2011 ACCF/AHA guideline for the diagnosis and treatment of hypertrophic cardiomyopathy: Executive summary

The Association of Epicardial Adipose Tissue Volume and Atrial Fibrillation in Patients With Hypertrophic Cardiomyopathy: As Assessed by Cardiac MR

BACKGROUND

Epicardial adipose tissue (EAT) is a metabolically active visceral fat linked to cardiovascular disease. Prior studies demonstrated the predictive value of EAT volume (EATV) in atrial fibrillation (AF) among hypertrophic obstructive cardiomyopathy patients.

PURPOSE

To investigate the association between EATV and AF in hypertrophic cardiomyopathy (HCM).

STUDY TYPE

Retrospective.

POPULATION

Two hundred and twenty-four HCM patients (including 79 patients with AF and 145 patients without AF, 154 men) and 80 healthy controls (54 men).

FIELD STRENGTH/SEQUENCE

3.0 T scanner; balanced steady-state free precession (SSFP) cine sequence, gradient echo.

ASSESSMENT

EAT thickness was assessed in the 4-chamber and basal short-axis planes. EAT volume was calculated by outlining the epicardial border and visceral pericardium layer on short-axis cine images.

STATISTICAL TESTS

Shapiro-Wilk test, Student's t test or the Mann-Whitney U test, chi-square test or Fisher's exact test, Multivariate linear regression analyses, Multivariable binary logistic regression analysis. Intraclass correlation coefficient. Significance was determined at P < 0.05.

RESULTS

EATV and EAT volume index (EATVI) were significantly greater in HCM patients with AF than those without AF (126.6 ± 25.9 mL vs. 90.5 ± 24.5 mL, and 73.0 ± 15.9 mL/m2 vs. 51.3 ± 13.4 mL/m2). EATVI was associated with AF in multivariable linear regression analysis among HCM patients (β = 0.62). Multivariable logistic regression analysis revealed that compared to other indicators, the area under curve (AUC) of EATVI was 0.86 (cut-off, 53.9 mL/m2, 95% CI, 0.80-0.89), provided a better performance, with the sensitivity of 96.2% and specificity of 58.6%. The combined model exhibited superior association with AF presence compared to the clinical model (AUC 0.96 vs. 0.76) and the imaging model (AUC 0.96 vs. 0.93).

DATA CONCLUSION

EATVI was associated with AF. EATVI was significantly correlated with incident AF, and provided a better performance in HCM patients compared to other indicators.

EVIDENCE LEVEL

3 TECHNICAL EFFICACY: Stage 2.

Clinical characteristics and prognosis of patients with hypertrophic cardiomyopathy and heart failure with preserved ejection fraction

BACKGROUND

Whether heart failure with preserved ejection fraction (HFpEF) is associated with an increased risk of developing systolic dysfunction and a poor prognosis in hypertrophic cardiomyopathy (HCM) patients is unknown.

OBJECTIVE

We aimed to assess risk factors for the development of end-stage (ES) heart failure (HF) (ejection fraction < 50%) and compare the prognosis of different HF phenotypes.

METHODS

This retrospective study was conducted on patients with HCM in China between January 2009 and February 2023. Patients were stratified into three different groups: HCM-non-HF, HCM-HFpEF and HCM-heart failure with reduced ejection fraction (HCM-HFrEF). The primary outcome was a composite of major adverse cardiac events (MACEs), including all-cause deaths, HF hospitalization, sudden cardiac death and ventricular tachycardia.

RESULTS

Of 3,620 HCM patients enrolled, 1,553 (42.9%) had non-HF, 1,666 (46.0%) had HFpEF, and 579 patients (11.1%) had HFrEF at baseline. During the median follow-up period of 4.0 years (IQR 1.4-9.4 years), patients with HCM-HFpEF exhibited a higher incidence of ES-HF than those with HCM-non-HF (12.4% vs. 2.7%, P < 0.001). HFpEF was an independent risk factor for ES-HF development (HR 3.84, 2.54-5.80, P < 0.001). MACEs occurred in 26.9% with a higher incidence in HCM-HFpEF than HCM-non-HF (36.6% vs 12.2%, P < 0.001). HFpEF was an independent predictor of MACEs (HR 2.13, 1.75-2.59, P < 0.001).

CONCLUSIONS

HFpEF is common in HCM. Compared to non-HF, it increases the risk of LVEF decline and poor prognosis. It may aid in risk stratification and need close echocardiography follow-up.

Is There a Role for Alcohol Septal Ablation in Young Patients with Medically Refractory Hypertrophic Obstructive Cardiomyopathy?

Surgical myectomy is recommended for symptomatic hypertrophic obstructive cardiomyopathy (HOCM) after optimal pharmacological therapy. Percutaneous transluminal septal myocardial ablation (PTSMA) is reserved for high-risk adults. Symptomatic patients below 25 years underwent either surgery or PTSMA after heart-team discussion and informed consent. Echocardiography assessed gradients in surgical group. PTSMA group underwent invasive transseptal hemodynamic assessment, selective coronary angiography and super-selective cannulation of septal perforators using microcatheters. Contrast echocardiography through the microcatheter identified the myocardial target for PTSMA. Hemodynamic and electrocardiographic monitoring guided alcohol injection. Both groups were continued on beta-blockers. Symptoms, echocardiographic gradients and Brain natriuretic peptide (NTproBNP) measurements were assessed on follow-up. Twelve patients aged 5-23 years (11-98 kg) formed the study group. Indications for PTSMA in 8 patients included abnormal mitral valve anatomy warranting replacement (n = 3), Jehovah's witness (n = 2), severe neurodevelopmental and growth retardation (n = 1) and refusal of surgery (n = 2). PTSMA targeted first perforator (n = 5), second perforator (n = 2) and anomalous septal artery from left main trunk (n = 1). Outflow gradient reduced from 92.5 ± 19.7 to 33.1 ± 13.5 mmHg. At a median follow-up of 38 months (range 3-120 weeks), the peak instantaneous echocardiographic gradient was 32 ± 16.5 mmHg. Gradient reduced in four surgical patients from 86.5 ± 16.3 mmHg to 42 ± 14.7 mm Hg. All patients were in NYHA class I/II on follow-up. The mean NTproBNP in PTSMA group reduced from 6084 ± 3628 pg/ml to 3081 ± 2019 pg/ml; it was 1396 and 1795 pg/ml in surgery. PTSMA may be considered in medically refractory high-risk young patients. It relieves symptoms and reduces gradient. Though surgery is preferred in young patients, PTSMA may have a role in selected patients.

High-Sensitivity Cardiac Troponin T Elevation in Hypertrophic Cardiomyopathy Is Associated With Ventricular Arrhythmias

OBJECTIVE

To investigate the relationship between high-sensitivity cardiac troponin T (hs-cTnT) levels and sudden cardiac death (SCD) in patients with hypertrophic cardiomyopathy (HCM).

METHODS

A referral HCM population with prospectively obtained hs-cTnT concentration from March 1, 2018, to April 23, 2020, was reviewed. Patients with end-stage renal disease or an abnormal hs-cTnT level not collected in an outpatient protocolled fashion were excluded. The hs-cTnT level was compared with demographic characteristics, comorbidities, conventional HCM-associated SCD risk factors, imaging, exercise testing, and prior cardiac events.

RESULTS

Of 112 included patients, 69 (62%) had an elevated hs-cTnT concentration. The level of hs-cTnT correlated with known risk factors for SCD, including nonsustained ventricular tachycardia (P=.049) and septal thickness (P=.02). When patients were stratified by having a normal vs an elevated hs-cTnT concentration, patients with elevated hs-cTnT concentration were more likely to have experienced an implantable cardioverter-defibrillator discharge for ventricular arrhythmia, ventricular arrhythmia with hemodynamic instability, or cardiac arrest (incidence rate ratio, 2.96; 95% CI, 1.11 to 10.2). When sex-specific hs-cTnT cutoffs were removed, this association was no longer present (incidence rate ratio, 1.50; 95% CI, 0.66 to 3.60).

CONCLUSION

In a protocolized, outpatient HCM population, hs-cTnT elevations were common and were associated with more arrhythmic expressivity of the HCM substrate as indicated by previous ventricular arrhythmias and appropriate implantable cardioverter-defibrillator shocks only when sex-specific hs-cTnT cutoffs were used. Further research should use different hs-cTnT reference values by sex to determine whether an elevated hs-cTnT value is an independent risk factor for SCD in patients with HCM.

