Coronary Heart Disease In African Americans Research Articles

Effects of cardiac rehabilitation with and without meditation on myocardial blood flow using quantitative positron emission tomography: A pilot study

BackgroundPsychosocial stress is recognized as a risk factor for coronary heart disease (CHD). High rates of CHD in African-Americans may be related to psychosocial stress. However, standard cardiac rehabilitation (CR) usually does not include a systematic stress-reduction technique. Previous studies suggest that the Transcendental Meditation (TM) technique may reduce CHD risk factors and clinical events. This pilot study explored the effects of standard CR with and without TM on a measure of CHD in African-American patients. MethodsFifty-six CHD patients were assigned to CR, CR + TM, TM alone, or usual care. Testing was done at baseline and after 12 weeks. The primary outcome was myocardial flow reserve (MFR) assessed by 13N-ammonia positron emission tomography (PET). Secondary outcomes were CHD risk factors. Based on guidelines for analysis of small pilot studies, data were analyzed for effect size (ES). ResultsFor 37 patients who completed posttesting, there were MFR improvements in the CR + TM group (+20.7%; ES = 0.64) and the TM group alone (+12.8%; ES = 0.36). By comparison, the CR-alone and usual care groups showed modest changes (+ 5.8%; ES = 0.17 and − 10.3%; ES = − 0.31), respectively. For the combined TM group, MFR increased (+ 14%, ES = 0.56) compared to the combined non-TM group (− 2.0%, ES = − 0.08). ConclusionsThese pilot data suggest that adding the TM technique to standard cardiac rehabilitation or using TM alone may improve the myocardial flow reserve in African-American CHD patients. These results may be applied to the design of controlled clinical trials to definitively test these effects. Trial registrationClinicalTrials.gov registration # NCT01810029.

Physical Activity, Inflammation, Coronary Artery Calcification, and Incident Coronary Heart Disease in African Americans: Insights From the Jackson Heart Study

ObjectiveTo examine associations between physical activity (PA), inflammation, coronary artery calcification (CAC), and incident coronary heart disease (CHD) in African Americans. MethodsAmong Jackson Heart Study participants without prevalent CHD at baseline (n=4295), we examined the relationships between PA and high-sensitivity C-reactive protein, the presence of CAC (Agatston score ≥100), and incident CHD. Based on the American Heart Association’s Life’s Simple 7 metrics, participants were classified as having poor, intermediate, or ideal PA. ResultsAfter adjustment for possible confounding factors, ideal PA was associated with lower high-sensitivity C-reactive protein levels (β, −0.15; 95% CI, −0.15 to −0.002) and a lower prevalence of CAC (odds ratio, 0.70; 95% CI, 0.51-0.96) compared with poor PA. During a median of 12.8 years of follow-up, there were 164 incident CHD events (3.3/1000 person-years). Ideal PA was associated with a lower rate of incident CHD compared with poor PA (hazard ratio, 0.55; 95% CI, 0.31-0.98). ConclusionIn a large community-based African American cohort, ideal PA was associated with lower inflammation levels, a lower prevalence of CAC, and a lower rate of incident CHD. These findings suggest that promotion of ideal PA may be an important way to reduce the risk of subclinical and future clinical CHD in African Americans.

Genome-wide association study of coronary heart disease and its risk factors in 8,090 African Americans: the NHLBI CARe Project.

Coronary heart disease (CHD) is the leading cause of mortality in African Americans. To identify common genetic polymorphisms associated with CHD and its risk factors (LDL- and HDL-cholesterol (LDL-C and HDL-C), hypertension, smoking, and type-2 diabetes) in individuals of African ancestry, we performed a genome-wide association study (GWAS) in 8,090 African Americans from five population-based cohorts. We replicated 17 loci previously associated with CHD or its risk factors in Caucasians. For five of these regions (CHD: CDKN2A/CDKN2B; HDL-C: FADS1-3, PLTP, LPL, and ABCA1), we could leverage the distinct linkage disequilibrium (LD) patterns in African Americans to identify DNA polymorphisms more strongly associated with the phenotypes than the previously reported index SNPs found in Caucasian populations. We also developed a new approach for association testing in admixed populations that uses allelic and local ancestry variation. Using this method, we discovered several loci that would have been missed using the basic allelic and global ancestry information only. Our conclusions suggest that no major loci uniquely explain the high prevalence of CHD in African Americans. Our project has developed resources and methods that address both admixture- and SNP-association to maximize power for genetic discovery in even larger African-American consortia.

