Family history of coronary heart disease and pre-clinical carotid artery atherosclerosis in African-Americans and whites: the ARIC study: Atherosclerosis Risk in Communities

Sex differences in long-term clinical outcomes of acute myocardial infarction according to the presence of diabetes mellitus

BACKGROUND/AIMS

This study compared long-term clinical outcomes between male and female acute myocardial infarction (AMI) patients with and without diabetes mellitus (DM).

METHODS

From November 2011 to December 2015, 13,104 patients with AMI were enrolled in the Korea Acute Myocardial Infarction Registry National Institutes of Health (KAMIR-NIH) (4,458 diabetic patients and 8,646 non-diabetic patients). Propensity score matching (PSM) was used to reduce bias due to confounding variables. Following PSM, 2,046 diabetic patients, 1,023 males (69.8 ± 9.4 years) and 1,023 females (69.9 ± 9.4 years); and 3,412 non-diabetic patients, 1,706 males (70.0 ± 10.4 years) and 1,706 females (70.4 ± 10.8 years) were analyzed. Clinical outcomes were compared between male and female patients with and without diabetes over a 3-year clinical follow-up.

RESULTS

In diabetic patients, mortality (21.1% vs. 21.5%, p = 0.813) and major adverse cardiac events (MACE) (30.6% vs. 31.4%, p = 0.698) were not significantly different between males and females. However, mortality (15.8% vs. 12.0%, p = 0.002) and MACE (20.8% vs. 15.6%, p < 0.001) were significantly higher in male non-diabetic patients than in female non-diabetic patients. The predictors of mortality for both males and females in the diabetic and non-diabetic groups were old age, heart failure, renal dysfunction, anemia, and no percutaneous coronary intervention.

CONCLUSION

The long-term clinical outcomes in AMI patients with DM did not significantly differ by sex. However, the mortality and MACE in non-diabetic male patients were higher than those in females.

Premature Parental Cardiovascular Disease and Subclinical Disease Burden in the Offspring

Background Offspring of parents with premature cardiovascular disease (CVD) have an increased risk of developing subclinical and clinical CVD. It is unclear whether this association differs by vascular beds in the offspring or by the age cut points used to define premature parental CVD. Methods and Results Using 3 generations of Framingham Heart Study participants, we assessed prevalent coronary artery calcification, the progression of coronary artery calcification over 6.1 years (median), carotid intima media thickness and the ankle-brachial index in 1046 offspring of parents with premature CVD before age 70 years, in 1618 offspring with both parents free of CVD and in 923 offspring with parents with CVD after age 70 years. We used different age cut points (55, 60, 65, and 70 years) to define premature parental CVD. In multivariable-adjusted models, offspring of parents with premature CVD (onset before age 65 years) displayed greater odds for prevalent coronary artery calcification (odds ratio [OR], 1.81; 95% CI, 1.35-2.43), higher carotid intima media thickness (OR, 1.50; 95% CI, 0.92-2.44) and lower ankle-brachial index (OR, 1.89; 95% CI, 1.00-3.58). These associations were generally consistent across different age cut points used to define premature parental CVD. The association with the progression of coronary artery calcification was less consistent. Conclusions Parental premature CVD is associated with increased subclinical CVD burden in the offspring, with consistent relations across different vascular beds and for different age cut points used to define premature parental CVD. Future studies should evaluate whether screening for subclinical CVD traits is warranted in offspring with premature parental CVD.

