[Cardiomyopathies: a practical approach to the assessment and management of patients and their families]. / Kardiomyopathien: ein praktischer Ansatz für Abklärung und Management der betroffenen Patienten und deren Familien.

INTRODUCTION: The new 2023 European Society of Cardiology (ESC) Guidelines for the management of cardiomyopathies addresses all cardiomyopathies in a single document for the first time. The focus is on a phenotype-oriented diagnostic approach, multimodal imaging and genetic testing to establish the most accurate diagnosis possible. Additionally, new recommendations for risk stratification for sudden cardiac death in various cardiomyopathy phenotypes are provided. MRI and genetic testing have significantly gained importance in this context. Recommendations for comprehensive clinical and genetic cascade screening in relatives of individuals with cardiomyopathies have been revised. This article presents the most important innovations of these guidelines in a practice-oriented approach.

Fabry disease: development and progression of left ventricular hypertrophy despite long-term enzyme replacement therapy.

BACKGROUND: Enzyme replacement therapy (ERT) may halt or attenuate disease progression in patients with Anderson-Fabry disease (AFD). However, whether left ventricular hypertrophy (LVH) can be prevented by early therapy or may still progress despite ERT over a long-term follow-up is still unclear. METHODS: Consecutive patients with AFD from the Independent Swiss-Fabry Cohort receiving ERT who were at least followed up for 5 years were included. Cardiac progression was defined as an increase of >10 g/m2 in left ventricular mass index (LVMI) between the first and the last available follow-up transthoracic echocardiography. RESULTS: 60 patients (35 (23-48) years, 39 (65%) men) were followed up for 10.5 (7.2-12.2) years. 22 had LVH at ERT start (LVMI of 150±38 g/m2). During follow-up, 22 (36%, 34±15 years) had LVMI progression of 12.1 (7-17.6) g/m2 per 100 patient-years, of these 7 (11%, 29±13 years) with no LVH at baseline. Three of them progressed to LVH. LVMI progression occurred mostly in men (17 of 39 (43%) vs 5 of 21 (24%), p<0.01) and after the age of 30 years (17 of 22 (77%)). LVH at ERT start was associated with LVMI progression (OR 1.3, 95% CI 1.1 to 2.6; p=0.02). A total of 19 (31%) patients experienced a major AFD-related event. They were predominantly men (17 of 19, 89%), older (45±11 vs 32±9 years) with baseline LVH (12 of 19, 63%), and 10 of 19 (52%) presented with LVMI progression. CONCLUSIONS: Over a median follow-up of >10 years under ERT, 36% of the patients still had LVMI cardiac progression, and 32%, predominantly older men, experienced major AFD-related events. LVH at treatment initiation was a strong predictor of LVMI progression and adverse events on ERT.

Assessment of treatment response in cardiac sarcoidosis based on myocardial 18F-FDG uptake.

Objective: Immunosuppressive therapy for cardiac sarcoidosis (CS) still largely consists of corticosteroid monotherapy. However, high relapse rates after tapering and insufficient efficacy are significant problems. The objective of this study was to investigate the efficacy and safety of non-biological and biological disease-modifying anti-rheumatic drugs (nb/bDMARDs) considering control of myocardial inflammation assessed by 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) of the heart. Methods: We conducted a retrospective analysis of treatment response to nb/bDMARDs of all CS patients seen in the sarcoidosis center of the University Hospital Zurich between January 2016 and December 2020. Results: We identified 50 patients with CS. Forty-five patients with at least one follow-up PET/CT scan were followed up for a mean of 20.5 ± 12.8 months. Most of the patients were treated with prednisone and concomitant nb/bDMARDs. At the first follow-up PET/CT scan after approximately 6.7 ± 3 months, only adalimumab showed a significant reduction in cardiac metabolic activity. Furthermore, comparing all serial follow-up PET/CT scans (143), tumor necrosis factor inhibitor (TNFi)-based therapies showed statistically significant better suppression of myocardial 18F-FDG uptake compared to other treatment regimens. On the last follow-up, most adalimumab-treated patients were inactive (n = 15, 48%) or remitting (n = 11, 35%), and only five patients (16%) were progressive. TNFi was safe even in patients with severely reduced left ventricular ejection fraction (LVEF), and a significant improvement in LVEF under TNFi treatment was observed. Conclusion: TNFi shows better control of myocardial inflammation compared to nbDMARDs and corticosteroid monotherapies in patients with CS. TNFi was efficient and safe even in patients with severely reduced LVEF.

