Group A) were compared with 111 sarcomeric HCM patients (Group B) sex, age and maximal wall thickness matched by 1:1 propensity score.

Results

AF patients showed shorter PR interval [155 (140–180) vs 163 (149–184) msec; p=0.005) and wider QRS interval [110 (100–134) vs 100 (90–106) msec; p&lt;0.0001). Additionally AF patients had a higher prevalence of complete (22% vs 3%; p&lt;0.0001) and incomplete (13% vs 1%; p&lt;0.0001) right bundle branch block (RBBB) and a higher percentage of ST segment depression (12% vs 1%; p=0.001) and inferior negative T waves (34% vs 19%; p=0.01). No differences in terms of Sokolow-Lyon and Cornell scores were found whereas total QRS score was higher in Group A [20 (16–27) vs 18 [14–22] mV; p=0.0004). Low QRS voltages and inferior Q waves were not present in AF patients. Among the 69 AF patients who underwent MRI, the 44 with late gadolinium enhancement (LGE) were older [59 (52–66) vs 53 (40–59) years; p=0.017] and had more frequently negative T waves on ECG, particularly in the inferior leads (64% vs 8%; p&lt;0.0001), compared to the 25 without LGE. At multivariate analysis, age and negative T waves were independently associated to the presence of LGE on CMR.

Conclusions

Compared to matched sarcomeric HCM, AF patients had a shorter PR, wider QRS and a higher percentage of RBBB in relation to to the different aetiology (storage vs “pure” hypertrophy). The higher total QRS score and the absence of inferior Q waves could reflect the more frequent concentric distribution of LVH. Additionally negative T waves, especially in inferior leads, are related to the presence of LGE on CMR (often in the postero-lateral wall).

Funding Acknowledgement

Type of funding source: None

Transcatheter Mitral Valve Repair in Cardiogenic Shock and Mitral Regurgitation: A Patient-Level, Multicenter Analysis

OBJECTIVES

The aim of this study was to evaluate the outcome of transcatheter mitral valve repair (TMVr) in patients with cardiogenic shock and significant mitral regurgitation (MR).

BACKGROUND

Patients in cardiogenic shock with severe MR have a poor prognosis in the setting of conventional medical therapy. Because of its favorable safety profile, TMVr is being increasingly used as an acute therapy in this population, though its efficacy remains unknown.

METHODS

A multicenter, collaborative, patient-level analysis was conducted. Patients with cardiogenic shock and moderate to severe (3+) or severe (4+) MR who were not surgical candidates were treated with TMVr. The primary outcome was in-hospital mortality. Secondary outcomes included 90-day mortality, heart failure (HF) hospitalization, and the combined event rate of 90-day mortality and HF hospitalization following dichotomization by TMVr device success.

RESULTS

Between January 2011 and February 2019, 141 patients across 14 institutions met the inclusion criteria. In-hospital mortality occurred in 22 patients (15.6%), at 90 days in 38 patients (29.5%), and at one year in 55 patients (42.6%). Median length of hospital stay following TMVr was 10 days (interquartile range: 6 to 20 days). HF hospitalization occurred in 26 patients (18.4%) at a median of 73 days (interquartile range: 26 to 546 days). When stratified by TMVr procedural results, successful TMVr reduced rates of in-hospital mortality (hazard ratio [HR]: 0.36; 95% confidence interval [CI]: 0.13 to 0.98; p = 0.04), 90-day mortality (HR: 0.36; 95% CI: 0.16 to 0.78; p = 0.01), and the composite of 90-day mortality and HF hospitalization (HR: 0.41; 95% CI: 0.19 to 0.90; p = 0.03).

CONCLUSIONS

TMVr may improve short- and intermediate-term mortality in high-risk patients with cardiogenic shock and moderate to severe MR. Randomized studies are needed to definitively establish MR as a therapeutic target in patients with cardiogenic shock.

Management of nonischemic-dilated cardiomyopathies in clinical practice: a position paper of the working group on myocardial and pericardial diseases of Italian Society of Cardiology

: Nonischemic-dilated cardiomyopathy (NIDCM) is an entity that gathers extremely heterogeneous diseases. This awareness, although leading to continuous improvement in survival, has increased the complexity of NIDCM patients' management. Even though the endorsed 'red-flags' approach helps clinicians in pursuing an accurate etiological definition in clinical practice, it is not clear when and how peripheral centers should interact with referral centers with specific expertise in challenging scenarios (e.g. postmyocarditis and genetically determined dilated cardiomyopathy) and with easier access to second-line diagnostic tools and therapies. This position paper will summarize each step in NIDCM management, highlighting the multiple interactions between peripheral and referral centers, from first-line diagnostic workup and therapy to advanced heart failure management and long-term follow-up.