Evaluation of single nucleotide polymorphisms in 6 candidate genes and carotid intima-media thickness in community-dwelling residents

Evidence suggests the existence of association between a large panel of modifiable biomarkers representing inflammation, coagulation, paraoxonase, and endothelial activation pathways and carotid atherosclerosis. Thus, this study investigated whether CRP, FGA, FGB, FGG, PON1, and EDNRA gene variants affected plasma hs-CRP, fibrinogen levels, and thickness of carotid intima media thickness (IMT). Nineteen single-nucleotide polymorphisms of CRP, FGA, FGB, FGG, PON1, and EDNRA genes were examined in 480 participants from 160 families. Carotid IMT was measured by ultrasound. Generalized linear models with generalized estimating equation were utilized to consider the dependence of subjects within families. In the recessive model, homozygotes for the minor alleles of rs1800789, rs1800790 and rs4220 SNPs in FGB gene indicated a reduced risk of IMT (Exp. β = 0.89, 0.89, 0.88), which remained significant after adjustment for confounding factors. Significant interaction effects between CRP SNP rs1130864 and rs3093059 and gender for IMT were observed with a significant association in men only. Men carrying minor-minor genotype of CRP SNP rs1130864 and rs3093059 had 0.70- and 0.78-fold lower IMT than men carrying minor-major/major-major genotype. We also observed that the interaction of CRP SNP rs1130864 and rs3093059 with obesity on IMT, hs-CRP and fibrinogen levels. These results support the hypothesis that inflammatory genes are involved in atherosclerosis, most likely via complex gene-gender and gene-obesity interactions.

Associations between a parental history of premature cardiovascular disease and coronary artery calcium and carotid intima-media thickness: the Coronary Artery Risk Development In Young Adults (CARDIA) study

BACKGROUND

It is unclear if associations between a parental history of premature CVD (pCVD) and subclinical atherosclerosis are attenuated by adjustment for long-term risk factor levels through middle adulthood.

DESIGN

Prospective community-based cohort study.

METHODS

CARDIA participants who attended the year-20 exam (n = 2283, mean age 45 years) were grouped by pCVD status: maternal only, paternal only, any parental, and no parental history (referent). We used separate logistic regression models, adjusted for average risk factor levels over a 20-year follow up to assess associations of parental pCVD and subclinical atherosclerosis in offspring.

RESULTS

White participants with any parental history of pCVD had a higher odds of coronary artery calcium (CAC) >0 than participants with no parental history (OR 1.55, 95% CI 1.01-2.37). This was largely driven by the association of a paternal history of pCVD with CAC >0 (OR 2.15, 95% CI 1.42-3.23), which was minimally attenuated by multivariable adjustment (OR 2.09, 95% CI 1.31-3.32). Similarly, adjusted associations between parental pCVD and intima-media thickness (IMT) >90% were observed in white participants with a paternal history of pCVD (OR 1.93, 95% CI 1.10-3.39) and any parental history pCVD (OR 1.67, 95% CI 1.02-2.74). No significant associations between a parental history of pCVD and the odds of subclinical atherosclerosis were observed in black participants.

CONCLUSIONS

Parental pCVD is independently associated with early development of subclinical atherosclerosis; these associations may be race-specific for participants in their fifth decade of life.

Carotid intima-media thickness as a surrogate marker of cardiovascular disease in diabetes

BACKGROUND

Diabetes mellitus is associated with a high risk of cardiovascular disease. Carotid intima-media thickness (CIMT) is increasingly used as a surrogate marker for atherosclerosis. Its use relies on its ability to predict future clinical cardiovascular end points.

METHODS

This review examines the evidence linking CIMT as a surrogate marker of vascular complications in people with type 1 and type 2 diabetes. We have also reviewed the various treatment strategies which have been shown to influence CIMT.

CONCLUSIONS

CIMT measurement is an effective, noninvasive tool which can assist in identifying people with diabetes who are at higher risk of developing microvascular and macrovascular complications. It may also help to evaluate the effectiveness of various treatment strategies used to treat people with diabetes.

Subclinical atherosclerosis in subjects with family history of premature coronary artery disease

BACKGROUND

First-degree relatives (FDRs) of subjects with early onset of coronary heart disease (CHD) have higher risk of developing cardiovascular disease. We verified early CHD by angiography in index patients and extensively phenotyped their FDRs to investigate the relationship of traditional and nontraditional cardiovascular risk factors to carotid ultrasound measures of subclinical atherosclerosis.

