A novel variant in the platelet endothelial aggregation receptor-1 gene is associated with increased platelet aggregability

OBJECTIVE

Platelet endothelial aggregation receptor-1 (PEAR1) is a recently identified platelet transmembrane protein that becomes activated by platelet contact. We looked for novel genetic variants in PEAR1 and studied their association with agonist-induced native platelet aggregation and with the inhibitory effect of aspirin on platelets.

METHODS AND RESULTS

We genotyped PEAR1 for 10 single nucleotide polymorphisms (SNPs), selected for optimal gene coverage at a density of 4 kb, in 1486 apparently healthy individuals from two generations of families with premature CAD. Subjects had a mean age of 45 years; 62% were white and 38% black. Platelet aggregation to collagen, epinephrine, and ADP was measured in platelet rich plasma, at baseline and after 2 weeks of aspirin (ASA, 81 mg/d), and genotype-phenotype associations were examined separately by ethnicity using multivariable generalized linear models adjusted for covariates. The C allele of SNP rs2768759 [A/C], located in the promoter region of the gene, was common in whites and uncommon in blacks (allele frequency 70.2% versus 17.7%). The C allele was generally associated in both ethnic groups with increased aggregation of native platelets to each agonist. After ASA, the associations were stronger and more consistent and remained significant when post-ASA aggregation was adjusted for baseline aggregation, consistent with a relationship between the C allele and reduced platelet responsiveness to ASA. The PEAR1 SNP explained up to 6.9% of the locus specific genetic variance in blacks and up to 2.5% of the genetic variance in whites after ASA.

CONCLUSIONS

PEAR1 appears to play an important role in agonist-induced platelet aggregation and in the response to ASA in both whites and blacks.

Platelet inhibition by aspirin 81 and 325 mg/day in men versus women without clinically apparent cardiovascular disease

Compared with men, women have greater platelet aggregation before and after low-dose aspirin. It is not known whether high-dose aspirin therapy brings residual platelet aggregation in women closer to that in men. Our objective was to compare inhibition of platelet aggregation in women and men after low- and high-dose aspirin. We enrolled healthy subjects (n=106) in a trial of 14 days of aspirin 81 mg/day followed by 14 days of 325 mg/day. Platelet function was measured at baseline and after the 2 aspirin doses. Women had greater baseline platelet activation measurements. After the 2 aspirin doses, men and women had near complete suppression of platelet aggregation to arachidonic acid in whole blood and in platelet-rich plasma (PRP), the direct cyclo-oxygenase-1 pathway affected by aspirin. For indirect pathways, women had significantly greater residual platelet activation to collagen and adenosine diphosphate (ADP) in whole blood after the 2 aspirin doses and in response to collagen and ADP in PRP after aspirin 325 mg/day only. After aspirin 325 mg/day, women continued to have greater residual platelet aggregation compared with men after aspirin 81 mg/day in response to collagen (p=0.016 in whole blood, p=0.037 in PRP), ADP (p<0.001 in whole blood, p=0.012 in PRP), and epinephrine (p=0.03 in PRP). Excretion of urinary thromboxane metabolite (urinary 11-dehydrothromboxane B2) decreased after aspirin to a similar extent in men and women. In conclusion, women continue to have greater residual platelet activity after high-dose aspirin compared with men treated with a lower dose of aspirin.

Pharmacogenomics of platelet responsiveness to aspirin

Aspirin is the most widely used drug in the world for cardiovascular protection. Aspirin's ability to suppress platelet function varies widely among individuals and lesser suppression of platelet function is associated with increased risk of myocardial infarction, stroke and cardiovascular death. Platelet response to aspirin is a complex phenotype involving multiple genes and molecular pathways. Aspirin response phenotypes can be categorized as directly or indirectly related to cyclooxygenase-1 (COX-1) activity, with phenotypic variation indirectly related to COX-1 being much more prominent. Recent data indicate that variability in platelet response to aspirin is genetically determined, but the specific gene variants that contribute to phenotypic variation are not known. An understanding of the relationship between genotype, aspirin response phenotype and clinical outcome will help to bring about a personalized approach to antiplatelet therapy that maximizes antithrombotic benefit whilst minimizing bleeding risk for individual patients.