Temporal and Global Trends of the Incidence of Sudden Cardiac Death in Hypertrophic Cardiomyopathy

BACKGROUND

Since the initial clinical description of hypertrophic cardiomyopathy (HCM) over 60 years ago, sudden cardiac death (SCD) has been the most visible and feared complication of HCM.

OBJECTIVES

This study sought to characterize the temporal, geographic, and age-related trends of reported SCD rates in adult HCM patients.

METHODS

Electronic databases were systematically searched up to November 2021 for studies reporting on SCD event rates in HCM patients. Patients with SCD equivalents (appropriate implantable cardioverter-defibrillator [ICD] shocks and nonfatal cardiac arrests) were not included. A random-effects model was used to pool study estimates calculating the overall incidence rates (IR) for each time-era, geographic region, and age group. We analyzed 2 periods (before vs after 2000, following clinical implementation of ICD in HCM). Following 2000, 5-year intervals were used to demonstrate the temporal change in SCD rates.

RESULTS

A total of 98 studies (N = 70,510 patients and 431,407 patient-years) met our inclusion criteria. The overall rate of HCM SCD was 0.43%/y (95% CI: 0.37-0.50%/y; I² = 75%; SCD events: 1,938; person-years of follow-up: 408,715), with young patients (<18 years of age) demonstrating a >2-fold-risk for sudden death vs adult patients 18-60 years of age (IR: 1.09%; 95% CI: 0.69%-1.73% vs IR: 0.43%; 95% CI: 0.37%-0.50%) (P value for subgroup differences <0.01). Contemporary SCD rates from 2015 to present were 0.32%/y and significantly lower compared with 2000 or earlier (IR: 0.32%; 95% CI: 0.20%-0.52% vs IR: 0.73%; 95% CI: 0.53%-1.02%, respectively). Reported SCD rates for HCM were lowest in North America (IR: 0.28%; 95% CI: 0.18%-0.43%,) and highest in Asia (IR: 0.67%; 95% CI: 0.54%-0.84%).

CONCLUSIONS

Contemporary HCM-related SCD rates are low (0.32%/y) representing a 2-fold decrease compared with prior treatment eras. Young HCM patients are at the highest risk. The maturation of SCD risk stratification strategies and the application of primary prevention ICD to HCM are likely responsible for the notable decline over time in SCD events. In addition, worldwide geographic disparities in SCD rates were evident, underscoring the need to increase access to SCD prevention treatment for all HCM patients.

Temporal Changes in Cardiac Morphology and Its Relationship with Clinical Characteristics and Outcomes in Patients with Hypertrophic Cardiomyopathy

In this study, we aimed to assess a large cohort of nonapical hypertrophic cardiomyopathy (HC) patients who have undergone 2 serial cardiac magnetic resonance studies to examine morphological dynamics and their correlation to patient characteristics and clinical outcomes. A total of 214 patients with nonapical HC were enrolled in this study, with 2 sequential cardiac magnetic resonance studies separated by a mean interval of 4.8 ± 2.1 years. Progression of indexed left ventricular mass (LVMI) was correlated with lower LVMI at baseline (p <0.00001) and older age >50 years. In terms of maximal wall thickness (MWT), progression was associated with lower baseline MWT and with the presence of LV outflow tract obstruction. No association was demonstrated between the degree of progression of LVMI or MWT and baseline LV volumes, the severity of mitral regurgitation, gender, or the presence of pathogenic HC variants. Progression of left atrial size was significantly associated with the development of atrial fibrillation (p = 0.014; odds ratio 1.18, confidence interval 1.03 to 1.35) and admission for heart failure (p = 0.018; odds ratio 1.18, confidence interval 1.03 to 1.36). No correlation was demonstrated between changes in LV mass or MWT and clinical outcomes of admission for heart failure, progression to New York Heart Association 2/3, progression to end-stage HC, or implantable cardioverter-defibrillator implantation. In conclusion, our study provides novel insights into the natural history of HC from a morphological perspective. It shows that HC is a dynamic disease in which LV morphology and hypertrophy extent change over time, with the presence of risk factors associated with disease progression.

Prognostic factors in hypertrophic cardiomyopathy in children: An MRI based study

BACKGROUND

Clinical and prognostic role of cardiac magnetic resonance (CMR) in adult population with hypertrophic cardiomyopathy (HCM) have been largely assessed. We sought to investigate the role of CMR for predicting cardiovascular events in children with HCM.

METHODS

CMR was performed in 116 patients with HCM (37 sarcomeric mutations, 31 other mutations, mean age 10.4 ± 4.3 yrs). CMR protocol included cine imaging for evaluation of morphology and function and late gadolinium enhancement (LGE). Hard cardiac events (sustained VT, resuscitated cardiac arrest, sudden cardiac death, end-stage heart failure, heart transplant and appropriate ICD intervention) were recorded through a median follow-up of 4 (1-7) years.

RESULTS

During follow-up 21 heart cardiac events occurred. At maximal-rank statistic the optimal cut-point for LGE extent for predicting events was ≥2%. Syncope, non-sustained ventricular tachycardia (NSVT) and LGE extent ≥2% were independent predictors of events. At Harrel's C statistic combination of LGE extent ≥2% and syncope was the strongest model for predicting events. HR of patients with LGE extent ≥2% and no history of syncope was 3.6 (1.1-12.2) that increased to 37.6 (5.4-161) in those with LGE extent ≥2% and syncope. The median time dependent AUC of LGE extent (0.88, 95% CI 0.86-0.89) was significantly higher than that of syncope (0.63, 95% CI 0.61-0.66, p < 0.0001) and NSVT (0.52, 95% CI 0.50-0.53, p < 0.0001).

CONCLUSIONS

In children with HCM, LGE and syncope were independent predictors of hard cardiac events at follow-up.

Post-operative management of hypertrophic obstructive cardiomyopathy

Hypertrophic obstructive cardiomyopathy patients are at increased risk of sudden cardiac arrest due to dynamic left ventricular outflow tract obstruction, myocardial ischaemia and arrhythmias. Septal myectomy remains the gold standard therapy for patients with hypertrophic obstructive cardiomyopathy (HOCM) refractory to other therapy. This review comprehensively focuses on the post-operative management and complications of HOCM patients undergoing surgical correction. Although these patients are at risk of various perioperative complications from anaesthesia and surgery due to the underlying complexity of their disease, surgical myectomy is associated with excellent long-term outcomes if carried out in experienced centers.

The clinical utility of pediatric cardiomyopathy genetic testing: From diagnosis to a precision medicine-based approach to care

Background

Pediatric-onset cardiomyopathies are rare yet cause significant morbidity and mortality in affected children. Genetic testing has a major role in the clinical evaluation of pediatric-onset cardiomyopathies, and identification of a variant in an associated gene can be used to confirm the clinical diagnosis and exclude syndromic causes that may warrant different treatment strategies. Further, risk-predictive testing of first-degree relatives can assess who is at-risk of disease and requires continued clinical follow-up.

Aim of Review

In this review, we seek to describe the current role of genetic testing in the clinical diagnosis and management of patients and families with the five major cardiomyopathies. Further, we highlight the ongoing development of precision-based approaches to diagnosis, prognosis, and treatment.

Key Scientific Concepts of Review

Emerging application of genotype-phenotype correlations opens the door for genetics to guide a precision medicine-based approach to prognosis and potentially for therapies. Despite advances in our understanding of the genetic etiology of cardiomyopathy and increased accessibility of clinical genetic testing, not all pediatric cardiomyopathy patients have a clear genetic explanation for their disease. Expanded genomic studies are needed to understand the cause of disease in these patients, improve variant classification and genotype-driven prognostic predictions, and ultimately develop truly disease preventing treatment.

Videoscope-assisted transaortic myectomy in patients with hypertrophic cardiomyopathy with complex left ventricular anatomy

BACKGROUND

The transaortic approach is the most common method of septal myectomy. However, difficulties arise due to a limited view of the surgical field. Here, we report our experience with videoscope-assisted transaortic myectomy.

METHODS

We reviewed myectomy operations that were performed between July 2015 and June 2019 at Chung-Ang University Hospital, Seoul, South Korea. Patients who previously had cardiac surgery, alcohol septal ablation, or concomitant disease which required combined surgery, were excluded. Among the 21 patients included, 10 patients underwent videoscope-assisted transaortic myectomy (VA group), and 11 patients underwent myectomy in a conventional manner (CO group). The preoperative data, echocardiographic images, operative records, and postoperative outcomes of these patients were reviewed.