Association of Glycemic Index and Glycemic Load With Risk of Incident Coronary Heart Disease Among Whites and African Americans With and Without Type 2 Diabetes: The Atherosclerosis Risk in Communities Study

In this study we examined whether high glycemic index (GI) and glycemic load (GL) diets are associated with increased risk of developing coronary heart disease (CHD) in Whites and African Americans with and without type 2 diabetes. Data on 13,051 patients ages 45 to 64 years from the Atherosclerosis Risk in Communities study were analyzed. The ARIC food frequency questionnaire baseline data provided GI and GL indices. A propensity score was created to estimate the effect of a patient's covariates on energy-adjusted GI or GL. During a maximum of 17 years of follow-up, 1683 cases of CHD (371 with diabetes and 1312 without diabetes) were recorded. For every 5-units increase in GI, there was a 1.16-fold (95% confidence interval [95% CI], 1.01-1.33) increased risk of incident CHD in African Americans. For every 30-units increase in GL, there was a 1.11-fold (95% CI, 1.01-1.21) increased risk of incident CHD in Whites. High GL was an especially important CHD risk factor for Whites without diabetes (per 30-units increase; hazard ratio, 1.14; 95% CI, 1.02-1.26). However, these relationships were not seen in individuals with diabetes. Nutritional advice to reduce the GI and GL in diets of African Americans and Whites subjects (without diabetes) may play a role in reducing CHD risk.

CYP2J2 and CYP2C8 polymorphisms and coronary heart disease risk: the Atherosclerosis Risk in Communities (ARIC) study

The cytochromes P450 epoxygenases CYP2J2 and CYP2C8 synthesize epoxyeicosatrienoic acids, which regulate endothelial function. We sought to determine if genetic variation in CYP2J2 and CYP2C8 was associated with coronary heart disease risk. We genotyped 2065 Atherosclerosis Risk in Communities study participants (1085 incident coronary heart disease cases, 980 noncases) for polymorphisms in CYP2J2 and CYP2C8. Using a case-cohort design, associations between genotype and incident coronary heart disease risk were evaluated using proportional hazards regression. The influence of cigarette smoking on these associations was also evaluated. False discovery rate q-values were estimated to minimize the impact of the multiple statistical comparisons completed. All analyses were race stratified. The CYP2J2 G-50T polymorphism variant -50T allele was associated with significantly lower risk of incident coronary heart disease in African-Americans (adjusted hazard rate ratio 0.58, 95% confidence interval 0.35-0.96, P=0.036, q=0.051); however, no significant association was observed in Caucasians. Overall, the I264M, I269F, and K399R polymorphisms in CYP2C8 were not significantly associated with risk of incident coronary heart disease. In Caucasians, the relationship between the I264M and K399R polymorphisms and incident coronary heart disease risk was significantly modified by cigarette smoking status (P for interaction=0.008, q=0.064), with the highest risk observed in smokers carrying at least one variant allele. The G-50T polymorphism in CYP2J2 may be an important risk factor for the development of coronary heart disease events in African-Americans, whereas cigarette smoking may modify the relationship between the I264M and K399R polymorphisms in CYP2C8 and coronary heart disease risk in Caucasians. Confirmation of these findings in an independent population is warranted.

Relation of aortic valve sclerosis to risk of coronary heart disease in African-Americans

To assess the relation between aortic valve sclerosis (AVS) and subsequent occurrence of coronary heart disease (CHD) events, we analyzed echocardiographic data obtained from 2,279 middle-aged African-Americans enrolled in the Jackson Mississippi Atherosclerosis Risk in Communities study cohort who were free of known CHD at the time of the examination. Cox regression analyses demonstrated a hazard ratio of 3.8 for incident first myocardial infarction or fatal CHD after adjusted for multiple risk factors, including markers of inflammation. An amplification of CHD risk in the AVS subgroup with high levels of serum inflammatory markers (the highest quartile of fibrinogen and von Willebrand Factor levels) demonstrated greater than fivefold higher risk of CHD associated with AVS than risk in the lowest quartile.