METHODS AND RESULTS

B-mode carotid ultrasound was used to assess the combined intimamedia thickness and plaque burden in 111 FDRs (65 men, 44.4 +/- 11 and 46 women, 44.7 +/- 13 years old) of 82 index patients (men <50 and women <60 years of age at the time of the event). The biochemical and anthropometrical characteristics of the FDRs were compared with those of healthy controls matched for sex, age, ethnicity, and body mass index. First-degree relatives had increased average total thickness (a combined measure of intimamedia thickness and plaque) compared to controls (0.76 mm, interquartile range [IQR] 0.69-1.01 vs 0.69 mm, IQR 0.60-0.88, P < .001) even after adjusting for age, total cholesterol-to-high-density lipoprotein cholesterol ratio, systolic blood pressure, waist circumference, and smoking (beta = 0.143, P < .05). No differences were observed in average intimamedia thickness measurements alone. Of the nontraditional risk factors, only plasma homocysteine was higher in FDRs then in controls (9.6 mg/L, IQR 8.0-11.1 versus 7.5 mg/L, IQR 6.4-8.7, P < .001), after adjusting for all other confounding variables.

CONCLUSION

First-degree relatives of patients with angiographically confirmed CHD have higher burden of subclinical atherosclerosis even when considered in the context of traditional risk factors. Noninvasive assessment of carotid artery plaques and intimamedia thickness and plasma homocysteine measurements may be useful in such patients.

Familial aggregation in patients with non-alcoholic steatohepatitis

We encountered three families that showed NASH accumulation. In family #1, a 21-year-old son and 10-year-old daughter were diagnosed with nonalcoholic steatohepatitis (NASH). They shared two adiponectin-gene single nucleotide polymorphisms (SNP). In family #2, a 51-year-old mother and 27-year-old son were diagnosed with NASH and shared the SNPs of other genes. In family #3, a 66-year-old mother and 34-year-old son were diagnosed with NASH and shared the SNPs of other genes. SNP sites differed among the three families, suggesting that the genes associated with the occurrence of NASH might be different in each patient.

Family history of premature coronary heart disease and coronary artery calcification: Multi-Ethnic Study of Atherosclerosis (MESA)

BACKGROUND

A family history of premature coronary heart disease (CHD) is a known risk factor for CHD events. The purpose of this study was to assess the strength of the association between a family history of premature CHD and coronary artery calcification (CAC) in a multiethnic cohort of asymptomatic individuals. We also sought to determine whether individuals with a reported family history of premature CHD have an increased atherosclerotic burden among those classified as being at low to intermediate risk on the basis of the conventional Framingham risk score.

METHODS AND RESULTS

The association of family history of premature CHD with CAC was assessed in 5347 asymptomatic individuals (47% men; mean age 62+/-10 years) in the Multi-Ethnic Study of Atherosclerosis (MESA). The demographics (age, gender, and race)-adjusted OR for CAC > 0 with versus without a family history of premature CHD was 1.94 (95% CI, 1.64 to 2.29). On adjustment for CHD risk factors, the association was slightly attenuated to an OR of 1.84 (95% CI, 1.55 to 2.19). Family history of premature CHD was significantly associated with CAC in all ethnic groups. The age-, gender-, and race-adjusted prevalence of CAC > 0 was significantly higher with presence of any family history of premature CHD than for those with no family history of premature CHD among individuals classified as low risk (35% versus 23%, P<0.0001) and among those at intermediate risk (70% versus 60%, P=0.01). Similarly, the prevalence of age-gender-race-based CAC > or = 75th percentile in low-risk (24% versus 14%, P=0.0003) and intermediate-risk (34% versus 20%, P<0.001) individuals was also higher among those with a family history of premature CHD. Compared with those without a family history of premature CHD, the association with the presence of CAC was strongest in participants reporting such history in both a parent and a sibling (odds ratio, 2.74; 95% CI, 1.64 to 4.59), followed by those reporting a family history in a sibling only (odds ratio, 2.06; 95% CI, 1.64 to 2.58) and those reporting a family history of premature CHD only in a parent (odds ratio, 1.52; 95% CI, 1.19 to 1.93).