RESULTS

There were no differences in baseline characteristics between groups VA and CO. The main indications for videoscope-assisted transaortic myectomy in group VA were midventricular septal muscle resection (70%), abnormal papillary muscle resection (40%), and abnormal chordal connection resection (30%). Eight (80%) patients had multiple indications for videoscope-assisted transaortic myectomy. There was no surgical mortality in either group. Postoperative patients showed less than moderate mitral regurgitation and a New York Heart Association class either III or IV. There were no differences in hospital days (9.5 vs. 12.0 days; p = .383), nor postoperative pressure gradient (14 vs. 15 mmHg; p > .99).

CONCLUSIONS

Videoscope-assisted transaortic myectomy is an effective surgical technique in selective hypertrophic cardiomyopathy patients with complex intraventricular anatomy, diffuse hypertrophy, and midventricular obstruction.

Left Atrial Strain and Function in Pediatric Hypertrophic Cardiomyopathy

BACKGROUND

Left atrial (LA) strain and dysfunction are early markers of diastolic dysfunction, associated with poor exercise capacity in adults with hypertrophic cardiomyopathy (HCM). Literature on assessment of LA mechanics in pediatric HCM is lacking. The aim of this study was to assess LA strain and LA function in pediatric patients who have HCM with (phenotype positive [P+]) and without (genotype positive, phenotype negative [G+P-]) ventricular hypertrophy and evaluate their correlation with exercise stress test parameters.

METHODS

Seventy-eight children (3-25 years of age) with HCM (P+, n = 46; G+P-, n = 32) and 20 healthy control subjects were retrospectively studied. LA conduit function, reservoir function, and pump function were computed using phasic LA volumetric analysis. LA reservoir strain (LASr) and LA contractile strain were measured using speckle-tracking echocardiography. Exercise test findings within 12 months of echocardiography were recorded.

RESULTS

LA conduit function (36% vs 48%, P < .001) and LA reservoir function (137% vs 180%, P < .001) were lower in P+ than in G+P- patients. LA contractile function did not differ between the groups (31% vs 32%, P = .87). Compared with patients with G+P- HCM, those with P+HCM had lower four-chamber LASr (29% vs 41%, P < .001), two-chamber LASr (30% vs 41%, P < .001), average LASr (29% vs 42%, P < .001), and LA contractile strain (9% vs 12%, P = .016). In the cohort of patients with HCM who underwent stress testing (n = 35), LA conduit function weakly correlated with aerobic capacity (r = 0.42, P = .019).

CONCLUSIONS

Children with P+HCM have reduced LA function, measurable by both volumetric and strain analysis. Altered LA mechanics are associated with poor exercise capacity. This study lays the foundation for the evaluation of novel LA parameters in pediatric HCM and warrants larger longitudinal studies to assess its clinical significance.

Left Ventricular Hypertrophy Is More Prevalent in Type B than Type A Aortic Dissection

OBJECTIVES

Several factors determining differences between types A and B aortic dissection (AD) have been reported; however, little data exist examining their differences in left ventricular hypertrophy (LVH). We compared the prevalence of LVH in patients with types A and B AD.

METHODS

We retrospectively analyzed 334 patients with acute AD (227 type A; 107 type B). Concentric hypertrophy (CH; increased left ventricular mass index [LVMI] and relative wall thickness [RWT]) is one of four types of left ventricular (LV) geometry thought to be most associated with hypertension. We compared LVMI and the prevalence of CH in patients with types A or B AD. Multivariate logistic regression analyses of variables associated with type B AD were performed.

RESULTS

Comparing type A and B AD, LVMI (95 ± 26 vs.107 ± 28, p <0.001) and prevalence of CH (26% vs. 44%, p = 0.001) were higher in type B AD. In multivariate analysis, CH was an independent factor associated with type B AD (odds ratio: 2.62, confidence interval: 1.54-4.47, p <0.001).

CONCLUSIONS

Our data suggested LVH was more prevalent in type B than in type A AD. Considering LVH usually results from hypertension, patients with type B AD may be more affected by hypertension than those with type A.

Discordant clinical features of identical hypertrophic cardiomyopathy twins

Hypertrophic cardiomyopathy (HCM) is a disease of heart muscle, which affects ∼1 in 500 individuals and is characterized by increased left ventricular wall thickness. While HCM is caused by pathogenic variants in any one of eight sarcomere protein genes, clinical expression varies considerably, even among patients with the same pathogenic variant. To determine whether background genetic variation or environmental factors drive these differences, we studied disease progression in 11 pairs of monozygotic HCM twins. The twin pairs were followed for 5 to 14 y, and left ventricular wall thickness, left atrial diameter, and left ventricular ejection fraction were collected from echocardiograms at various time points. All nine twin pairs with sarcomere protein gene variants and two with unknown disease etiologies had discordant morphologic features of the heart, demonstrating the influence of nonhereditable factors on clinical expression of HCM. Whole genome sequencing analysis of the six monozygotic twins with discordant HCM phenotypes did not reveal notable somatic genetic variants that might explain their clinical differences. Discordant cardiac morphology of identical twins highlights a significant role for epigenetics and environment in HCM disease progression.

Harmonizing the Collection of Clinical Data on Genetic Testing Requisition Forms to Enhance Variant Interpretation in Hypertrophic Cardiomyopathy (HCM): A Study from the ClinGen Cardiomyopathy Variant Curation Expert Panel

Diagnostic laboratories gather phenotypic data through requisition forms, but there is no consensus as to which data are essential for variant interpretation. The ClinGen Cardiomyopathy Variant Curation Expert Panel defined a phenotypic data set for hypertrophic cardiomyopathy (HCM) variant interpretation, with the goal of standardizing requisition forms. Phenotypic data elements listed on requisition forms from nine leading cardiomyopathy testing laboratories were compiled to assess divergence in data collection. A pilot of 50 HCM cases was implemented to determine the feasibility of harmonizing data collection. Laboratory directors were surveyed to gauge potential for adoption of a minimal data set. Wide divergence was observed in the phenotypic data fields in requisition forms. The 50-case pilot showed that although demographics and assertion of a clinical diagnosis of HCM had 86% to 98% completion, specific phenotypic features, such as degree of left ventricular hypertrophy, ejection fraction, and suspected syndromic disease, were completed only 24% to 44% of the time. Nine data elements were deemed essential for variant classification by the expert panel. Participating laboratories unanimously expressed a willingness to adopt these data elements in their requisition forms. This study demonstrates the value of comparing and sharing best practices through an expert group, such as the ClinGen Program, to enhance variant interpretation, providing a foundation for leveraging cumulative case-level data in public databases and ultimately improving patient care.

Efficacy and safety of direct oral anticoagulants (DOACs) versus vitamin K antagonist (VKA) among patients with atrial fibrillation and hypertrophic cardiomyopathy: a systematic review and meta-analysis

Background/objectives: Long-term oral anticoagulant therapy is recommended for patients with hypertrophic cardiomyopathy (HCM) who develop atrial fibrillation (AF) to prevent cardioembolic complications. In patients with non-valvular AF, direct oral anticoagulants (DOACs) has been proved to be non-inferior to adjusted-dose vitamin K antagonist (VKA). However, the role of DOACs in patients with AF in the setting of HCM has not been fully established.Methods: A comprehensive literature review was conducted by searching for published articles indexed in MEDLINE and EMBASE databases from inception through 1 May 2019. Eligible studies must start with recruitment of patients with AF in the setting of HCM who received either DOACs or VKA. The studies must follow them for the occurrence of ischaemic stroke. Hazard ratio (HR) and confidence interval (CI) of developing ischaemic stroke between the two groups must be reported. Pooled HR was calculated using a random-effect, generic inverse variance method of DerSimonian and Laird.Results: A total of three retrospective cohort studies with 4,418 participants met the eligibility criteria and were included into the meta-analysis. A significantly lower risk of all-cause death was observed in the DOACs group than in the VKA group with the pooled HR of 0.43 (95% CI, 0.33-0.58, I² = 0%). However, the risk of ischaemic stroke among patients with AF and HCM who received DOACs was not significantly different from those who received VKA with the pooled HR of 0.95 (95% CI, 0.73-1.22, I² = 0%). Both major bleeding and intracranial bleeding were also not significantly different between those who received DOACs versus those who received VKA with the pooled HR of 0.94 (95% CI, 0.70-1.26, I² = 0%) and 0.61 (95% CI, 0.27-1.37, I² = 0%), respectively.Conclusions: The current study found that the risk of all-cause death was significantly reduced but the risk of ischaemic stroke, major bleeding and intracranial bleeding were not significantly different between patients with AF and HCM who had received DOACs and those who received VKA.

