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

2024 AHA/ACC/AMSSM/HRS/PACES/SCMR Guideline for the Management of Hypertrophic Cardiomyopathy: A Report of the American Heart Association/American College of Cardiology Joint Committee on Clinical Practice Guidelines

AIM

The "2024 AHA/ACC/AMSSM/HRS/PACES/SCMR Guideline for the Management of Hypertrophic Cardiomyopathy" provides recommendations to guide clinicians in the management of patients with hypertrophic cardiomyopathy.

METHODS

A comprehensive literature search was conducted from September 14, 2022, to November 22, 2022, encompassing studies, reviews, and other evidence on human subjects that were published in English from PubMed, EMBASE, the Cochrane Library, the Agency for Healthcare Research and Quality, and other selected databases relevant to this guideline. Additional relevant studies, published through May 23, 2023, during the guideline writing process, were also considered by the writing committee and added to the evidence tables, where appropriate.

STRUCTURE

Hypertrophic cardiomyopathy remains a common genetic heart disease reported in populations globally. Recommendations from the "2020 AHA/ACC Guideline for the Diagnosis and Treatment of Patients With Hypertrophic Cardiomyopathy" have been updated with new evidence to guide clinicians.

2024 AHA/ACC/AMSSM/HRS/PACES/SCMR Guideline for the Management of Hypertrophic Cardiomyopathy: A Report of the American Heart Association/American College of Cardiology Joint Committee on Clinical Practice Guidelines

AIM

The "2024 AHA/ACC/AMSSM/HRS/PACES/SCMR Guideline for the Management of Hypertrophic Cardiomyopathy" provides recommendations to guide clinicians in the management of patients with hypertrophic cardiomyopathy.

METHODS

A comprehensive literature search was conducted from September 14, 2022, to November 22, 2022, encompassing studies, reviews, and other evidence on human subjects that were published in English from PubMed, EMBASE, the Cochrane Library, the Agency for Healthcare Research and Quality, and other selected databases relevant to this guideline. Additional relevant studies, published through May 23, 2023, during the guideline writing process, were also considered by the writing committee and added to the evidence tables, where appropriate.

STRUCTURE

Hypertrophic cardiomyopathy remains a common genetic heart disease reported in populations globally. Recommendations from the "2020 AHA/ACC Guideline for the Diagnosis and Treatment of Patients With Hypertrophic Cardiomyopathy" have been updated with new evidence to guide clinicians.

Management of hypertrophic cardiomyopathy

Hypertrophic cardiomyopathy is an important cause of heart failure and arrhythmias, including sudden death, with a major impact on the healthcare system. Genetic causes and different phenotypes are now increasingly being identified for this condition. In addition, specific medications, such as myosin inhibitors, have been recently shown as potentially able to modify its symptoms, hemodynamic abnormalities and clinical course. Our article aims to provide a comprehensive outline of the epidemiology, diagnosis and treatment of hypertrophic cardiomyopathy in the current era.

Clinical course of adults with co-occurring hypertrophic cardiomyopathy and hypertension: A scoping review

Introduction

Hypertension affects approximately 50 % of patients with hypertrophic cardiomyopathy (HCM) but clinical course in adults with co-occurring HCM and hypertension is underexplored. Management may be challenging as routine anti-hypertensive medications may worsen obstructive HCM, the most common HCM phenotype. In this scoping review, we sought to synthesize the available literature related to clinical course and outcomes in adults with both conditions and to highlight knowledge gaps to inform future research directions.

Methods

We searched 5 electronic databases (PubMed, CINAHL, Scopus, Embase, Web of Science) to identify peer-reviewed articles, 2011-2023. We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses-Scoping Review (PRISMA-ScR) guideline.

Results

Eleven articles met eligibility. Adults with both conditions were older and had higher rates of obesity and diabetes than adults with HCM alone. Results related to functional class and arrhythmia were equivocal in cross-sectional studies. Only 1 article investigated changes in medical therapy among adults with both conditions. Hypertension was a predictor of worse functional class, but was not associated with all-cause mortality, heart failure-related mortality, or sudden-death. No data was found that related to common hypertension-related outcomes, including renal disease progression, nor patient-reported outcomes, including quality of life.

Conclusions

Our results highlight areas for future research to improve understanding of co-occurring HCM and hypertension. These include a need for tailored approaches to medical management to optimize outcomes, evaluation of symptom burden and quality of life, and investigation of hypertension-related outcomes, like renal disease and ischemic stroke, to inform cardiovascular risk mitigation strategies.