CONCLUSIONS

An association between family history of premature CHD and the presence of any CAC, as well as advanced CAC, was observed in the present population-based multiethnic study. The relationship was independent of other risk factors and Framingham risk score, which supports the utility of including information on family history of premature CHD in current methods of global risk assessment and practice guidelines.

Race (black-white) and gender divergences in the relationship of childhood cardiovascular risk factors to carotid artery intima-media thickness in adulthood: the Bogalusa Heart Study

It has been established that childhood cardiovascular (CV) risk factors are predictive of adulthood vascular changes as measured by carotid intima-media thickness (IMT). However, whether this relationship is race- and gender-specific is not known. This aspect was examined in a black-white cohort of 868 adults (29% blacks, 42% males) aged 25-44 years who were examined at least twice in childhood for traditional CV risk factors with an average follow-up period of 26.4 years. The average value of the two earliest childhood measurements was used as the childhood value, standardized to age, race, and gender-specific z-score. Carotid IMT was measured by B-mode ultrasonography. The mean of the maximum carotid IMT readings of three right and three left far walls for common, bulb and internal segments was used. In univariate analysis, significant correlates of adulthood carotid IMT (standardized to age-, race- and gender-specific z-score) were, in the order of decreasing magnitude, triglyceride and LDL cholesterol in white males; systolic blood pressure, LDL cholesterol, and body mass index (BMI) in white females; systolic blood pressure in black males; BMI and systolic blood pressure in black females. In multivariate regression analysis, significant predictors of carotid IMT were triglycerides and LDL cholesterol in white males; systolic blood pressure and LDL cholesterol in white females; systolic blood pressure in black males; and BMI and LDL cholesterol in black females. In conclusion, the predictability of childhood CV risk factors for increased carotid IMT in adulthood varies by race and gender. The prevention implications of these findings need further investigation.

Expanding the definition of a positive family history for early-onset coronary heart disease

PURPOSE

Assessing familial risk for early-onset coronary heart disease (CHD) is typically limited to first-degree relatives with early-onset CHD. To evaluate the impact of additional family history, we examined the associations between various family history definitions and early-onset CHD.

METHODS

By using the national HealthStyles 2003 survey data, we assessed associations between self-reported family history and personal history of early-onset CHD (diagnosed at or before age 60 years), adjusting for demographics, hypercholesterolemia, hypertension, and obesity.

RESULTS

Of 4,035 respondents, 60% were female and 72% were white, with a mean age of 48.8 years; 4.4% had early-onset CHD. In addition to having at least one first-degree relative with early-onset CHD, other significant associations included having at least one first-degree relative with late-onset CHD, at least one second-degree relative with early-onset CHD, and two or more affected second-degree relatives regardless of age of onset of CHD. Early-onset stroke in at least one first-degree relative and, in women, having at least one first-degree relative with diabetes were also significantly associated with early-onset CHD.

CONCLUSIONS

Family history beyond early-onset CHD in first-degree relatives is significantly associated with prevalent CHD diagnosed at or before age 60 years.

Postprandial hypertriglyceridemia and carotid intima-media thickness in north Indian type 2 diabetic subjects