Genotype-Related Clinical Characteristics and Myocardial Fibrosis and their Association with Prognosis in Hypertrophic Cardiomyopathy

BACKGROUND

The spectrum of genetic variants and their clinical significance of Hypertrophic cardiomyopathy (HCM) have been poorly studied in Asian patients. The objectives of this study were to assess the spectrum of genetic variants and genotype-phenotype relationships within a Korean HCM population.

METHODS

Eighty-nine consecutive unrelated HCM patients were included. All patients underwent genotypic analysis for 23 HCM-associated genes. Clinical parameters including echocardiographic and cardiac magnetic resonance (CMR) parameters were evaluated. A composite of major adverse cardiac and cerebrovascular events was assessed.

RESULTS

Genetic variants were detected in 55 of 89 subjects. Pathogenic variants or likely pathogenic variants were identified in 27 of HCM patients in MYBPC3, TNNI3, MYH7, and MYL7. Variants of uncertain significance were identified in 28 patients. There were significant differences in the presence of non-sustained ventricular tachycardia (p = 0.030) and myocardial fibrosis on CMR (p = 0.029) in the detected compared to the not-detected groups. Event-free survival was superior in the not-detected group (p = 0.006).

CONCLUSION

Genetic variants in patients with HCM are relatively common and are associated with adverse clinical events and myocardial fibrosis on CMR. Genotypic analysis may add important information to clinical variables in the assessment of long-term risk for HCM patients.

Influence of Gender on Clinical Characteristics and Outcomes in Chinese Patients With Hypertrophic Cardiomyopathy

BACKGROUND

Gender plays a crucial role in the prevalence, clinical presentation, management and outcomes of various cardiovascular diseases. The aim of this study was to evaluate the impact of gender on clinical manifestations and outcomes in the Chinese patients with hypertrophic cardiomyopathy (HCM).

METHODS

We evaluated 576 Chinese patients (316 males) who were diagnosed with HCM at West China Hospital from 2008 to 2016 and followed over 3.2 ± 2.3 years.

RESULTS

Compared to male patients, female patients were older (57.2 ± 16.7 years vs. 53.0 ± 15.7 years, P = 0.002) and more symptomatic [New York Heart Association class III-IV symptoms 46.9% vs. 30.7%, P < 0.001] at the time of diagnosis, and had higher left ventricular outflow tract gradient at rest [33 (12-58) mmHg vs. 24 (8-42) mmHg, P = 0.007]. During the follow-up period, survival analysis showed no significant differences in the incidences of all-cause mortality (P = 0.657) and cardiovascular mortality (P = 0.214) but the rate of rehospitalization due to heart failure was higher in females than in males (P = 0.015). Multivariable Cox analysis showed that left ventricular ejection fraction (hazard ratio [HR], 0.96 [95% confidence interval [CI], 0.94-0.99]; P = 0.003) and New York Heart Association class III-IV (HR, 2.86 [95% CI, 1.38-5.94]; P = 0.005) were independently associated with cardiovascular mortality.

CONCLUSIONS

Compared to males, females were older and more symptomatic at presentation, and had higher risk of progression to heart failure in Chinese HCM patients but there were no differences in cardiovascular mortality.

Importance of surgical expertise in septal myectomy for obstructive hypertrophic cardiomyopathy

OBJECTIVE

In 2011, a multidisciplinary hypertrophic cardiomyopathy (HCM) program with a dedicated myectomy surgeon was implemented at our institution. We hypothesized that a dedicated approach allows better identification and management of mitral regurgitation (MR) during septal myectomy (SM) for obstructive HCM with significant mitral regurgitation.

METHODS

Between 2006 and 2018, 181 patients had SM at our institution. This study consists of 53 patients with preoperative moderate or greater MR associated with systolic anterior motion who underwent isolated SM with or without mitral intervention. Patients were divided into those who underwent SM by a dedicated myectomy surgeon (group D, n = 31) or by a non-dedicated surgeon (group ND, n = 22). Primary outcome of interest was rate of mitral valve replacement (MVR) at SM. Secondary outcomes include in-hospital mortality, need for permanent pacemaker, mitral valve reoperation, and residual MR and left ventricular outflow tract gradient on postoperative echocardiography.

RESULTS

12 patients (55%) had a concomitant MVR during septal myectomy in group ND compared to 2 patients (6%) in group D (p < 0.01). Among patients who did not undergo MVR, patients in group D less commonly had residual MR than patients in ND after SM (p < 0.01). Group D had 100% survival with NYHA class I in 94% patients at follow-up visit (p = 0.01). Reoperation for MVR was required in four patients in group ND vs. none in group D (p < 0.01).

CONCLUSIONS

A dedicated surgeon is able to spare the mitral valve in patients undergoing SM. This study emphasizes the importance of surgical expertise in this cohort.

Appropriate and inappropriate shocks in hypertrophic cardiomyopathy patients with subcutaneous implantable cardioverter-defibrillators: An international multicenter study

BACKGROUND

Subcutaneous implantable cardioverter-defibrillators (S-ICDs) are attractive for preventing sudden cardiac death in hypertrophic cardiomyopathy (HCM) as they mitigate risks of transvenous leads in young patients. However, S-ICDs may be associated with increased inappropriate shock (IAS) in HCM patients.

OBJECTIVE

The purpose of this study was to assess the incidence and predictors of appropriate shock and IAS in a contemporary HCM S-ICD cohort.

METHODS

We collected electrocardiographic and clinical data from HCM patients who underwent S-ICD implantation at 4 centers. Etiologies of all S-ICD shocks were adjudicated. We used Firth penalized logistic regression to derive adjusted odds ratios (aORs) for predictors of IAS.

RESULTS

Eighty-eight HCM patients received S-ICDs (81 for primary and 7 for secondary prevention) with a mean follow-up of 2.7 years. Five patients (5.7%) had 9 IAS episodes (3.8 IAS per 100 patient-years) most often because of sinus tachycardia and/or T-wave oversensing. Independent predictors of IAS were higher 12-lead electrocardiographic R-wave amplitude (aOR 2.55 per 1 mV; 95% confidence interval 1.15-6.38) and abnormal T-wave inversions (aOR 0.16; 95% confidence interval 0.02-0.97). There were 2 appropriate shocks in 7 secondary prevention patients and none in 81 primary prevention patients, despite 96% meeting Enhanced American College of Cardiology/American Heart Association criteria and the mean European HCM Risk-SCD score predicting 5.7% 5-year risk. No patients had sudden death or untreated sustained ventricular arrhythmias.

CONCLUSION

In this multicenter HCM S-ICD study, IAS were rare and appropriate shocks confined to secondary prevention patients. The R-wave amplitude increased IAS risk, whereas T-wave inversions were protective. HCM primary prevention implantable cardioverter-defibrillator guidelines overestimated the risk of appropriate shocks in our cohort.

Access and Outcomes Among Hypertrophic Cardiomyopathy Patients in a Large Integrated Health System

Background

Hypertrophic cardiomyopathy (HCM) is the most common inherited cardiomyopathy. Current guidelines endorse management in expert centers, but patient socioeconomic status can affect access to specialty care. The effect of socioeconomic status and specialty care access on HCM outcomes has not been examined.

