Association Between Race and Clinical Profile of Patients Referred for Hypertrophic Cardiomyopathy

Ventricular late gadolinium enhancement by cardiac MRI as a predictor of atrial fibrillation in hypertrophic cardiomyopathy

BACKGROUND

Atrial fibrillation (AF) increases stroke and mortality in patients with hypertrophic cardiomyopathy (HCM). Cardiac MRI (CMR) is increasingly used to detect late gadolinium enhancement (LGE) as a reliable indicator of left ventricular fibrosis, a potential predisposing factor of AF. Our research explored the correlation between left ventricular LGE and AF prevalence in HCM.

METHODS

This retrospective study involved 351 HCM patients who underwent CMR. LGE percentages (0%, 1-5%, 6-14%, ≥15%) on CMR were compared with AF prevalence in HCM patients. Demographic, comorbidity, and imaging data were analyzed using appropriate univariate and multivariate analyses assessing for significant differences in AF prevalence. The predetermined significance level was p < 0.05.

RESULTS

CMR demonstrated increased LGE in those with AF (p = 0.004). Increased LGE correlated with increased AF rates: 27.6% (0% LGE), 38.5% (1-5% LGE), 44.4% (6-14% LGE), and 54.7% (≥15% LGE) (p = 0.101, p = 0.043, p = 0.002, respectively, vs. 0% LGE). Adjusted for age, differences persisted and were most evident for LGE >15% (p = 0.001). Multivariate analysis, factoring age, gender, BMI, RVSP, and LVEF, supported LGE (odds ratio of 1.20, p = 0.036) and LAVI (odds ratio 1.05, 1.02-1.07, p < 0.001) as predictive markers for AF prevalence.

CONCLUSIONS

Our study suggests a correlation between ventricular LGE and AF in patients with HCM. LGE exceeding 15% was associated with a significant increase in AF prevalence. These patients may require more frequent AF monitoring.

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.

The Paradigm of Sudden Death Prevention in Hypertrophic Cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is a relatively common and, often, inherited cardiac disease, once regarded as largely untreatable with ominous prognosis and, perhaps, most visibly as a common cause of sudden cardiac death (SCD) in the young. However, HCM is now more accurately considered a treatable disease with management options that significantly alter its clinical course. This is particularly true for SCD because the penetration of implantable cardioverter-defibrillators into HCM practice enables primary prevention device therapy that reliably terminates potentially lethal ventricular tachyarrhythmias (3% to 4%/year). This therapeutic advance is largely responsible for >10-fold decrease in the overall disease-related mortality to 0.5%/year, independent of patient age. A guideline-based clinical risk stratification algorithm has evolved, which included variables identifiable with cardiac magnetic resonance: ≥1 risk markers judged major within the clinical profile of an individual patient, associated with a measure of physician judgment and shared decision-making, can be sufficient to consider the recommendation of a prophylactic defibrillator implant. Implantable cardioverter-defibrillator decisions using the American College of Cardiology and the American Heart Association traditional major risk marker strategy are associated with a 95% sensitivity for identifying those patients who subsequently experience appropriate therapy, albeit often 5 to 10+ years after implant but without heart failure deterioration or death after a device intervention. A mathematical SCD risk score proposed by European Society of Cardiology is associated with a relatively low sensitivity (33%) for predicting and preventing SCD events but with potential for less device overtreatment.

Ethnic and sex-related differences at presentation in apical hypertrophic cardiomyopathy: An observational cross-sectional study

BACKGROUND

We investigated whether ethnicity and sex are associated with different clinical presentations and cardiovascular magnetic resonance (CMR) findings in individuals with apical hypertrophic cardiomyopathy (ApHCM).

METHODS

A retrospective observational cohort study of consecutive ApHCM patients from a large tertiary referral center in the United Kingdom (UK). Demographic, clinical, 12‑lead electrocardiogram (ECG) and CMR findings were collected. Participants presented in our clinics between 2010 and 2020. 'Pure' ApHCM was defined as isolated apical hypertrophy and 'mixed' with both apical and septal hypertrophy but with the apical segments of a greater wall thickness. Deep T-wave inversion was defined as ≥5 mm in any electrocardiogram lead.

