Background:In-hospital cardiac arrest (IHCA) is common, and outcomes vary substantially across US hospitals, but reasons for these differences are largely unknown. We set out to better understand how top-performing hospitals organize their resuscitation teams to achieve high survival rates for IHCA.Methods:We calculated risk-standardized IHCA survival to discharge rates across American Heart Association Get With The Guidelines–Resuscitation registry hospitals between 2012 and 2014. We identified geographically and academically diverse hospitals in the top, middle, and bottom quartiles of survival for IHCA and performed a qualitative study that included site visits with in-depth interviews of clinical and administrative staff at 9 hospitals. With the use of thematic analysis, data were analyzed to identify salient themes of perceived performance by informants.Results:Across 9 hospitals, we interviewed 158 individuals from multiple disciplines including physicians (17.1%), nurses (45.6%), other clinical staff (17.1%), and administration (20.3%). We identified 4 broad themes related to resuscitation teams: (1) team design, (2) team composition and roles, (3) communication and leadership during IHCA, and (4) training and education. Resuscitation teams at top-performing hospitals demonstrated the following features: dedicated or designated resuscitation teams; participation of diverse disciplines as team members during IHCA; clear roles and responsibilities of team members; better communication and leadership during IHCA; and in-depth mock codes.Conclusions:Resuscitation teams at hospitals with high IHCA survival differ from non–top-performing hospitals. Our findings suggest core elements of successful resuscitation teams that are associated with better outcomes and form the basis for future work to improve IHCA.

Background:Genome-wide transcriptome analysis has greatly advanced our understanding of the regulatory networks underlying basic cardiac biology and mechanisms driving disease. However, so far, the resolution of studying gene expression patterns in the adult heart has been limited to the level of extracts from whole tissues. The use of tissue homogenates inherently causes the loss of any information on cellular origin or cell type-specific changes in gene expression. Recent developments in RNA amplification strategies provide a unique opportunity to use small amounts of input RNA for genome-wide sequencing of single cells.Methods:Here, we present a method to obtain high-quality RNA from digested cardiac tissue from adult mice for automated single-cell sequencing of both the healthy and diseased heart.Results:After optimization, we were able to perform single-cell sequencing on adult cardiac tissue under both homeostatic conditions and after ischemic injury. Clustering analysis based on differential gene expression unveiled known and novel markers of all main cardiac cell types. Based on differential gene expression, we could identify multiple subpopulations within a certain cell type. Furthermore, applying single-cell sequencing on both the healthy and injured heart indicated the presence of disease-specific cell subpopulations. As such, we identified cytoskeleton-associated protein 4 as a novel marker for activated fibroblasts that positively correlates with known myofibroblast markers in both mouse and human cardiac tissue. Cytoskeleton-associated protein 4 inhibition in activated fibroblasts treated with transforming growth factor ? triggered a greater increase in the expression of genes related to activated fibroblasts compared with control, suggesting a role of cytoskeleton-associated protein 4 in modulating fibroblast activation in the injured heart.Conclusions:Single-cell sequencing on both the healthy and diseased adult heart allows us to study transcriptomic differences between cardiac cells, as well as cell type-specific changes in gene expression during cardiac disease. This new approach provides a wealth of novel insights into molecular changes that underlie the cellular processes relevant for cardiac biology and pathophysiology. Applying this technology could lead to the discovery of new therapeutic targets relevant for heart disease.