Sustainability of a multiple risk factor intervention on cardiovascular disease in high-risk African American families

OBJECTIVES

To determine the long-term effect of a community-based risk reduction intervention at five years after completion of a one-year randomized clinical trial and to determine the sustainability of the beneficial effects seen one year after the intervention.

METHODS

30- to 59- year-old African American siblings of probands with premature coronary heart disease (CHD) were randomized for care of multiple CHD risk factors to either one year of community-based care (CBC) provided by a nurse practitioner/community health worker team or enhanced usual care (EUC). At five years, 307 (84.6%) of the siblings returned for reevaluation.

MAIN OUTCOME MEASURES

Changes in and achievement of goal levels of low-density lipoprotein cholesterol (LDL-C), systolic and diastolic blood pressure (SBP and DBP, respectively), and smoking cessation at five years.

RESULTS

No significant differences were seen between groups in mean LDL-C, SBP, and DBP or in the overall percentages achieving goal LDL-C, blood pressure, or smoking status. Changes after completion of the intervention suggest that the CBC group lost the beneficial effects for mean LDL-C and for percentage at goal LDL-C, while the EUC group continued to improve. CBC was associated with greater sustainability and less refractoriness of one-year results for LDL-C and blood pressure goals.

CONCLUSIONS

Although no group differences were found in mean risk factor levels at five years, data indicate that CBC is both feasible and associated with earlier sustainability of positive risk factor changes compared with EUC.

Casual chocolate consumption and inhibition of platelet function

Observational studies have associated reduced cardiovascular mortality with chocolate consumption. Feeding studies of high-dose, flavanol-rich chocolate show antiplatelet effects, but the effect of casual chocolate consumption on platelet function is unknown. Healthy adults (N=1535) were proscribed from consuming foods affecting platelet function, including chocolate, for 48 hours and completed a 24-hour dietary recall before ex vivo platelet testing with the Platelet Function Analyzer (PFA)-100 (Dade Behring, Inc, Deerfield, IL) test and in vivo testing with urinary 11-dehydro thromboxane B2 (Tx-M) measurements. Some participants (n=141) reported ignoring the prohibition of consuming chocolate before platelet testing. Despite having similar baseline characteristics, chocolate consumers had longer PFA closure times (130 vs 123 seconds, P=.005) and decreased Tx-M levels (175 vs 290 ng/mol creatinine, P=.03). Chocolate remained a significant independent predictor of both ex vivo and in vivo platelet function testing after adjusting for confounders. The authors concluded that even consuming modest amounts of commercial chocolate has important antiplatelet effects.

Symptoms, depression, and quality of life in patients with heart failure

BACKGROUND

Little is known about symptoms and their burden in outpatients with chronic heart failure. Diverse symptoms may be associated with poor heart failure-related quality of life, and depression may be related to increased symptoms.

METHODS AND RESULTS

The number of symptoms and symptom distress (physical symptoms on the Memorial Symptom Assessment Scale-Short Form), depression (Geriatric Depression Scale-Short Form), and heart failure-related quality of life (Kansas City Cardiomyopathy Questionnaire) were measured cross-sectionally in 60 patients with heart failure from two outpatient cardiology clinics. Patients experienced a mean of nine symptoms in the previous week. More than half reported shortness of breath, lack of energy, pain, feeling drowsy, or dry mouth. In unadjusted analyses, more severe depression was associated with a greater number of symptoms (r = 0.51, P < .0001) and greater overall symptom distress (r = 0.58, P < .0001). For each additional depression symptom, the number of symptoms reported increased by 0.6 after adjustment for age, race, and N-terminal pro-brain natriuretic peptide (P = .01). The number of symptoms accounted for 32% of the variance in quality of life (P < .0001).

CONCLUSIONS

Patients with heart failure report a large number of distressing symptoms. Depression in patients with heart failure is associated with a greater number of symptoms, which in turn is associated with a decrease in heart failure-related quality of life. Treatment of depression and the diverse symptoms reported by patients with heart failure might significantly improve quality of life.

