Living Arrangement: a Contributor to Vascular Disease in Asymptomatic African American Women.

BACKGROUND: Diminished social support lias shown to lead to worse cardiovascular outcomes and since cardiovascular disease (CVD) is the leading cause of death in the United States (U.S.), it is critical to non-invasively study its precursor- vascular disease (VD). Assessing the impact social support lias on vascular outcomes can unveil potential CVD susceptibilities in at-risk populations. African American women exhibit the greatest burden of CVD morbidity and mortality; therefore, the purpose of tins study is to examine the association between living arrangement/social support and impaired vascular function in asymptomatic African American women. METHODS: Vascular function was assessed by a non-invasive screening tool, HDI/PulseWave CR-2000, during screenings at community outreach events on participants clinically free of CVD. Vascular disease was defined as abnormal/impaired vascular function. Living arrangement, a binary variable (living with someone/living alone), was determined by survey responses (N=67) and represented social support. Multivariable analyses were used to estimate adjusted odds ratios (AORs) and 95% confidence intervals (95% CIs) to determine the association between living arrangement and vascular disease after controlling for confounders. Analyses were conducted using SAS 9.2. RESULTS: Of those who lived alone, 82% had vascular disease (p=0.03). After adjusting for family CVD, and other CVD risk factors, those who lived with a spouse/partner or relative were 78% (p=0.04) less likely to develop vascular disease (AOR=0.22; 95% 0=0.05, 0.98). CONCLUSIONS: Our study provides preliminary evidence to suggest that among African American women, clinically free of CVD, living arrangement is associated with vascular disease. While living alone may place individuals at an increased risk of CVD because of the association, living with a spouse/partner or relative may act as a protective factor against vascular disease and reduce the risk of CVD. Public health practitioners may use individuals' living arrangement as preventive measure for CVD risk.

Risk factors for acute non-ST-segment elevation myocardial infarction in a population sample of predominantly African American patients with chest pain and normal coronary arteries.

BACKGROUND: We sought to investigate the relationship between echocardiographic left ventricular hypertrophy (LVH) and acute non-ST-elevation segment myocardial infarction (NSTE-MI) in patients with chest pain and angiographically normal coronary arteries. METHODS: Retrospective analysis of patients admitted for acute chest pain in a large urban hospital serving predominantly African American patients. RESULTS: 131 (of 700) patients had normal coronary arteries or only minimal luminal irregularities (ie, <10% luminal narrowing) on cardiac angiography and available cardiac biomarker data to define the presence or absence of MI. Mean age was 53 +/- 10 years, 76% were African Americans, 88% had a history of hypertension (49% uncontrolled) and 74% had LVH by echocardiography. Of these 131 patients, 22 (17%) had an acute NSTE-MI by creatine kinase MB criteria. The mean systolic blood pressure (BP) was significantly higher in patients with NSTE-MI compared with non-NSTE-MI group (156 +/- 30 vs 143 +/- 25 mm Hg, P=.04). Patients with NSTE-MI were more likely to have LVH (95% vs 70%, P=.03). NSTE-MI was present in 22% of patients with LVH compared with 3% without LVH (P=.02). The in-hospital course of NSTE-MI patients with LVH was not benign: 19% had persistent angina and positive stress thallium suggestive of recurrent myocardial ischemia and 48% had congestive heart failure. The results of multivariable model after adjusting for selected variables revealed that these two preexisting conditions were independently associated with NSTE-MI: LVH (OR=4.0, CI 1.06-10.05) and elevated systolic BP (OR=3.7, CI 1.01-10.64). CONCLUSION: These findings provide preliminary evidence that LVH and uncontrolled hypertension predispose to NSTE-MI in this patient group.

From hypertension to heart failure: role of nitric oxide-mediated endothelial dysfunction and emerging insights from myocardial contrast echocardiography.

There is growing evidence that nitric oxide (NO)-mediated endothelial dysfunction occurs in hypertension and may represent the earliest stage of target organ damage, which ultimately leads to hypertensive heart disease and heart failure (HF). An understanding of how impaired myocardial microvascular function and flow reserve relate to early remodeling during the transition to HF in patients with hypertension may lead to new therapeutic insights. The hypertrophied heart, which is a feature of the adverse structural remodeling in hypertensive heart disease, may be accompanied by impaired coronary flow reserve (CFR). Reduced CFR could potentially cause subendocardial ischemia during conditions of high metabolic demand, such as uncontrolled hypertension and tachycardia. Such vulnerability of the subendocardium to abnormal perfusion or ischemia may accelerate the progression from compensated hypertrophy to HF. In this review, we discuss preliminary evidence that altered NO balance may contribute to cardiac hypertrophy-mediated myocardial ischemia. We also describe early results with myocardial contrast echocardiography in the postulated transition from compensated hypertrophy to cardiac failure. These data support further evaluation of NO mediators as potential targets for novel therapies in hypertensive heart disease.