RESULTS

A total of 150 consecutive ApHCM patients (75% men, 25% women; 37% White, 25% Black, 24% Asian and 15% of Mixed/Other ethnicity) were included. Females were diagnosed at an older age compared to men, had less prominent ECG changes, had higher left atrial area index, and were more hypertensive. Black patients had higher left ventricular mass index, more hypertension, and more of the 'mixed' type of ApHCM. The majority of hypertensive male patients showed the 'mixed' phenotype.

CONCLUSIONS

Individuals of Black ethnicity and hypertensive male patients are more likely to present with mixed apical and basal hypertrophy, whereas White, Asian and non-hypertensive male patients tend to have hypertrophy limited to the apex. Females present at an older age and are less likely to have deep T wave inversion on ECG.

Patient-reported outcomes in clinical studies of patients with hypertrophic cardiomyopathy

OBJECTIVES

This study aimed to characterize patient-reported outcomes (PROs) in registered clinical studies of participants with hypertrophic cardiomyopathy (HCM).

BACKGROUND

Therapy for HCM is primarily targeted toward alleviation of symptoms and improvement in function and quality of life. Yet, the contemporary landscape of PROs in HCM clinical research has not been investigated.

METHODS

ClinicalTrials.gov was queried to identify clinical studies of HCM that reported PROs as outcome measures. All studies of HCM as the disease condition were included, and PROs were identified using specific search terms in the Outcome Measures field. Study characteristics were collected and compared between those that did versus did not report PROs.

RESULTS

From November 1987 to February 2022, 181 studies including participants with HCM were registered on ClinicalTrials.gov. Of these, 35 (19%) included PROs as outcome measures. Studies reporting PROs were more likely to be designated as interventional (85.7% vs. 46.6%; p < 0.001) and to involve randomization (65.7% vs. 24.7%; p = 0.003) compared with those that did not report PROs. Prior to 2007, no clinical studies that reported PROs were registered in ClinicalTrials.gov; however, PRO reporting has increased over the last 15 years. Of the 66 PRO tools or domains included as outcome measures, the Kansas City Cardiomyopathy Questionnaire was the most often used.

CONCLUSIONS

Only approximately one in five registered clinical studies of participants with HCM report PROs. As medical, percutaneous, and surgical therapies for HCM continue to advance, HCM-specific PRO tools that assess the impacts of these new treatments on meaningful patient-related endpoints are urgently needed.

Mavacamten-A Targeted Therapy for Hypertrophic Cardiomyopathy

ABSTRACT

The pathophysiology of hypertrophic cardiomyopathy is primarily comprised of dynamic left ventricular outflow tract obstruction, mitral regurgitation, and diastolic dysfunction. Symptoms such as dyspnea, angina, or syncope can occur because of left ventricular (LV) hypertrophy and reduced LV cavity size. Currently, focus on symptom relief through optimizing LV preload and reducing inotropy is the mainstay of therapy through the use of β-blockers, nondihydropyridine calcium channel blockers, and disopyramide. Mavacamten is a novel cardiac myosin inhibitor recently approved by the Food and Drug Administration for the treatment of obstructive hypertrophic cardiomyopathy. Mavacamten normalizes myosin and actin cross-bridging to decrease contractility and ultimately reduce LV outflow tract gradients to maximize cardiac output. In this review, we report on the mechanism of action of mavacamten, safety profile, and phase 2 and 3 clinical trial data. Because of the risk of heart failure resulting from systolic dysfunction, careful patient selection and close monitoring are key for implementing this therapy into cardiovascular practice.