Incidence of coronary artery disease in siblings of patients with premature coronary artery disease: 10 years of follow-up

Although family history of premature coronary artery disease (CAD) confers increased risk of CAD, the magnitude of this increase beyond that expected from the risk factors incorporated in the Framingham Risk Equation (FRE) remains unknown. We prospectively determined the accuracy of the FRE 10-year incident CAD events prediction in initially healthy siblings of patients with documented premature CAD. We recruited 784 siblings (30 to 59 years) of 449 patients hospitalized with CAD <60 years of age (1983 to 1995). We compared the estimated 10-year incidence of total CAD events by the gender-specific FREs at baseline, to the observed incidence at 10 years of follow-up. In men, the 10-year actual CAD event rate was 20%, only half of which was predicted by the FRE (12% vs 20%, p <0.001). In women, the observed CAD event rate was 7.1% (p <0.001 vs men), modestly but not significantly greater than the 6.3% predicted by the FRE (p = 0.34). Thus, there was a significant 66.6% excess risk in men, and a nonsignificant 12.7% excess risk in women beyond the risk predicted by the FRE for total CAD events. The FRE and its known classic risk factor profile failed to accurately predict total incident 10-year CAD events in individuals with a sibling history of premature CAD, most particularly in men. In conclusion, in families with a history of premature CAD, the excess risk observed cannot be attributed to traditional risk factors, suggesting a major role for as yet undetermined genetic and other susceptibility factors.

Heritability of platelet function in families with premature coronary artery disease

BACKGROUND

Variations in platelet function among individuals may be related to differences in platelet-related genes. The major goal of our study was to estimate the contribution of inheritance to the variability in platelet function in unaffected individuals from white and African American families with premature coronary artery disease.

METHODS

Platelet reactivity, in the absence of antiplatelet agents, was assessed by in vitro aggregation and the platelet function analyzer closure time. Heritability was estimated using a variance components model.

RESULTS

Both white (n = 687) and African American (n = 321) subjects exhibited moderate to strong heritability (h(2)) for epinephrine- and adenosine diphosphate-induced aggregation (0.36-0.42 for white and >0.71 for African American subjects), but heritability for collagen-induced platelet aggregation in platelet-rich plasma was prominent only in African American subjects. Platelet lag phase after collagen stimulation was heritable in both groups (0.47-0.50). A limited genotype analysis demonstrated that the C825T polymorphism of GNB3 was associated with the platelet aggregation response to 2 muM epinephrine, but the effect differed by race.

CONCLUSIONS

Considering the few and modest genetic effects reported to affect platelet function, our findings suggest the likely existence of undiscovered important genes that modify platelet reactivity, some of which affect multiple aspects of platelet biology.

A monocyte chemoattractant protein-1 gene polymorphism is associated with occult ischemia in a high-risk asymptomatic population

Monocyte chemoattractant protein-1 (MCP-1) recruits monocytes into atherosclerotic plaques. A single nucleotide polymorphism in the MCP-1 gene promoter (-2578A>G) results in greater production of MCP-1 protein. We examined the association of this polymorphism with occult coronary artery disease (CAD) and its interaction with CAD risk factor burden, as assessed by the Framingham risk score (FRS) for hard events. We genotyped 679 apparently healthy 24-59-year-old siblings (SIBS) of people with premature CAD, tested for occult ischemia with exercise treadmill tests and thallium-201 single photon emission computed tomography, and assessed CAD risk factors to calculate the FRS. Occult ischemia occurred in 18% of SIBS and overall was somewhat more prevalent in those with the G allele (20.6%) compared to those without (15.6%), p=0.095. In SIBS at higher risk (highest quartile of FRS, >or=6.8%), occult ischemia occurred significantly more frequently in those with the G allele (44.4% versus 26.1%, p=0.017), while there was no significant difference in SIBS with lower FRS. After adjusting for individual risk factors included in the FRS, multivariate logistic regression modeling demonstrated that the G allele independently predicted occult ischemia in the entire study population (p=0.014, OR=1.86, 95% CI=1.14-3.04). This study demonstrates for the first time that the MCP-1 gene -2578A>G polymorphism is associated with an excess risk of coronary atherosclerosis in an asymptomatic population and demonstrates an apparent interaction with CAD risk factor burden.

