Arrhythmias and ion channelopathies causing sudden cardiac death in Hispanic/Latino and Indigenous populations.

The limited literature and increasing interest in studies on cardiac electrophysiology, explicitly focusing on cardiac ion channelopathies and sudden cardiac death in diverse populations, has prompted a comprehensive examination of existing research. Our review specifically targets Hispanic/Latino and Indigenous populations, which are often underrepresented in healthcare studies. This review encompasses investigations into genetic variants, epidemiology, etiologies, and clinical risk factors associated with arrhythmias in these demographic groups. The review explores the Hispanic paradox, a phenomenon linking healthcare outcomes to socioeconomic factors within Hispanic communities in the United States. Furthermore, it discusses studies exemplifying this observation in the context of arrhythmias and ion channelopathies in Hispanic populations. Current research also sheds light on disparities in overall healthcare quality in Indigenous populations. The available yet limited literature underscores the pressing need for more extensive and comprehensive research on cardiac ion channelopathies in Hispanic/Latino and Indigenous populations. Specifically, additional studies are essential to fully characterize pathogenic genetic variants, identify population-specific risk factors, and address health disparities to enhance the detection, prevention, and management of arrhythmias and sudden cardiac death in these demographic groups.

Socioeconomic deprivation and racialised disparities in competitive athletes with sudden cardiac arrest from the USA.

OBJECTIVE: To explore the association of socioeconomic deprivation and racialised outcomes in competitive athletes with sudden cardiac arrest (SCA) in the USA. METHODS: SCA cases from the National Center for Catastrophic Sports Injury Research (July 2014 to June 2021) were included. We matched Area Deprivation Index (ADI) scores (17 metrics to grade socioeconomic conditions) to the 9-digit zip codes for each athlete's home address. ADI is scored 1-100 with higher scores indicating greater neighbourhood socioeconomic deprivation. Analysis of variance was used to assess differences in mean ADI by racial groups. Tukey post hoc testing was used for pairwise comparisons. RESULTS: 391 cases of SCA in competitive athletes (85.4% male; 16.9% collegiate, 68% high school, 10.7% middle school, 4.3% youth) were identified via active surveillance. 79 cases were excluded due to missing data (19 race, 60 ADI). Of 312 cases with complete data, 171 (54.8%) were white, 110 (35.3%) black and 31 (9.9%) other race. The mean ADI was 40.20 (95% CI 36.64, 43.86) in white athletes, 57.88 (95% CI 52.65, 63.11) in black athletes and 40.77 (95% CI 30.69, 50.86) in other race athletes. Mean ADI was higher in black versus white athletes (mean difference 17.68, 95% CI 10.25, 25.12; p=0.0036) and black versus other race athletes (mean difference 17.11, 95% CI 4.74, 29.47; p<0.0001). CONCLUSIONS: Black athletes with SCA come from areas with higher neighbourhood socioeconomic deprivation than white or other race athletes with SCA. Our findings suggest that socioeconomic deprivation may be associated with racialised disparities in athletes with SCA.

Evaluation of Sudden Cardiac Arrest by Race/Ethnicity Among Residents of Ventura County, California, 2015-2020.

