NAA10 gene related Ogden syndrome with obstructive hypertrophic cardiomyopathy: A rare case report

RATIONALE

Ogden syndrome is an exceptionally rare X-linked disease caused by mutations in the NAA10 gene. Reported cases of this syndrome are approximately 20 children and are associated with facial dysmorphism, growth delay, developmental disorders, congenital heart disease, and arrhythmia.

PATIENT CONCERNS

We present the clinical profile of a 3-year-old girl with Ogden syndrome carrying a de novo NAA10 variant [NM_003491:c.247C>T, p.(Arg83Cys)]. During infancy, she exhibited features such as left ventricular hypertrophy, protruding eyeballs, and facial deformities.

DIAGNOSIS

Clinical diagnosis included Ogden syndrome, congenital heart disease (obstructive hypertrophic cardiomyopathy, left ventricular outflow tract obstruction, mitral valve disease, tricuspid valve regurgitation), tonsillar and adenoidal hypertrophy, and speech and language delay.

INTERVENTIONS

The girl was considered to have hypertrophic cardiomyopathy (HCM) and received oral metoprolol as a treatment for HCM at our hospital. The drug treatment effect was not ideal, and her hypertrophy myocardial symptoms were aggravated and she had to be hospitalized for surgery.

OUTCOMES

The girl underwent a modified Morrow procedure under cardiopulmonary bypass and experienced a favorable postoperative recovery. No pulmonary infections or significant complications were observed during this period. The patient's family expressed satisfaction with the treatment process.

LESSONS

The case emphasizes the HCM of Odgen syndrome, and early surgery should be performed if drug treatment is ineffective.

Posterior Papillary Muscle Suspension for Treating Systolic Anterior Motion in Hypertrophic Obstructive Cardiomyopathy

Systolic anterior motion of the anterior mitral leaflet can persist after ventricular septal myectomy for obstructive hypertrophic cardiomyopathy, resulting in residual pressure gradients and mitral regurgitation. However, additional procedures for systolic anterior motion involving mitral valve leaflet suturing and resection may lead to future valve disease. Therefore, we adopted posterior papillary muscle suspension, a subvalvular procedure for functional mitral regurgitation, to treat systolic anterior motion without directly intervening in the mitral valve leaflets. Papillary muscle suspension toward the posterior mitral annulus moved the papillary muscles away from the interventricular septum and successfully eliminated the systolic anterior motion and midventricular pressure gradient. In terms of avoiding direct mitral interventions, this procedure is a viable option for systolic anterior motion, especially in cases of very mild mitral regurgitation.

Exercise Capacity in Patients With Obstructive Hypertrophic Cardiomyopathy: SEQUOIA-HCM Baseline Characteristics and Study Design

Patients with obstructive hypertrophic cardiomyopathy (oHCM) have increased risk of arrhythmia, stroke, heart failure, and sudden death. Contemporary management of oHCM has decreased annual hospitalization and mortality rates, yet patients have worsening health-related quality of life due to impaired exercise capacity and persistent residual symptoms. Here we consider the design of clinical trials evaluating potential oHCM therapies in the context of SEQUOIA-HCM (Safety, Efficacy, and Quantitative Understanding of Obstruction Impact of Aficamten in HCM). This large, phase 3 trial is now fully enrolled (N = 282). Baseline characteristics reflect an ethnically diverse population with characteristics typical of patients encountered clinically with substantial functional and symptom burden. The study will assess the effect of aficamten vs placebo, in addition to standard-of-care medications, on functional capacity and symptoms over 24 weeks. Future clinical trials could model the approach in SEQUOIA-HCM to evaluate the effect of potential therapies on the burden of oHCM. (Safety, Efficacy, and Quantitative Understanding of Obstruction Impact of Aficamten in HCM [SEQUOIA-HCM]; NCT05186818).

A systematic review of present and future pharmaco-structural therapies for hypertrophic cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is a common contemporary, treatable, genetic disorder that can be compatible with normal longevity. While current medical therapies are ubiquitous, they are limited by a lack of solid evidence, are often inadequate, poorly tolerated, and do not alter the natural disease course. As such, there has long been a need for effective, evidence-based, and targeted disease-modifying therapies for HCM. In this review, we redefine HCM as a treatable condition, evaluate current strategies for therapeutic intervention, and discuss novel myosin inhibitors. The majority of patients with HCM have elevated left ventricular outflow tract gradients, which predicts worse symptoms and adverse outcomes. Conventional pharmacological therapies for symptomatic HCM can help improve symptoms but are often inadequate and poorly tolerated. Septal reduction therapies (surgical myectomy and alcohol septal ablation) can safely and effectively reduce refractory symptoms and improve outcomes in patients with obstructive HCM. However, they require expertise that is not universally available and are not without risks. Currently, available therapies do not alter the disease course or the progressive cardiac remodeling that ensues, nor subsequent heart failure and arrhythmias. This has been regarded as an unmet need in the care of HCM patients. Novel targeted pharmacotherapies, namely cardiac myosin inhibitors, have emerged to reverse key pathophysiological changes and alter disease course. Their favorable outcomes led to the early Food and Drug Administration approval of mavacamten, a first-in-class myosin modulator, changing the paradigm for the pharmacological treatment of HCM.