Hypertriglyceridemia is an important risk factor for coronary heart disease (CHD) and in the development of atherosclerosis, especially in subgroups of the population like those with type 2 diabetes. Although triglycerides are generally increased in the postprandial period, the association between postprandial triglyceride (ppTG) levels and atherosclerosis has not been investigated in north Indian type 2 diabetic subjects known to have a very high prevalence rate of premature CHD and insulin resistance. To investigate the role of ppTG levels in atherosclerosis in type 2 diabetes, we examined the correlation between ppTG levels and carotid intima-media thickness (IMT). Carotid IMT was determined by high resolution B-mode ultrasonography in 86 newly detected type 2 diabetic subjects (1-12 months duration) having good glycemic control (HbA(1C)<7%) and 45 non-diabetic subjects matched according to age and body mass index (BMI). Plasma glucose, insulin, total cholesterol, LDL-cholesterol, HDL-cholesterol and triglycerides were measured after overnight fasting. Plasma insulin and glucose were also measured 2h and plasma triglycerides 4h after breakfast. The mean carotid IMT in diabetic subjects was higher than those in non-diabetic subjects (0.77+/-0.15 mm versus 0.53+/-0.16 mm, P<0.001). Based on the fasting and postprandial triglyceride levels, the diabetic subjects were divided into three groups: normo-normo (NN); normo-hyper (NH); hyper-hyper (HH) [NN: fTG<1.70 mmol/L and ppTG<2.30 mmol/L; NH: fTG<1.70 mmol/L and ppTG>2.30 mmol/L; HH: fTG>1.70 mmol/L and ppTG>2.30 mmol/L]. Carotid IMT was significantly increased in the NH (0.79+/-0.09 mm) and HH (0.82+/-0.06 mm) groups compared with the NN group (0.59+/-0.09 mm, P<0.001). Although ppTG, age, fasting LDL-cholesterol, HOMA-estimated insulin resistance, HbA(1C) were all independently correlated with carotid IMT, age and ppTG levels had the strongest statistical influence (P<0.002).

Genetics of Ultrasonographic Carotid Atherosclerosis

The search for genes related to the cause of common complex disorders such as cardiovascular disease has been frustrating, partly because of the many factors known to contribute to cardiovascular disease and the potential "distance" of cardiovascular disease as a phenotype from genes and gene products. Linkage and association studies for phenotypes more proximal in the pathway from DNA sequence variation to overt clinical disease, such as ultrasound-defined carotid atherosclerosis, may potentially be more enlightening. Only one genetic variant previously reported to be associated with atherosclerosis or clinically evident cardiovascular disease, matrix metalloproteinase (MMP) 3, has shown consistently positive associations with carotid disease, although it has not been studied widely. Another, PON1 L55M, is weakly associated in subgroups only, and 2, ApoE and MTHFR, are equivocal. Genetic variants reported to be associated with clinical cardiovascular disease show weak or no relationship to carotid atherosclerosis. This may reflect the known inconsistency in associations of genetic variants with clinical cardiovascular disease itself. Alternatively, genetic determinants of ultrasound-defined carotid atherosclerosis may differ from those of clinically manifest cardiovascular disease and may require pursuit through large-scale genomic studies of carotid atherosclerosis as a distinct phenotype. Only 1 genetic variant, MMP 3, has shown consistently positive associations with ultrasonographic carotid disease, although it has not been studied widely. Another, PON1 L55 mol/L, is weakly associated in subgroups only. Genetic variants reported to be associated with clinical cardiovascular disease show weak or no relationship to carotid atherosclerosis.

Carotid intima-media thickness is associated with premature parental coronary heart disease: the Framingham Heart Study

BACKGROUND

A family history of coronary heart disease (CHD) is an independent risk factor for cardiovascular events. However, the mechanisms underlying this susceptibility have not been fully elucidated. We hypothesized that an important mediator of the familial predisposition to CHD is subclinical atherosclerosis, which is detectable by noninvasive imaging.

METHODS AND RESULTS

We studied 1662 subjects (mean age 57, 51% women) in the Framingham Offspring Study who underwent carotid ultrasonography and had both biological parents in the original (parental) cohort. Parental CHD events were validated prospectively by a physician endpoint committee. The associations of carotid intima-media thickness (IMT) with premature parental CHD (occurring before age 60) and any parental CHD (no age restriction) were examined in age- and multivariable-adjusted analyses. Age-adjusted mean internal carotid IMT was higher in subjects who had at least one parent with premature CHD than in those without a validated parental history of premature CHD (men 1.13 versus 1.04 mm, P<0.01; women 0.92 versus 0.85 mm, P=0.03). In both sexes, these differences remained significant after adjustment for cardiovascular risk factors. In analyses without a restriction on parental age of CHD onset, the association between carotid IMT and parental CHD was not statistically significant. There was also no significant association of common carotid IMT with premature or any parental CHD.