Methods and Results

We conducted a retrospective cohort study that examined outcomes among HCM patients receiving care in the Yale New Haven Health System between June 2011 and December 2017. Patients were assigned to lower or higher socioeconomic status groups (LSES/HSES) based on medical insurance provider and to receivers of specialty care (SC) at Yale's Inherited Cardiomyopathy clinic or general cardiology care (GC). The primary outcome was all‐cause death, and the secondary outcome was all‐cause hospitalization. We identified 953 HCM patients; 820 (86%) were HSES and 133 (14%) were LSES. Forty‐three (4.5%) patients died from cardiac and noncardiac causes. LSES patients within the general cardiology care cohort had significantly higher all‐cause mortality compared with HSES patients (adjusted hazard ratio, [95% CI]=10.06 [4.38–23.09]; P<0.001). This was not noted in the specialty care cohort (adjusted hazard ratio, [95% CI]=2.87 [0.56–14.73]; P=0.21). The moderator effect of specialty care on mortality difference between LSES versus HSES, however, did not reach statistical significance (hazard ratio, 0.29 [0.05–1.77]; P=0.18). Specialist care was associated with increased hospitalization (adjusted hazard ratio, [95% CI]=3.28 [1.11–9.73]; P=0.03 for LSES; 2.19 [1.40–3.40]; P=0.001 for HSES).

Conclusions

Socioeconomically vulnerable HCM patients had higher mortality when not referred to specialty care. Further study is needed to understand the underlying causes.

Retrospective analysis of clinical phenotype and prognosis of hypertrophic cardiomyopathy complicated with hypertension

We here studied the clinical features, cardiac structure, and functional changes and prognosis of hypertrophic cardiomyopathy (HCM) patients with hypertension (HTN). A total of 90 HCM patients with HTN and 172 patients without HTN were divided into a hypertensive group and non-hypertensive group. The clinical characteristics, cardiac structure and function, and prognosis of the two groups were compared. Our study found that HCM patients with HTN had fewer syncope events in their medical histories (8% vs. 22%, P < 0.01) and sudden deaths in the family (3% vs. 10%, P < 0.05). The prevalence of apical hypertrophy (18% vs. 7%, P < 0.01) and midventricular obstruction (26% vs. 15%, P < 0.05) was higher in the HTN group. Besides, simple HCM patients had more pathogenic gene mutations, while those with HTN were more likely to have mutations of uncertain clinical significance (64% vs. 24%, P < 0.05). Evaluation of 5-year survival rate showed a trend for a worse prognosis in HCM patients with HTN, but the results were not statistically insignificant (P = 0.065). In conclusion, we found that the clinical phenotypes of HCM patients with HTN differed from those of patients with HCM alone, suggesting that HTN may play a pathogenic role in the pathogenesis of hypertensive hypertrophic cardiomyopathy patients.

Neonatal cardiac hypertrophy: the role of hyperinsulinism-a review of literature

Hypertrophic cardiomyopathy (HCM) in neonates is a rare and heterogeneous disorder which is characterized by hypertrophy of heart with histological and functional disruption of the myocardial structure/composition. The prognosis of HCM depends on the underlying diagnosis. In this review, we emphasize the importance to consider hyperinsulinism in the differential diagnosis of HCM, as hyperinsulinism is widely associated with cardiac hypertrophy (CH) which cannot be distinguished from HCM on echocardiographic examination. We supply an overview of the incidence and treatment strategies of neonatal CH in a broad spectrum of hyperinsulinemic diseases. Reviewing the literature, we found that CH is reported in 13 to 44% of infants of diabetic mothers, in approximately 40% of infants with congenital hyperinsulinism, in 61% of infants with leprechaunism and in 48 to 61% of the patients with congenital generalized lipodystrophy. The correct diagnosis is of importance since there is a large variation in prognoses and there are various strategies to treat CH in hyperinsulinemic diseases.Conclusion: The relationship between CH and hyperinsulism has implications for clinical practice as it might help to establish the correct diagnosis in neonates with cardiac hypertrophy which has both prognostic and therapeutic consequences. In addition, CH should be recognized as a potential comorbidity which might necessitate treatment in all neonates with known hyperinsulinism.What is Known:• Hyperinsulinism is currently not acknowledged as a cause of hypertrophic cardiomyopathy (HCM) in textbooks and recent Pediatric Cardiomyopathy Registry publications.What is New:• This article presents an overview of the literature of hyperinsulinism in neonates and infants showing that hyperinsulinism is associated with cardiac hypertrophy (CH) in a broad range of hyperinsulinemic diseases.• As CH cannot be distinguished from HCM on echocardiographic examination, we emphasize the importance to consider hyperinsulinism in the differential diagnosis of HCM/CH as establishing the correct diagnosis has both prognostic and therapeutic consequences.

Obesity is associated with worse long-term outcomes in hypertrophic cardiomyopathy patients with acute myocardial infarction

BACKGROUND

Hypertrophic cardiomyopathy is associated with poor prognosis. In our previous study, it has been reported that patients with acute myocardial infarction and hypertrophic cardiomyopathy exhibited worse long-term outcomes than those with acute myocardial infarction without hypertrophic cardiomyopathy and those with hypertrophic cardiomyopathy without acute myocardial infarction. In this article, we aimed to assess the impact of body mass index on the long-term outcomes of hypertrophic cardiomyopathy patients with acute myocardial infarction.

METHODS

Seventy-eight consecutive patients with hypertrophic cardiomyopathy and acute myocardial infarction were included. Obesity was defined as body mass index ⩾28 kg/m² adapted to Chinese. The long-term endpoints were major adverse cardiac events and secondary endpoints, which included re-hospitalization, recurrent angina, thrombosis, bleeding, heart failure, and arrhythmias.

RESULTS

There were no differences in observed in-hospital mortality or 5-year mortality between the two groups of hypertrophic cardiomyopathy and acute myocardial infarction patients divided by body mass index. However, significantly increased incidence of re-percutaneous coronary intervention and stroke was observed in the obese group (re-percutaneous coronary intervention: 0.0% vs. 21.4%, p = 0.007; stroke: 5.6% vs. 28.6%, p = 0.042). The 5-year outcomes of major adverse cardiac events were inferior in the obese group (log-rank p = 0.020).

CONCLUSION

Acute myocardial infarction and hypertrophic cardiomyopathy patients who were obese exhibited worse long-term outcomes than those without obesity.

Evaluation of Hypertrophic Cardiomyopathy: Newer Echo and MRI Approaches

PURPOSE OF REVIEW

This review discusses the basic and evolving echocardiographic and cardiac magnetic resonance (CMR) approaches in the diagnosis and management of patients with hypertrophic cardiomyopathy (HCM).

RECENT FINDINGS

Newer imaging technologies and techniques in both echocardiography and CMR have proved to add incremental value to our understanding of HCM. 3D reconstruction in echocardiography and CMR allows for more accurate morphological and volumetric assessment of the left ventricle. Echocardiographic and CMR-based left atrial assessment, including for its mechanical properties, has been shown to be correlated to outcomes and development of atrial fibrillation. Tissue characterization and scar burden quantification by late gadolinium enhancement on CMR has revolutionized our understanding of fibrotic processes in HCM and their contribution to disease severity and clinical outcomes. Cardiac imaging plays a crucial role in HCM patients. Using echocardiography and CMR as complementary modalities allows for improved diagnostics, optimization of treatment, and better prognostication.

Changes in Biological Pathways During 6,000 Years of Civilization in Europe

The beginning of civilization was a turning point in human evolution. With increasing separation from the natural environment, mankind stimulated new adaptive reactions in response to new environmental factors. In this paper, we describe direct signs of these reactions in the European population during the past 6,000 years. By comparing whole-genome data between Late Neolithic/Bronze Age individuals and modern Europeans, we revealed biological pathways that are significantly differently enriched in nonsynonymous single nucleotide polymorphisms in these two groups and which therefore could be shaped by cultural practices during the past six millennia. They include metabolic transformations, immune response, signal transduction, physical activity, sensory perception, reproduction, and cognitive functions. We demonstrated that these processes were influenced by different types of natural selection. We believe that our study opens new perspectives for more detailed investigations about when and how civilization has been modifying human genomes.

Novel Therapies for Prevention and Early Treatment of Cardiomyopathies

Heritable cardiomyopathies are a class of heart diseases caused by variations in a number of genetic loci. Genetic variants on one allele lead to either a degraded protein, which causes a haploinsufficiency of that protein, or a nonfunctioning protein that subverts the molecular system within which the protein works. Over years, both of these mechanisms eventually lead to diseased heart tissue and symptoms of a failing heart. Most cardiomyopathy treatments repurpose heart failure drugs to manage these symptoms and avoid adverse outcomes. There are few therapies that correct the underlying pathogenic genetic or molecular mechanism. This review will reflect on this unmet clinical need in genetic cardiomyopathies and consider a variety of therapies that address the mechanism of disease rather than patient symptoms. These therapies are genetic, targeting a defective gene or transcript, or ameliorating a genetic insufficiency. However, there are also a number of small molecules under exploration that modulate downstream faulty protein products affected in cardiomyopathies.