Cytokine Profile in Striated Muscle Laminopathies: New Promising Biomarkers for Disease Prediction

Laminopathies are a wide and heterogeneous group of rare human diseases caused by mutations of the LMNA gene or related nuclear envelope genes. The variety of clinical phenotypes and the wide spectrum of histopathological changes among patients carrying an identical mutation in the LMNA gene make the prognostic process rather difficult, and classical genetic screens appear to have limited predictive value for disease development. The aim of this study was to evaluate whether a comprehensive profile of circulating cytokines may be a useful tool to differentiate and stratify disease subgroups, support clinical follow-ups and contribute to new therapeutic approaches. Serum levels of 51 pro- and anti-inflammatory molecules, including cytokines, chemokines and growth factors, were quantified by a Luminex multiple immune-assay in 53 patients with muscular laminopathy (Musc-LMNA), 10 with non-muscular laminopathy, 22 with other muscular disorders and in 35 healthy controls. Interleukin-17 (IL-17), granulocyte colony-stimulating factor (G-CSF) and transforming growth factor beta (TGF-β2) levels significantly discriminated Musc-LMNA from controls; interleukin-1β (IL-1β), interleukin-4 (IL-4) and interleukin-8 (IL-8) were differentially expressed in Musc-LMNA patients compared to those with non-muscular laminopathies, whereas IL-17 was significantly higher in Musc-LMNA patients with muscular and cardiac involvement. These findings support the hypothesis of a key role of the immune system in Musc-LMNA and emphasize the potential use of cytokines as biomarkers for these disorders.

Modifications of medical treatment and outcome after percutaneous correction of secondary mitral regurgitation

Aims

The optimization of guideline‐directed medical therapy (GDMT) in reduced ejection fraction heart failure (HFrEF) is associated with improved survival and can reduce the severity of secondary mitral regurgitation (SMR). Highest tolerated doses should be achieved before percutaneous mitral valve repair (pMVR) and drugs titration further pursued after procedure. The degree of GDMT titration in patients with HFrEF and SMR treated with pMVR remains unexplored. We sought to evaluate the adherence to GDMT in HFrEF in patients undergoing pMVR and to explore the association between changes in GDMT post‐pMVR and prognosis.

Methods and results

We included all the patients with HFrEF and SMR ≥ 3 + treated with pMVR between 2012 and 2019 and with available follow‐up. GDMT, comprehensive of dosages, was systematically recorded. The study endpoint was a composite of death and heart transplantation. Among 133 patients successfully treated, 121 were included (67 ± 12 years old, 77% male patients). Treatment rates of angiotensin‐converting enzyme inhibitors/angiotensin receptor blockers/angiotensin receptor neprilysin inhibitor (ACEIs/ARBs/ARNI), beta‐blockers, and mineralcorticoid receptor antagonist at baseline and follow‐up were 73% and 79%, 85% and 84%, 70% and 70%, respectively. At baseline, 33% and 32% of patients were using >50% of the target dose of ACEI/ARB/ARNI and beta‐blockers. At follow‐up (median time 4 months), 33% of patients unchanged, 34% uptitrated, and 33% of patients downtitrated GDMT. Downtitration of GDMT was independently associated with higher risk of death/heart transplantation (hazard ratio: 2.542, 95%confidence interval: 1.377–4.694, P = 0.003).

Conclusions

Guideline‐directed medical therapy is frequently underdosed in HFrEF patients with SMR undergoing pMVR. Downtitration of medications after procedure is associated with poor prognosis.

A Pathogenic Galactosidase A Mutation Coexisting With an MYBPC3 Mutation in a Female Patient With Hypertrophic Cardiomyopathy

The coexistence of GLA (Pro259Ser, c.775C>T) and MYBPC3 (c.1351+2T>C) mutations was found in a female patient with hypertrophic cardiomyopathy. Histology documented abundant vacuolisation with osmiophilic lamellar bodies and positive Gb3 immunohistochemistry. In the presence of a hypertrophic cardiomyopathy phenotype, the systematic search for unusual findings is mandatory to rule out a phenocopy.