Heritability of Platelet Responsiveness to Aspirin in Activation Pathways Directly and Indirectly Related to Cyclooxygenase-1

Background— The inability of aspirin (acetylsalicylic acid [ASA]) to adequately suppress platelet function is associated with future risk of myocardial infarction, stroke, and cardiovascular death. Genetic variation is a proposed but unproved mechanism for insufficient ASA responsiveness.

Methods and Results— We examined platelet ASA responsiveness in 1880 asymptomatic subjects (mean age, 44±13 years; 58% women) recruited from 309 white and 208 black families with premature coronary heart disease. Ex vivo platelet function was determined before and after ingestion of ASA (81 mg/d for 2 weeks) with the use of a panel of measures that assessed platelet activation in pathways directly and indirectly related to cyclooxygenase-1, the enzyme inhibited by ASA. The proportion of phenotypic variance related to CHD risk factor covariates was determined by multivariable regression. Heritability of phenotypes was determined with the use of variance components models unadjusted and adjusted for covariates. ASA inhibited arachidonic acid–induced aggregation and thromboxane B 2 production by ≥99% ( P <0.0001). Inhibition of urinary thromboxane excretion and platelet activation in pathways indirectly related to cyclooxygenase-1 was less pronounced and more variable (inhibition of 0% to 100%). Measured covariates contributed modestly to variability in ASA response phenotypes ( r 2 =0.001 to 0.133). Phenotypes indirectly related to cyclooxygenase-1 were strongly and consistently heritable across races (h 2 =0.266 to 0.762; P <0.01), but direct cyclooxygenase-1 phenotypes were not.

Conclusions— Heritable factors contribute prominently to variability in residual platelet function after ASA exposure. These data suggest a genetic basis for the adequacy of platelet suppression by ASA and potentially for differences in the clinical efficacy of ASA.

Spiritual well-being and depression in patients with heart failure

BACKGROUND

In patients with chronic heart failure, depression is common and associated with poor quality of life, more frequent hospitalizations, and higher mortality. Spiritual well-being is an important, modifiable coping resource in patients with terminal cancer and is associated with less depression, but little is known about the role of spiritual well-being in patients with heart failure.

OBJECTIVE

To identify the relationship between spiritual well-being and depression in patients with heart failure.

DESIGN

Cross-sectional study.

PARTICIPANTS

Sixty patients aged 60 years or older with New York Heart Association class II-IV heart failure.

MEASUREMENTS

Spiritual well-being was measured using the total scale and 2 subscales (meaning/peace, faith) of the Functional Assessment of Chronic Illness Therapy-Spiritual Well-being scale, depression using the Geriatric Depression Scale-Short Form (GDS-SF).

RESULTS

The median age of participants was 75 years. Nineteen participants (32%) had clinically significant depression (GDS-SF > 4). Greater spiritual well-being was strongly inversely correlated with depression (Spearman's correlation -0.55, 95% confidence interval -0.70 to -0.35). In particular, greater meaning/peace was strongly associated with less depression (r = -.60, P < .0001), while faith was only modestly associated (r = -.38, P < .01). In a regression analysis accounting for gender, income, and other risk factors for depression (social support, physical symptoms, and health status), greater spiritual well-being continued to be significantly associated with less depression (P = .05). Between the 2 spiritual well-being subscales, only meaning/peace contributed significantly to this effect (P = .02) and accounted for 7% of the variance in depression.

CONCLUSIONS

Among outpatients with heart failure, greater spiritual well-being, particularly meaning/peace, was strongly associated with less depression. Enhancement of patients' sense of spiritual well-being might reduce or prevent depression and thus improve quality of life and other outcomes in this population.

Effect of soy protein-containing isoflavones on lipoproteins in postmenopausal women

OBJECTIVE

Some clinical trials have demonstrated a beneficial effect of dietary soy protein on improving lipoproteins. Research also has documented that serum lipoproteins and some lipoprotein subclasses are altered as a consequence of menopause, resulting in a more atherogenic lipid profile. The purpose of this study was to determine the effects of isolated soy protein-containing isoflavones on lipoproteins and lipoprotein subclasses in both African American and white postmenopausal women with borderline to moderate low-density lipoprotein cholesterol elevations.