Safety and efficacy of anti-tachycardia pacing in patients with hypertrophic cardiomyopathy implanted with an ICD

BACKGROUND

In hypertrophic cardiomyopathy (HCM) patients implanted with an implantable cardioverter defibrillator (ICD), clinical outcomes of antitachycardia pacing (ATP) have been poorly explored. In a retrospective analysis of a cohort of consecutive HCM patients implanted with an ICD, we aimed to assess the efficacy, safety, and clinical value of ATP.

METHODS

The cohort of HCM patients implanted with a transvenous ICD and followed in our center was assessed for device intervention from implantation to last clinical follow-up.

RESULTS

Overall 77 patients (45 males; mean age: 46 ± 16 years) were analyzed. After 67 ± 41 months, 24 patients had 49 ventricular tachycardia/fibrillation (VT/VF) appropriately treated (5.8% per year). Among 39 monomorphic VTs, ATP was effective in 27 (success rate: 69%). Mean time from VT onset to ATP delivery was 9.1 ± 4.9 s. The only clinical variable improving ATP success was use of beta-blockers (81% vs 50%; P = .04). Out of 12 ineffectively treated VTs, one was immediately shocked, four self-terminated after 18 ± 12 s, and seven (18%) were accelerated to a new VT. ATP was also delivered for 27 of 42 inappropriately detected episodes and induced two de novo VTs (7%). In the per patient analysis, 14 out 77 (18%) patients had one or more appropriate and effective ATP (3.4% per year), and only six (8%; 1.4% per year) received more than one ATP.

CONCLUSION

ATP is moderately effective for the treatment of monomorphic VTs in HCM patients. However, the rate of appropriate ATP therapies is low, ATP is often prematurely delivered, and ATP-induced arrhythmia degeneration is of concern.

Advanced Heart Failure Management and Transplantation

Hypertrophic cardiomyopathy is a genetic heart disease with heterogeneous clinical features, including progression to advanced heart failure. The development of these symptoms can be related to outflow obstruction but in some patients reflects an underlying process of fibrosis and progressive ventricular dysfunction. For patients with end-stage disease, traditional heart failure therapies have not proved beneficial. As such, more advanced therapies, such as left ventricular assist device or cardiac transplantation, should be considered for these patients. Although left ventricular assist device support is used infrequently due to the restrictive physiology underlying hypertrophic cardiomyopathy, transplant represents an effective treatment, with encouraging long-term outcome data.

Practice Variation among an International Group of Genetic Counselors on when to Offer Predictive Genetic Testing to Children at Risk of an Inherited Arrhythmia or Cardiomyopathy

Cascade predictive genetic testing is available for many families as a means to identify individuals at risk of long QT syndrome (LQTS), catecholaminergic polymorphic ventricular tachycardia (CPVT), hypertrophic cardiomyopathy (HCM), and arrhythmogenic right ventricular cardiomyopathy (ARVC). The general issue of offering predictive genetic testing to minors has been an area of ethical debate among genetic counselors and other healthcare professionals for many years. An online questionnaire was circulated to four international genetic counseling associations to assess the views of cardiac genetic counselors regarding when to offer predictive genetic testing to children at risk of LQTS, CPVT, HCM, and ARVC. Analysis was both quantitative and qualitative. The study sample comprised 98 respondents. The majority reported that they offer predictive genetic testing before 5 years of age to children at risk of LQTS (83%) and CVPT (75%) and before 10 years of age to children at risk of HCM (66%) or ARVC (70%). Influencing factors included country of practice, clinical setting, and years of experience. The rationale provided for when to offer predictive genetic testing is encompassed by the ethical principles of beneficence, non-maleficence, autonomy, and informed consent. In conclusion, significant practice variation exists among cardiac genetic counselors regarding predictive genetic testing for children at risk of an inherited cardiomyopathy. These variations call for more research in the area to assist with the development of evidence-based guidelines.

The effect of hypertension on cardiac structure and function in different types of hypertrophic cardiomyopathy: A single-center retrospective study

OBJECTIVES

To determine whether hypertension (HTN) affects cardiac structure and function in different types of hypertrophic cardiomyopathy (HCM).

DESIGN

Patients with obstructive HCM (n = 40), septal HCM (n = 88), and apical HCM (n = 42) were separated into hypertensive and non-hypertensive subgroups, and echocardiographic parameters at baseline and at follow-up were compared between the subgroups.

RESULTS

At follow-up, hypertensive obstructive HCM patients showed a decrease in end-diastolic volume (from 93.87 ± 26.08 mL to 79.06 ± 20.07 mL; p= 0.045) and in left ventricular end-diastolic diameter (from 45.00 ± 5.32 mm to 41.83 ± 4.58 mm; p =0.042). Non-hypertensive obstructive HCM patients showed a decrease in maximum aortic velocity (from 2.01 ± 0.53 m/s to 1.28 ± 0.25 m/s; p= 0.011) and in aortic maximum pressure gradient (from 17.22 ± 9.57 mm Hg to 6.79 ± 2.44 mm Hg; p= 0.03). Hypertensive apical HCM patients showed an increase in end-diastolic volume (from 95.28 ± 16.54 mL to 119.74 ± 25.19 mL; p= 0.016) and in left ventricular end-diastolic diameter (from 45.28 ± 3.36 mm to 50.20 ± 4.56 mm; p= 0.007).

CONCLUSIONS

HTN can affect left ventricular capacity in obstructive HCM and apical HCM, causing a decrease in ventricular capacity in the former and increase in the latter; it has no significant effect on the size of the left ventricular cavity in septal HCM. HTN can lead to a poor therapeutic effect on aortic flow rate and pressure gradient in obstructive HCM patients.

Percutaneous Mechanical Circulatory Support Using Impella Devices for Decompensated Cardiogenic Shock: A Pediatric Heart Center Experience

Cardiogenic shock remains a significant cause of mortality and morbidity in children with heart failure. Percutaneous mechanical circulatory support may be an additional tool to augment left heart support and decompression in addition to conventional therapies. This report aims to review the clinical and hemodynamic outcomes of the Impella device at a pediatric center. A retrospective review of all implants between October 2014 and November 2016 was conducted. Clinical outcomes, device implant techniques, complications, and hemodynamic data were collected. Statistical analysis was performed on hemodynamic and echocardiographic data. There were 10 Impella device placements in 8 patients with a median age of 17 years (6.5-25) and support duration of 8 days (1-21). Implant diagnosis included 5 patients with either posttransplant rejection or allograft vasculopathy, 2 patients with myocarditis, and 1 patient with refractory ventricular tachycardia. Extracorporeal membrane oxygenation support was required in 4 patients. Significant reduction in pulmonary capillary wedge pressures/left atrial pressures (p = 0.031) and increase in near infrared spectroscopy (p = 0.039) was seen pre- and post-Impella implant. All patients survived to discharge from the intensive care unit with one late death. Percutaneous mechanical circulatory support is a viable option in experienced pediatric centers as a mode to augment cardiac output or to decompress the left heart in patients on extracorporeal membrane oxygenation or with cardiogenic shock.

Clinical, Radiographic, and Microbiologic Features of Infective Endocarditis in Patients With Hypertrophic Cardiomyopathy

Infective endocarditis (IE) is an infection of the inner lining of the heart with high morbidity and mortality despite medical and surgical advancements in recent decades. Hypertrophic cardiomyopathy (HC) is one of several medical conditions that have been linked to an increased risk of IE, but there is a paucity of data on this association. We therefore sought to define the clinical phenotype of IE in patients with HC at a single tertiary care center. A retrospective cohort of 30 adult patients with HC diagnosed with IE between January 1, 2006 and December 31, 2016 at Mayo Clinic Rochester were identified. Similar rates of aortic (n = 14) and mitral (n = 16) valve involvement by IE were noted (47% vs 53%). This finding persisted even in patients with left-ventricular outflow tract obstruction and systolic anterior motion of the mitral valve. Symptomatic embolic complications occurred in 10 cases (33%). Surgical intervention was performed in 11 cases (37%). One-year mortality was remarkably low at 7%. In conclusion, in the largest single-center cohort of IE complicating HC, there were similar rates of both mitral and aortic valve involvement regardless of the presence of left ventricular outflow tract obstruction, which is contrary to a long-standing tenet regarding the association of HC and IE. Moreover, no "high risk" IE subset was identified based on HC-related parameters.