Clinical and CMR characteristics associated with cardiac events in patients with Fabry disease.

BACKGROUND: The assessment of late gadolinium enhancement (LGE) and left ventricular hypertrophy (LVH) by cardiac magnetic resonance (CMR) as diagnostic and prognostic maker in Fabry disease is advancing. We aimed to investigate the impact of clinical characteristics and CMR findings on cardiac outcome in patients with FD. METHODS: In this study 55 patients with genetically confirmed FD and available CMR imaging were included. The primary endpoint was defined as a composite of cardiac events including cardiac death, new occurrence of atrial fibrillation, heart failure, ventricular tachycardia and bradycardia requiring device insertion. RESULTS: During a median follow-up of 4.9 years (IQR 3.7-5.9), 9 patients (16.3%) reached the primary cardiac end point. The global amount of LGE was associated with an increased risk for primary endpoint in the univariate analysis (HR 1.4 per 10% increase in LGE, p = 0.002). However maximal wall thickness (MWT) was the sole independent predictor of the primary endpoint in a stepwise logistic regression model (HR 9.8 per mm increase in MWT, p < 0.0001). Kaplan-Meier analysis revealed significant difference in event free survival rate between patients with and without LVH (Long-rank p = 0.006) and in patients with and without LGE (Long-rank p < 0.001). Patients without LVH and LGE were free of adverse cardiac events. CONCLUSION: LVH and LGE detected by CMR were associated with adverse cardiac events in FD. In particular maximal wall thickness can be useful in cardiac risk stratification of FD patients.

Sarcoidosis - a multisystem disease.

Sarcoidosis is a systemic inflammatory disease, characterised by granuloma formation upon an unknown trigger in genetically predisposed individuals. The inflammation is characterised by an activation of both the innate immune system, with macrophages differentiating into epitheloid cells and dendritic cells, and the adaptive immune system, particularly T helper (Th) 1 and Th17 cells. Since all organs can be affected to varying extents, clinical presentation is often diverse. Most commonly, the lungs, lymph nodes, skin and eyes are involved, whereas cardiac, renal and neurological manifestations are less common but associated with higher morbidity. Depending on the clinical symptoms, a detailed evaluation including thorough clinical examination, imaging and laboratory tests should explore all possible organ involvements. In some patients, fatigue manifests as a para-sarcoidosis symptom impacting quality of life, even if sarcoidosis is in remission. Some acute syndromic presentations, such as Löfgren's syndrome, have a good prognosis and are commonly self-limiting. If possible, a topical treatment, for example for cutaneous sarcoidosis or bronchial involvement, should be applied. Treatment of severe cases with persisting disease activity necessitates long-term immunosuppressive drugs, with glucocorticoids as the first-line option. Steroid-sparing and second-line drugs include methotrexate, azathioprine, mycophenolate mofetil and immunomodulators such hydroxychloroquine, with the latter being first-line therapy in cutaneous sarcoidosis. Tumour necrosis factor-alpha inhibitors (particularly adalimumab and infliximab) are used as third-line agents but are administered earlier in cases of persistent disease activity, severe organ-involvement or intolerance to conventional drugs. Treatment decisions should be based on a multidisciplinary approach, depending on organ involvement and treatment tolerability. Para-sarcoidosis manifestations, particularly fatigue, should also be carefully addressed, where the patient could also be enrolled in multidimensional rehabilitation programmes. With various organ involvement and different phenotypes, larger studies including real-world data from registries are necessary to evaluate different sarcoidosis endotypes and preferential treatment pathways.

Right ventricular involvement in left ventricular non-compaction cardiomyopathy.