DESIGN

This was a randomized, double-blind, controlled clinical trial including 216 postmenopausal women. After a 4-week run-in period with a casein protein-based supplement, participants were randomly assigned to continue the casein placebo or receive soy protein-containing isoflavones for a period of 12 weeks.

RESULTS

In the soy group, the total cholesterol, low-density lipoprotein cholesterol, and low-density lipoprotein particle number decreased significantly as compared with the placebo group at 6 weeks. Although this decrease continued at 12 weeks in the soy group, the difference from the placebo group was attenuated for total cholesterol and low-density lipoprotein particle number. Multivariate analyses controlling for age, race, change in weight, change in dietary fat intake, and change in kilocalorie energy expenditure revealed that treatment remained a significant independent predictor of change in total cholesterol (P = 0.01), low-density lipoprotein cholesterol (P = 0.02), and low-density lipoprotein particle number (P = 0.002) after 6 weeks of dietary soy.

CONCLUSIONS

Increased consumption of soy protein replacing animal protein that is high in fat may help improve atherogenic lipid profiles.

Glucose levels in the normal range predict incident diabetes in families with premature coronary heart disease

PURPOSE

Little is known about excess risk of incident diabetes conferred by fasting plasma glucose (FPG) within the normal range (<5.6 mmol/l) for high risk families.

METHODS

Healthy 30-59 year old non-diabetic siblings (N = 542) of index cases with documented premature coronary disease were followed prospectively for type 2 diabetes.

RESULTS

During 8.7+/-3 years of follow-up, incident diabetes was identified in 7.8%. Rates were incremental with baseline non-diabetes FPG thresholds of 5.0, 5.6, 6.1, and 6.7 mmol/l (p for trend < 0.0001). FPG was the strongest predictor of incident diabetes even across levels within the normal range. The multivariable adjusted relative risk was 14.9 (95% CI = 3.4-65.2) at FPG thresholds > or =5.0 mmol/l versus FPG <5.0 mmol/l. The maximal diagnostic efficiency for FPG was 5.50 mmol/l; with sensitivity and specificity 0.782. All FPG thresholds in the normal range between 5.0 and 5.6 mmol/l showed efficiency levels >0.74. The overall area under the ROC curve predicting incident diabetes for normal and prediabetes ranges of FPG was 0.867.

CONCLUSION

Higher FPG levels within the designated "normal" range in high risk families are a potent independent risk factor for type 2 diabetes and may serve as a sentinel to trigger primary preventive interventions.

Relation between atherosclerosis risk factors and aspirin resistance in a primary prevention population

Resistance to inhibition of platelet function by aspirin may contribute to future myocardial infarction and stroke. Adverse cardiovascular outcomes have been associated with aspirin resistance on several different platelet function assays, including the level of urinary 11-dehydro thromboxane B2 (Tx-M), platelet aggregation to arachidonic acid and adenosine diphosphate, and closure time on the platelet function analyzer-100. We examined the concordance of these aspirin-resistance assays and their relation to cardiovascular risk factors in a primary prevention population. Asymptomatic patients (n = 1,311) at increased risk for coronary heart disease were evaluated before and after 2 weeks of aspirin (81 mg/day). Aspirin resistance was defined according to published criteria for these 3 assays of platelet function. Subjects were characterized for the presence of atherosclerosis risk factors. Agreement among the 3 assays was poor. Only 5 patients met aggregation criteria for aspirin resistance. Attenuated suppression of urinary Tx-M by aspirin was associated with a greater atherosclerotic risk profile and Framingham risk score in multivariable regression analysis. Aspirin resistance by platelet function analyzer-100 was associated only with increased von Willebrand factor levels and not with atherosclerotic risk profile. In conclusion, in a primary prevention population, different published criteria for aspirin resistance classify distinct groups of patients as aspirin resistant with very little overlap. Higher Tx-M, which reflects decreased suppression of thromboxane production in vivo, is the only criterion associated with atherosclerosis risk factors, suggesting that this measurement may represent the most relevant approach for identifying asymptomatic subjects whose aspirin treatment will "fail."