CONCLUSIONS

These findings suggest that subclinical atherosclerosis, assessed in the carotid arteries, is more prevalent in individuals with a family history of CHD. Early-onset parental CHD, in particular, identifies offspring with a strong familial predisposition to atherosclerosis.

Early carotid atherosclerosis and family history of vascular disease: specific effects on arterial sites have implications for genetic studies

OBJECTIVE

Carotid artery intima-media thickness (IMT) is an intermediate phenotype for atherosclerosis. In a community population (n=5400), we determined whether a parental history of myocardial infarction (MI) or stroke is associated with increased IMT and whether associations differ at specific sites in the carotid arterial tree.

METHODS AND RESULTS

Using regression modeling, the proportion of IMT that remains unexplained after controlling for vascular risk factors was determined. A parental history of stroke was associated with both increased common carotid artery (CCA) and increased internal carotid artery (ICA)-IMT, but in young individuals (<or=60 years of age), the association was stronger with ICA-IMT, with an odds ratio (95% CI) for ICA-IMT in the highest quartile of 2.31 (1.67 to 3.21), P<0.001, compared with 1.53 (1.07 to 2.20), P=0.019, for CCA-IMT. In contrast, a parental history of MI was associated with increased CCA-IMT both overall and in young individuals but not with ICA-IMT, with an odds ratio (95% CI) for increased CCA-IMT of 2.51 (1.94 to 3.25), P<0.001, compared with 1.03 (0.78 to 1.35), P=0.861, for ICA-IMT.

CONCLUSIONS

IMT has a significant familial component that is independent of conventional risk factors. Associations for stroke and MI differ at specific sites in the carotid arterial tree. Although commonly used aggregate CCA/ICA-IMT measures may be appropriate for candidate gene studies investigating stroke risk, these results suggest that CCA-IMT alone may be a better marker for MI risk.

Genetic and environmental contributions to atherosclerosis phenotypes in men and women: heritability of carotid intima-media thickness in the Framingham Heart Study

BACKGROUND AND PURPOSE

Carotid intima-media thickness (IMT) is a quantitative measure of subclinical atherosclerosis that is predictive of subsequent myocardial infarction and stroke. There is controversy regarding the proportion of variability in IMT explained by genetic factors. Thus, it is uncertain whether carotid IMT is a heritable trait that can be used in genetic studies.

METHODS

From 1996 to 1998, we measured carotid IMT in 906 men (mean age, 56.7 years) and 980 women (mean age, 57.4 years) from 586 extended families (1630 sib pairs) in the Framingham Offspring cohort. B-mode carotid ultrasonography was used to define mean and maximum IMT of the common carotid artery (CCA) and internal carotid artery (ICA). Correlation coefficients were calculated in pairs of siblings. Variance component methods were used to estimate heritability with crude, age- and sex-adjusted, and multivariable-adjusted normalized deviates.

RESULTS

Multivariable-adjusted correlation coefficients for mean CCA and ICA IMT were 0.16 and 0.16, respectively. Crude, age- and sex-adjusted, and multivariable-adjusted heritabilities were 0.67, 0.44, and 0.38 for the mean CCA IMT (all P<0.001) and 0.43, 0.37, and 0.35 for the mean ICA IMT (all P<0.001). For CCA IMT, 27% of the overall variance was due to measured covariates; 38% was due to heritable factors.

CONCLUSIONS

These data suggest that a substantial proportion of the variability in carotid IMT is explained by genetic factors. Further studies of genetic linkage and candidate gene association are warranted to identify specific genetic variants predisposing to subclinical atherosclerosis and stroke.