BACKGROUND: Left ventricular non-compaction cardiomyopathy (LVNC) features extensive trabeculations. Involvement of the right ventricle (RV) has been reported; however, distinction from normal RV trabeculation is difficult. This study aimed at assessing RV morphology and function in LVNC by cardiac magnetic resonance (CMR) and transthoracic echocardiography (TTE). METHODS: Dimensional and functional parameters were assessed according to guidelines. Novel CMR parameters were RV end-diastolic (ED) trabeculated area, RV ED trabeculated volume, and RV ED non-compacted to compacted (NC/N) ratio in short axis (SAX) as well as in four-chamber view (4CH). RESULTS: Twenty patients with LVNC and 20 controls were included. RV size and function were comparable in LVNC and controls and exhibited a good correlation between TTE and CMR. Although RV trabeculated area, RV trabeculated volume, and RV ED NC/C ratio in SAX as well as in 4CH were larger in LVNC, there was a major overlap with values in controls. RV ED NC/C ratio in SAX correlated with LV ED NC/C ratio (not in 4CH). Quantitative assessment of RV non-compaction was not feasible in TTE. CONCLUSIONS: Right ventricle size and function in LVNC can be measured by CMR and TTE, while RV trabeculation can only be quantified by CMR. RV myocardium displays more trabeculations in LVNC; however, overlap with normal individuals is extensive, not allowing separation of patients with LVNC from controls.

Left ventricular mechanics and cardiovascular outcomes in non-compaction phenotype.

AIMS: This study aims at understanding left ventricular (LV) mechanics of non-compaction (LVNC) phenotype using echocardiographic strain analysis and at assessing the association of functional parameters with cardiovascular (CV) outcomes. METHODS AND RESULTS: Longitudinal (GLS) and circumferential strain (GCS) as well as rotation of the LV were analyzed in 55 LVNC patients and 55 matched controls. Cardiovascular outcomes were documented for a median follow-up duration of 6 years. GLS and GCS were impaired in LVNC. Similary, regional longitudinal and circumferential strain as well as twist were reduced. CV events occurred in 28 LVNC patients. Apical peak circumferential strain (APCS), peak systolic rotation of apical segments (APSR), and twist were strongly associated with events. This was independent of and incremental to LVEF and non-compacted to compacted myocardial thickness ratio (NC:C ratio). The association of twist with events was also independent of and slightly superior to GLS. CONCLUSIONS: GLS, GCS, regional strain, and twist were impaired in LVNC. APCS, APSR, and twist exhibited strong association with CV events independent of and incremental to LVEF and NC:C ratio, and in case of twist even GLS. Thus, STE-derived parameters may complement the echocardiographic assessment of LVNC patients in clinical routine.

Differentiating hereditary arrhythmogenic right ventricular cardiomyopathy from cardiac sarcoidosis fulfilling 2010 ARVC Task Force Criteria.

BACKGROUND: The clinical presentation of cardiac sarcoidosis (CS) may resemble that of arrhythmogenic right ventricular cardiomyopathy (ARVC). OBJECTIVE: The purpose of this study was to identify clinical variables to better discriminate between patients with genetically determined ARVC and those with CS fulfilling definite 2010 ARVC Task Force Criteria (TFC). METHODS: In this multicenter study, 10 patients with CS fulfilling definite 2010 ARVC TFC were age and gender matched with 10 genetically proven ARVC patients. A cardiac 18F-fluorodeoxyglucose positron emission tomographic (18F-FDG PET) scan was required for patients to be included in the study. RESULTS: The 2010 ARVC TFC did not reliably differentiate between the 2 diseases. CS patients presented with longer PR intervals, advanced atrioventricular block (AVB), and longer QRS duration (P <.001 and P = .009, respectively), whereas T-wave inversions (TWIs) in the peripheral leads were more common in ARVC patients (P = .009). CS patients presented with more extensive left ventricular involvement and lower left ventricular ejection fraction (LVEF), whereas ARVC patients had a larger right ventricular outflow tract (RVOT) (P = .044). PET scan positivity was only present in CS patients (90% vs 0%). CONCLUSION: The 2010 ARVC TFC do not reliably differentiate between CS patients fulfilling 2010 ARVC TFC and those with hereditary ARVC. Prolonged PR interval, advanced AVB, longer QRS duration, right ventricular apical involvement, reduced LVEF, and positive 18F-FDG PET scan should raise the suspicion of CS, whereas larger RVOT dimensions, subtricuspid involvement and peripheral TWI favor a diagnosis of hereditary ARVC.

Diagnostic criteria for left ventricular non-compaction in cardiac computed tomography.