Sex differences in platelet reactivity and response to low-dose aspirin therapy

CONTEXT

Recent randomized trials suggest that women may not accrue the same cardioprotective benefits as men do from low-dose aspirin therapy used in primary prevention. Failure of aspirin to suppress platelet aggregation in women is one hypothesized mechanism.

OBJECTIVE

To examine differential platelet reactivity to low-dose aspirin therapy by sex.

DESIGN, SETTING, AND PARTICIPANTS

A clinical trial of aspirin at 81 mg/d for 14 days was conducted in 571 men and 711 women. Baseline and post-aspirin therapy measures included platelet aggregation to arachidonic acid, adenosine diphosphate, epinephrine, and platelet function analyzer closure time.

MAIN OUTCOME MEASURE

Sex differences in cyclooxygenase 1 (COX-1) direct and indirect platelet activation pathways before and after administration of aspirin.

RESULTS

In 10 of the 12 platelet agonist exposures, women's platelets were significantly more reactive at baseline. However, after aspirin therapy, the percent aggregation to arachidonic acid (the direct COX-1 pathway) decreased more in women than in men (P<.001) and demonstrated near total suppression of residual platelet reactivity in both men and women. In COX-1 indirect pathways, women experienced the same or more platelet inhibition than men in 8 of the 9 assays yet retained modestly greater platelet reactivity after aspirin therapy. In multivariable analysis, female sex significantly predicted aggregation to 2 muM and 10 muM of adenosine diphosphate (P = .02 and <.001, respectively) and collagen at 5 mug/mL (P<.001) independent of risk factors, age, race, menopausal status, and hormone therapy.

CONCLUSIONS

Women experienced the same or greater decreases in platelet reactivity after aspirin therapy, retaining modestly more platelet reactivity compared with men. However, most women achieved total suppression of aggregation in the direct COX-1 pathway, the putative mechanism for aspirin's cardioprotection.

Comparison of coronary calcium and stress myocardial perfusion imaging in apparently healthy siblings of individuals with premature coronary artery disease

Detection of subclinical coronary atherosclerosis is possible using exercise myocardial perfusion imaging for inducible ischemia or multidetector computed tomography for coronary artery calcium (CAC), which is used to detect subclinical coronary atherosclerosis. The extent to which these screening tests converge in an asymptomatic population that is at increased risk for coronary artery disease remains unknown. We compared the concordance of findings in 260 asymptomatic middle-age siblings of hospitalized index patients <60 years of age with documented coronary artery disease. All subjects underwent maximal exercise testing with postexercise and delayed attenuation-corrected thallium single-photon emission computed tomography and multidetector computed tomography for CAC. An abnormal exercise single-photon emission computed tomographic (SPECT) result occurred in >50% of subjects with a CAC score >100, but also in 12% with no CAC, 9% with CAC scores of 1 to 10, and 20% with CAC scores of 11 to 100. In subjects with an abnormal exercise SPECT result, 59% had CAC scores < or =100. Overall, there was only a modest agreement between an abnormal exercise SPECT result and high CAC scores. In conclusion, although moderate or severe CAC is often associated with inducible ischemia, the absence of CAC or the presence of only mild CAC by no means precludes inducible myocardial ischemia. These screening tests may reflect different aspects or stages of coronary disease in an asymptomatic middle-age population.

Women with a low Framingham risk score and a family history of premature coronary heart disease have a high prevalence of subclinical coronary atherosclerosis

BACKGROUND

The Framingham risk estimation (FRE) serves as the basis for identifying which asymptomatic adults should be treated with aspirin and lipid-lowering therapy in primary prevention. However, the FRE generally yields low estimates of 10-year "hard" coronary heart disease (CHD) event risk with few women (< 70 years) qualifying for preventive pharmacologic therapy despite relatively high lifetime risk. We postulated that traditional risk factor assessment might fail to identify a sizeable portion of women with a sibling history for premature CHD as having advanced subclinical atherosclerosis.