Impact of Race and Ethnicity on Use and Outcomes of Septal Reduction Therapies for Obstructive Hypertrophic Cardiomyopathy

Background Information on impact of race and ethnicity on use and early outcomes of septal reduction therapies (SRTs) for obstructive hypertrophic obstructive cardiomyopathy are limited. Methods and Results Using the National Inpatient Sample from January 2012 through December 2019, we identified all adult admissions with a primary diagnosis of obstructive hypertrophic cardiomyopathy and those undergoing SRT. Predictors of receiving SRT and outcomes including in-hospital mortality, complications, and resource use were evaluated in racial and ethnic groups. Among a total of 18 895 adult admissions with obstructive hypertrophic cardiomyopathy, SRT was performed in 7255 (38.4%) admissions. Septal myectomy was performed in 4930 (26.1%), while alcohol septal ablation was performed in 2325 (12.3%). In adjusted analysis, Black patient (versus White patient adjusted odds ratio, 0.65 [95% CI, 0.57-0.73]; P<0.001) and Hispanic patient admissions (versus White adjusted odds ratio, 0.78 [95% CI, 0.66-0.92]; P=0.003) were less likely to receive SRT. Among admissions undergoing SRT, in-hospital mortality was significantly higher for Hispanic (adjusted odds ratio, 3.38 [95% CI, 1.81-6.30], P<0.001) and other racial and ethnic groups (adjusted odds ratio 2.02 [95% CI, 1.00-4.11]; P=0.05) compared with White patient admissions, whereas Black patient admissions had comparable mortality. Black, Hispanic, and other ethnic group patients had higher rates of SRT complications and more frequent dismissals to acute care facilities. Conclusions Among obstructive hypertrophic cardiomyopathy hospitalizations, minoritized racial groups were less likely to receive SRT. Importantly, hospitalizations of Hispanic and other ethnic patients undergoing SRT had significantly higher in-hospital mortality and complication rates. Further studies with granular echocardiographic information to assess indications for SRT are needed to better understand these differences.

Current and emerging perspectives on pathophysiology, diagnosis, and management of hypertrophic cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is the most common genetically inherited cardiomyopathy with an autosomal dominant inheritance pattern. A disease-causing gene is found between 34% and >60% of the times and the two most frequently mutated genes, which encode sarcomeric proteins, are MYBPC3 and MYH7. HCM is a diagnosis of exclusion since secondary causes of left ventricular hypertrophy should first be ruled out. These include hypertension, aortic stenosis, infiltrative disease, metabolic and endocrine disorders, mitochondrial cardiomyopathies, neuromuscular disorders, malformation syndromes and some chronic drug use. The disease is characterized by great heterogeneity of its clinical manifestations, however diastolic dysfunction and increased ventricular arrhythmogenesis are commonly seen. Current HCM therapies focus on symptom management and prevention of sudden cardiac death. Symptom management includes the use of pharmacological agents, elimination of medication promoting outflow track obstruction, control of comorbid conditions and invasive procedures, whereas in the prevention of sudden cardiac death, implantable cardiac defibrillators and antiarrhythmic drugs are used. A targeted therapy for LVOTO represented by allosteric cardiac myosin inhibitors has been developed. In terms of sport participation, a more liberal approach is recently recommended, after careful evaluation and common-shared decision. The application of the current therapies has lowered HCM mortality rates to <1.0%/year, however it appears to have shifted focus to heart failure and atrial fibrillation, as the predominant causes of disease-related morbidity and mortality and, therefore, unmet treatment need. With improved understanding of the genetic and molecular basis of HCM, the present decade will witness novel treatments for disease prevention and modification.

What Causes Hypertrophic Cardiomyopathy?

Hypertrophic cardiomyopathy (HCM) is a global and relatively common cause of patient morbidity and mortality and is among the first reported monogenic cardiac diseases. For 30 years, the basic etiology of HCM has been attributed largely to variants in individual genes encoding cardiac sarcomere proteins, with the implication that HCM is fundamentally a genetic disease. However, data from clinical and network medicine analyses, as well as contemporary genetic studies show that single gene variants do not fully explain the broad and diverse HCM clinical spectrum. These transformative advances place a new focus on possible novel interactions between acquired disease determinants and genetic context to produce complex HCM phenotypes, also offering a measure of caution against overemphasizing monogenics as the principal cause of this disease. These new perspectives in which HCM is not a uniformly genetic disease but likely explained by multifactorial etiology will also unavoidably impact how HCM is viewed by patients and families in the clinical practicing community going forward, including relevance to genetic counseling and access to healthcare insurance and psychosocial wellness.