PURPOSE: Left ventricular non-compaction (LVNC) is characterized by a 2-layered myocardium composed of a noncompacted (NC) and a compacted (C) layer. The echocardiographic NC:C ratio is difficult to assess in many patients. The aim of the study was to assess the value of cardiac computed tomography (CCT) for the diagnosis of LVNC. METHODS: In this prospective controlled study, segmental analysis of transthoracic echocardiography (TTE) and prospective ECG-triggered CCT was performed in 17 patients with LVNC and 19 healthy controls. In TTE maximal NC and C thickness was measured at enddiastole and endsystole in the segment with most prominent trabeculation in short axis views. In CCT, maximal segmental NC and C thickness was measured during diastole, and NC:C ratio was determined. Spearman's correlation coefficient and receiver operating characteristic curves were calculated. RESULTS: The median [IQR] radiation dose was 1.3[1.2-1.5]mSv. The CCT thickness of the C layer was significantly lower in patients with LVNC as compared to controls in the inferolateral, midventricular, lateral-, inferior-, and septal-apical segments. The CCT NC:C ratio differed significantly between LVNC and controls in the inferior-midventricular and all the apical segments. NC:C ratio correlated significantly between TTE and CCT at enddiastole (σ = 0.8) and endsystole (σ = 0.9). Using a CCT NC:C ratio ≥1.8, all LVNC patients could be identified. CONCLUSION: LVNC can be diagnosed with ECG-triggered low-dose CCT and discriminated from normal individuals using a NC:C ratio of ≥1.8 in diastole. There is a very good correlation of NC:C ratio in TTE and CCT.

Cardiovascular magnetic resonance T2* mapping for the assessment of cardiovascular events in hypertrophic cardiomyopathy.

Background: Hypertrophic cardiomyopathy (HCM) is associated with an increased risk of adverse cardiac events. Beyond classic risk factors, relative myocardial ischaemia and succeeding myocardial alterations, which can be detected using either contrast agents or parametric mapping in cardiovascular magnetic resonance (CMR) imaging, have shown an impact on outcome in HCM. CMR may help to risk stratify using parametric T2* mapping. Therefore, the aim of the present study was to evaluate the association of T2* values or fibrosis with cardiovascular events in HCM. Methods: The relationship between T2* with supraventricular, ventricular arrhythmia or heart failure was retrospectively assessed in 91 patients with HCM referred for CMR on a 1.5T MR imaging system. Fibrosis as a reference was added to the model. Patients were subdivided into groups according to T2* value quartiles. Results: 47 patients experienced an event of ventricular arrhythmia, 25 of atrial fibrillation/flutter and 17 of heart failure. T2*≤28.7 ms yielded no association with ventricular events in the whole HCM cohort. T2* of non-obstructive HCM showed a significant association with ventricular events in univariate analysis, but not in multivariate analysis. For the combined endpoint of arrhythmic events, there was already an association for the whole HCM cohort, but again only in univariate analyses. Fibrosis stayed the strongest predictor in all analyses. There was no association for T2* and fibrosis with heart failure. Conclusions: Decreased T2* values by CMR only provide a small association with arrhythmic events in HCM, especially in non-obstructive HCM. No information is added for heart failure.

Right ventricle and outcome in left ventricular non-compaction cardiomyopathy.