No Protective Effect of Alcohol Consumption on Coronary Heart Disease (CHD) in African Americans: Average Volume of Drinking over the Life Course and CHD Morbidity and Mortality in a U.S. National Cohort

The association between average volume of drinking and coronary heart disease (CHD) morbidity and mortality in African Americans compared with whites was explored, based on a representative US sample. A prospective cohort study with interview follow-up after 10 years and outcome follow-up over about 15 years was used. The sample consisted of 1,158 African Americans and 6,607 whites, all 40 years of age and older with no history of heart disease at baseline. Alcohol intake was measured with a quantity-frequency measure. Incidence of CHD was the sum of non-fatal and fatal events as determined from hospital records and death certificates. The event with the earliest date was defined as the incident event. With respect to CHD, African Americans showed markedly higher risks and significantly fewer protective effects compared with whites. Thus the cardioprotective effects of alcohol were not present in a representative sample of African Americans. On the contrary: Moderate to high average volume of alcohol was associated with increased risk of CHD in African Americans. Patterns of drinking as a potential cause for this finding are discussed.

Coronary heart disease in African Americans.

African Americans have the highest overall mortality rate from coronary heart disease (CHD) of any ethnic group in the United States, particularly out-of-hospital deaths, and especially at younger ages. Although all of the reasons for the excess CHD mortality among African Americans have not been elucidated, it is clear that there is a high prevalence of certain coronary risk factors, delay in the recognition and treatment of high-risk individuals, and limited access to cardiovascular care. The clinical spectrum of acute and chronic CHD in African Americans is similar to that in whites. However, African Americans have a higher risk of sudden cardiac death and present more often with unstable angina and non-Q-wave myocardial infarction than whites. African Americans have less obstructive coronary artery disease on angiography, but may have a similar or greater total burden of coronary atherosclerosis. Ethnic differences in the clinical manifestations of CHD may be explained largely by the inherent heterogeneity of the coronary syndromes, and the disproportionately high prevalence and severity of hypertension and type 2 diabetes in African Americans. Identification of high-risk individuals for vigorous risk factor modification-especially control of hypertension, regression of left ventricular hypertrophy, control of diabetes, treatment of dyslipidemia, and smoking cessation--is key for successful risk reduction.

Prediction of coronary heart disease in African-Americans and whites using multiple-risk-factor assessment equations Herbert J. Marx, Henry F. C. Weil, Thomas A. Pearson, Edward F. Philbin, Tara A. Erb, Paul L. Jenkins, Charles K. Francis, Roberta G. Reed. Mary Imogene Bassett Hospital, Cooperstown, NY, Harlem Hospital, New York City, NY

Prediction of coronary heart disease in African-Americans and whites using multiple-risk-factor assessment equations Herbert J. Marx, Henry F. C. Weil, Thomas A. Pearson, Edward F. Philbin, Tara A. Erb, Paul L. Jenkins, Charles K. Francis, Roberta G. Reed. Mary Imogene Bassett Hospital, Cooperstown, NY, Harlem Hospital, New York City, NY

Family risk score of coronary heart disease (CHD) as a predictor of CHD: the Atherosclerosis Risk in Communities (ARIC) study and the NHLBI family heart study.

Family history of coronary heart disease (CHD) has been found to be a risk factor for CHD in numerous studies. Few studies have addressed whether a quantitative measure of family history of CHD (family risk score, FRS) predicts CHD in African Americans. This study assessed the association between FRS and incident CHD of participants, and the variation of the association by gender and race. Participants in the study were a biracial population-based cohort with 3,958 African Americans and 10,580 Whites aged 45-64 years old in the ARIC baseline survey (1987-1989). They were randomly selected from four U. S. communities. During follow-up (1987-1993), 352 participants experienced the onset of CHD. Incidence density of CHD (per 1,000 person-years) was 7.8 and 3.6 among African-American men (AAM) and women (AAW), and 7.2 and 2.2 among White men (WM) and women (WW). The hazard rate ratio (HRR) of CHD associated with one standard deviation increase of FRS was 1.52 in AAW, 1.46 in AAM, 1.41 in WW, and 1.68 in WM. The HRRs decreased 4.6% in AAW, 1.4% in WW, 5.7% in AAM, and 3.0% in WM, but increased 2.1% in AAM after adjustment for selected covariates. FRS predicts incident CHD in African Americans and Whites, men and women. The relation of FRS to incident CHD can be only partially explained by the selected risk factors in the biological causal pathways: IMT, T-G, LDL, HDL, Lp(a), fibrinogen and hypertension. No significant difference by race has been found in this study.