Ventricular Septal Myectomy for Obstructive Hypertrophic Cardiomyopathy (Analysis Spanning 60 Years Of Practice): AJC Expert Panel

Surgical myectomy remains the time-honored primary treatment for hypertrophic cardiomyopathy patients with drug refractory limiting symptoms due to LV outflow obstruction. Based on >50 years experience, surgery reliably reverses disabling heart failure by permanently abolishing mechanical outflow impedance and mitral regurgitation, with normalization of LV pressures and preserved systolic function. A consortium of 10 international currently active myectomy centers report about 11,000 operations, increasing significantly in number over the most recent 15 years. Performed in experienced multidisciplinary institutions, perioperative mortality for myectomy has declined to 0.6%, becoming one of the safest currently performed open-heart procedures. Extended myectomy relieves symptoms in >90% of patients by ≥ 1 NYHA functional class, returning most to normal daily activity, and also with a long-term survival benefit; concomitant Cox-Maze procedure can reduce the number of atrial fibrillation episodes. Surgery, preferably performed in high volume clinical environments, continues to flourish as a guideline-based and preferred high benefit: low treatment risk option for adults and children with drug refractory disabling symptoms from obstruction, despite prior challenges: higher operative mortality/skepticism in 1960s/1970s; dual-chamber pacing in 1990s, alcohol ablation in 2000s, and now introduction of strong negative inotropic drugs potentially useful for symptom management.

Sex and Race Disparities in Hypertrophic Cardiomyopathy: Unequal Implantable Cardioverter-Defibrillator Use During Hospitalization

OBJECTIVE

To evaluate if there are sex and race disparities in use of implantable cardioverter-defibrillator (ICD) devices for prevention of sudden cardiac death in patients with hypertrophic cardiomyopathy (HCM).

PATIENTS AND METHODS

Using the National Inpatient Sample from January 2003 through December 2014, we identified all adult admissions with a diagnosis of HCM and an ICD implantation. Race was classified as White versus non-White. Trends in ICD use, predictors of ICD implantation, device-related complications, hospitalization costs, and lengths of stay were evaluated.

RESULTS

Among a total of 23,535 adult hospitalizations for HCM, ICD implantation was performed in 3954 (16.8%) admissions. Over the study period, there was an overall increasing trend in ICD use (11.6% in 2003 to 17.0% in 2014, P<.001). Compared with admissions not receiving an ICD, those receiving an ICD had shorter median lengths of in-hospital stay but higher hospitalization costs (P<.001). Compared with men and White race, female sex (odds ratio, 0.72; 95% CI, 0.66 to 0.78; P<.001) and non-White race (odds ratio, 0.87; 95% CI, 0.79 to 0.96; P<.001) were associated with lower adjusted odds of receiving an ICD. Women and non-White hospitalizations had higher rates of device related complications, longer lengths of in-hospital stay, and higher hospitalization costs compared with men and White race, respectively (all P<.01).

CONCLUSION

Among HCM hospitalizations, ICD devices are underused in women and racial minorities independent of demographics, hospital characteristics, and comorbidities. Women and racial minorities also had higher rates of complications and greater resource use compared with men and those belonging to the White race, respectively.

Hypertrophic Cardiomyopathy: New Concepts and Therapies

Hypertrophic cardiomyopathy (HCM), a relatively common, globally distributed, and often inherited myocardial disorder, transformed over the last several years into a treatable condition with the emergence of effective management options that alter natural history at all ages. Now available are a matured risk stratification algorithm selecting patients for prophylactic implantable defibrillators that prevent arrhythmic sudden death; low-risk, high-benefit surgical myectomy to reverse progressive heart failure symptoms due to left ventricular outflow obstruction; anticoagulation prophylaxis to prevent atrial fibrillation-mediated embolic stroke; and heart transplant for refractory end-stage disease in the absence of obstruction. Those strategies have resulted in reduction of HCM-related morbidity and reduction of mortality to 0.5% per year.