BACKGROUND: The risk of adverse events in patients with left ventricular non-compaction cardiomyopathy (LVNC) is substantial. Information on prognostic factors, however, is limited. This study was designed to assess the prognostic value of right ventricular (RV) size and function in LVNC patients. METHODS: Cox regression analyses were used to determine the association of indexed RV end-diastolic area (RV-EDAI), indexed end-diastolic diameter (RV-EDDI), fractional area change (FAC), and tricuspid annular systolic excursion (TAPSE) with the occurrence of death or heart transplantation (composite endpoint). RESULTS: Out of 127 patients (53.2 ±â€¯17.8 years; 61% males, median follow-up time was 7.7 years), 17 patients reached the endpoint. In a univariate analysis, RV-EDAI was the strongest predictor of outcome [HR 1.48 (1.24-1.77) per cm2/m2; p < 0.0001]. FAC was predictive as well [HR 1.44 (1.16-1.83) per 5% decrease; p = 0.0009], while TAPSE was not (p=ns). RV-EDAI remained an independent predictor in a bivariable analysis with indexed left ventricular ED volume [HR 1.41 (1.18-1.70) per cm2/m2; p = 0.0002], while analysis of FAC and left ventricular ejection fraction demonstrated that FAC was not independent [HR 1.20 (0.98-1.52); per 5% decrease; p = 0.0721]. RV-EDAI 11.5 cm2/m2 was the best cut-off value for separating patients in terms of outcome. Patients with RV-EDAI >11.5 cm2/m2 had a survival rate of 18.5% over 12 years as compared to 93.8% in patients with RV-EDAI <11.5 cm2/m2 (p < 0.0001). CONCLUSION: Increased end-diastolic RV size and decreased systolic RV function are predictors of adverse outcome in patients with LVNC. Patients with RV-EDAI >11.5 cm2/m2 exhibit a significantly lower survival than those <11.5 cm2/m2.

Cardiovascular magnetic resonance T2* mapping for structural alterations in hypertrophic cardiomyopathy.

PURPOSE: Hypertrophic cardiomyopathy (HCM) is characterized by a heterogeneous morphology and variable prognosis. A mismatch between left ventricular mass (LVM) and microvascular circulation with corresponding relative ischemia has been implicated to cause myocardial replacement fibrosis that deteriorates prognosis. Besides parametric T1 mapping, Cardiovascular Magnetic Resonance (CMR) T2* mapping is able to identify ischemia as well as fibrosis in cardiac and extracardiac diseases. Therefore, we aimed to investigate the value of T2* mapping to characterize structural alterations in patients with HCM. METHODS: CMR was performed on a 1.5 T MR imaging system (Achieva, Philips, Best, Netherlands) using a 5-channel coil in patients with HCM (n = 103, 50.6 ± 16.4 years) and in age- and gender-matched controls (n = 20, 44.8 ± 16.9 years). T2* mapping (1 midventricular short axis slice) was acquired in addition to late gadolinium enhancement (LGE). T2* values were compared between patients with HCM and controls as well as between HCM patients with- and without fibrosis. RESULTS: HCM patients showed significantly decreased T2* values compared to controls (26.2 ± 4.6 vs. 31.3 ± 4.3 ms, p < 0.001). Especially patients with myocardial fibrosis presented with decreased T2* values in comparison to those without fibrosis (25.2 ± 4.0 vs. 28.7 ± 5.3 ms, p = 0.003). A regression model including maximum wall thickness, LVM and T2* values provided good overall diagnostic accuracy of 80% to diagnose HCM with and without fibrosis. CONCLUSION: In this study, parametric mapping identified lower T2* values in HCM patients compared to controls, especially in a sub-group of patients with myocardial fibrosis. As myocardial fibrosis has been suggested to influence prognosis of patients with HCM, T2* mapping may add information for identifying a higher risk sub-group of HCM patients.

Hypertrophic obstructive cardiomyopathy: what, when, why, for whom?

Hypertrophic cardiomyopathy is the most common genetic cardiovascular disorder and is associated with symptoms of heart failure and increased risk of sudden cardiac death. The most common condition is obstruction of the left ventricular outflow tract. Surgical septal myectomy and alcohol septal ablation are the 2 accepted modes of septal reduction therapy and are indicated when there are advanced symptoms and a peak left ventricular outflow gradient ≥50 mmHg. Advantages of alcohol septal ablation are limited groin approach, reduction of obstruction of the left ventricular outflow tract and functional improvement, but there are higher chances for intracardiac device implantation and residual obstruction. Septal myectomy offers very low mortality, absolute and immediate resolution of obstruction of the left ventricular outflow tract and survival comparative to a matched general population with almost negligible residual obstruction. It is recommended that patients with obstructive hypertrophic cardiomyopathy should be treated at experienced centres.

Impact of growing cohorts of adults with con-genital heart disease on clinical workload: a 20-year experience at a tertiary care centre.