Importance: Sudden cardiac arrest (SCA) is a major public health problem. Owing to a lack of population-based studies in multiracial/multiethnic communities, little information is available regarding race/ethnicity-specific epidemiologic factors of SCA. Objective: To evaluate the association of race/ethnicity with burden, outcomes, and clinical profile of individuals experiencing SCA. Design, Setting, and Participants: A 5-year prospective, population-based cohort study of out-of-hospital SCA was conducted from February 1, 2015, to January 31, 2020, among residents of Ventura County, California (2018 population, 848 112: non-Hispanic White [White], 45.8%; Hispanic/Latino [Hispanic], 42.4%; Asian, 7.3%; and Black, 1.7% individuals). All individuals with out-of-hospital SCA of likely cardiac cause and resuscitation attempted by emergency medical services were included. Exposures: Data on circumstances and outcomes of SCA from prehospital emergency medical services records and data on demographics and pre-SCA clinical history from detailed archived medical records, death certificates, and autopsies. Main Outcomes and Measures: Annual age-adjusted SCA incidence by race and ethnicity and SCA circumstances and outcomes by ethnicity. Clinical profile (cardiovascular risk factors, comorbidity burden, and cardiac history) by ethnicity, overall, and stratified by sex. Results: A total of 1624 patients with SCA were identified (1059 [65.2%] men; mean [SD] age, 70.9 [16.1] years). Race/ethnicity data were available for 1542 (95.0%) individuals, of whom 1022 (66.3%) were White, 381 (24.7%) were Hispanic, 86 (5.6%) were Asian, 31 (2.0%) were Black, and 22 (1.4%) were other race/ethnicity. Annual age-adjusted SCA rates per 100 000 residents of Ventura County were similar in White (37.5; 95% CI, 35.2-39.9), Hispanic (37.6; 95% CI, 33.7-41.5; P = .97 vs White), and Black (48.0; 95% CI, 30.8-65.2; P = .18 vs White) individuals, and lower in the Asian population (25.5; 95% CI, 20.1-30.9; P = .006 vs White). Survival to hospital discharge following SCA was similar in the Asian (11.8%), Hispanic (13.9%), and non-Hispanic White (13.0%) (P = .69) populations. Compared with White individuals, Hispanic and Asian individuals were more likely to have hypertension (White, 614 [76.3%]; Hispanic, 239 [79.1%]; Asian, 57 [89.1%]), diabetes (White, 287 [35.7%]; Hispanic, 178 [58.9%]; Asian, 37 [57.8%]), and chronic kidney disease (White, 231 [29.0%]; Hispanic, 123 [40.7%]; Asian, 33 [51.6%]) before SCA. Hispanic individuals were also more likely than White individuals to have hyperlipidemia (White, 380 [47.2%]; Hispanic, 165 [54.6%]) and history of stroke (White, 107 [13.3%]; Hispanic, 55 [18.2%]), but less likely to have a history of atrial fibrillation (White, 251 [31.2%]; Hispanic, 59 [19.5%]). Conclusions and Relevance: The results of this study suggest that the burden of SCA was similar in Hispanic and White individuals and lower in Asian individuals. The Asian and Hispanic populations had shared SCA risk factors, which were different from those of the White population. These findings underscore the need for an improved understanding of race/ethnicity-specific differences in SCA risk.

The Association of Structural Inequities and Race With Out-of-Hospital Sudden Death During the COVID-19 Pandemic.

[Figure: see text].

Bringing Critical Race Praxis Into the Study of Electrophysiological Substrate of Sudden Cardiac Death: The ARIC Study.

Background Race is an established risk factor for sudden cardiac death (SCD). We sought to determine whether the association of electrophysiological substrate with SCD varies between black and white individuals. Methods and Results Participants from the ARIC (Atherosclerosis Risk in Communities) study with analyzable ECGs (n=14 408; age, 54±6 years; 74% white) were included. Electrophysiological substrate was characterized by ECG metrics. Two competing outcomes were adjudicated: SCD and non-SCD. Interaction of ECG metrics with race was studied in Cox proportional hazards and Fine-Gray competing risk models, adjusted for prevalent cardiovascular disease, risk factors, and incident nonfatal cardiovascular disease. At the baseline visit, adjusted for age, sex, and study center, blacks had larger spatial ventricular gradient magnitude (0.30 mV; 95% CI, 0.25-0.34 mV), sum absolute QRST integral (18.4 mV*ms; 95% CI, 13.7-23.0 mV*ms), and Cornell voltage (0.30 mV; 95% CI, 0.25-0.35 mV) than whites. Over a median follow-up of 24.4 years, SCD incidence was higher in blacks (2.86 per 1000 person-years; 95% CI, 2.50-3.28 per 1000 person-years) than whites (1.37 per 1000 person-years; 95% CI, 1.22-1.53 per 1000 person-years). Blacks with hypertension had the highest rate of SCD: 4.26 (95% CI, 3.66-4.96) per 1000 person-years. Race did not modify an association of ECG variables with SCD, except QRS-T angle. Spatial QRS-T angle was associated with SCD in whites (hazard ratio, 1.38; 95% CI, 1.25-1.53) and hypertension-free blacks (hazard ratio, 1.52; 95% CI, 1.09-2.12), but not in blacks with hypertension (hazard ratio, 1.15; 95% CI, 0.99-1.32) (P-interaction=0.004). Conclusions Race did not modify associations of electrophysiological substrate with SCD and non-SCD. Electrophysiological substrate does not explain racial disparities in SCD rate.