Associations of Race and Ethnicity With Presentation and Outcomes of Hypertrophic Cardiomyopathy: JACC Focus Seminar 6/9

Significant racial and ethnicity-based disparities in clinical presentation, management, and outcome of hypertrophic cardiomyopathy (HCM) are reported. Black patients with HCM are more likely to present with heart failure but are less commonly referred for symptom management, sudden cardiac death stratification, surgical septal myectomy, or for implantable cardioverter-defibrillators, all interventions that increase survival. Prevalence of bystander cardiopulmonary resuscitation is lower for Black patients than for White patients. Black patients with HCM have decreased survival after hospital discharge following out-of-hospital cardiac arrest. Biomedical and social interventions are urgently needed to reduce ethnicity-based disparities, which have an impact on outcomes in HCM and other cardiovascular diseases. There is also a need to focus on implementation science to support durable adoption of evidence-based therapies in Black patients and communities.

Disease Expression and Outcomes in Black and White Adults With Hypertrophic Cardiomyopathy

Background

There is limited research on hypertrophic cardiomyopathy (HCM), which is the most common inherited cardiac disorder, in diverse populations, including Black individuals. Current literature lacks comprehensive data on HCM disease expression, comorbidities, and outcomes in this historically disadvantaged group. The purpose of this study was to examine structural HCM characteristics, comorbidities, and outcomes in a Black and White cohort with HCM.

Methods and Results

The study was a subgroup analysis from a longitudinal, prospective study on HCM, with supplemental chart review. The sample included adults (≥18 years) with a clinical diagnosis of HCM, who self‐identified as Black/African American or White. The study sample comprised 434 individuals; 57 (13.1%) were Black, and 180 (41.5%) were women. Black patients were younger than White patients, 54.6 (13.4) versus 62.5 (14.8) years, P=0.001. Black patients were more likely to have sub‐basal and diffuse hypertrophy, 22 (38.6%) versus 56 (14.9%), P<0.001, 6 (10.5%) versus 15 (4%), P=0.017, mid‐LV obstruction, 7 (12.3%) versus 21 (5.5%), P=0.025, and cardiac fibrosis ≥15%, 10 (22.2%) versus 19 (8.8%), P=0.009, than White patients. Black patients were more likely to experience appropriate implantable cardioverter defibrillator interventions, 5 (38.5) versus 5 (6.8), P<0.001 and were more likely to have ≥2 sudden death risk factors. Comorbidities were largely similar between groups, though more Black participants had Class II obesity, 12 (21.8) versus 30 (8.1), P<0.001. Both groups had similar rates of genetic testing usage.

Conclusions

This study underscores the need for continued research of HCM in Black populations, including tailored approaches to diagnosis and precise evaluation of cardiac anatomy.

Evolution of risk stratification and sudden death prevention in hypertrophic cardiomyopathy: Twenty years with the implantable cardioverter-defibrillator

Hypertrophic cardiomyopathy (HCM) is a relatively common inherited myocardial disorder, once regarded as largely untreatable with ominous prognosis and most visibly as a common cause of sudden death (SD) in the young. Over the last several years, HCM has been transformed into a contemporary treatable disease with management options that significantly alter clinical course. With the use of implantable cardioverter-defibrillators (ICDs) in the HCM patient population, a new paradigm has emerged, with primary prevention device therapy reliably terminating potentially lethal ventricular tachyarrhythmias (3%-4% per year) and being largely responsible for a >10-fold decrease in disease-related mortality (to 0.5% per year), independent of age. An evidenced-based and guideline directed clinical risk stratification algorithm has evolved, including variables identified with cardiac magnetic resonance. One or more risk markers judged major and relevant within a patient's clinical profile can be considered sufficient to recommend a primary prevention implant (associated with a measure of physician judgment and shared decision-making). ICD decisions using the prospective individual risk marker strategy have been associated with 95% sensitivity for identifying patients who subsequently experienced appropriate ICD therapy, (albeit often delayed substantially for >5 or >10 years after implant), but without heart failure deterioration or HCM death following device intervention. A rigid mathematically derived statistical risk model proposed by the European Society of Cardiology is associated with low sensitivity (ie, 33%) for predicting SD events. Introduction of prophylactically inserted ICDs to HCM 20 years ago has significantly altered the clinical course and landscape of this disease. SD prevention has reduced HCM mortality significantly, making preservation of life and the potential for normal longevity a reality for most patients.