Imaging in Hypertrophic Cardiomyopathy: Beyond Risk Stratification

A multimodality imaging evaluation in hypertrophic cardiomyopathy is often used for risk stratification. Recent developments in imaging have allowed for better diagnosis, prognosis, and decision-making for a variety of therapies from medical to interventional. Echocardiography and magnetic resonance have been integral in evaluating subtype, left ventricular function, tissue characterization, left atrial measurements, valvular function, and presence of left ventricular aneurysm and outflow tract obstruction. These factors have helped to quantify risk of atrial fibrillation and determine the likely usefulness of pharmacologic therapy and septal reduction therapy. This review covers these in detail.

Complications of exercise and pharmacologic stress echocardiography

Stress echocardiography is a diagnostic cardiovascular exam that is commonly utilized for multiple indications, including but not limited to the assessment of obstructive coronary artery disease, valvular disease, obstructive hypertrophic cardiomyopathy, and diastolic function. Stress echocardiography can be performed via both exercise and pharmacologic modalities. Exercise stress is performed with either treadmill or bicycle-based exercise. Pharmacologic stress is performed via either dobutamine or vasodilator-mediated (i.e., dipyridamole, adenosine) stress testing. Each of these modalities is associated with a low overall prevalence of major, life-threatening adverse outcomes, though adverse events are most common with dobutamine stress echocardiography. In light of the recent COVID-19 pandemic, the risk of infectious complications to both the patient and stress personnel cannot be negated; however, when certain precautions are taken, the risk of infectious complications appears minimal. In this article, we review each of the stress echocardiographic modalities, examine major potential adverse outcomes and contraindications, assess the risks of stress testing in the setting of a global pandemic, and examine the utilization and safety of stress testing in special patient populations (i.e., language barriers, pediatric patients, pregnancy).

Clinical course and outcomes in adults with co-occurring hypertrophic cardiomyopathy and hypertension: a scoping review protocol

INTRODUCTION

Hypertension affects 40%-60% of adults with hypertrophic cardiomyopathy (HCM), the most common inherited cardiac condition. It can be a diagnostic confounder for HCM, contributing to delayed diagnosis. Clinically, treatment of co-occurring hypertension and HCM poses challenges as first-line and second-line antihypertensive medications are often contraindicated in HCM. The clinical course in adults with hypertension and HCM is also not well understood, and studies examining patient outcomes in this population are equivocal. In this paper, we aim to outline the protocol of a scoping review, a type of literature review, to systematically synthesise existing knowledge on adults with co-occurring HCM and hypertension, highlighting knowledge and evidence gaps, and identifying future research directions to optimise outcomes in this population.

METHODS AND ANALYSIS

This review is guided by Arksey and O'Malley's conceptual framework on conducting scoping reviews. We will search five electronic databases (PubMed, CINAHL, Scopus, Embase and Web of Science) and reference lists of publications to identify eligible articles focusing on medical therapy, clinical course or outcomes in adults with HCM and hypertension, between 2011 and 2023. Our search strategy and presentation of results will be guided by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses-Scoping Review guideline. First, two independent reviewers will screen articles, by title and abstract, followed by a full-text screen to identify eligible articles. Relevant data will be extracted and synthesised.

ETHICS AND DISSEMINATION

Ethical approval is not required for this review as it is a secondary data collection of published articles and does not involve human subject participation. We will present results of this review at relevant professional conferences and patient-centred educational events. Results will be published in a peer-reviewed journal.

TRIAL REGISTRATION NUMBER

https://osf.io/cy8qb/?view_only=98197f4850584e51807ff9b62533a706.

The Role of Cardiopulmonary Exercise Testing in Hypertrophic Cardiomyopathy

This review emphasizes the importance of cardiopulmonary exercise testing (CPET) in patients diagnosed with hypertrophic cardiomyopathy (HCM). In contrast to standard exercise testing and stress echoes, which are limited due to the ECG changes and wall motion abnormalities that characterize this condition, CPET allows for the assessment of the complex pathophysiology and severity of the disease, its mechanisms of functional limitation, and its risk stratification. It is useful tool to evaluate the risk for sudden cardiac death and select patients for cardiac resynchronization therapy (CRT), cardiac transplantation, or mechanical circulatory support, especially when symptomatology and functional status are uncertain. It may help in differentiating HCM from other forms of cardiac hypertrophy, such as athletes' heart. Finally, it is used to guide and monitor therapy as well as for exercise prescription. It may be considered every 2 years in clinically stable patients or every year in patients with worsening symptoms. Although performed only in specialized centers, CPET combined with echocardiography (i.e., CPET imaging) and invasive CPET are more informative and provide a better assessment of cardiac functional status, left ventricular outflow tract obstruction, and diastolic dysfunction during exercise in patients with HCM.