Improvement in coronary microvascular dysfunction evaluated by cardiac magnetic resonance in patients with hypertrophic obstructive cardiomyopathy after transapical beating-heart septal myectomy

Background

Coronary microvascular dysfunction (CMD) is a pathophysiological mechanism underlying hypertrophic obstructive cardiomyopathy (HOCM). However, few studies have investigated the potential effect of transapical beating-heart septal myectomy (TA-BSM) on coronary microvascular function. This study aimed to evaluate coronary microvascular function in HOCM after TA-BSM using cardiac magnetic resonance (CMR) and to investigate the determinants of improvement in coronary microvascular dysfunction.

Materials and methods

28 patients with HOCM who underwent TA-BSM were prospectively enrolled in this study from March 2022 to April 2023. All patients received CMR before and after TA-BSM. CMR-derived parameters were compared, including the maximum wall thickness, native T1 value, T2 value, late gadolinium enhancement (LGE), and perfusion indexes (Slopemax, Timemax, and Slmax). Univariate and multivariate linear regression identified variables associated with the rate of Slopemax change.

Results

Compared with the preoperative parameters, left ventricular function and myocardial perfusion were significantly improved after TA-BSM (all P < 0.05), although still lower than in healthy controls. In the analysis of the myocardial perfusion parameter rate of change, the rate of Slopemax change was the most significant (P = 0.002) in HOCM. In the multivariable regression analysis, age (adjusted β = 0.551), weight of the resected myocardium (adjusted β = 0.191), maximum wall thickness (adjusted β = -0.406), LGE (adjusted β = 0.260), and Δ left ventricular outflow tract (LVOT) pressure gradient (adjusted β = -0.123) were significantly associated with the rate of Slopemax change in HOCM (P < 0.05 for all).

Conclusion

Coronary microvascular dysfunction in both hypertrophic and non-hypertrophic myocardial segments was improved in patients after TA-BSM. Microcirculatory perfusion evaluated by CMR can be a potential tool to evaluate the improvement of CMD in HOCM.

Identifying Obstructive Hypertrophic Cardiomyopathy from Nonobstructive Hypertrophic Cardiomyopathy: Development and Validation of a Model Based on Electrocardiogram Features

Background

The clinical presentation and prognosis of hypertrophic cardiomyopathy (HCM) are heterogeneous between nonobstructive HCM (HNCM) and obstructive HCM (HOCM). Electrocardiography (ECG) has been used as a screening tool for HCM. However, it is still unclear whether the features presented on ECG could be used for the initial classification of HOCM and HNCM.

Objective

We aimed to develop a pragmatic model based on common 12-lead ECG features for the initial identification of HOCM/HNCM.

Methods

Between April 1st and September 30th, 2020, 172 consecutive HCM patients from the International Cooperation Center for Hypertrophic Cardiomyopathy of Xijing Hospital were prospectively included in the training cohort. Between January 4th and February 30th, 2021, an additional 62 HCM patients were prospectively included in the temporal internal validation cohort. External validation was performed using retrospectively collected ECG data with definite classification (390 HOCM and 499 HNCM ECG samples) from January 1st, 2010 to March 31st, 2020. Multivariable backward logistic regression (LR) was used to develop the prediction model. The discrimination performance, calibration and clinical utility of the model were evaluated.

Results

Of all 30 acquired ECG parameters, 10 variables were significantly different between HOCM and HNCM (all P < 0.05). The P wave interval and SV1 were selected to construct the model, which had a clearly useful C-statistic of 0.805 (0.697, 0.914) in the temporal validation cohort and 0.776 (0.746, 0.806) in the external validation cohort for differentiating HOCM from HNCM. The calibration plot, decision curve analysis, and clinical impact curve indicated that the model had good fitness and clinical utility.

Conclusion

The pragmatic model constructed by the P wave interval and SV1 had a clearly useful ability to discriminate HOCM from HNCM. The model might potentially serve as an initial classification of HCM before referring patients to dedicated centers and specialists.

Highlights

What are the novel findings of this work? Evident differences exist in the ECG presentations between HOCM and HNCM.To the best of our knowledge, this study is the first piece of evidence to quantify the difference in the ECG presentations between HOCM and HNCM.Based on routine 12-lead ECG data, a probabilistic model was generated that might assist in the initial classification of HCM patients.