Association of Race With Disease Expression and Clinical Outcomes Among Patients With Hypertrophic Cardiomyopathy

Importance

Racial differences are recognized in multiple cardiovascular parameters, including left ventricular hypertrophy and heart failure, which are 2 major manifestations of hypertrophic cardiomyopathy. The association of race with disease expression and outcomes among patients with hypertrophic cardiomyopathy is not well characterized.

Objective

To assess the association between race, disease expression, care provision, and clinical outcomes among patients with hypertrophic cardiomyopathy.

Design, Setting, and Participants

This retrospective cohort study included data on black and white patients with hypertrophic cardiomyopathy from the US-based sites of the Sarcomeric Human Cardiomyopathy Registry from 1989 through 2018.

Exposures

Self-identified race.

Main Outcomes and Measures

Baseline characteristics; genetic architecture; adverse outcomes, including cardiac arrest, cardiac transplantation or left ventricular assist device implantation, implantable cardioverter-defibrillator therapy, all-cause mortality, atrial fibrillation, stroke, and New York Heart Association (NYHA) functional class III or IV heart failure; and septal reduction therapies. The overall composite outcome consists of the first occurrence of any component of the ventricular arrhythmic composite end point, cardiac transplantation, left ventricular assist device implantation, NYHA class III or IV heart failure, atrial fibrillation, stroke, or all-cause mortality.

Results

Of 2467 patients with hypertrophic cardiomyopathy at the time of analysis, 205 (8.3%) were black (130 male [63.4%]; mean [SD] age, 40.0 [18.6] years) and 2262 (91.7%) were white (1351 male [59.7%]; mean [SD] age, 45.5 [20.5] years). Compared with white patients, black patients were younger at the time of diagnosis (mean [SD], 36.5 [18.2] vs 41.9 [20.2] years; P < .001), had higher prevalence of NYHA class III or IV heart failure at presentation (36 of 205 [22.6%] vs 174 of 2262 [15.8%]; P = .001), had lower rates of genetic testing (111 [54.1%] vs 1404 [62.1%]; P = .03), and were less likely to have sarcomeric mutations identified by genetic testing (29 [26.1%] vs 569 [40.5%]; P = .006). Implantation of implantable cardioverter-defibrillators did not vary by race; however, invasive septal reduction was less common among black patients (30 [14.6%] vs 521 [23.0%]; P = .007). Black patients had less incident atrial fibrillation (35 [17.1%] vs 608 [26.9%]; P < .001). Black race was associated with increased development of NYHA class III or IV heart failure (hazard ratio, 1.45; 95% CI, 1.08-1.94) which persisted on multivariable Cox proportional hazards regression (hazard ratio, 1.97; 95% CI, 1.34-2.88). There were no differences in the associations of race with stroke, ventricular arrhythmias, all-cause mortality, or the overall composite outcome.

Conclusions and Relevance

The findings suggest that black patients with hypertrophic cardiomyopathy are diagnosed at a younger age, are less likely to carry a sarcomere mutation, have a higher burden of functionally limited heart failure, and experience inequities in care with lower use of invasive septal reduction therapy and genetic testing compared with white patients. Further study is needed to assess whether higher rates of heart failure may be associated with underlying ancestry-based disease pathways, clinical management, or structural inequities.

