African American-Caucasian American differences in aortic valve replacement in patients with severe aortic stenosis.

BACKGROUND: Among patients with severe aortic stenosis (AS), there are limited data on aortic valve replacement (AVR), reasons for nonreceipt and mortality by race. METHODS: Utilizing the Duke Echocardiography Laboratory Database, we analyzed data from 110,711 patients who underwent echocardiography at Duke University Medical Center between 1999 and 2013. We identified 1,111 patients with severe AS who met ≥1 of 3 criteria for AVR: ejection fraction ≤50%, diagnosis of heart failure, or need for coronary artery bypass surgery. Logistic regression models were used to assess the association between race, AVR and 1-year mortality. χ2 testing was used to assess potential racial differences in reasons for AVR nonreceipt. RESULTS: Among the 1,111 patients (143 AA and 968 CA) eligible for AVR, AA were more often women, had more diabetes, renal insufficiency, aortic regurgitation and left ventricular hypertrophy. CA were more often smokers, had more ischemic heart disease, hyperlipidemia and higher median income levels. There were no racial differences in surgical risk utilizing logistic euroSCORES. Relative to CA, AA had lower rates of AVR (adjusted odds ratio 0.46, 95% CI 0.3-0.71, P < .001) yet similar 1-year mortality (aHR 0.81, 95% CI 0.57-1.17, P = .262). There were no significant differences in reasons for AVR nonreceipt. CONCLUSIONS: We identified 143 African Americans (AA) and 968 Caucasian Americans(CA) with severe AS who met prespecified criteria for AVR.. AA relative to CA were more often women, had more diabetes, renal insufficiency, and left ventricular hypertrophy, however had less tobacco use, ischemic heart disease, hyperlipidemia and lower median income levels. Among patients with severe AS, AA relative to CA had lower rates of AVR (adjusted odds ratio 0.46, 95% CI 0.3-0.71, P < .001) without significant differences in reasons for AVR nonreceipt and similar 1-year mortality.

Exogenous GDF11, but not GDF8, reduces body weight and improves glucose homeostasis in mice.

Insulin resistance is associated with aging in mice and humans. We have previously shown that administration of recombinant GDF11 (rGDF11) to aged mice alters aging phenotypes in the brain, skeletal muscle, and heart. While the closely related protein GDF8 has a role in metabolism, limited data are available on the potential metabolic effects of GDF11 or GDF8 in aging. To determine the metabolic effects of these two ligands, we administered rGDF11 or rGDF8 protein to young or aged mice fed a standard chow diet, short-term high-fat diet (HFD), or long-term HFD. Under nearly all of these diet conditions, administration of exogenous rGDF11 reduced body weight by 3-17% and significantly improved glucose tolerance in aged mice fed a chow (~30% vs. saline) or HF (~50% vs. saline) diet and young mice fed a HFD (~30%). On the other hand, exogenous rGDF8 showed signifcantly lesser effect or no effect at all on glucose tolerance compared to rGDF11, consistent with data demonstrating that GFD11 is a more potent signaling ligand than GDF8. Collectively, our results show that administration of exogenous rGDF11, but not rGDF8, can reduce diet-induced weight gain and improve metabolic homeostasis.

Racial and Ethnic Differences in Treatment and Outcomes of Severe Aortic Stenosis: A Review.

Aortic stenosis (AS) is among the most common valvular heart diseases encountered in the United States. In this review the authors examine differences between racial and ethnic groups in the epidemiology and management of severe AS, explore potential explanations for these findings, and discuss the implications for improving the delivery of care to racially and ethnically diverse populations. Underrepresented racial and ethnic groups experience a paradoxically lower prevalence or incidence of AS relative to white subjects, despite having a higher prevalence of traditional risk factors. Historically, UREGs with severe AS have had lower rates of both surgical and transcatheter aortic valve replacement and experienced more post-surgical complications, including, bleeding, worsening heart failure, and rehospitalization. Last, UREGs with severe AS have an increased risk for morbidity and mortality relative to white patients. To date much of the research on AS has examined black-white differences, so there is a need to understand how other racial and ethnic groups with severe AS are diagnosed and treated, with examination of their resulting outcomes. Overall, racial and ethnic disparities in health care access and care delivery are a public health concern given the changing demographics of the U.S. population. These differences in AS management and outcomes highlight the need for additional research into contributing factors and appropriate interventions to address the lower rates of aortic valve replacement and higher morbidity and mortality among UREGs.