Clinical Trials in Hypertrophic Cardiomyopathy Therapy: A Comprehensive Analysis of Trials Registered in Global Clinical Databases

Background

With the disappointing results associated with the use of cardiac myosin inhibitors in the treatment of hypertrophic cardiomyopathy (HCM), the development of new therapies in clinical trials for HCM has rapidly increased. We assessed the characteristics of therapeutic intervention in HCM registered on ClinicalTrials.gov and the International Clinical Trials Registry Platform (ICTRP).

Methods

We conducted a cross-sectional, descriptive study of clinical trials for therapeutic intervention in HCM registered on ClinicalTrials.gov and ICTRP.

Results

This study analyzed 137 registered trials. Regarding study designs of these trials, 77.37% were purpose of treatment, 59.12% were randomized, 50.36% were parallel assignment, 45.26% were performed with masking, 48.18% recruited less than 50 participants, and 27.74% were Phase 2 trials. In total, 67 trials were new drug trials, of which 35 drugs were tested in these trials, and 13 trials involved treatment with mavacamten. Of these 67 clinical drug trials, 44.78% of trials involved the study of amines, and 16.42% involved 1-ring heterocyclic compounds. Regarding the NCI Thesaurus Tree, 23.81% of trials involved myosin inhibitors, 23.81% of trials involved drugs belonging to agents affecting the cardiovascular system, and 20.63% were involved in testing cation channel blockers. The drug-target network showed that myosin-7, potassium voltage-gated channel subfamily h member 2, beta-1 adrenergic receptor, carnitine o-palmitoyltransferase 1, and liver isoform were the most targeted pathways of the clinical trials analyzed in the drug-target network.

Conclusion

The number of clinical trials investigating therapeutic interventions for HCM has increased in recent years. Ultimately, recent HCM therapeutic clinical trials generally did not incorporate either randomized controlled trials or masking and were small studies recruiting fewer than 50 participants. Although recent research has focused on targeting myosin-7, the molecular signaling mechanisms involved in the pathogenesis of HCM have the potential to elucidate novel target pathways.

Survival After Septal Reduction in Patients >65 Years Old With Obstructive Hypertrophic Cardiomyopathy

BACKGROUND

Obstructive hypertrophic cardiomyopathy (oHCM) is increasingly being diagnosed in elderly patients.

OBJECTIVES

The authors sought to study long-term outcomes of septal reduction therapies (SRT) in Medicare patients with oHCM, and hospital volume-outcome relation.

METHODS

Medicare beneficiaries aged >65 years who underwent SRT, septal myectomy (SM) or alcohol septal ablation (ASA), from 2013 through 2019 were identified. Primary outcome was all-cause mortality, and secondary outcomes included heart failure (HF) readmission and need for redo SRT in follow-up. Overlap propensity score weighting was used to adjust for differences between both groups. Relation between hospital SRT volume and short-term and long-term mortality was studied.

RESULTS

The study included 5,679 oHCM patients (SM = 3,680 and ASA = 1,999, mean age 72.9 vs 74.8 years, women 67.2% vs 71.1%; P < 0.01). SM patients had fewer comorbidities, but after adjustment, both groups were well balanced. At 4 years (IQR: 2-6 years), although there was no difference in long-term mortality between SM and ASA (HR: 0.87; 95% CI: 0.74-1.03; P = 0.1), on landmark analysis, SM was associated with lower mortality after 2 years of follow-up (HR: 0.72; 95% CI: 0.60-0.87; P < 0.001) and had lower need for redo SRT. Both reduced HF readmissions in follow-up vs 1 year pre-SRT. Higher-volume centers had better outcomes vs lower-volume centers, but 70% of SRT were performed in low-volume centers.

CONCLUSIONS

SRT reduced HF readmission in Medicare patients with oHCM. SM is associated with lower redo and better long-term survival compared with ASA. Despite better outcomes in high-volume centers, 70% of SRT are performed in low-volume U.S. centers.

Phase 2 Study of Aficamten in Patients With Obstructive Hypertrophic Cardiomyopathy

BACKGROUND

Left ventricular outflow tract (LVOT) obstruction is a major determinant of heart failure symptoms in obstructive hypertrophic cardiomyopathy (oHCM). Aficamten, a next-in-class cardiac myosin inhibitor, may lower gradients and improve symptoms in these patients.

OBJECTIVES

This study aims to evaluate the safety and efficacy of aficamten in patients with oHCM.

METHODS

Patients with oHCM and LVOT gradients ≥30 mm Hg at rest or ≥50 mm Hg with Valsalva were randomized 2:1 to receive aficamten (n = 28) or placebo (n = 13) in 2 dose-finding cohorts. Doses were titrated based on gradients and ejection fraction (EF). Safety and changes in gradient, EF, New York Heart Association functional class, and cardiac biomarkers were assessed over a 10-week treatment period and after a 2-week washout.