P1248 What are the suspicious echocardiographic features of a malignant cardiac mass?

BACKGROUND

Cardiac Masses (CM) represent a rare and heterogeneous group with a prevalence of 0.3% at autopsy, divided in benign masses - primary tumors and pseudotumors - and malignant ones - primitive tumors and metastasis, either directly invading the heart and pericardium or as a consequence of hematologic spread. 2-D Echocardiography is nowadays the first line approach to define nature and management of CM, but is it enough to guide a therapeutic strategy?

PURPOSE

To evaluate echocardiographic CM malignancy features in patients admitted to our Centre between 1997 and 2017.

MATERIALS AND METHODS

We retrospectively evaluated a population of 180 consecutive patients (45% males; mean age 60 ± 16 years; BMI 25 ± 5 Kg/m2), referred to our echocardiographic lab with suspicion CM. All patients were examined in both left lateral and supine position, and heart was visualized from all available echocardiographic windows. Definite diagnosis was obtained by histologic examination of biopsy, surgical samples or, in cases of cardiac thrombi, by radiological evidence of thrombus resolution after adequate anticoagulant treatment. We excluded normal anatomical variants in the group of pseudotumors due to the impossibility of obtaining histological examination. Comparisons between categorical variables were performed by Chi-square or Fisher exact test. P values ≤ 0.05 were considered significant. Variables with statistical signification lower than p ≤ 0.05 in univariable analysis were included in logistic regression analysis to determinate independent predictors of malignant masses.

RESULTS

We detected 129 benign CM (76% primitive tumors and 24% pseudotumors) and 51 malignant cardiac tumors (45% primitive tumors and 55% metastasis). In 7 cases a poor acoustic window did not allow an optimal examination; in remaining 173 patients, the classical 2-D echocardiogram identified 157 masses with a diagnostic accuracy of 91%. Benign tumors and pseudotumours were localized predominantly in left heart chambers, while malignant primitive tumors and metastasis were mainly detected in right heart, in pericardium or in pulmonary artery branches (p &lt; 0.001). The largest ecocardiographic diameter appeared greater for the malignant masses (mean of 49 ± 26 mm) than benign ones (30 ± 16 mm, p = 0.003). The occurrance of any pericardial effusion (p &lt; 0.001), extension to pericardium (p = 0.01) or to main vessels (p = 0.006) were also associated with malignant masses. Finally, multivariate analysis showed only largest diameter (p = 0.001) and pericardial effusion (p &lt; 0.001) were independent predictors of malignancy.

CONCLUSION

2D Echocardiography is an excellent, non invasive technique for first line evaluation of patients with suspicion CM. It is safe, accurate and have high diagnostic accuracy in identifying CM and their benign or malignant nature. In particular, a large mass associated with any pericardial effusion must pose suspect of malignancy.

P663 Is echocardiogram alone sufficient for cardiac masses characterization?

BACKGROUND

Cardiac Masses (CM) represent an heterogeneous group with a prevalence of 0.3% at autopsy, divided in benign masses (primary tumors and pseudotumors) and malignant ones (primitive tumors and metastasis). 2-D Echocardiography is nowadays the first line approach to define nature and management of CM, but is it enough to guide a therapeutic strategy?

PURPOSE

To evaluate echocardiographic diagnosis accuracy for CM in patients admitted to our Centre between 1997 and 2017.

MATERIALS AND METHODS

We retrospectively evaluated a population of 180 consecutive patients (45% males; mean age 60 ± 16 years; BMI 25 ± 5 Kg/m2), referred to our echocardiographic lab with suspicion CM. All patients were examined in both left lateral and supine position, and heart was visualized from all available echocardiographic windows. Definite diagnosis was obtained by histologic examination of biopsy, surgical samples or, in cases of cardiac thrombi, by radiological evidence of thrombus resolution after adequate anticoagulant treatment. We excluded normal anatomical variants in the group of pseudotumors due to the impossibility of obtaining histological examination. Sensitivity, specificity, predictive accuracy for a positive test, and predictive accuracy for a negative test were calculated by standard formulas (corrected for prevalence by Bayes theorem).