Comparative frequency of angiographic coronary artery disease in African Americans and Hispanics.

BACKGROUND: African Americans and Hispanics are the two largest racial minority groups in the United States. Both groups have a high prevalence of cardiovascular disease risk factors, and African Americans have the highest mortality from cardiovascular disease of any racial group in the United States. Whereas a large body of clinical data compares African Americans and Whites or Hispanics and Whites with regard to coronary artery disease (CAD), limited data are available for such comparison between African Americans and Hispanics. METHODS AND RESULTS: We retrospectively reviewed the angiographic and clinical data of 480 consecutive patients who underwent coronary angiography for suspected CAD in an inner city hospital between January 1997 and December 1998 in order to ascertain the frequency of CAD. One hundred eighty-nine (189) African Americans and 163 Hispanics met the inclusion criteria. The mean ages of African-American and Hispanic patients were similar, 56.3 +/- 10.9 years vs 55.6 +/- 11.4 years, respectively, P=.59. The frequency of angiographic CAD was 56.6% for African Americans and 54.6% for Hispanics, odds ratio [OR] 0.92, 95% confidence interval [CI] 0.60-1.41, P=.71). Coronary artery disease (CAD) involving the left anterior descending coronary artery occurred significantly more in Hispanic compared to African-American patients (44.8% vs 33.7%, OR 1.58, 95% CI 1.03-2.44, P=.04). Coronary artery disease (CAD) risk factors occurred more in Hispanics compared to African Americans. CONCLUSION: The frequency of angiographic CAD was not different for African-American and Hispanic patients (56.6% vs 54.6%, OR 0.92, 95% CI 0.60-1.41, P=.71) even though differences were seen in CAD risk factors.

Morehouse Community Physicians Network (CPN) hypertension registry: patterns of care and opportunities for targeted medical education.

BACKGROUND: Provider-focused strategies for improving outcomes in hypertension have produced mixed results. Studies suggest that the effectiveness of a chosen strategy increases when it is tailored to the specific situation. The hypertension registry includes data on African-American hypertensives who receive care in community-based primary care settings. We examined the registry to identify patterns of care and opportunities for provider-focused interventions to improve patient outcomes. METHODS AND RESULTS: The registry will include all records of hypertensive patients from 50 community-based primary care practices at full enrollment. Data from nine practices were manually abstracted into an electronic database and analyzed. Seven hundred and ten records were included in this report. Approximately 70% are female, average age 47 +/- 13 years, 5.3% are uninsured, and more than 60% have at least a high school education. Registry patients have multiple co-morbid conditions: 28% are diabetic, 8% have left ventricular hypertrophy, 5% have congestive heart failure, 6.5% have renal insufficiency, 5% have cerebrovascular disease, 3.5% have previous myocardial infarction and 2% have peripheral vascular disease. Among those with diabetes, mean glycosylated hemoglobin was 7.4 +/- 2. Pattern of antihypertensive use showed 43% on diuretics, 28% on calcium channel blockers, 24% on angiotensin converting enzyme inhibitors, 20% on beta blockers and 16% on angiotensin receptor blockers. Overall, 37% were at goal blood pressure and among those with diabetes, only 16% reached goal blood pressure. CONCLUSION: We conclude that the blood pressure control rates of African Americans in the registry trail those of the general population. This provides a unique opportunity to study the underlying factors and design tailored interventions to address this disparity in health outcome.

The Community Physicians' Network (CPN): an academic-community partnership to eliminate healthcare disparities.