Comparison of Valsalva Maneuver, Amyl Nitrite, and Exercise Echocardiography to Demonstrate Latent Left Ventricular Outflow Obstruction in Hypertrophic Cardiomyopathy

Guidelines recommend exercise stress echocardiogram (ESE) for patients with hypertrophic cardiomyopathy (HC) if a 50 mm Hg gradient is not present at rest or provoked with Valsalva or amyl nitrite, to direct medical and surgical management. However, no study has directly compared all 3 methods. We sought to evaluate efficacy and degree of provocation of left ventricular outflow gradients by ESE, and compare with Valsalva and amyl nitrite. In patients with HC between 2002 and 2015, resting echocardiograms and ESEs within 1 year were retrospectively reviewed. Gradients elicited by each provocation method were compared. Rest and ESE were available in 97 patients (mean age 54 ± 18 years, 57% male); 78 underwent Valsalva maneuver and 41 amyl nitrite provocation. Median gradients (interquartile range) were 10 mm Hg (7,19) at rest, 16 mm Hg (9,34) with Valsalva, 23 mm Hg (13,49) with amyl nitrite, and 26 mm Hg (13,58) with ESE. ESE and amyl nitrite were able to provoke obstruction (≥30 mm Hg) and severe obstruction (≥50 mm Hg) more frequently than Valsalva. In patients with resting gradient <30 mm Hg (n = 83), provocation maneuvers demonstrated dynamic obstruction in 51%; in those with Valsalva gradient <30 mm Hg (n = 57), ESE or amyl nitrite provoked a gradient in 44%; and in those with amyl nitrite gradient <30 mm Hg (n = 20), ESE provoked a gradient in 29%. No demographic or baseline echocardiographic parameter predicted provocable obstruction. In conclusion, ESE is clinically useful; however, different provocation maneuvers may be effective in different patients with HC, and all maneuvers may be required to provoke dynamic obstruction in symptomatic patients.

Hypertrophic Cardiomyopathy-Past, Present and Future

Hypertrophic cardiomyopathy (HCM) is the most common genetic cardiomyopathy with a prevalence of 1 in 500 in the general population. Since the first pathological case series at post mortem in 1957, we have come a long way in its understanding, diagnosis and management. Here, we will describe the history of our understanding of HCM including the initial disease findings, diagnostic methods and treatment options. We will review the current guidelines for the diagnosis and management of HCM, current gaps in the evidence base and discuss the new and promising developments in this field.

Septal alcoholization in hypertrophic cardiomyopathy: about 11 cases

Outcomes of septal alcoholization in hypertrophic obstructive cardiomyopathy are not enough studied in all centers. The purpose of this study was to determine the outcomes of septal alcoholization in hypertrophic obstructive cardiomyopathy in our hospital. A retrospective and prospective descriptive study focused on all patients aged at least 18 years treated by alcohol septal ablation between July 2005 and June 2010 in the cardiology unit of Clermont-Ferrand teaching Hospital. The inclusion criteria were, hypertrophic obstructive cardiomyopathy with left ventricular outflow tract obstruction ≥ 50 mmHg, symptomatic despite optimal medical therapy. The clinical, paraclinical data and the results of alcohol ablation were collected from medical records of patients and a telephone conversation with the patients or their physicians. These data were analyzed by EPI info 6.04. Eleven patients with average age of 56.27 ± 15, 83 were included of which 81.8% of men. The main indications of alcohol septal were dyspnea stage NYHA II-IV (45.5%), lipothymia (18.2%) and invalidating angina (18.2%). Main electrocardiographic abnormalities were left ventricular hypertrophy and disorders of repolarization with 72.7% each. Minor conductive disorders were found in 45.5% of the cases. The left ventricular outflow tract obstruction was 98.18 ± 25.93 mmHg before alcohol septal ablation and 18.91 ± 31.97 mmHg after a follow-up of 25.64 ± 21.97 months. The success rate was 81.8%. Conductive disorders (45.5%) required the establishment of a definitive pacemaker in 36.4% of the patients. A cardiac defibrillator was implanted at 27.3%. Septal alcoholization was succesful.

Hypertrophic obstructive cardiomyopathy: the Mayo Clinic experience

BACKGROUND

Hypertrophic cardiomyopathy (HCM) is a primary myocardial disease characterized by left ventricular hypertrophy in the absence of other etiologies. Clinical presentation may vary from asymptomatic to sudden cardiac death. Medical treatment is the first-line therapy for symptomatic patients. Extended left ventricular septal myectomy is the procedure of choice if medical treatment is unsuccessful or intolerable.

MAYO CLINIC EXPERIENCE

More than 3,000 patients have had septal myectomy for HCM at the Mayo Clinic (MN, USA) from 1993 to 2016. Risk of hospital death after isolated septal myectomy for obstructive HCM is <1% and is similar to the risk of operation for elective mitral valve repair. Complications, such as complete heart block requiring permanent pacemaker, are uncommon (2%), although partial or complete left bundle branch block is a frequent finding on the postoperative ECG. Relief of left ventricular outflow tract (LVOT) obstruction with septal myectomy dramatically improves symptoms and exercise capacity in symptomatic patients with obstructive HCM. More than 90% of severely symptomatic patients have improvement by at least two functional classes, and reduction of outflow gradients by myectomy decreases or eliminates symptoms of dyspnea, angina and/or syncope. Basal obstruction with systolic anterior motion (SAM) is treated by transaortic myectomy. The transapical approach was applied in 115 patients with obstructive midventricular and apical variants of HCM between 1993 and 2012. All patients with midventricular obstruction had gradient relief and none developed an apical aneurysm or ventricular septal defect. Recurrent obstruction after satisfactory myectomy was rare.

CONCLUSIONS

Septal myectomy effectively and definitively relieves LVOT obstruction and cardiac symptoms in patients with obstructive HCM. In experienced centers, early mortality for isolated septal myectomy is less than 1%, and overall results are excellent and continue to improve in the current era.

Usefulness of Preoperative Transforming Growth Factor-Beta to Predict New Onset Atrial Fibrillation After Surgical Ventricular Septal Myectomy in Patients With Obstructive Hypertrophic Cardiomyopathy

Postoperative atrial fibrillation (AF) occurs frequently after cardiac surgery and contributes significantly to mortality. Transforming growth factor-beta (TGF-β) is associated with postoperative AF after coronary artery bypass grafting and valve surgery. We performed a prospective study to evaluate the role of TGF-β as a predictor of AF after myectomy. A total of 109 consecutive obstructive hypertrophic cardiomyopathy patients without previous AF who underwent myectomy were identified. We measured plasma TGF-β levels before surgery, monitored heart rhythm until discharge, and followed patients for a mean of 36 ± 10 months. AF was documented in 19 patients (17%). AF patients were older (50 ± 10 vs 43 ± 15 years, p = 0.037). Patients who developed AF had higher plasma TGF-β levels (1,695 ± 2,011 vs 1,099 ± 2,494 pg/ml, p = 0.011), more major adverse cardiac events (32% vs 7%, p = 0.006), and more strokes (16% vs 0%, p = 0.005) than patients who did not. TGF-β level ≥358 pg/ml predicted AF with sensitivity and specificity of 58% and 77% (p = 0.011), respectively. Higher TGF-β levels were associated with pulmonary hypertension (25% vs 8%, p = 0.033). In multivariable regression analysis, age (odds ratio 1.05, 95% confidence interval 1.00 to 1.11, p = 0.041) and TGF-β levels (odds ratio 2.42, 95% confidence interval 1.30 to 4.50, p = 0.005) predicted AF independently. In conclusion, elevated preoperative TGF-β value is an independent predictor of postoperative AF in hypertrophic cardiomyopathy patients after surgical ventricular septal myectomy.

Implantable cardioverter defibrillator therapy in hypertrophic cardiomyopathy: an updated systematic review and meta-analysis of outcomes and complications

BACKGROUND

Since the introduction of the implantable cardioverter-defibrillator (ICD) in patients with hypertrophic cardiomyopathy (HCM), the incidence of sudden cardiac death (SCD) has been significantly reduced. Given its widespread use, it is important to identify the outcomes associated with ICD use in patients with HCM. The present paper is a systematic review and meta-analysis of the rates of appropriate and inappropriate interventions, mortality, and device complications in HCM patients with an ICD.