Racial Differences in Sudden Cardiac Death.

BACKGROUND: Blacks have a higher incidence of out-of-hospital sudden cardiac death (SCD) in comparison with whites. However, the racial differences in the cumulative risk of SCD and the reasons for these differences have not been assessed in large-scale community-based cohorts. The objective of this study is to compare the lifetime cumulative risk of SCD among blacks and whites, and to evaluate the risk factors that may explain racial differences in SCD risk in the general population. METHODS: This is a cohort study of 3832 blacks and 11 237 whites participating in the Atherosclerosis Risk in Communities Study (ARIC). Race was self-reported. SCD was defined as a sudden pulseless condition from a cardiac cause in a previously stable individual, and SCD cases were adjudicated by an expert committee. Cumulative incidence was computed using competing risk models. Potential mediators included demographic and socioeconomic factors, cardiovascular risk factors, presence of coronary heart disease, and electrocardiographic parameters as time-varying factors. RESULTS: The mean (SD) age was 53.6 (5.8) years for blacks and 54.4 (5.7) years for whites. During 27.4 years of follow-up, 215 blacks and 332 whites experienced SCD. The lifetime cumulative incidence of SCD at age 85 years was 9.6, 6.6, 6.5, and 2.3% for black men, black women, white men, and white women, respectively. The sex-adjusted hazard ratio for SCD comparing blacks with whites was 2.12 (95% CI, 1.79-2.51). The association was attenuated but still statistically significant in fully adjusted models (hazard ratio, 1.38; 95% CI, 1.11-1.71). In mediation analysis, known factors explained 65.3% (95% CI 37.9-92.8%) of the excess risk of SCD in blacks in comparison with whites. The single most important factor explaining this difference was income (50.5%), followed by education (19.1%), hypertension (22.1%), and diabetes mellitus (19.6%). Racial differences were evident in both genders but stronger in women than in men. CONCLUSIONS: Blacks had a much higher risk for SCD in comparison with whites, particularly among women. Income, education, and traditional risk factors explained ≈65% of the race difference in SCD. The high burden of SCD and the racial-gender disparities observed in our study represent a major public health and clinical problem.

Epidemiological investigation of sudden cardiac death in multiethnic Xinjiang Uyghur autonomous region in Northwest China.

BACKGROUND: The epidemiological characteristics of sudden cardiac death (SCD) in the autonomous region of Xinjiang Uygur have been largely unknown. This study aimed to evaluate the incidence and demographic risk factors of SCD in Xinjiang, China. METHODS: This retrospective study reviewed medical records from 11 regions in Xinjiang with different geography (north and south of the Tian Shan mountain range), gross domestic product, and ethnicity (Han, Uyghur, Kazakh, and Hui). SCD was defined as unexpected death due to cardiac reasons within 1 hour after the onset of acute symptoms, including sudden death, unexpected death, and nonviolent death. Monitoring was conducted throughout 2015. Demographic and mortality data were recorded and age-adjusted standardized risk ratio (SRR) was analyzed. RESULTS: Among 3,224,103 residents, there were 13,308 all-cause deaths and 1244 events of SCD (784 men and 460 women; overall incidence 38.6 per 100,000 residents). SCD was associated with age (χ2 = 2105.3), but not geography. Men had an increased risk of SCD compared with women (SRR: 1.75, 95% CI: 1.10-2.79). The risk of SCD was highest in residents of the Uyghur (SRR: 1.59, 95% CI: 1.05-2.42) and Kazakh (SRR: 1.92, 95% CI: 1.29-2.87) compared with those of the Han. Poor economic development was associated with elevated risk of SCD (SRR: 1.55, 95% CI: 1.02-2.38). CONCLUSION: SCD is an important public health issue in China. Our understanding of the demographic differences on SCD in Xinjiang, China may improve the risk stratification and management to reduce the incidence and lethality of SCD.

Ethnic differences in sudden cardiac arrest resuscitation.