INTRODUCTION: Disparities in health care are maintained by three primary factors: 1) patient factors which include multiple risk factors and comorbidities; 2) healthcare practitioner factors comprising inconsistent application of practice guidelines due to a limited database of clinical trials of effective therapies in African Americans and other underrepresented minorities; and 3) barriers in the healthcare delivery system resulting in poor access to care. The Morehouse School of Medicine Community Physicians' Network (CPN) was established to address disparities in health care by focusing on provider-specific strategies. OBJECTIVES: To: 1) use disease-specific registries to identify treatment gaps and facilitate quality improvement processes among CPN practices; 2) develop practice-specific and guideline-based educational messages to promote quality care; 3) engage and train CPN-physicians for participation in approved NIH, other government, and industry-supported clinical protocols; and 4) develop a data repository of all CPN-sponsored clinical trials that include significant numbers of African Americans and other underrepresented minorities. METHODS: The disease-specific outpatient registries will have the following features: 1) data structures and data elements will use standard database codes and a data dictionary; 2) HIPPA-compliant data abstraction and data transfer tool; 3) baseline chart review to establish practice patterns and provide practice-specific feedback; 4) annual update of registry; 5) data registry and repository maintained on Morehouse School of Medicine's secure servers; 6) registry publications will include only aggregate data, without identification of contributing practices; 7) an electronic medical records platform will be encouraged as the ultimate data management tool for CPN practices. In addition, up to three continuing medical education (CME) programs each year will feature national speakers and promote evidence-based practice guidelines. RESULTS: Eighty-five primary care and subspecialty practices are actively enrolled in CPN with a total of 385,000 annual outpatient visits. The makeup of insurance status is: HMO/PPO (45%); Medicare only (19%); Medicare HMO (11%); Medicare plus (8%); Medicaid (6%); Uninsured (11%). CONCLUSIONS: The Community Physicians' Network will address specific gaps in the health care of African-American and other minority patients by promoting quality care among its members and by facilitating participation in approved clinical trial protocols. The unique academic community partnership is consistent with the NIH roadmap goal of eliminating healthcare disparities.

The prevalence of cognitive impairment among African-American patients with congestive heart failure.

This cross-sectional study sought to determine the prevalence of cognitive impairment among African-American patients with congestive heart failure (CHF). We studied 100 African-American CHF patients (aged 55-87 years) in New York Heart Association classes II-IV, who are enrolled in an ongoing, randomized, controlled trial, evaluating the effectiveness of a telemonitoring intervention to improve access to ambulatory care for heart failure patients. These CHF patients were recruited from an inner-city practice, rural physician practices and an urban physician practice in Atlanta. The Mini-Mental Status Examination (MMSE) was used to measure cognition. Cognitive impairment was defined as a MMSE score of less than 24. The crude prevalence of cognitive impairment was 10% in this population of African Americans with CHF. The results of multivariate logistic regression analysis indicated an increase in odds of cognitive impairment with increasing age [odds ratio (OR) = 1.10 and 95% confidence interval, 1.00-1.20; p=0.042]. There was no significant relationship between cognitive impairment and gender, education status, depression and severity of CHF. This study indicates that cognitive impairment is relatively prevalent among African Americans with CHF, but lower than previously reported among Caucasians with CHF.

The 894T allele of endothelial nitric oxide synthase gene is related to left ventricular mass in African Americans with high-normal blood pressure.

BACKGROUND AND OBJECTIVES: The 894T allele in exon 7 of the endothelial nitric oxide synthase (eNOS) gene has been inconsistently associated with hypertension in different racial groups. Because high-normal blood pressure (BP) confers an increased risk for the development of hypertension and other cardiovascular disorders, including left ventricular hypertrophy (LVH), we tested the hypothesis that the allelic variation (894T) in the eNOS gene would directly correlate with alterations in LV mass (LVM) in individuals with high-normal BP. METHODS: Genotype distribution of G894T was compared between 20 African Americans (10 females/10 males) with high-normal BP (systolic BP of 130-139 and/or diastolic BP of 85-89 mmHg) and 64 counterparts (37 females/27 males) with normal BP (<130/85 mmHg). Echocardiographic LVM was calculated (Devereux formula) and indexed to body surface area to define the presence of LVH (LVMI >134/110 g/m2 for men/women). RESULTS: For the entire group, the 894T allelic frequencies (15, 48%) and G894T genotype distributions were consistent with the Hardy-Weinberg equilibrium expectations (estimated disequilibrium coefficient = 0.0118, P=0.40). LVMI was significantly higher in homozygous carriers (TT) of the rare 894T allele (n = 3 females/0 males) than in heterozygous GT (n = 13 females/7 males) and individuals bearing the GG (n=34 females/27 males) variant (124 +/- 70 vs. 82 +/- 24 and 82 +/- 19 g/m2, respectively, P < 0.05). The observed relationship between eNOS 894T allele and LVMI was restricted to individuals with high-normal BP (r = 0.94, P = 0.03) but not in those with normal BP (r = 0.39, P =0.64), by analysis of variance (ANOVA) after adjusting for age, gender, body mass index, smoking and systolic BP. CONCLUSION: These findings, not previously described, provide important preliminary evidence to suggest an increased susceptibility to LVH in African Americans who carry the 894T variant of the eNOS gene and have high-normal blood pressure.