RESULTS

We detected 129 benign CM and 51 malignant cardiac tumors. In 7 cases a poor acoustic window did not allow an optimal examination; in remaining 173 patients, the classical 2-D echocardiogram identified 157 masses with a diagnostic accuracy of 91%. Of 173 CM diagnosed, 146 were classified by echocardiographer as benign masses (125 true benign on histological examination) and 27 as malignant ones (all malignant after histological confirmation); the results showed 56% sensitivity, 100% specificity, 100% positive predictive value, 98% negative predictive value, with 88% overall diagnostic accuracy in identifying the nature of masses. 23 cases were undetermined and needed second level instrumental investigations to be characterized. Diagnostic accuracy for distinguishing primary benign tumors and pseudotumors decreased to 80%, with a significant increase in both "false" benign tumors (9 out of 91) and "false" pseudotumors (15 out of 34) with 85% sensitivity, 68% specificity, 10% positive predictive value, 99% negative predictive value.

CONCLUSION

2D Echocardiography is an excellent, non invasive technique for first line evaluation of patients with suspicion CM. It is safe, reliable with a high predictive value and diagnostic accuracy in identifying CM and their benign or malignant nature. In contrast, these results were insufficient to start an anticoagulant in suspicion thrombus or cardiac surgery for primary tumor, since second level instrumental examinations needed. 2D Echocardiography alone seems unuseful for classifying malignant masses in primitive or metastasis.

Differences in cardiac phenotype and natural history of laminopathies with and without neuromuscular onset

Objective

To investigate differences in cardiac manifestations of patients affected by laminopathy, according to the presence or absence of neuromuscular involvement at presentation.

Methods

We prospectively analyzed 40 consecutive patients with a diagnosis of laminopathy followed at a single centre between 1998 and 2017. Additionally, reports of clinical evaluations and tests prior to referral at our centre were retrospectively evaluated.

Results

Clinical onset was cardiac in 26 cases and neuromuscular in 14. Patients with neuromuscular presentation experienced first symptoms earlier in life (11 vs 39 years; p <  0.0001) and developed atrial fibrillation/flutter (AF) and required pacemaker implantation at a younger age (28 vs 41 years [p = 0.013] and 30 vs 44 years [p = 0.086] respectively), despite a similar overall prevalence of AF (57% vs 65%; p = 0.735) and atrio-ventricular (A-V) block (50% vs 65%; p = 0.500). Those with a neuromuscular presentation developed a cardiomyopathy less frequently (43% vs 73%; p = 0.089) and had a lower rate of sustained ventricular tachyarrhythmias (7% vs 23%; p = 0.387). In patients with neuromuscular onset rhythm disturbances occurred usually before evidence of cardiomyopathy. Despite these differences, the need for heart transplantation and median age at intervention were similar in the two groups (29% vs 23% [p = 0.717] and 43 vs 46 years [p = 0.593] respectively).

Conclusions

In patients with laminopathy, the type of disease onset was a marker for a different natural history. Specifically, patients with neuromuscular presentation had an earlier cardiac involvement, characterized by a linear and progressive evolution from rhythm disorders (AF and/or A-V block) to cardiomyopathy.

P6455Differences in cardiac phenotype and natural history of laminopathies with and without neuromuscular presentation

Aim

To look for differences in cardiac phenotype and natural history of patients affected by laminopathy, according to the presence or less of neuromuscular involvement at clinical presentation.

Methods

We prospectively analyzed 47 consecutive pts with a genetic diagnosis of laminopathy followed at a single centre between 1994 and 2017. Additionally, reports of clinical and instrumental evaluations before referral at our centre were retrospectively evaluated.

Results

Neuromuscular presentation, mainly as Emery-Dreifuss muscular dystrophy (EDMD), was present in 21 (46%) cases (14 LMNA and 7 EMD gene mutations). These pts had symptoms earlier (9 vs 39 years, p<0.001) in life compared to pts without neuromuscular onset (26 LMNA gene mutations), and clinical manifestations anticipated the first evidence of cardiac disease by a mean time of 15±8 years (maximum time gap of 38 years). Despite a similar prevalence of atrial fibrillation/flutter (AF) (71% vs 65%, p=0.758) and atrio-ventricular blocks (48% vs 65%, p=0.250), pts with neuromuscular onset experienced AF and pace-maker implantation at a significantly younger age (27 vs 41 yrs, p=0.015 and 23 vs 44 yrs, p=0.027 respectively). Differently a higher prevalence of sinus node dysfunction (33% vs 4%; p=0.015) and atrial paralysis (14% vs 4%; p=0.311) was reported in pts with neuromuscular onset. Prevalence of cardiomyopathy (CMP) (73% vs 33%, p=0.008) and sustained ventricular tachyarrhythmias were higher among pts with cardiac onset (23% vs 4%, p=0.111) whereas the prevalence of heart transplantations and median age of recipients were similar in the two groups (24% vs 20%, p=1.000 and 46 vs 43, p=0.592 years respectively). All pts with neuromuscular onset who received a diagnosis of CMP had a previous history of rhythm disturbance except 2 cases, where a concomitant diagnosis of the 2 disorders was formulated. On the contrary a strict temporal progression from rhythm disturbances to CMP (or viceversa) was not appreciable in the other group: AF and AVBs could precede the diagnosis of CMP be diagnosed at the same time or later.