RESULTS

From baseline to 10 weeks, aficamten reduced gradients at rest (mean difference: -40 ± 27 mm Hg, and -43 ± 37 mm Hg in Cohorts 1 and 2, P = 0.0003 and P = 0.0004 vs placebo, respectively) and with Valsalva (-36 ± 27 mm Hg and -53 ± 44 mm Hg, P = 0.001 and <0.0001 vs placebo, respectively). There were modest reductions in EF (-6% ± 7.5% and -12% ± 5.9%, P = 0.007 and P < 0.0001 vs placebo, respectively). Symptomatic improvement in ≥1 New York Heart Association functional class was observed in 31% on placebo, and 43% and 64% on aficamten in Cohorts 1 and 2, respectively (nonsignificant). With aficamten, N-terminal pro-B-type natriuretic peptide was reduced (62% relative to placebo, P = 0.0002). There were no treatment interruptions and adverse events were similar between treatment arms.

CONCLUSIONS

Aficamten resulted in substantial reductions in LVOT gradients with most patients experiencing improvement in biomarkers and symptoms. These results highlight the potential of sarcomere-targeted therapy for treatment of oHCM.

Cardiovascular outcomes by time-varying New York Heart Association class among patients with obstructive hypertrophic cardiomyopathy: a retrospective cohort study

AIMS

Assess the relationship between New York Heart Association (NYHA) functional class and cardiovascular (CV) outcomes in obstructive hypertrophic cardiomyopathy (HCM).

MATERIALS AND METHODS

This retrospective cohort study used the Optum Market Clarity database with linked claims and electronic health records. Adults (aged ≥18 years) with obstructive HCM and ≥1 NYHA class assessment after first HCM diagnosis were eligible (selection period: 2007-2021). Thirteen outcomes were assessed following the index date (first documented NYHA class assessment after first HCM diagnosis in the study period): all-cause mortality; first occurrences of all-cause hospitalization; CV-related hospitalization; primary ischemic stroke or transient ischemic attack (TIA); myocardial infarction (MI); deep vein thrombosis (DVT) or pulmonary embolism (PE); and major adverse CV event (MACE); as well as first incident events of atrial fibrillation or flutter; primary ischemic stroke or TIA; heart failure; acute MI; DVT/PE; and a composite endpoint of pacemaker and cardiac resynchronization therapy. Their associations with the index NYHA class were described using the Kaplan-Meier method (mortality) or cumulative incidence functions (other outcomes). Hazard ratios between NYHA class over time and outcomes were evaluated using time-varying Cox models, adjusting for age at first observed HCM diagnosis, sex, and race.

RESULTS

Among 4,631 eligible patients, the mean age was 59 years at the first observed HCM diagnosis (female, 47%; White, 77%). The risks of all outcomes increased with worse (higher) index NYHA class and worsening NYHA class over time. Deterioration in the NYHA class from the index date was associated with increased risks of outcomes.

LIMITATIONS

The study population may not be representative of all patients with obstructive HCM in the real world. Documented NYHA classes may not fully reflect the longitudinal variation of NYHA class for each patient.

CONCLUSIONS

Worsening NYHA class was associated with increased risks of all-cause mortality and CV outcomes in obstructive HCM.

[Mitral valve replacement in patients with obstructive hypertrophic cardiomyopathy]

OBJECTIVE

To analyze the incidence and causes of mitral valve replacement in patients with obstructive hypertrophic cardiomyopathy (HCM).

MATERIAL AND METHODS

There were 172 patients (98 women and 74 men) with obstructive HCM and severe mitral valve insufficiency between November 2017 and May 2023. All patients complained of chronic heart failure NYHA class III. Surgical correction of left ventricular outflow tract (LVOT) obstruction and mitral valve repair with elimination of systolic anterior motion were technically successful in 160 (93.0%) patients.

RESULTS

The need for mitral valve replacement was noted in 12 (7.0%) patients. Mean cardiopulmonary bypass time was 83.5±19.2 min (94; 127), aortic cross-clamping - 62.8±14.3 min (70; 102). In 5 cases, primary mitral valve replacement was scheduled due to obvious organic lesion of the mitral valve (tearing of chords, rheumatic lesion with leaflet restriction). In 7 patients, valve replacement was forced after ineffective primary septal myectomy (LVOT pressure gradient, severe mitral insufficiency).

CONCLUSION

Mitral valve replacement is an involuntary strategy after ineffective myectomy with severe mitral insufficiency and high LVOT pressure gradient.