Relation of endothelial nitric oxide synthase gene to plasma nitric oxide level, endothelial function, and blood pressure in African Americans.

BACKGROUND: The role of eNOS gene polymorphisms on plasma nitrite or nitrate (NOx) level, endothelial function, and blood pressure (BP) remains unclear. METHODS: We estimated the relationship of eNOS polymorphisms (the T(-786)C in the 5'-flanking promoter region, T(-786)C; 27-bp repeat in intron 4, eNOS4; and Glu298Asp in exon 7, G894T) with plasma NOx level, brachial endothelial function assessed by ultrasound measure of brachial artery flow-mediated dilation (FMD), and BP in 60 healthy African Americans, 30 men and 30 women aged 18 to 73 years. RESULTS: Among them, 73.1%, 23.9%, and 3.0% carried TT, TC, and CC of T(-786)C, respectively, 14.5%, 27.5%, 53.6%, and 1.4% carried aa, ab, bb, and bc of eNOS4 polymorphism, respectively, and 70.4%, 23.9%, and 5.6% carried GG, GT, and TT of G894T, respectively. G894T and eNOS4 were observed in linkage disequilibrium. Mean values of age, plasma NOx, FMD, systolic and diastolic BPs were not significantly different (P >.05) by eNOS polymorphisms. Plasma NO(x) level was found to be associated with systolic BP (r = 0.51, P =.03), and diastolic BP (r = 0.41, P =.08), but not with FMD, in individuals with "a" allele of eNOS4 polymorphism after adjustment for age, body mass index, serum glucose, and smoking status. CONCLUSIONS: We reveal a positive association between plasma NOx level and BP in normotensive African Americans who carry the "a" allele of eNOS4. Because the frequency of the rare allele "a" is significantly higher in African Americans than in other ethnic groups, this finding may provide a clue to understanding the genetic susceptibility to hypertension in African Americans.

Diastolic heart failure: the forgotten manifestation of hypertensive heart disease.

Heart failure (HF) is a progressively debilitating disorder characterized by frequent hospital admissions and high annual mortality rates. Coronary artery disease (CAD), hypertension, and aging are major risk factors for the development/progression of HF. For years, most of the attention has been focused on HF caused by reduced left ventricular (LV) systolic function, largely attributable to CAD. It is now generally accepted that nearly 50% of elderly patients with HF might have normal or preserved LV systolic function. This condition is commonly referred to as a distinct type of HF caused by LV diastolic dysfunction, and it often accompanies hypertensive heart disease. Isolated diastolic HF is increasingly recognized as the dominant cause of symptoms and hospitalizations from HF in a large proportion of individuals aged 65 and older. However, the clinicians caring for patients with diastolic HF do not fully understand its cause, how it progresses, or how it could be appropriately diagnosed and treated. Because varying degrees of systolic and diastolic dysfunction might coexist in any individual patient, and given the limitation of current diagnostic tools, the overall impact of isolated diastolic HF continues to evolve. Ongoing clinical trials are testing new strategies for treatment of diastolic HF.

Contribution of exercise-induced mitral regurgitation to exercise stroke volume and exercise capacity in patients with left ventricular systolic dysfunction.

BACKGROUND: Functional mitral regurgitation (MR) is common in patients with heart failure and left ventricular (LV) dysfunction, and its severity may vary over time, depending primarily on the loading conditions. Because dynamic changes in the severity of functional MR may affect forward stroke volume, we hypothesized that exercise-induced changes in MR severity influence the stroke volume response of patients with LV dysfunction to exercise, and hence their exercise capacity. METHODS AND RESULTS: Heart failure patients (n=25; mean age 53+/-12 years) with LV dysfunction underwent dynamic bicycle exercise at steady-state levels of 30%, 60%, and 90% of predetermined peak VO2. During each exercise level, right heart pressures, cardiac output, VO2, and MR severity were measured simultaneously. During exercise, MR severity, as evaluated by the ratio of MR jet over left atrium area, increased from 15+/-8% to 33+/-15%. Peak VO2, exercise-induced changes in stroke volume, and those in capillary wedge pressure correlated with the changes in MR (r=-0.55, -0.87, and 0.62, respectively, P<0.01). The changes in MR severity also correlated with those in end-diastolic (r=-0.75, P<0.01) and end-systolic (r=-0.72, P<0.01) sphericity indexes and those in the coaptation distance (r=0.86, P<0.01). CONCLUSIONS: Our data indicate that in patients with LV dysfunction, exercise-induced changes in MR severity limit the stroke volume adaptation during exercise and therefore contribute to limitation of exercise capacity.