OBJECTIVE: Ethnic differences in sudden cardiac arrest resuscitation have not been fully explored and studies have yielded inconsistent results. We examined the association of ethnicity with factors affecting sudden cardiac arrest outcomes. METHODS: Retrospective cohort study of 3551 white, 440 black and 297 Asian sudden cardiac arrest cases in Seattle and King County, Washington, USA. RESULTS: Compared with whites, blacks and Asians were younger, had lower socioeconomic status and were more likely to have diabetes, hypertension and end-stage renal disease (all p<0.001). Blacks and Asians were less likely to have a witnessed arrest (whites 57.6%, blacks 52.1%, Asians 46.1%, p<0.001) or receive bystander cardiopulmonary resuscitation (whites 50.9%, blacks 41.4%, Asians 47.1%, p=0.001), but had shorter average emergency medical services response time (mean in minutes: whites 5.18, blacks 4.75, Asians 4.85, p<0.001). Compared with whites, blacks were more likely to be found in pulseless electrical activity (blacks 20.9% vs whites 16.6%, p<0.001), and Asians were more likely to be found in asystole (Asians 41.1% vs whites 30.0%, p<0.001). One of the strongest predictors of resuscitation outcomes was initial cardiac rhythm with 25% of ventricular fibrillation, 4% of patients with pulseless electrical activity and 1% of patients with asystole surviving to hospital discharge (adjusted OR of resuscitation in pulseless electrical activity compared with ventricular fibrillation: 0.30, 95% CI 0.24 to 0.34, p<0.001, adjusted OR of resuscitation in asystole relative to ventricular fibrillation 0.21, 95% CI 0.17 to 0.26, p<0.001). Survival to hospital discharge was similar across all three ethnicities. CONCLUSIONS: While there were differences in some prognostic characteristics between blacks, whites and Asians, we did not detect a significant difference in survival following sudden cardiac arrest between the three ethnic groups. There was, however, an ethnic difference in presenting rhythm, with pulseless electrical activity more prevalent in blacks and asystole more prevalent in Asians.

Primary prevention implantable cardioverter-defibrillators in older racial and ethnic minority patients.

BACKGROUND: Racial and ethnic minorities are under-represented in clinical trials of primary prevention implantable cardioverter-defibrillators (ICDs). This analysis investigates the association between primary prevention ICDs and mortality among Medicare, racial/ethnic minority patients. METHODS AND RESULTS: Data from Get With The Guidelines-Heart Failure Registry and National Cardiovascular Data Registry's ICD Registry were used to perform an adjusted comparative effectiveness analysis of primary prevention ICDs in Medicare, racial/ethnic minority patients (nonwhite race or Hispanic ethnicity). Mortality data were obtained from the Medicare denominator file. The relationship of ICD with survival was compared between minority and white non-Hispanic patients. Our analysis included 852 minority patients, 426 ICD and 426 matched non-ICD patients, and 2070 white non-Hispanic patients (1035 ICD and 1035 matched non-ICD patients). Median follow-up was 3.1 years. Median age was 73 years, and median ejection fraction was 23%. Adjusted 3-year mortality rates for minority ICD and non-ICD patients were 44.9% (95% confidence interval [CI], 44.2%-45.7%) and 54.3% (95% CI, 53.4%-55.1%), respectively (adjusted hazard ratio, 0.79; 95% CI, 0.63-0.98; P=0.034). White non-Hispanic patients receiving an ICD had lower adjusted 3-year mortality rates of 47.8% (95% CI, 47.3%-48.3%) compared with 57.3% (95% CI, 56.8%-57.9%) for those with no ICD (adjusted hazard ratio, 0.75; 95% CI, 0.67%-0.83%; P<0.0001). There was no significant interaction between race/ethnicity and lower mortality risk with ICD (P=0.70). CONCLUSIONS: Primary prevention ICDs are associated with lower mortality in nonwhite and Hispanic patients, similar to that seen in white, non-Hispanic patients. These data support a similar approach to ICD patient selection, regardless of race or ethnicity.

Systematic echocardiography is not efficacious when screening an ethnically diverse cohort of athletes in West Asia.