METHODS

We conducted a systematic review and meta-analysis on 27 studies reporting outcomes and complications after ICD implantation in patients with HCM. ICD interventions, device complications, and mortality were extracted for analysis.

RESULTS

A total of 3,797 patients with HCM and ICD implantation were included (mean age, 44.5 years; 63% male), of which 83% of patients had an ICD for primary prevention of SCD. The cardiac mortality was 0.9% (95% CI: 0.7-1.3) per year and non-cardiac mortality was 0.8% (95% CI: 0.6-1.2) per year. Annualized appropriate intervention rate was 4.8% and annualized inappropriate intervention was 4.9%. The annual incidence of lead malfunction, lead displacement and infection was 1.4%, 1.3%, and 1.1%, respectively.

CONCLUSIONS

ICD use in patients with HCM produces low rates of cardiac and non-cardiac mortality, and an appropriate intervention rate of 4.8% per year. However, moderate rates of inappropriate intervention and device complications warrant careful patient selection in order to optimize the risk to benefit ratio in this select group of patients.

Hypertrophic cardiomyopathy in children

Hypertrophic cardiomyopathy (HCM) occurs in 1 of 500 adults and is considered to be one of the most common causes of death in young people under 35 years of age. Children with HCM are usually asymptomatic and the overall annual mortality beyond the first year of life is 1%. Septal myectomy is safe and effective in children with obstructive HCM and published data shows improved late survival compared to untreated HCM. Patient selection and surgical expertise remain critical components to ensuring successful outcomes of septal myectomy, particularly when considering prophylactic myectomy in a seemingly asymptomatic patient.

Precision Cardiovascular Medicine: State of Genetic Testing

In the 15 years following the release of the first complete human genome sequences, our understanding of rare and common genetic variation as determinants of cardiovascular disease susceptibility, prognosis, and therapeutic response has grown exponentially. As such, the use of genomics to enhance the care of patients with cardiovascular diseases has garnered increased attention from clinicians, researchers, and regulatory agencies eager to realize the promise of precision genomic medicine. However, owing to a large burden of "complex" common diseases, emphasis on evidence-based practice, and a degree of unfamiliarity/discomfort with the language of genomic medicine, the development and implementation of genomics-guided approaches designed to further individualize the clinical management of a variety of cardiovascular disorders remains a challenge. In this review, we detail a practical approach to genetic testing initiation and interpretation as well as review the current state of cardiovascular genetic and pharmacogenomic testing in the context of relevant society and regulatory agency recommendations/guidelines.

Exercise and β-blocker therapy recommendations for inherited arrhythmogenic conditions

BACKGROUND

Management of individuals with long QT syndrome, catecholaminergic polymorphic ventricular tachycardia, hypertrophic cardiomyopathy, and arrhythmogenic right ventricular cardiomyopathy may involve exercise restriction and/or β-blocker therapy.

OBJECTIVE

This study assessed the practices of a group of paediatric electrophysiologists regarding the management of genotype-positive/phenotype-positive and genotype-positive/phenotype-negative individuals with these conditions.

METHOD

An online survey was circulated to members of the Pediatric and Congenital Electrophysiology Society in May, 2014. The survey included questions addressing the respondents' approach regarding exercise recommendations and prescription of β-blocker therapy.

RESULTS

A total of 45 cardiologists completed the survey. The majority of respondents restricted symptomatic patients from competitive sports; however, only approximately half restricted phenotype-negative mutation carriers from this level of activity. Recommendations were less consistent regarding other types of activities. A trend was identified regarding physician physical activity and exercise recommendations for phenotype-negative mutation carriers. Less-active physicians were more likely to restrict exercise. β-blocker therapy was discussed by the majority of respondents for symptomatic patients and a significant number of asymptomatic patients.

CONCLUSION

Exercise restriction for patients with long QT syndrome, catecholaminergic polymorphic ventricular tachycardia, hypertrophic cardiomyopathy, and arrhythmogenic right ventricular cardiomyopathy varies based on several factors including phenotype, type of exercise, guidelines referred to, and physicians' own level of activity.

Short and long-term outcomes of alcohol septal ablation with the trans-radial versus the trans-femoral approach: A single center-experience

BACKGROUND

Although the trans-radial approach (TR) has been applied to various subsets of patients in percutaneous coronary intervention, the feasibility, efficacy, acute procedural and long-term outcomes of TR versus trans-femoral approach (TF) for alcohol septal ablation (ASA) have not yet been determined.

OBJECTIVES

The aim of this study was to compare the short and long-term outcomes of ASA with the TR approach compared to the TF approach.

METHODS

We retrospectively analyzed 240 patients who underwent an ASA procedure at our institution from November 1999 to November 2015. The TR approach was performed in 172 cases and the TF approach in the remaining 68 cases.

RESULTS

The use of TR approach progressively increased from 62% in 1999-2005 to 91% in 2011-2015 (p=0.0001). The TF and TR group had similar age, baseline NYHA class (NYHA 3 or 4) and mean left ventricular outflow tract peak gradient before ASA. Total contrast used (TR: 73.2±47.2ml; TF: 88.7±49.3ml, p=0.11), total radiation Air kerma area product (TR: 43.7±48.0Gycm(-2); TF: 55.9±48.2Gycm(-2); p=0.39) and peak left ventricular outflow tract gradient immediately after ASA (TR: 19.1±19.6mmHg; TF: 20.4±18.0mmHg, p=0.63) were similar in both groups. Procedural success was 91.9% and 91.2% in the TR and TF groups, respectively (p=0.53). At 30days, there was 2 intra-hospital death (1 in TF and 1 in TR), 1 major stroke in the TF group and 1 coronary artery dissection in the TR group. Vascular complications were less frequent in the TR group (0.58% vs. 7.3%; p=0.002). The mean length of follow-up was 4.56±4.34years (IQR 0.69-8.2; median 2.92years; maximum: 15.5years). By Kaplan-Meier estimate, the observed survival in the overall cohort was comparable to the expected survival for a sex and age-matched comparable general French population at 10years (86.9 vs. 83.6%, p=0.88). Survival was similar between the TR and TF group (92.1% vs. 89.7% at 6years, respectively; p=0.71).

CONCLUSIONS

Alcohol septal ablation from the radial approach can be performed with similar acute and long-term success, but with lower vascular complications compared to the femoral approach.

Rapid Device-Detected Nonsustained Ventricular Tachycardia in the Risk Stratification of Hypertrophic Cardiomyopathy

BACKGROUND

Nonsustained ventricular tachycardia (NSVT) detected by ambulatory Holter (Holter NSVT) is a major risk factor for sudden cardiac death in hypertrophic cardiomyopathy (HCM). We hypothesized that the prognostic utility of Holter NSVT in HCM would improve with prolonged monitoring and a higher heart rate cut-off for detection.

METHODS

We enrolled 60 patients (44 ± 14 years) with HCM, who had a prophylactic implantable cardioverter defibrillator (ICD). Positive Holter NSVT (prior to implant) was defined as ≥3 beats at ≥120 beats per minute (bpm). We assessed the prevalence of rapid NSVT (RNSVT) detected by their ICD within 12 months of its implant, defined as 4-16 beats at ≥150-200 bpm. The primary outcome was appropriate ICD therapy (antitachycardia pacing and shocks) for sustained ventricular arrhythmia (VA).

RESULTS

Holter NSVT was detected in 34 patients. RNSVT occurred in 21 (35%) patients of whom five did not have Holter NSVT. Over a median follow-up of 61 (interquartile range 29, 129) months after ICD implant, nine patients had VA. RNSVT, but not Holter NSVT, was significantly associated with VA (hazard ratio 6.2, 95% confidence interval [1.3-30], P = 0.01) by multivariable Cox regression analysis that included conventional risk factors. Receiver operating characteristic analysis for RNSVT (area under curve 0.80, P = 0.005) showed that the occurrence of ≥2 episodes of RNSVT discriminated patients for VA optimally (sensitivity 78%, specificity 84%, positive predictive value 47%, negative predictive value 96%).

CONCLUSIONS

In this pilot study, RNSVT detected by continuous monitoring independently predicted VA in HCM and offered superior discrimination of VA risk compared to conventional risk factors, including Holter NSVT. Future studies are needed to validate these findings in a larger, unselected HCM cohort.