METHODS

We studied 102 asymptomatic women (mean age 51 +/- 7 years) who were the sisters of a proband hospitalized with documented premature CHD. Participants underwent risk factor assessment and multidetector computed tomography for coronary artery calcium (CAC) scoring. Based on FRE prediction of 10-year risk for hard CHD events, participants were classified as low risk (< 10%) (n = 100), intermediate risk (10%-20%) (n = 2), or high risk (> 20%) (n = 0). Significant subclinical atherosclerosis was defined as age-sex adjusted > 75th percentile CAC scores.

RESULTS

Ninety-eight percent were at low risk (mean FRE of only 2% +/- 2%). However, 40% had detectable CAC, 12% had CAC > 100, and 6% had CAC > or = 400. Based on CAC score percentiles, 32% had significant subclinical atherosclerosis and 17% ranked above the 90th percentile.

CONCLUSION

Among women classified as low risk by FRE, a third had significant subclinical atherosclerosis. Sisters of probands with premature CHD appear to be a high-risk group and may warrant noninvasive screening for subclinical atherosclerosis to appropriately target individuals for more aggressive primary prevention therapy than what is currently recommended.

Predictors of low-density lipoprotein particle size in a high-risk African-American population

A predominance of small, dense, low-density lipoprotein particles (pattern B) has been associated with increased cardiovascular risk independent of absolute cholesterol levels in primarily white populations. Because of the putative association of pattern B with increased risk, some investigators have proposed that routine measurement of low-density lipoprotein particle size may be beneficial for cardiovascular risk assessment. Because no studies have specifically examined this possibility in African-Americans, it remains unclear whether measurement of low-density lipoprotein particle size adds information beyond that of traditional lipid risk factors. We compared standard lipid profile measurements with extended measurements concurrently in an apparently healthy, high-risk population of African-American siblings of patients who had premature cardiovascular disease. We determined the extent to which patients who had pattern B would be identifiable from the usual lipid profile. A high triglyceride level alone was a strong independent correlate of pattern B. In subjects whose triglyceride level was >/=150 mg/dl, 67% had pattern B, whereas only 17% of subjects whose triglyceride level was <150 mg/dl had pattern B. The area under the receiver-operating characteristic curve was 0.77. Our data suggest that the standard lipid profile, primarily fasting triglyceride measurement, appears to be a useful surrogate for direct measurement of particle size in a high-risk African-American population.

Interaction of Body Mass Index and Framingham Risk Score in Predicting Incident Coronary Disease in Families

Background— Siblings of individuals with premature coronary heart disease (CHD) have a marked excess risk of CHD risk factors and premature CHD. The impact of body mass index (BMI) on incident CHD in these families and the extent to which it may be mediated by associated risk factors are unknown. The aim of this study was to examine the effect of high BMI on incident CHD in white and black families with premature CHD and to estimate the heritability of BMI.

Methods and Results— Risk factors, BMI, and Framingham Risk Score (FRS) were assessed at baseline and incident CHD was determined prospectively in 827 apparently healthy siblings of probands with premature CHD aged <60 years. During a mean follow-up of 8.7 years, 13.3% of siblings had incident CHD events. Event rates were higher in obese and overweight siblings than in those with normal weight (15.3% and 16.0% versus 8.1%, respectively; P =0.01). Multivariable Cox proportional hazards analyses demonstrated the independent prognostic value of BMI when added to FRS ( P =0.02). A marked interaction between obesity (BMI ≥30 kg/m 2 ) and high FRS (>20%) was seen for incident CHD ( P for interaction=0.008), with an adjusted hazard ratio compared with low-FRS/normal-weight siblings of 14.63 (95% CI, 6.40 to 33.44; P <0.0001). BMI heritability (h 2 ) was moderate for whites and low for blacks (52% and 29%, respectively).

Conclusions— High BMI contributed independently and significantly to incident CHD, beginning in the overweight range, and was most notable for obese siblings with a high-risk FRS.

Impact of a Community-Based Multiple Risk Factor Intervention on Cardiovascular Risk in Black Families With a History of Premature Coronary Disease

BACKGROUND

Black subjects with a family history of premature coronary heart disease (CHD) have a marked excess risk, yet barriers prevent effective risk reduction. We tested a community-based multiple risk factor intervention (community-based care [CBC]) and compared it with "enhanced" primary care (EPC) to reduce CHD risk in high-risk black families.