Conclusions

In pts affected by laminopathy neuromuscular involvement, when present, was most often the first clinical manifestation and preceded cardiological involvement, with a long time frame in some cases. Except for sinus node dysfunction, much more frequent in patients with EDMD, a similar prevalence of rhythm disturbances was reported, although pts with neuromuscular clinical onset were younger at diagnosis of AF and at PM implantation. Pts without neuromuscular presentation had a higher prevalence of CMP and ventricular arrhythmias, albeit a similar rate of heart transplantation. In pts with neuromuscular onset, cardiac involvement was characterized by a stepwise progression from rhythm disturbances to CMP, where a strict temporal progression from rhythm disturbances to CMP was not observed in the group of pts without neuromuscular clinical onset.

P900Electrocardiographic findings in Anderson-Fabry disease versus sarcomeric hypertrophic cardiomyopathy

Background

Cardiac involvement is one of the most frequent and disabling organ damage in Anderson-Fabry (AF) disease, causing hypertrophic cardiomyopathy (HCM), conduction disturbances, arrhythmias and coronary disease. Differential diagnosis from sarcomeric HCM is often very challenging, especially for patients with exclusive cardiac involvement.

Purpose

To gain new insights from standard electrocardiogram (ECG) in AF disease, and identify ECG differences from sarcomeric HCM.

Methods

Sixty-two consecutive patients (27 males, mean age: 62±16 years) with definite diagnosis of AF disease from 2 Italian centres were evaluated for ECG analysis and divided in 2 groups, according to the presence (Group A, N=39) or the absence (Group B, N=26) of cardiac involvement [hypertrophy detected at echocardiogram or cardiac magnetic resonance (CMR)]. All ECGs were analysed by 2 independent investigators. For Group A, when CMR was performed, a correlation between CMR and ECG was assessed. Patients with cardiac involvement were matched with 78 sarcomeric HCM patients according to sex, age and septal wall thickness on echocardiogram.

Results

Two AF patients out 39 with cardiac involvement (5%) had normal ECG. Short PR and I degree atrio-ventricular (AV) block were both reported in 6 (15%) cases. Twenty-six (67%) patients showed left ventricular hypertrophy and the majority (85%) had abnormal repolarization. CMR was performed in 22 patients (56%); the 11 (50%) patients with replacement fibrosis had a higher mean Sokolow-Lyon score (4.1±1.8 vs 2.9±1.0 mV; p=0.05), more frequent ST segment depression (82 vs 27%; p=0.03) and negative T waves (91 vs 36%; p=0.027; sensitivity: 90%; specificity: 63%), compared with the 11 without replacement fibrosis.

When compared with sarcomeric HCM, AF patients with cardiac involvement had a significantly wider QRS (120±30 vs 100±16 msec; p<0.0001), a higher frequency of right bundle branch block (RBBB) (18 vs 3%; p=0.01), ST segment depression (54 vs 20%; p<0.0001) and negative T waves (72 vs 46%; p=0.01), typically in the inferior leads (44 vs 14%; p<0.0001). No significant differences in terms of pseudo-necrosis and QRS voltages were found.

Among Group B AF patients (26, mean age: 36±12 years), 4 had short PR and 5 incomplete RBBB. Four had an abnormal ECG (1 left atrial enlargement, 2 unspecific repolarization abnormalities, 1 Sokolow score of 3.5 mV).