BACKGROUND: Population based studies show a steady increase in adult patients with congenital heart defects. The aim of this study was to assess the evolution of such a patient cohort and its burden on clinical care at a dedicated tertiary care centre. METHODS: All patients with congenital heart disease followed up by a dedicated multidisciplinary team at our institution were identified (n = 1725). Disease characteristics, the increase in patient numbers and interventions and the increase in selected complications were analysed and compared between the first (1996-2005) and second (2006-2015) decades of the study period. RESULTS: Between the two decades of the study period, the number of patients in follow-up increased by 109%, the number of patients who died or underwent transplantation more than doubled and the number of outpatient visits increased by 195%. One fourth of all patients underwent at least one surgical procedure and 14% had at least one percutaneous intervention. The increase in surgical procedures between the two decades was 27% and the increase in percutaneous interventions 159%. Between the two decades the number of patients requiring direct current cardioversion increased from 32 to 95 (+197%), the number of patients requiring admission for infective endocarditis increased from 7 to 29 (+314%) and the number of women followed up during pregnancy increased from 18 to 115 (+539%). CONCLUSION: As a result of the increasing number and complexity of adult survivors with congenital heart disease more resources will be needed to cope with the demands of this novel cohort of complex patients in adult cardiology.

Burden and impact of congenital syndromes and comorbidities among adults with congenital heart disease.

BACKGROUND: Our aim was to assess the overall burden of congenital syndromes and non-cardiac comorbidities among adults with congenital heart disease and to assess their impact on circumstances of living and outcomes. METHODS: Within a cohort of 1725 adults with congenital heart defects (65% defects of moderate or great complexity) followed at a single tertiary care center, congenital syndromes and comorbidities were identified by chart review. Their association with arrhythmias, circumstances of living and survival was analyzed. RESULTS: Within the study cohort, 232 patients (13%) had a genetic syndrome, 51% at least one comorbidity and 23% ≥2 comorbidities. Most prevalent comorbidities were systemic arterial hypertension (11%), thyroid dysfunction (9%), psychiatric disorders (9%), neurologic disorders (7%), chronic lung disease (7%), and previous stroke (6%). In contrast to higher congenital heart defect complexity, the presence of comorbidities had no impact on living circumstances but patients with comorbidities were less likely to work full-time. Atrial arrhythmias were more common among patients with moderate/great disease complexity and those with comorbidities but were less common among patients with congenital syndromes (p<0.01 for all comparisons). Patients with ≥2 comorbidities had lower survival estimates compared to those with ≤1 comorbidity (p=0.013). CONCLUSION: Congenital syndromes and comorbidities are highly prevalent in adults with congenital heart disease followed at specialist centers and add to the overall complexity of care. The presence of these additional factors has an impact on living circumstances, is associated with arrhythmias and needs to be further explored as prognostic markers.

Prognostic power of NT-proBNP in left ventricular non-compaction cardiomyopathy.

BACKGROUND: The risk of adverse events in patients with left ventricular non-compaction cardiomyopathy (LVNC) is substantial. This study was designed to determine the prognostic value of NT-proBNP, left ventricular ejection fraction (LVEF), NYHA class, and exercise capacity in LVNC patients. METHODS: Cox regression analyses were performed for evaluating the prognostic value of NT-proBNP, LVEF, NYHA class, and exercise capacity on the occurrence of death or heart transplantation. 153 patients were included. RESULTS: During 1013 person-years (longest follow-up 18.5years) 23 patients (15%) died or underwent heart transplantation. We observed a significant relationship of NT-proBNP (adjusted HR 2.44, 95% CI 1.45-4.09, for every NT-proBNP doubling, p=0.0007) and LVEF (adjusted HR for age 60years: 2.68, 95% CI 1.62-4.41, p=0.0001) with the risk of death or heart transplantation. Combined covariate analysis indicated a strong influence of NT-proBNP (adjusted 2.89, 95% CI 1.33-6.26, p=0.007), whereas LVEF was no longer significant (adjusted HR 0.82, 95% CI 0.42-1.67, p=0.66) demonstrating a favorable prognostic power of NT-proBNP over LVEF. An increase in NYHA class was associated with a worse outcome, and exercise capacity revealed a trend in the same direction. For all the abovementioned analyses, similar results were obtained when assessing the values at first presentation. CONCLUSION: This study provides evidence that an increase in NT-proBNP is a strong predictor of outcome in patients with LVNC. The prognostic power of NT-proBNP is at least as good as that of LVEF, indicating that routine NT-proBNP measurement may improve risk assessment in LVNC.