BACKGROUND: The clinical and economic value of including systematic echocardiography (ECHO) alongside the 12-lead electrocardiograpm (ECG) when undertaking pre-participation screening in athletes has not been examined, yet several sporting organistations recommend its inclusion. DESIGN: To examine the efficacy of systematic ECHO alongside the ECG, to identify sudden cardiac death (SCD) disease and to provide a cost-analysis of a government-funded pre-participation screening programme. METHODS: A total 1628 athletes presented for cardiological consultation, ECG, and ECHO as standard, with further cardiac examinations performed if necessary to confirm or exclude pathology. The efficacy of systematic ECHO was compared to an ECG-led programme, with ECHO reserved as a follow-up examination. RESULTS: To screen 1628 athletes with ECG and ECHO cost US$743,996. There were 54 24-h-blood pressure/ECG Holter recordings, 62 exercise tests, 25 CMRs, two electrophysiological studies, and two genetic tests, which cost US$67,734: total US$811,730. Eight athletes (0.5%) were identified with hypertrophic cardiomyopathy (HCM) and two (0.1%) with Wolff-Parkinson-White syndrome. The cost per identifed athlete was US$81,173. All 10 athletes presented an abnormal ECG. No athlete diagnosed with HCM was identified by ECHO in isolation. When adopting a ECG-led screening protocol, 15% of athletes required ECHO as a follow-up examination, resulting in a US$380,600 cost reduction (47% saving), with the cost per diagnosis reduced to US$43,113. CONCLUSIONS: Athletes diagnosed with a disease associated with SCD were identified via an abnormal ECG and/or physical examination, personal symptoms, or family history. Screening athletes with systematic ECHO is not economically or clinically effective.

Barriers and facilitators to learning and performing cardiopulmonary resuscitation in neighborhoods with low bystander cardiopulmonary resuscitation prevalence and high rates of cardiac arrest in Columbus, OH.

BACKGROUND: Residents who live in neighborhoods that are primarily black, Latino, or poor are more likely to have an out-of-hospital cardiac arrest, less likely to receive cardiopulmonary resuscitation (CPR), and less likely to survive. No prior studies have been conducted to understand the contributing factors that may decrease the likelihood of residents learning and performing CPR in these neighborhoods. The goal of this study was to identify barriers and facilitators to learning and performing CPR in 3 low-income, high-risk, and predominantly black neighborhoods in Columbus, OH. METHODS AND RESULTS: Community-Based Participatory Research approaches were used to develop and conduct 6 focus groups in conjunction with community partners in 3 target high-risk neighborhoods in Columbus, OH, in January to February 2011. Snowball and purposeful sampling, done by community liaisons, was used to recruit participants. Three reviewers analyzed the data in an iterative process to identify recurrent and unifying themes. Three major barriers to learning CPR were identified and included financial, informational, and motivational factors. Four major barriers were identified for performing CPR and included fear of legal consequences, emotional issues, knowledge, and situational concerns. Participants suggested that family/self-preservation, emotional, and economic factors may serve as potential facilitators in increasing the provision of bystander CPR. CONCLUSIONS: The financial cost of CPR training, lack of information, and the fear of risking one's own life must be addressed when designing a community-based CPR educational program. Using data from the community can facilitate improved design and implementation of CPR programs.

Variation in rates of fatal coronary heart disease by neighborhood socioeconomic status: the atherosclerosis risk in communities surveillance (1992-2002).

PURPOSE: Racial and gender disparities in out-of-hospital deaths from coronary heart disease (CHD) have been well-documented, yet disparities by neighborhood socioeconomic status (nSES) have been less systematically studied in US population-based surveillance efforts. METHODS: We examined the association of nSES, classified into tertiles, with 3,743 out-of-hospital fatal CHD events, and a subset of 2,191 events classified as sudden, among persons aged 35 to 74 years in four US communities under surveillance by the Atherosclerosis Risk in Communities (ARIC). Poisson generalized linear mixed models generated age-, race- (white, black) and gender-specific standardized mortality rate ratios and 95% confidence intervals (RR, 95% CI). RESULTS: Regardless of nSES measure used, inverse associations of nSES with all out-of-hospital fatal CHD and sudden fatal CHD were seen in all race-gender groups. The magnitude of these associations was larger among women than men. Further, among blacks, associations of low nSES (vs. high nSES) were stronger for sudden cardiac deaths (SCD) than for all out-of-hospital fatal CHD. CONCLUSIONS: Low nSES was associated with an increased risk of out-of-hospital CHD death and SCD. Measures of the neighborhood context are useful tools in population-based surveillance efforts for documenting and monitoring socioeconomic disparities in mortality over time.