Surgical Management for Systolic Anterior Motion (SAM) of the Mitral Valve in Obstructive Hypertrophic Myopathy

In patients with obstructive hypertrophic cardiomyopathy, left ventricular outflow tract (LVOT) obstruction can be created by the hypertrophic interventricular septum (IVS) as well as systolic anterior motion (SAM) of the anterior mitral leaflet (AML). Sufficient septal myectomy is a fundamental surgical technique to treat LVOT obstruction, however, direct surgical management for SAM is another key aspect. Besides the hypertrophic IVS, mitral valve, subvalvular apparatus, and papillary muscle may play important role for SAM and several surgical techniques have been proposed to treat SAM in literature. In this review, each surgical technique is classified by the anatomical structure on which the surgical procedure is applied. The AML is the main surgical site and is applied with plication (vertical plication, resection–plication–release strategy), extension (the AML extension, transverse incision of the AML), sutured (edge-to-edge repair, anterior leaflet retention plasty), or traction (floating stitch, papillary muscle-to-anterior annulus stitches, paradoxical stitches, transposition of a directed chorda tendinea to the AML). Height reduction of the posterior mitral valve leaflet and papillary muscle reorientation are other techniques. We should understand theoretical aspects of each technique on correction of anatomical and functional abnormalities of the structure and should apply them under proper indication.

Effects of Metoprolol on Exercise Hemodynamics in Patients With Obstructive Hypertrophic Cardiomyopathy

BACKGROUND

The relationship between exercise hemodynamics, loading conditions, and medical treatment in patients with obstructive hypertrophic cardiomyopathy (HCM) is incompletely understood.

OBJECTIVES

This study aimed to investigate the effect of metoprolol on invasive hemodynamic parameters at rest and during exercise in patients with obstructive HCM.

METHODS

This randomized, double-blind, placebo-controlled crossover trial enrolled 28 patients with obstructive HCM and New York Heart Association functional class ≥II. Patients were randomized to initiate either metoprolol 150 mg or placebo for 2 consecutive 2-week periods. Right-heart catheterization and echocardiography were performed at rest and during exercise at the end of each treatment period. The primary outcome was the difference in pulmonary capillary wedge pressure (ΔPCWP) between peak exercise and rest.

RESULTS

No treatment effect on ΔPCWP was observed between metoprolol and placebo treatment (21 ± 9 mm Hg vs 23 ± 9 mm Hg; P = 0.12). At rest, metoprolol lowered heart rate (P < 0.0001), left ventricular outflow tract (LVOT) gradient (P = 0.01), and increased left ventricular end-diastolic volume (P = 0.02) and stroke volume (SV) (+6.4; 95% CI: 0.02-17.7; P = 0.049). During peak exercise, metoprolol was associated with a lower heart rate (P < 0.0001), a lower LVOT gradient (P = 0.0005), lesser degree of mitral regurgitation (P = 0.004), and increased SV (+9 mL; 95% CI: 2-15 mL; P = 0.008).

CONCLUSIONS

In patients with obstructive HCM, exercise was associated with an abnormal rise in PCWP, which was unaffected by metoprolol. However, metoprolol increased SV at rest and peak exercise following changes in end-diastolic volume, LVOT gradient, and degree of mitral regurgitation. (The Effect of Metoprolol in Patients With Hypertrophic Obstructive Cardiomyopathy [TEMPO]; NCT03532802).

Stable Rates of Obstructive Hypertrophic Cardiomyopathy in a Contemporary Era

Hypertrophic cardiomyopathy is the most common genetic heart disease in the US, with an estimated prevalence of 1 in 500. However, the extent to which obstructive hypertrophic cardiomyopathy is clinically recognized is not well-established. Therefore, the objective of this study was to estimate the annual prevalence of clinically diagnosed oHCM in the US from 2016 to 2018. Data from the MarketScan® database were queried from years 2016 to 2018 to identify patients with ≥1 claim of oHCM (International Statistical Classification of Disease and Related Health Problems diagnosis code: I42.1). Prevalence rates for oHCM were calculated and stratified by sex and age. In 2016, 4,612 unique patients had clinical diagnosis of oHCM, resulting in an estimated oHCM prevalence of 1.65 per 10,000. The prevalence of oHCM in males and females was 2.07 and 1.26, respectively. Prevalence of oHCM was highest in patients 55–64 years of age (4.82). Prevalence of oHCM generally increased with age, from 0.36 per 10,000 in those under 18 to 4.82 per 10,000 in those 55–65. Trends in prevalence of oHCM over time, including by sex and age group, remained similar and consistent in 2017 and 2018. The prevalence of oHCM was stable over the 3-year time period, including higher rates of oHCM in males and patients aged 55–64 years. These results suggest that the majority of privately insured patients with oHCM are undiagnosed in the US and reinforce the need for policies and research to improve the clinical identification of oHCM patients in the US.

Differences in Short-Term Outcomes and Hospital-Based Resource Utilization Between Septal Reduction Strategies for Hypertrophic Obstructive Cardiomyopathy

BACKGROUND

Given clinical equipoise in a subset of obstructive hypertrophic cardiomyopathy (OHCM) patients who are candidates for both alcohol septal ablation (ASA) or septal myectomy (SM), other considerations such as cost, readmissions, and hospital length of stay (LOS) may be important to optimize healthcare resource utilization and inform shared decision making.

METHODS

In this retrospective observational analysis of the United States Nationwide Readmissions Database years 2012-2014, we identified adults who underwent isolated septal reduction (SR) for OHCM. We studied the differences in short-term outcomes (inpatient mortality and 90-day readmission rate) and in-hospital resource utilization (LOS and costs) between the SR strategies.