METHODS AND RESULTS

Black 30- to 59-year-old siblings of a proband with CHD aged <60 years were randomized for care of BP > or =140/90 mm Hg, LDL cholesterol > or =3.37 mmol/L, or current smoking to EPC (n=168) or CBC (n=196) and monitored for 1 year. EPC and CBC were designed to eliminate barriers to care. The CBC group received care by a nurse practitioner and a community health worker in a community setting. The CBC group was 2 times more likely to achieve goal levels of LDL cholesterol and blood pressure compared with the EPC group (95% CI, 1.11 to 4.20 and 1.39 to 3.88, respectively) with adjustment for baseline levels of age, sex, education, and baseline use of medications. The CBC group demonstrated a significant reduction in global CHD risk, whereas no reduction was seen in the EPC group (P<0.0001).

CONCLUSIONS

Eliminating known barriers may not be sufficient to reduce CHD risk in primary care settings. An alternative community care model that addresses barriers may be a more effective way to ameliorate CHD risk in high-risk black families.

Spiritual beliefs and barriers among managed care practitioners

PURPOSE

Ninety percent of American adults believe in God and 82% pray weekly. A majority wants their physicians to address spirituality during their health care visit. However, clinicians incorporate spiritual discussion in less than 20% of visits. Our objectives were to measure clinician beliefs and identify perceived barriers to integrating spirituality into patient care in a statewide, primary care, managed care group.

METHODS

Practitioners completed a 30-item survey including demographics and religious involvement (DUREL), spirituality in patient care (SPC), and barriers (BAR). We analyzed data using frequencies, means, standard deviations, and ANOVA.

FINDINGS

Clinicians had a range of religious denominations (67% Christian, 14% Jewish, 11% Muslim, Hindu or Buddhist, 8% agnostic), were 57% female and 24% had training in spirituality. Sixty-six percent reported experiencing the divine. Ninety-five percent felt that a patient's spiritual outlook was important to handling health difficulties and 68% percent agreed that addressing spirituality was part of the physician's role. Ninety-five percent of our managed care group noted 'lack of time' as an important barrier, 'lack of training' was indicated by 69%, and 21% cited 'fear of response from administration'.

CONCLUSIONS

Managed care practitioners in a time constrained setting were spiritual themselves and believed this to be important to patients. Respondents indicated barriers of time and training to implementing these beliefs. Comparing responses from our group to those in other published surveys on clinician spirituality, we find similar concerns. Clinician education may overcome these barriers and improve ability to more fully meet their patients' expressed needs regarding spirituality and beliefs.

Assessment of global coronary heart disease risk in overweight and obese African-American women

OBJECTIVE

To examine, with the use of national guidelines, coronary heart disease (CHD) risk with increasing BMI for primary prevention in urban African-American women.

RESEARCH METHODS AND PROCEDURES

Participants were recruited for CHD risk factor screening from 20 churches as part of a larger study of nutrition and fitness (Project Joy). All participants had a demographic, smoking and medical history assessment, and the following measurements were taken: weight, height, waist circumference, blood pressure, lipid levels, and glucose. Three methods of defining risk, the Framingham Point Scoring System, a count of risk factors, and the presence of the multiple metabolic syndrome, based on the National Cholesterol Education Program Adult Treatment Panel III Report and BMI classes established by the Clinical Guidelines, were used.

RESULTS

A total of 396 women were eligible. Participants were 40 to 80 years of age and had marked excess prevalence of overweight and obesity (84%); 55% were obese. There was a linear increase in risk factors as BMI increased. Lipids did not differ significantly among BMI classifications. Seventeen percent of women had multiple metabolic syndrome. Eight percent and 16% of women in the normal and overweight BMI classes, respectively, had two or more modifiable risk factors. There was no difference in number of modifiable risk factors among the obese classes. The Framingham Point Scoring System assigned a <10% risk of a hard CHD event in 10 years to 97% of the women.

DISCUSSION

National risk assessment guidelines for primary prevention of CHD may not be adequate for overweight and obese urban African-American women and require further study.