Exclusión social y muerte súbita cardiaca / Social exclusion and sudden cardiac death

Anualmente fallecen en los llamados países del primer mundo de forma inesperada debido a enfermedades del corazón y los vasos sanguíneos, entre 350 000 y 400 000 personas según reportes oficiales. Esto equivale a 1 000 muertes súbitas cada día. La situación de salud en 31 de los 35 países del continente americano, donde las cardiopatías constituyen la primera causa de muerte, no dista mucho de lo observado en Occidente y Estados Unidos y es en general un problema que sigue creciendo. Existen factores de tipo médico que deben ser tomados en cuenta al analizar el comportamiento del fenómeno en cada uno de los países pero existen también factores de índole política de abordaje impostergable para lograr resultados favorables en la disminución de la morbilidad y mortalidad por enfermedades cardiovasculares y finalmente, en la mortalidad súbita. Se profundiza en la vinculación existente entre exclusión social y enfermedad cardiovascular y se plantea la interrogante de si la exclusión social juega un papel determinante en la elevada incidencia de muerte súbita cardiaca en la era actual. La respuesta a esta interrogante solo puede ser encontrada en el sistema económico, político y social que impere en las naciones. Solo globalizando las oportunidades de atención médica, incluyendo a los que tienen poco o nada tienen, no excluyendo, otorgando a todos acceso a las nuevas tecnologías en el campo de la medicina, se puede afrontar el reto del incremento de la pandemia cardiovascular en el siglo XXI y por ende, de la muerte súbita

In the so-called first world countries, 350 000 to 400 000 people die suddenly from heart and blood vessel diseases, according to official data. This means 1000 sudden deaths every day. The health situation in 31 out of the 35 countries in the American continent, where heart diseases are the first cause of death, is not very far from the situation in the United States and the Western nations since this is generally a growing problem. There are some medical factors that should be taken into account when analyzing the behaviour of this phenomenon in each country, but there are also political factors that must be approached to accomplish favourable results in the reduction of morbidity and mortality from cardiovascular diseases and of sudden cardiac mortality. The linking of social exclusion and cardiovascular disease is deeply studied. The answer to the question of whether the social exclusion presently plays a determining role in the high incidence of sudden cardiac death or not can only be found in the economic, political and social system existing in the nations. The globalization of the medical care opportunities by including rather than excluding those who have a little or nothing at all - giving everybody access to the new technologies in the medical field - is the means to face the challenge of the rise of cardiovascular pandemic in the 21st century, and hence, of the sudden death

Disparities in the use of primary prevention and defibrillator therapy among blacks and women.

OBJECTIVES: This study determines whether there are racial or gender disparities in the use of implantable cardioverter-defibrillator therapy for primary prevention of sudden cardiac death. BACKGROUND: Primary prevention of sudden death with implantable cardioverter-defibrillator therapy has been shown to improve survival for high-risk patients with coronary artery disease and left ventricular dysfunction. METHODS: The Center for Medicare and Medicaid Services Medicare database from the year 2002 was used to identify patients who were potential candidates for implantable cardioverter-defibrillator therapy on the basis of a combination of International Classification of Diseases, Ninth Revision, Clinical Modification codes that reflected the presence of an ischemic cardiomyopathy. This cohort was analyzed to determine which patients received implantable cardioverter-defibrillator therapy during the same year. The clinical characteristics of the potential implantable cardioverter-defibrillator candidates were compared with those who actually received an implantable cardioverter-defibrillator. RESULTS: A total 132565 Medicare patients hospitalized during 2002 were identified as having an ischemic cardiomyopathy; 10370 (8%) of these patients underwent implantable cardioverter-defibrillator implantation during the same year. The percentage of patients who underwent implantable cardioverter-defibrillator implantation was higher for men compared with women (10.2% vs 3.5%; P<.001) and whites compared with blacks (8.1 vs 5.4; P<.001). After multivariate analysis, age, gender, and race remained independent predictors of implantable cardioverter-defibrillator implantation. Women with an ischemic cardiomyopathy were 65% less likely to receive implantable cardioverter-defibrillator therapy compared with men (P<.001), and black patients were 31% less likely to receive implantable cardioverter-defibrillator therapy compared with patients of other races (P < .001). CONCLUSIONS: Use of implantable cardioverter-defibrillator therapy for primary prevention of sudden death among the elderly population identified as having an ischemic cardiomyopathy was significantly lower among women compared with men, and among blacks compared with whites. Further exploration of gender and racial barriers to appropriate implantable cardioverter-defibrillator use for primary prevention is needed.