Conclusions

Standard ECG can detect cardiac involvement in AF disease. A good correlation was reported between repolarization abnormalities and replacement fibrosis on CMR. Wide QRS and RBBB were more frequent among AF patients compared to age-sex-matched sarcomeric HCM ones, probably due to the different aetiology of the diseases (infiltrative disease vs pure hypertrophy).

Elevated TGF β2 serum levels in Emery-Dreifuss Muscular Dystrophy: Implications for myocyte and tenocyte differentiation and fibrogenic processes

Among rare diseases caused by mutations in LMNA gene, Emery-Dreifuss Muscular Dystrophy type 2 and Limb-Girdle muscular Dystrophy 1B are characterized by muscle weakness and wasting, joint contractures, cardiomyopathy with conduction system disorders. Circulating biomarkers for these pathologies have not been identified. Here, we analyzed the secretome of a cohort of patients affected by these muscular laminopathies in the attempt to identify a common signature. Multiplex cytokine assay showed that transforming growth factor beta 2 (TGF β2) and interleukin 17 serum levels are consistently elevated in the vast majority of examined patients, while interleukin 6 and basic fibroblast growth factor are altered in subgroups of patients. Levels of TGF β2 are also increased in fibroblast and myoblast cultures established from patient biopsies as well as in serum from mice bearing the H222P Lmna mutation causing Emery-Dreifuss Muscular Dystrophy in humans. Both patient serum and fibroblast conditioned media activated a TGF β2-dependent fibrogenic program in normal human myoblasts and tenocytes and inhibited myoblast differentiation. Consistent with these results, a TGF β2 neutralizing antibody avoided fibrogenic marker activation and myogenesis impairment. Cell intrinsic TGF β2-dependent mechanisms were also determined in laminopathic cells, where TGF β2 activated AKT/mTOR phosphorylation. These data show that TGF β2 contributes to the pathogenesis of Emery-Dreifuss Muscular Dystrophy type 2 and Limb-Girdle muscular Dystrophy 1B and can be considered a potential biomarker of those diseases. Further, the evidence of TGF β2 pathogenetic effects in tenocytes provides the first mechanistic insight into occurrence of joint contractures in muscular laminopathies.

Development of a Novel Risk Prediction Model for Sudden Cardiac Death in Childhood Hypertrophic Cardiomyopathy (HCM Risk-Kids)

Importance

Sudden cardiac death (SCD) is the most common mode of death in childhood hypertrophic cardiomyopathy (HCM), but there is no validated algorithm to identify those at highest risk.

Objective

To develop and validate an SCD risk prediction model that provides individualized risk estimates.

Design, Setting, and Participants

A prognostic model was developed from a retrospective, multicenter, longitudinal cohort study of 1024 consecutively evaluated patients aged 16 years or younger with HCM. The study was conducted from January 1, 1970, to December 31, 2017.

Exposures

The model was developed using preselected predictor variables (unexplained syncope, maximal left-ventricular wall thickness, left atrial diameter, left-ventricular outflow tract gradient, and nonsustained ventricular tachycardia) identified from the literature and internally validated using bootstrapping.

Main Outcomes and Measures

A composite outcome of SCD or an equivalent event (aborted cardiac arrest, appropriate implantable cardioverter defibrillator therapy, or sustained ventricular tachycardia associated with hemodynamic compromise).

Results

Of the 1024 patients included in the study, 699 were boys (68.3%); mean (interquartile range [IQR]) age was 11 (7-14) years. Over a median follow-up of 5.3 years (IQR, 2.6-8.3; total patient years, 5984), 89 patients (8.7%) died suddenly or had an equivalent event (annual event rate, 1.49; 95% CI, 1.15-1.92). The pediatric model was developed using preselected variables to predict the risk of SCD. The model's ability to predict risk at 5 years was validated; the C statistic was 0.69 (95% CI, 0.66-0.72), and the calibration slope was 0.98 (95% CI, 0.59-1.38). For every 10 implantable cardioverter defibrillators implanted in patients with 6% or more of a 5-year SCD risk, 1 patient may potentially be saved from SCD at 5 years.

Conclusions and Relevance

This new, validated risk stratification model for SCD in childhood HCM may provide individualized estimates of risk at 5 years using readily obtained clinical risk factors. External validation studies are required to demonstrate the accuracy of this model's predictions in diverse patient populations.