RESULTS

Of the 2250 patients in this study, ASA was performed in 1113 (49.5%) and SM in 1137 (50.5%). Inpatient mortality occurred in 21 patients (0.9%), with similar rates between strategies (10 SM patients [0.9%] vs 11 ASA patients [1.0%]; P=.30). Of the 2229 patients who survived to discharge, 298 (13.4%) were readmitted 386 times within 90 days with a similar readmission rate between SM (14.9%) and ASA (11.8%; P=.16). During the index admission, average LOS and cost were significantly lower for ASA (3.9 days, United States [US] $20,322) compared with SM (7.6 days, US $39,470; P<.001). Average LOS and cost during 90-day readmissions were similar between ASA and SM. Combining index admissions and readmissions, patients undergoing ASA had significantly lower LOS and hospitalization costs.

CONCLUSIONS

In this non-randomized observational study of OHCM patients undergoing isolated septal reduction, ASA was associated with similar short-term outcomes, including mortality, but substantially lower hospitalization costs and LOS compared with SM.

Randomized Trial of Metoprolol in Patients With Obstructive Hypertrophic Cardiomyopathy

BACKGROUND

The use of β-adrenergic receptor blocking agents in symptomatic patients with obstructive hypertrophic cardiomyopathy (HCM) rests on clinical experience and observational cohort studies.

OBJECTIVES

This study aimed to investigate the effects of metoprolol on left ventricular outflow tract (LVOT) obstruction, symptoms, and exercise capacity in patients with obstructive HCM.

METHODS

This double-blind, placebo-controlled, randomized crossover trial enrolled 29 patients with obstructive HCM and New York Heart Association (NYHA) functional class II or higher symptoms from May 2018 to September 2020. Patients received metoprolol or placebo for 2 consecutive 2-week periods in random order. The effect parameters were LVOT gradients, NYHA functional class, Canadian Cardiovascular Society (CCS) angina class, Kansas City Cardiomyopathy Questionnaire Overall Summary Score (KCCQ-OSS), and cardiopulmonary exercise testing.

RESULTS

Compared with placebo, the LVOT gradient during metoprolol was lower at rest (25 mm Hg [interquartile range (IQR): 15-58 mm Hg] vs 72 mm Hg [IQR: 28-87 mm Hg]; P = 0.007), at peak exercise (28 mm Hg [IQR: 18-40 mm Hg] vs 62 mm Hg [IQR: 31-113 mm Hg]; P < 0.001), and postexercise (45 mm Hg [IQR: 24-100 mm Hg] vs 115 mm Hg [IQR: 55-171 mm Hg]; P < 0.0001). During metoprolol treatment, 14% of patients were in NYHA functional class III or higher compared with 38% of patients receiving placebo (P < 0.01). Similarly, no patients were in CCS class III or higher during metoprolol treatment compared with 10% during placebo treatment (P < 0.01). These findings were confirmed by higher KCCQ-OSS during metoprolol treatment (76.2 ± 16.2 vs 73.8 ± 19.5; P = 0.039). Measures of exercise capacity, peak oxygen consumption, and N-terminal pro-B-type natriuretic peptide did not differ between the study arms.

CONCLUSIONS

Compared with placebo, metoprolol reduced LVOT obstruction at rest and during exercise, provided symptom relief, and improved quality of life in patients with obstructive HCM. Maximum exercise capacity remained unchanged. (The Effect of Metoprolol in Patients with Hypertrophic Obstructive Cardiomyopathy [TEMPO]; NCT03532802).

Projecting the Long-term Clinical Value of Mavacamten for the Treatment of Obstructive Hypertrophic Cardiomyopathy in the United States: An Assessment of Net Health Benefit

PURPOSE

The aim of the study was to project the long-term net health benefits of mavacamten for the treatment of symptomatic obstructive hypertrophic cardiomyopathy (HCM) in the United States.

METHODS

A Markov model with 4 mutually exclusive health states (New York Heart Association [NYHA] functional classes I, II, and III/IV and death) was developed to project the life-years (LYs) and quality-adjusted life-years (QALYs) over a lifetime horizon for patients with symptomatic obstructive HCM receiving mavacamten with or without β-blocker (BB) or calcium channel blocker (CCB) monotherapy or placebo with or without BB or CCB monotherapy. The model simulated a patient cohort with a starting age of 59 years and 41% women. Transition probabilities across NYHA functional classes were estimated using data from the Phase III Clinical Study to Evaluate Mavacamten (MYK-461) in Adults With Symptomatic Obstructive Hypertrophic Cardiomyopathy (EXPLORER-HCM) and the EXPLORER long-term extension (EXPLORER-LTE) cohort from the Long-term Safety Extension Study of Mavacamten in Adults who Have Completed MAVERICK-HCM or EXPLORER-HCM (MAVA-LTE) trial and were extrapolated after week 30. The mortality risks of NYHA functional class I were assumed to be the age- and sex-specific mortality risks of the US general population. The mortality risks for NYHA class II and III/IV were estimated using those for class I in conjunction with the relative mortality risks derived using patients with obstructive HCM from a large real-world registry. Health state utilities for each treatment were estimated from EXPLORER-HCM. Both LYs and QALYs were aggregated over a lifetime for each treatment arm, discounted at 3% annually, and compared between the 2 arms. Sensitivity analyses were conducted to evaluate the robustness of the model findings.