Background:Myeloid-derived suppressor cells (MDSCs) are a heterogeneous population of cells that expand in cancer, inflammation, and infection and negatively regulate inflammation and the immune response. Heart failure (HF) is a complex clinical syndrome wherein inflammation induction and incomplete resolution can potentially contribute to HF development and progression. However, the role of MDSCs in HF remains unclear.Methods:The percentage of MDSCs in patients with HF and in mice with pressure overload–induced HF using isoproterenol infusion or transverse aortic constriction (TAC) was detected by flow cytometry. The effects of MDSCs on isoproterenol- or TAC-induced HF were observed on depleting MDSCs with 5-fluorouracil (50 mg/kg) or gemcitabine (120 mg/kg), transferring purified MDSCs, or enhancing endogenous MDSCs with rapamycin (2 mg·kg?1·d?1). Hypertrophic markers and inflammatory factors were detected by ELISA, real-time polymerase chain reaction, or Western blot. Cardiac functions were determined by echocardiography and hemodynamic analysis.Results:The percentage of human leukocyte antigen-D–related (HLA-DR)?CD33+CD11b+ MDSCs in the blood of patients with HF was significantly increased and positively correlated with disease severity and increased plasma levels of cytokines, including interleukin-6, interleukin-10, and transforming growth factor–?. Furthermore, MDSCs derived from patients with HF inhibited T-cell proliferation and interferon-? secretion. Similar results were observed in TAC- and isoproterenol-induced HF in mice. Pharmaceutical depletion of MDSCs significantly exacerbated isoproterenol- and TAC-induced pathological cardiac remodeling and inflammation, whereas adoptive transfer of MDSCs prominently rescued isoproterenol- and TAC-induced HF. Consistently, administration of rapamycin significantly increased endogenous MDSCs by suppressing their differentiation and improved isoproterenol- and TAC-induced HF, but MDSC depletion mostly blocked beneficial rapamycin-mediated effects. Mechanistically, MDSC-secreted molecules suppressed isoproterenol-induced hypertrophy and proinflammatory gene expression in cardiomyocytes in a coculture system. Neutralization of interleukin-10 blunted both monocytic MDSC- and granulocytic MDSC–mediated anti-inflammatory and antihypertrophic effects, but treatment with a nitric oxide inhibitor only partially blocked the antihypertrophic effect of monocytic MDSCs.Conclusions:Our findings revealed a cardioprotective role of MDSCs in HF by their antihypertrophic effects on cardiomyocytes and anti-inflammatory effects through interleukin-10 and nitric oxide. Pharmacological targeting of MDSCs by rapamycin constitutes a promising therapeutic strategy for HF.

Consistent epidemiological data demonstrate that patients with heart failure with preserved ejection fraction (HFpEF) are more likely to be women than men. Exploring mechanisms behind this sex difference in heart failure epidemiology may enrich the understanding of underlying HFpEF pathophysiology and phenotypes, with the ultimate goal of identifying therapeutic approaches for the broader HFpEF population. In this review we evaluate the influence of sex on the key domains of cardiac structure and function, the systemic and pulmonary circulation, as well as extracardiac factors and comorbidities that may explain the predisposition of women to HFpEF. We highlight the potential role of factors exclusive to or more prevalent in women such as pregnancy, preeclampsia, and iron deficiency. Finally, we discuss existing controversies and gaps in knowledge, as well as the clinical importance of known sex differences in the context of the potential need for sex-specific diagnostic criteria, improved risk stratification models, and targeted therapies.

South Asians (from Bangladesh, Bhutan, India, the Maldives, Nepal, Pakistan, and Sri Lanka) make up one quarter of the world’s population and are one of the fastest-growing ethnic groups in the United States. Although native South Asians share genetic and cultural risk factors with South Asians abroad, South Asians in the United States can differ in socioeconomic status, education, healthcare behaviors, attitudes, and health insurance, which can affect their risk and the treatment and outcomes of atherosclerotic cardiovascular disease (ASCVD). South Asians have higher proportional mortality rates from ASCVD compared with other Asian groups and non-Hispanic whites, in contrast to the finding that Asian Americans (Asian Indian, Chinese, Filipino, Japanese, Korean, and Vietnamese) aggregated as a group are at lower risk of ASCVD, largely because of the lower risk observed in East Asian populations. Literature relevant to South Asian populations regarding demographics and risk factors, health behaviors, and interventions, including physical activity, diet, medications, and community strategies, is summarized. The evidence to date is that the biology of ASCVD is complex but is no different in South Asians than in any other racial/ethnic group. A majority of the risk in South Asians can be explained by the increased prevalence of known risk factors, especially those related to insulin resistance, and no unique risk factors in this population have been found. This scientific statement focuses on how ASCVD risk factors affect the South Asian population in order to make recommendations for clinical strategies to reduce disease and for directions for future research to reduce ASCVD in this population.