Procedural Sedation in Congenital Heart Disease

Procedural sedation in patients with congenital heart disease (CHD) is associated with significant morbidity and mortality. It is vital for the practitioner to fully understand the complexity of lesions, their hemodynamics, and the impact of medications commonly used for procedural sedation on the stability of systemic vascular resistance and pulmonary flow. According to the literature, we explain the interaction of the systemic vascular resistance and pulmonary flow in such lesions and divide them into five categories outlined in this article: (1) CHDs with left-to-right shunt with normal pulmonary arterial pressure and resistance, (2) CHD with left-to-right shunt and moderate to severe elevation of pulmonary arterial pressure with near-normal pulmonary vascular resistance, (3) CHD with pulmonary flow dependent on systemic vascular resistance, (4) patients with congenital coronary stenosis and coronary anomalies, and 5) aortic obstructive lesions.

Cardiac Multimodality Imaging in Hypertrophic Cardiomyopathy: What to Look for and When to Image

Hypertrophic cardiomyopathy (HCM), now recognized as a common cardiomyopathy of complex genomics and pathophysiology, is defined by the presence of left ventricular hypertrophy of various morphologies and severity, significant hemodynamic consequences, and diverse phenotypic, both structural and clinical, profiles. Advancements in cardiac multimodality imaging, including echocardiography, cardiac magnetic resonance imaging, and cardiac computed tomography, with and without angiography have greatly improved the diagnosis of HCM, and enable precise measurements of cardiac mass, volume, wall thickness, function, and physiology. Multimodality imaging provides comprehensive and complementary information and hasemerged as the bedrock for the diagnosis, clinical assessment, serial monitoring, and sudden cardiac death risk stratification of patients with HCM. This review highlights the role of cardiac multimodality imaging in the modern diagnosis and management of HCM.

How to build a successful hypertrophic cardiomyopathy team and ensure training the next generation of myectomy surgeons

Transaortic extended septal myectomy is the most reliable method for septal reduction for symptomatic patients with obstructive hypertrophic cardiomyopathy. In addition, surgical management of nonobstructive hypertrophic cardiomyopathy is possible for selected patients with diastolic heart failure and small left ventricular end-diastolic cavity dimensions. These procedures, however, are performed infrequently in many centers, and trainees may not be exposed to the preoperative evaluation and intraoperative management of patients with hypertrophic cardiomyopathy. In this paper, we review what we believe are the central features for creating a successful program for septal myectomy and detail our strategies to optimize instruction in these techniques for residents and fellows.

Echocardiographic evaluation of hypertrophic cardiomyopathy: A review of up-to-date knowledge and practical tips

Hypertrophic cardiomyopathy (HCM) is the most frequent cardiac disease with genetic substrate, affecting about .2%-.5% of the population. The proper diagnosis is important for optimal management and follow-up. Echocardiography plays an essential role in the assessment of patients with HCM including diagnosis, screening, management formulation, prognosis, and follow up. It also helps to differentiate HCM from other diseases. The advancement of software and probe technology added many echo modalities and techniques that helped in refining the diagnostic and assessing the prognosis of patients with HCM. In this review, we briefly summarize how to integrate the different echocardiographic modalities to obtain comprehensive assessment supported by an updated knowledge of the latest guidelines and recently published articles. Many practical tips and tricks are included in this review to improve the diagnostic accuracy of echocardiography and minimize errors during interpretation.

Perioperative Implications of the 2020 American Heart Association/American College of Cardiology Guidelines for the Diagnosis and Treatment of Patients with Hypertrophic Cardiomyopathy: A Focused Review

Hypertrophic cardiomyopathy is a complex disease with significant implications for patients and the physicians called upon to care for them during the perioperative period. In this article, the 2020 American Heart Association and American College of Cardiology clinical practice guidelines for the evaluation and management of pediatric and adult patients with hypertrophic cardiomyopathy are reviewed, with a particular focus on perioperative considerations for the anesthesiologist.

Hypertrophic Obstructive Cardiomyopathy: Discrepancy Between Hemodynamic Measurements in the Cardiac Laboratory and Operating Room Is to Be Expected

OBJECTIVES

It is not uncommon to observe some discrepancy in hemodynamic values characterizing left ventricular outflow tract (LVOT) obstruction preoperatively and in the operating room in patients with hypertrophic obstructive cardiomyopathy. Interpretation of this discrepancy can be challenging. To clarify the extent of the discrepancy, the authors compared hemodynamic variables in patients undergoing septal myectomy at the time of preoperative and intraoperative evaluation.

DESIGN

Retrospective study.

SETTING

Single academic medical center.