FINDINGS

Over a lifetime, treatment with mavacamten with or without BB or CCB monotherapy was associated with 3.67 incremental LYs compared with placebo with or without BB or CCB monotherapy (13.00 vs 9.33 LYs). Compared with individuals in the placebo group, patients in the mavacamten group were projected to spend 6.17 additional LYs in NYHA functional class I and 0.04 and 2.46 fewer LYs in NYHA functional classes II and III/IV, respectively. With utilities incorporated, mavacamten with or without BB or CCB monotherapy was associated with 4.17 additional QALYs compared with placebo with or without BB or CCB monotherapy (11.74 vs 7.57 QALYs). In the sensitivity analyses, incremental benefits ranged from 1.55 to 6.21 LYs and from 2.48 to 6.19 QALYs across the scenarios.

IMPLICATIONS

This model projected substantial net health benefits associated with mavacamten for symptomatic obstructive HCM owing to improved patient survival and quality of life. The projected QALY gain underscored the likely long-term clinical value of mavacamten in symptomatic obstructive HCM.

The Echocardiographic Parameters of Systolic Function Are Associated with Specific Metabolomic Fingerprints in Obstructive and Non-Obstructive Hypertrophic Cardiomyopathy

The purpose of this study was to assess whether metabolomics, associated with echocardiography, was able to highlight pathophysiological differences between obstructive (OHCM) or non-obstructive (NOHCM) hypertrophic cardiomyopathy. Thirty-one HCM patients underwent standard and advanced echocardiography; a plasma sample was collected for metabolomic analysis. Results. Patients with OHCM compared with subjects with NOHCM had higher values of 2DLVEF (66.5 ± 3.3% vs. 60.6 ± 1.8%, p < 0.01), S wave (7.6 ± 1.1 vs. 6.3 ± 0.7 cm/s, p < 0.01) and 3D global longitudinal strain (17.2 ± 4.2%, vs. 13.4 ± 1.3%, p < 0.05). A 2-group PLS-Discriminant Analysis was performed to verify whether the two HCM groups differed also based on the metabolic fingerprint. A clear clustering was shown (ANOVA p = 0.014). The most discriminating metabolites resulted as follows: in the NOHCM Group, there were higher levels of threitol, aminomalonic acid, and sucrose, while the OHCM Group presented higher levels of amino acids, in particular those branched chains, of intermediates of glycolysis (lactate) and the Krebs cycle (fumarate, succinate, citrate), of fatty acids (arachidonic acid, palmitoleic acid), of ketone bodies (2-OH-butyrate). Our data point out a different systolic function related to a specific metabolic activity in the two HCM phenotypic forms, with specific metabolites associated with better contractility in OHCM.

Risk Factors of Pulmonary Arterial Hypertension and Its Relationship With Atrial Fibrillation in Patients With Obstructive Hypertrophic Cardiomyopathy

Background: Pulmonary arterial hypertension (PH) is a common complication in patients with obstructive hypertrophic cardiomyopathy (OHCM). The risk factor of PH in patients with OHCM has not been fully elucidated, and even atrial fibrillation (AF) was considered a risk factor of PH. Thus, our study aimed to investigate risk factors of PH and the relationship between PH and AF in patients with OHCM.

Methods: We retrospectively enrolled 483 consecutive patients diagnosed with OHCM at Fuwai Hospital (Beijing, China) from January 2015 to December 2017. Clinical and echocardiographic parameters were compared between patients with and without PH.

Results: Eighty-two (17.0%) patients were diagnosed with PH in this study. Compared to patients without PH, those with PH were significantly older, had a lower body mass index (BMI), were more likely to be female and more symptomatic [New York Heart Association Class 3 or 4 symptoms], and had a higher AF prevalence. A multivariate analysis indicated that AF was an independent risk factor of PH (odds ratio [OR] 2.31, 95% confidence interval [CI] 1.03–5.20, p = 0.042). Moreover, PH was independently associated with a higher AF incidence after adjusting for age and left atrial diameter (OR 2.24, 95% CI 1.07–4.72, p = 0.034).

Conclusion: AF was independently associated with PH in patients with OHCM. Further, PH was significantly associated with an increased risk of AF, which suggested that AF could aggravate PH and that PH may promote AF processes, forming a vicious circle.