The electrocardiogram in the diagnosis and management of patients with hypertrophic cardiomyopathy

In an era of rapid technological development and evolving diagnostic possibilities, the electrocardiogram (ECG) is living an authentic "renaissance" in myocardial diseases. To date, the ECG remains an irreplaceable first step when evaluating patients with hypertrophic cardiomyopathy (HCM) and an abnormal ECG may be the only manifestation of disease at an early stage. In some instances, specific electrical anomalies may differentiate HCM from phenocopies such as cardiac amyloidosis and glycogen storage diseases. The exponential growth in knowledge of the complexity of HCM has led to new challenges in terms of early identification of the disease, differential diagnosis, risk stratification, and development of targeted therapies. In this scenario, the apparently "old fashioned" ECG and the array of ECG-based techniques, ranging from Holter monitoring and loop recorders to exercise testing, are as contemporary as ever. In the present review, we discuss the current role of the ECG in the diagnosis and management of HCM, focusing on various clinical settings where its appropriate use and interpretation can make a difference.

Intraoperative Diagnosis of Anderson-Fabry Disease in Patients With Obstructive Hypertrophic Cardiomyopathy Undergoing Surgical Myectomy

Importance

Diagnostic screening for Anderson-Fabry cardiomyopathy (AFC) is performed in the presence of specific clinical red flags in patients with hypertrophic cardiomyopathy (HCM) older than 25 years. However, left ventricular outflow tract obstruction (LVOTO) has been traditionally considered an exclusion criteria for AFC.

Objective

To examine a series of patients diagnosed with HCM and severe basal LVOTO undergoing myectomy in whom the diagnosis of AFC was suspected by the cardiac surgeon intraoperatively and confirmed by histological and genetic examinations.

Design, Setting, and Participants

This retrospective analysis of patients undergoing surgical septal reduction strategies was conducted in 3 European tertiary referral centers for HCM from July 2013 to December 2016. Patients with a clinical diagnosis of obstructive HCM referred for surgical management of LVOTO were observed for at least 18 months after the procedure (mean [SD] follow-up, 33 [14] months).

Main Outcomes and Measures

Etiology of patients with HCM who underwent surgical myectomy.

Results

From 2013, 235 consecutive patients with a clinical diagnosis of HCM underwent septal myectomy. The cardiac surgeon suspected a storage disease in 3 patients (1.3%) while inspecting their heart samples extracted from myectomy. The mean (SD) age at diagnosis for these 3 patients was 42 (4) years; all were male. None of the 3 patients presented with extracardiac features suggestive of AFC. All patients showed asymmetrical left ventricular hypertrophy, with maximal left ventricular thickness in the basal septum (19-31 mm), severe basal LVOTO (70-120 mm Hg), and left atrial dilatation (44-57 mm). Only 1 patient presented with late gadolinium enhancement on cardiovascular magnetic resonance at the right ventricle insertion site. The mean (SD) age at surgical procedure was 63 (5) years. On tactile sensation, the surgeon felt a spongy consistency of the surgical samples, different from the usual stony-elastic consistency typical of classic HCM, and this prompted histological examinations. Histology showed evidence of intracellular storage, and genetic analysis confirmed a GLA A gene mutation (p.Asn215Ser) in all 3 patients.

Conclusions and Relevance

Screening for AFC should be performed even in the absence of red flags in patients with HCM older than 25 years.

Histopathological comparison of intramural coronary artery remodeling and myocardial fibrosis in obstructive versus end-stage hypertrophic cardiomyopathy

BACKGROUND

Although imaging techniques have demonstrated the existence of microvascular abnormalities in hypertrophic cardiomyopathy (HCM), a detailed histopathological assessment is lacking as well as a comparison between different phases of the disease. We aimed to compare microvasculopathy and myocardial fibrosis in hypertrophic obstructive cardiomyopathy (HOCM) versus end-stage (ES) HCM.

METHODS

27 myectomy specimens of HOCM patients and 30 ES-HCM explanted hearts were analyzed. Myocardial fibrosis was quantitatively determined with dedicated software and qualitatively classified as scar-like or interstitial. Intramural coronary arteries were evaluated separately according to lumen diameter: 100-500 μ versus <100 μ. Microvasculopathy assessment included the description of medial and intimal abnormalities and stenosis grading. The two subgroups were compared considering only the anterobasal septum of ES explanted hearts.