INTERVENTIONS

Medical records review, study group-173 patients.

MEASUREMENTS AND MAIN RESULTS

While there was no statistically significant difference in resting peak LVOT gradients by preoperative transthoracic echocardiography (TTE) compared to intraoperative transesophageal echocardiography (46 mmHg [19-87 mmHg] v 36 mmHg [16-71 mmHg], p = 0.231), the former were higher compared to direct needle-resting LVOT gradient measurements before myectomy (49 mmHg [19-88 mmHg] v 32 mmHg [14-67 mmHg], p = 0.0022). The prevalence of systolic anterior motion was high (94.6% v 91.6%, P = 1.000) both on pre- and intraoperative evaluation. The incidence of moderate/severe mitral was higher intraoperatively (p < 0.0001). Pulmonary artery systolic pressures measured by pulmonary artery catheter provided higher values compared to preoperative TTE estimate (39 mmHg [34-45 mmHg] v 34 mmHg [28-41 mmHg], p < 0.0001).

CONCLUSIONS

Discrepancy between hemodynamic measurements in the cardiac laboratory and operating room is common and generally should not affect planned patients' care. These changes in hemodynamics might be explained by preoperative fasting, anesthetic agents, volume shifts while supine, and positive-pressure ventilation, as well as the difference in measurement techniques.

Squat-to-stand provocation of dynamic left ventricular outflow tract obstruction in hypertrophic cardiomyopathy: a case report

BACKGROUND

Left ventricular outflow tract (LVOT) obstruction is an important determinant of the management of hypertrophic cardiomyopathy (HCM). With a nationwide shortage of amyl nitrite in 2019, we implemented a 'repetitive squat-to-stand' manoeuvre to provoke LVOT obstruction during echocardiography.

CASE SUMMARY

A 64-year-old female was referred with symptomatic HCM refractory to pharmacologic therapy. Transthoracic echocardiography showed minor LVOT obstruction with conventional imaging at rest and during Valsalva manoeuvre, but severe obstruction was confirmed with the repetitive squat-to-stand manoeuvre. Alcohol septal ablation via the first septal perforator was performed with subsequent resolution of symptoms.

DISCUSSION

Due to the dynamic nature of LVOT obstruction, a series of provocative manoeuvres including Valsalva manoeuvre, inhalation of amyl nitrite, and exercise are often necessary to maximally augment ventricular obstruction. The recent unavailability of amyl nitrite during a nationwide shortage prompted the implementation of a protocol of repetitive squat-to-stand manoeuvre in our echocardiography laboratory. Rising from the squatting position decreases preload and afterload, both of which augment dynamic LVOT obstruction. Repetition of squatting and standing appears to enhance the sensitivity of the manoeuvre, particularly when exertional symptoms are reproduced. In this case, repetitive squat-to-stand manoeuvre led to the identification of severe LVOT obstruction which may not have been diagnosed otherwise, alteration of treatment to septal reduction therapy, and subsequent resolution of symptoms.

2020 AHA/ACC Guideline for the Diagnosis and Treatment of Patients With Hypertrophic Cardiomyopathy: Executive Summary: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

This executive summary of the hypertrophic cardiomyopathy clinical practice guideline provides recommendations and algorithms for clinicians to diagnose and manage hypertrophic cardiomyopathy in adult and pediatric patients as well as supporting documentation to encourage their use.

METHODS

A comprehensive literature search was conducted from January 1, 2010, to April 30, 2020, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Collaboration, Agency for Healthcare Research and Quality reports, and other relevant databases.

STRUCTURE

Many recommendations from the earlier hypertrophic cardiomyopathy guidelines have been updated with new evidence or a better understanding of earlier evidence. This summary operationalizes the recommendations from the full guideline and presents a combination of diagnostic work-up, genetic and family screening, risk stratification approaches, lifestyle modifications, surgical and catheter interventions, and medications that constitute components of guideline directed medical therapy. For both guideline-directed medical therapy and other recommended drug treatment regimens, the reader is advised to follow dosing, contraindications and drug-drug interactions based on product insert materials.

2020 AHA/ACC Guideline for the Diagnosis and Treatment of Patients With Hypertrophic Cardiomyopathy: Executive Summary: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

Aim This executive summary of the hypertrophic cardiomyopathy clinical practice guideline provides recommendations and algorithms for clinicians to diagnose and manage hypertrophic cardiomyopathy in adult and pediatric patients as well as supporting documentation to encourage their use. Methods A comprehensive literature search was conducted from January 1, 2010, to April 30, 2020, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Collaboration, Agency for Healthcare Research and Quality reports, and other relevant databases. Structure Many recommendations from the earlier hypertrophic cardiomyopathy guidelines have been updated with new evidence or a better understanding of earlier evidence. This summary operationalizes the recommendations from the full guideline and presents a combination of diagnostic work-up, genetic and family screening, risk stratification approaches, lifestyle modifications, surgical and catheter interventions, and medications that constitute components of guideline directed medical therapy. For both guideline-directed medical therapy and other recommended drug treatment regimens, the reader is advised to follow dosing, contraindications and drug-drug interactions based on product insert materials.