Effectiveness of Bokeria-Boldyrev ACH Solution in Surgerical Treatment of Adult Patients with Obstructive Hypertrophic Cardiomyopathy

The study examined effectiveness of pharmaco-cold cardioplegia employing solutions of enhanced buffer capacity during surgery of obstructive hypertrophic cardiomyopathy in adult patients (N=51) operated during 2013-2018. In group 1 (N=28), the cardioplegia was performed with HTK (Custodiol) solution, whereas in group 2 (N=23), it was carried out with Bokeria-Boldyrev ACH solution. The mean, minimum, and maximum ages in group 1 were 46, 21, and 64 years, respectively; in group 2 - 42, 14, and 70 years, respectively. In both groups, the patients were subjected to myoectomy of exit pathway in the left ventricle according to Bokeria-Morrow operation and annuloplasty of tricuspid valve accompanied by reconstructive surgery (or replacement) of mitral valve. Atrial fibrillation (if any) was suppressed with cryoablation (-60°С) of the openings of the right and left pulmonary veins. The surgery was carried out in hypothermic mode at 28°C. The significant intergroup differences were observed in the asystole latent period after the onset of antegrade or retrograde injection of cardioplegic solution. In group 1, the asystole latent periods determined after antegrade or retrograde injection were 53±7 or 170±30 sec, respectively; in group 2 - 32±6 and 97±11 sec (p<0.0001), respectively. The mean times of aortic cross-clumping in groups 1 and 2 were 66±8 and 64±6 min, respectively; the electromechanical action of the heart restored after aortic unclamping in 35±7 and 30±6 sec, respectively. The biochemical and clinical data revealed no significant intergroup differences. Overall, novel Bokeria-Boldyrev ACH cardioplegic solution secured effective protection of the myocardium against intraoperative ischemia in adult patients with obstructive hypertrophic cardiomyopathy and significantly decreased the asystole latent period.

[Surgical treatment of patients with obstructive hypertrophic cardiomyopathy]

OBJECTIVE

To analyze in-hospital results of surgical treatment of patients with obstructive hypertrophic cardiomyopathy.

MATERIAL AND METHODS

There were 15 patients (8 women and 6 men) with obstructive hypertrophic cardiomyopathy and severe mitral insufficiency for the period from November 2017 to March 2019. Mean age of patients was 55.9±7.1 years. All patients had chronic heart failure NYHA class III and secondary coronary insufficiency.

RESULTS

Surgical correction of LVOT obstruction and mitral valve repair with elimination of systolic anterior motion were technically successful in all cases. There was no need for mitral valve replacement in all patients. Heart failure NYHA class I-II in early postoperative period was observed in all cases.

CONCLUSION

Careful preoperative planning with a comprehensive analysis of hemodynamic and anatomical features of LV and certain surgical experience are essential for adequate correction of LVOT obstruction without atrioventricular node injury and mitral valve repair.

Evaluation of left ventricular diastolic function by global strain rate imaging in patients with obstructive hypertrophic cardiomyopathy: a simultaneous speckle tracking echocardiography and cardiac catheterization study

BACKGROUND

Impaired left ventricular (LV) diastolic function is a common pathophysiological feature of patients with hypertrophic cardiomyopathy (HCM). The noninvasive evaluation of diastolic function in these patients remains a challenge. Speckle tracking echocardiography (STE) provides direct information on intrinsic myocardial function and may improve the diagnostic of diastolic dysfunction in HCM patients.

METHODS AND RESULTS

We retrospectively analyzed 51 patients with obstructive HCM (HOCM). Strain rate (SR) curves were obtained for 18 different segments of the LV myocardium. The peak SR during the isovolumic relaxation period (SRIVR ) and the peak early diastolic strain rate (SRE ) were measured for each segment. Cardiac catheterization was performed within 24 hours after echocardiographic analysis. LV end-diastolic pressure (LVEDP) was measured and time constant of myocardial relaxation (τ) was calculated. We therefore correlated STE-derived with invasive indices and compared it with flow and tissue Doppler measurements. SRIVR and SRE were significantly reduced in all 51 HOCM patients (0.16 ± 0.09%/sec and 0.71 ± 0.25%/sec).The ratio of peak early mitral inflow velocities to SRIVR and SRE (E/SRIVR and E/SRE ) correlated well with LVEDP (r = 0.760, P < 0.001; r = 0.401, P = 0.004). Receiver operating characteristic analysis shown E/SRE ratio had the largest under curve area in predicting HOCM patients with seriously elevated LVEDP. In addition, SRIVR and SRE significantly related with τ (r = -0.611, P < 0.001; r = -0.369, P = 0.008).

CONCLUSIONS

Diastolic function was seriously impaired in HOCM patients. The E/SRE ratio can be used to predict LVEDP with acceptable accurate in HOCM patients. In addition, SRIVR is a reliable parameter to assess LV relaxation in patients with HOCM.