Lack of Phenotypic Differences by Cardiovascular Magnetic Resonance Imaging in MYH7 (ß-Myosin Heavy Chain)- Versus MYBPC3 (Myosin-Binding Protein C)-Related Hypertrophic Cardiomyopathy.

BACKGROUND: The 2 most commonly affected genes in hypertrophic cardiomyopathy (HCM) are MYH7 (ß-myosin heavy chain) and MYBPC3 (ß-myosin-binding protein C). Phenotypic differences between patients with mutations in these 2 genes have been inconsistent. Scarce data exist on the genotype-phenotype association as assessed by tomographic imaging using cardiac magnetic resonance imaging. METHODS AND RESULTS: Cardiac magnetic resonance imaging was performed on 358 consecutive genotyped hypertrophic cardiomyopathy probands at 5 tertiary hypertrophic cardiomyopathy centers. Genetic testing revealed a pathogenic mutation in 159 patients (44.4%). The most common genes identified were MYH7 (n=53) and MYBPC3 (n=75); 33.1% and 47% of genopositive patients, respectively. Phenotypic characteristics by cardiac magnetic resonance imaging of these 2 groups were similar, including left ventricular volumes, mass, maximal wall thickness, morphology, left atrial volume, and mitral valve leaflet lengths (all P=non-significant). The presence of late gadolinium enhancement (65% versus 64%; P=0.99) and the proportion of total left ventricular mass (%late gadolinium enhancement; 10.4±13.2% versus 8.5±8.5%; P=0.44) were also similar. CONCLUSIONS: This multicenter multinational study shows lack of phenotypic differences between MYH7- and MYBPC3-associated hypertrophic cardiomyopathy when assessed by cardiac magnetic resonance imaging. Postmutational mechanisms appear more relevant to thick-filament disease expression and outcome than the disease-causing variant per se.

High prevalence of baffle leaks in adults after atrial switch operations for transposition of the great arteries.

AIMS: To determine the prevalence of baffle leaks in adults after atrial switch operations for transposition of the great arteries, as these may predispose to paradoxical embolic events, particularly in patients with transvenous pacemaker or defibrillator leads. METHODS AND RESULTS: We routinely perform contrast echocardiography with agitated saline in all patients after atrial switch operations. For this study, we analysed patients who had saline contrast echocardiography between 2010 and 2012. The presence of baffle leaks and the severity of right-to-left shunting were assessed. We compared baseline characteristics and oxygen saturation at rest and during exercise between patients with and without baffle leaks. A total of 65 patients (56 Senning and 9 Mustard repair) without previously known baffle leaks were included (mean age 32 ± 8 years, 77% males). Right-to-left shunting was identified in 42 patients (65%) and occurred without provocation manoeuvres in 88%. There were no differences in baseline characteristics, echocardiographic findings, or exercise capacity between patients with and without baffle leaks, except for lower oxygen saturation at peak exercise in those with baffle leaks (29% had oxygen saturations below 90% at peak exercise compared to none without baffle leaks, P = 0.011). Four patients with baffle leaks had previous implantation of transvenous pacemaker leads; one of them had suffered a stroke. Two other patients with baffle leaks had a history of potential embolic stroke. CONCLUSIONS: Because of the high prevalence of baffle leaks in adults after atrial switch operations, we propose routine screening with agitated saline contrast, particularly prior to implantation of transvenous pacemaker or defibrillator leads.

Prevention of sudden death in hypertrophic cardiomyopathy: bridging the gaps in knowledge.

Sudden cardiac death (SCD) is the most devastating complication of hypertrophic cardiomyopathy (HCM). Although the annual rate of SCD in the general HCM population is <1% per year according to contemporary series, there is still a small subset of patients who are at increased risk of SCD. The greatest challenge in the management of HCM is identifying those at increased risk as an implantable cardioverter defibrillator is a potentially life-saving therapy. In this review, we sought to summarize the available data on SCD in HCM and provide a clinical perspective on the current differing and somewhat conflicting European and American recommendations on risk stratification, with balanced guidance with regards to rational clinical decision making. Additionally, we sought to learn more on the actual implementation of the guidelines by HCM experts worldwide.