RESULTS

Median value of fibrosis in the anterobasal septum of explanted hearts was 34.6% as opposed to 10.3% of myectomy specimens (p < 0.001). Scar-like fibrosis was widely found in ES hearts while interstitial fibrosis was distinctive of HOCM (p < 0.001). All slides showed 100-500 μ microvasculopathy without any differences between subgroups in terms of lumen narrowing, extent of the disease and type of parietal involvement. Among ES hearts these lesions were associated with scar-like fibrosis (p = 0.034). <100-μ microvasculopathy was also frequent with no differences between subgroups.

CONCLUSIONS

Microvasculopathy is an intrinsic feature of HCM with similar characteristics across the natural phases of the disease. Conversely, myocardial fibrosis changes over time with ES hearts showing a three-fold greater amount, mainly scar-like. ES showed a closer association between microvasculopathy and replacement fibrosis.

Antithrombotic Management during Percutaneous Mitral Valve Repair with the Mitraclip System in a Patient with Heparin-Induced Thrombocytopenia

Interventional cardiology procedures require full anticoagulation to prevent thrombus formation on catheters and devices with potential development of embolic complications. Bivalirudin, a short half-life direct thrombin inhibitor, has been largely used during percutaneous coronary interventions and represents the preferred alternative to heparin in patients with heparin-induced thrombocytopenia (HIT). However, few data are available about intraprocedural use of bivalirudin during transcatheter structural heart disease interventions. Activated clotting time (ACT) monitoring during bivalirudin infusion presents some limitations and it is not mandatory. We report a case of bivalirudin use in a patient with type-2 HIT during percutaneous mitral valve repair with the Mitraclip system (Abbott, Abbott Park, Illinois, United States). Despite use of standard bivalirudin dose (0.75 mg/kg bolus and 1.4 mg/kg/min infusion—reduced infusion rate was motivated by a glomerular filtration rate of 37 mL/min), the patient developed a large thrombus on the second clip during its orientation toward the mitral orifice. ACT was measured at that time and was suboptimal (240 seconds). The case was successfully managed with clip and thrombus retrieval, adjunctive 0.3 mg/kg bivalirudin bolus and increased infusion rate, and clip repositioning with ACT monitoring. This report makes the case for mandatory ACT checking and drug titration during high-risk catheter–based structural heart disease interventions, even when thromboprophylaxis is performed with bivalirudin. Additional coagulation tests may be useful to monitor bivalirudin response in similar cases.

Effectiveness of the 2014 European Society of Cardiology guideline on sudden cardiac death in hypertrophic cardiomyopathy: a systematic review and meta-analysis

OBJECTIVE

In 2014, the European Society of Cardiology (ESC) recommended the use of a novel risk prediction model (HCM Risk-SCD) to guide use of implantable cardioverter defibrillators (ICD) for the primary prevention of sudden cardiac death (SCD) in patients with hypertrophic cardiomyopathy (HCM). We sought to determine the performance of HCM Risk-SCD by conducting a systematic review and meta-analysis of articles reporting on the prevalence of SCD within 5 years of evaluation in low, intermediate and high-risk patients as defined by the 2014 guidelines (predicted risk <4%, 4%-<6% and ≥6%, respectively).

METHODS

The protocol was registered with PROSPERO (registration number: CRD42017064203). MEDLINE and manual searches for papers published from October 2014 to December 2017 were performed. Longitudinal, observational cohorts of unselected adult patients, without history of cardiac arrest were considered. The original HCM Risk-SCD development study was included a priori. Data were pooled using a random effects model.

RESULTS

Six (0.9%) out of 653 independent publications identified by the initial search were included. The calculated 5-year risk of SCD was reported in 7291 individuals (70% low, 15% intermediate; 15% high risk) with 184 (2.5%) SCD endpoints within 5 years of baseline evaluation. Most SCD endpoints (68%) occurred in patients with an estimated 5-year risk of ≥4% who formed 30% of the total study cohort. Using the random effects method, the pooled prevalence of SCD endpoints was 1.01% (95% CI 0.52 to 1.61) in low-risk patients, 2.43% (95% CI 1.23 to 3.92) in intermediate and 8.4% (95% CI 6.68 to 10.25) in high-risk patients.

CONCLUSIONS

This meta-analysis demonstrates that HCM Risk-SCD provides accurate risk estimations that can be used to guide ICD therapy in accordance with the 2014 ESC guidelines.

REGISTRATION NUMBER

PROSPERO CRD42017064203;Pre-results.