Understanding the Complexity of Heart Failure Risk and Treatment in Black Patients

Although care of patients with heart failure (HF) has improved in the past decade, important disparities in HF outcomes persist based on race/ethnicity. Age-adjusted HF-related cardiovascular disease death rates are higher for Black patients, particularly among young Black men and women whose rates of death are 2.6- and 2.97-fold higher, respectively, than White men and women. Similarly, the rate of HF hospitalization for Black men and women is nearly 2.5-fold higher when compared with Whites, with costs that are significantly higher in the first year after HF hospitalization. While the relative rate of HF hospitalization has improved for other race/ethnic minorities, the disparity in HF hospitalization between Black and White patients has not decreased during the last decade. Although access to care and socioeconomic status have been traditional explanations for the observed racial disparities in HF outcomes, contemporary data suggest that novel factors including genetic susceptibility as well as social determinants of health and implicit bias may play a larger role in health outcomes than previously appreciated. The purpose of this review is to describe the complex interplay of factors that influence racial disparities in HF incidence, prevalence, and disease severity, with a highlight on evolving knowledge that will impact the clinical care and address future research needs to improve HF disparities in Blacks.

An Integrated Review of Hypertrophic Cardiomyopathy in Black Populations: Underrecognized and Understudied

BACKGROUND

Hypertrophic cardiomyopathy (HCM) is the most common inherited cardiac disorder globally, affecting 0.2% to 0.5% of individuals. Existing clinical HCM guidelines do not address diverse populations, specifically minority groups who often experience health disparities.

OBJECTIVE

The aim of this study was to describe the state of the science of HCM in black populations.

METHODS

This integrated review guided by Whittemore and Knafl's methodology included literature search of multiple databases, data evaluation, and analysis. Publications between 2000 and 2020 were included if they addressed HCM cardiac anatomic manifestations, disease course, symptoms, quality of life, or outcomes in black populations.

RESULTS

Six articles met the inclusion criteria. Overall, blacks are underrepresented in HCM research. Certain HCM structural phenotypes are more commonly exhibited in blacks, and physiology drives HCM treatment. Sudden death events and all-cause mortality do not differ between blacks and whites with HCM. Fewer blacks with HCM undergo genetic testing than whites with HCM. The lack of diversity in general genomic databases has resulted in reclassification of several genetic variants identified as more common in blacks.

CONCLUSIONS

Blacks are underrepresented in HCM research, even those focused on elucidating HCM manifestations, disease course, and outcomes in black populations. This may be due in part to HCM research that is largely generated from specialty centers that can require patients to navigate complex healthcare systems to reach expert HCM care. Longitudinal studies with large samples of blacks with HCM are necessary to elucidate how HCM affects this population.

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.

Impact of Sex on Clinical Course and Survival in the Contemporary Treatment Era for Hypertrophic Cardiomyopathy

Background

The relation of sex to clinical presentation and course in hypertrophic cardiomyopathy (HCM) remains incompletely resolved. We assessed differences in clinical outcomes between men and women within our large HCM cohort.

Methods and Results

Of 2123 consecutive patients, a minority (38%) were women who were diagnosed with HCM at older ages or referred for subspecialty evaluation later than men (50±19 versus 44±16 and 55±18 versus 49±16; P<0.001). Women more commonly developed advanced New York Heart Association class III/IV symptoms (53% versus 35% in men; P<0.001), predominantly secondary to outflow obstruction. While end‐stage heart failure with systolic dysfunction (ejection fraction <50%) was similar in men (5% versus 4% in women; P=0.33), women were 3‐fold more likely to develop heart failure with preserved systolic function (7.5% versus 2.6%; P=0.002). Sudden death events terminated by defibrillator therapy were similar in women (0.9%/year) versus men (1.0%/year; hazard ratio, 0.92; 95% CI, 0.6–1.5; P=0.73). HCM mortality was uncommon, with identical rates in both sexes (0.3%/year; hazard ratio, 1.5; 95% CI, 0.7–3.4;, P=0.25). Age‐adjusted all‐cause mortality also did not differ between women and men (1.7% versus 1.3%/year; hazard ratio, 1.32; 95% CI, 0.92–1.91; P=0.13).

Conclusions

Survival was not less favorable in women with HCM. Contemporary treatments including surgical myectomy to reverse heart failure and defibrillators to prevent sudden death, were effective in both sexes contributing to low mortality. However, despite more frequent outflow obstruction, women with HCM are underrecognized and referred to centers later than men, often with more advanced heart failure. Greater awareness of HCM in women should lead to earlier diagnosis and treatment, with implications for improved quality of life.