Background:Community trends of acute decompensated heart failure (ADHF) in diverse populations may differ by race and sex.Methods:The ARIC study (Atherosclerosis Risk in Communities) sampled heart failure-related hospitalizations (?55 years of age) in 4 US communities from 2005 to 2014 using International Classification of Diseases, Ninth Revision, Clinical Modification codes. ADHF hospitalizations were validated by standardized physician review and computer algorithm, yielding 40?173 events after accounting for sampling design (unweighted n=8746).Results:Of the ADHF hospitalizations, 50% had reduced ejection fraction, and 39% had preserved EF (HFpEF). HF with reduced ejection fraction was more common in black men and white men, whereas HFpEF was most common in white women. Average age-adjusted rates of ADHF were highest in blacks (38.1 per 1000 black men, 30.5 per 1000 black women), with rates differing by HF type and sex. ADHF rates increased over the 10 years (average annual percentage change: black women +4.3%, black men +3.7%, white women +1.9%, white men +2.6%), mostly reflecting more acute HFpEF. Age-adjusted 28-day and 1-year case fatality proportions were ?10% and 30%, respectively, similar across race-sex groups and HF types. Only blacks showed decreased 1-year mortality over time (average annual percentage change: black women –5.4%, black men –4.6%), with rates differing by HF type (average annual percentage change: black women HFpEF –7.1%, black men HF with reduced ejection fraction –4.7%).Conclusions:Between 2005 and 2014, trends in ADHF hospitalizations increased in 4 US communities, primarily driven by acute HFpEF. Survival at 1 year was poor regardless of EF but improved over time for black women and black men.

Background:Late survival and symptomatic status of children with hypertrophic cardiomyopathy have not been well defined. We examined long-term outcomes for pediatric hypertrophic cardiomyopathy.Methods:The National Australian Childhood Cardiomyopathy Study is a longitudinal population-based cohort study of children (0–10 years of age) diagnosed with cardiomyopathy between 1987 and 1996. The primary study end point was time to death or cardiac transplantation.Results:There were 80 patients with hypertrophic cardiomyopathy, with a median age at diagnosis of 0.48 (interquartile range, 0.1, 2.5) years. Freedom from death/transplantation was 86% (95% confidence interval [CI], 77.0–92.0) 1 year after presentation, 80% (95% CI, 69.0–87.0) at 10 years, and 78% (95% CI, 67.0–86.0) at 20 years. From multivariable analyses, risk factors for death/transplantation included symmetrical left ventricular hypertrophy at the time of diagnosis (hazard ratio, 4.20; 95% CI, 1.60–11.05; P=0.004), Noonan syndrome (hazard ratio, 2.88; 95% CI, 1.02–8.08; P=0.045), higher posterior wall thickness z score (hazard ratio, 1.45; 95% CI, 1.22–1.73; P<0.001), and lower fractional shortening z score (hazard ratio, 0.84; 95% CI, 0.74–0.95; P=0.005) during follow-up. Nineteen (23%) subjects underwent left ventricular myectomy. At a median of 15.7 years of follow-up, 27 (42%) of 63 survivors were treated with ?-blocker, and 13 (21%) had an implantable cardioverter-defibrillator.Conclusions:The highest risk of death or transplantation for children with hypertrophic cardiomyopathy is within 1 year after diagnosis, with low attrition rates thereafter. Many subjects receive medical, surgical, or device therapy.