Biomarker changes with systolic anterior motion of the mitral valve in cats with hypertrophic cardiomyopathy

BACKGROUND

N-terminal pro B-type natriuretic peptide (NT-proBNP) and cardiac troponin-I (cTnI) are biomarkers commonly evaluated in cats with suspected heart disease. Many cats with hypertrophic cardiomyopathy (HCM) have systolic anterior motion of the mitral valve (SAM), but its influence on circulating NT-proBNP or cTnI concentrations is currently unknown.

HYPOTHESIS/OBJECTIVES

Cats with HCM and SAM (HCM^SAM+ ) have higher NT-proBNP and cTnI concentrations than do cats with HCM but without SAM (HCM^SAM- ).

ANIMALS

One hundred forty cats with HCM: 70 with SAM and 70 without SAM.

METHODS

Retrospective case-to-case study. Cats were recruited if diagnosed with HCM by echocardiography and results were available for NT-proBNP or cTnI concentrations or both. Cats with SAM were matched to those without SAM for clinical presentation, left atrial (LA) size and left ventricular (LV) fractional shortening.

RESULTS

A total of 119 NT-proBNP and 123 cTnI results were available. The HCM^SAM+ cats had higher median concentrations than did HCM^SAM- cats for NT-proBNP (729 pmoL/L; interquartile range [IQR], 275-1467 versus 65 pmoL/L; IQR, 25-271; P < .001) and cTnI (0.27 ng/mL; IQR, 0.10-0.81 versus 0.07 ng/mL; IQR, 0.01-0.43; P = .002). In general linear models for both NT-proBNP and cTnI, the independent explanatory variables were SAM, congestive heart failure, maximal LV wall thickness, and LA size.

CONCLUSIONS AND CLINICAL IMPORTANCE

For cats with HCM and equivalent LA size and LV systolic function, those with SAM had higher NT-proBNP and cTnI concentrations than did those without SAM. Presence of SAM should be considered when interpreting biomarker concentrations in cats with HCM.

Phenotyping Left Ventricular Obstruction With Postprandial Re-Test Echocardiography in Hypertrophic Cardiomyopathy

Dynamic left ventricular (LV) obstruction has important clinical and therapeutic implications in patients with hypertrophic cardiomyopathy (HC). Although absent at rest, LV obstruction may be elicited using varying stressors. Meal-related hemodynamic changes may favor LV obstruction and support postprandial (PP) symptoms in HC patients. The aim of this study was to evaluate PP-LV obstruction inducibility in HC patients in comparison with fasting Valsalva maneuver and exercise test. Ninety-two HC patients without LV obstruction underwent at-rest Transthoracic Echocardiography (TTE) during Valsalva maneuver and exercise test under fasting condition followed by at-rest re-test PP-TTE 30 to 60 minutes after a standardized midday meal. LV obstruction was noted and classified as being related to systolic anterior motion (SAM) of the mitral valve (SAM-related) and/or non-SAM-related (mid-cavity or apical), and intraventricular gradient was measured. At-rest re-test PP-TTE showed significant intraventricular gradient (>30 mm Hg) in 68 patients (60 SAM-related, 8 non-SAM related, 30 combined) with a higher prevalence (74%) of HC phenotype re-classified as obstructive compared with the fasting Valsalva maneuver (23%) or exercise test (33%) (p < 0.001). At multivariate analysis, a clinical history of PP symptoms and mitral anterior leaflet length and/or LV outflow ratio >2 were independently correlated with PP-TTE obstruction. In conclusion, PP TTE re-test is a simple and effective approach to unmask latent LV dynamic obstruction in daily clinical practice over fasting Valsalva maneuver or exercise test. PP clinical phenotype refinement may be relevant in targeting and evaluating HC therapy.

Multimodality Imaging in Hypertrophic Cardiomyopathy for Risk Stratification

In hypertrophic cardiomyopathy, multimodality imaging is crucial to confirm diagnosis, assess for presence and mechanism of left ventricular outflow tract obstruction, and risk stratification for sudden cardiac death. This review will focus on the application of imaging to assess established and emerging factors to be considered in sudden cardiac death risk stratification.