Family studies: their role in the evaluation of genetic cardiovascular risk factors

Early epidemiological studies showed that genetic factors contribute to the risk of cardiovascular disease. Genetic epidemiological studies based upon families can be used to investigate familial trait aggregation, to localize genes implicated in cardiovascular diseases in the human genome, and to establish the role of environmental factors. Family studies can be also used to identify the physiological role of candidate genes for cardiovascular diseases, and to characterize shared environmental risk factors and their impact on the expression of genetic predisposition. The present paper reviews the existing family studies with special emphasis on those which have studied healthy populations in relation to cardiovascular disease such as the Framingham Heart Study, the National Heart, Lung, and Blood Institute Family Heart Study, and the STANISLAS cohort.

Intima-media thickness: a new tool for diagnosis and treatment of cardiovascular risk

Increased intima-media thickness (IMT) is a non-invasive marker of early arterial wall alteration, which is easily assessed in the carotid artery by B-mode ultrasound, and more and more widely used in clinical research. Methods of IMT measurement can be categorized by two approaches: (i) measurement at multiple extracranial carotid sites in near and far walls and (ii) computerized measurement restricted to the far wall of the distal common carotid artery. Because IMT reflects global cardiovascular risk, its normal value might be better defined in terms of increased risk rather than in terms of statistical distribution within a healthy population. The available epidemiological data indicate that increased IMT (at or above 1 mm) represents a risk of myocardial infarction and/or cerebrovascular disease. Close relationships have been shown between: (i) most traditional cardiovascular risk factors; (ii) certain emerging risk factors such as lipoproteins, psychosocial status, plasma viscosity, or hyperhomocysteinemia; and (iii) various cardiovascular or organ damages such as white matter lesion of the brain, left ventricular hypertrophy, microalbuminuria or decreased ankle to brachial systolic pressure index. Thus, IMT gives a comprehensive picture of the alterations caused by multiple risk factors over time on arterial walls. Prospective primary and secondary prevention studies have also shown that increased IMT is a powerful predictor of coronary and cerebrovascular complications (risk ratio from 2 to 6) with a higher predictive value when IMT is measured at multiple extracranial carotid sites than solely in the distal common carotid artery. Therapeutic double-blind trials have shown that lipid-lowering drugs, such as resin and overall statines, and to a lesser extent antihypertensive drugs, such as calcium antagonists, may have a beneficial effect on IMT progression in asymptomatic or in coronary patients. However, methodological standardization of IMT measurement still needs to be implemented before routine measurement of IMT can be proposed in clinical practice as a diagnostic tool for stratifying cardiovascular risk in primary prevention and for aggressive treatment decision. It can be anticipated however, that the presence of increased carotid IMT in one individual with intermediate cardiovascular risk would lead to his classification into the high-risk category and thus influence the aggressiveness of risk factor modifications.

Genetic predisposition to coronary artery disease

Understanding the genetic basis of coronary artery disease (CAD) can improve management and prevention. Family and twin studies, animal models and gene association studies support a genetic basis for CAD. Genes contribute to CAD development and progression, and response to risk factor modification and lifestyle choices. Family history is the best indicator of a predisposition to CAD and further refinement is possible with biochemical and DNA testing. Many inherited cardiovascular risk factors can be modified, such as LDL cholesterol, homocysteine and lipoprotein(a). Early detection of CAD might lead to earlier intervention for genetically susceptible individuals. However, data are lacking regarding the efficacy of this approach in preventing clinical events. Despite this lack of evidence, knowledge of genetic CAD susceptibility has value in providing risk information and guiding decision making. Further research that investigates outcomes regarding genetic risk assessment for CAD is necessary.

Epidemiology and prevention of coronary heart disease in families

Although family histories are used primarily to aid in diagnosis and risk assessment, their value is enhanced when the family is considered as a unit for research and disease prevention. The value of a family history of coronary heart disease (CHD) is increased when the age, sex, number of relatives, and age at onset of disease are incorporated in a quantitative family risk score. Medical and lifestyle risk factors that aggregate in families include dyslipidemia, hypertension, obesity, hyperfibrinogenemia, diabetes mellitus, smoking habits, eating patterns, alcohol consumption, physical activity, and socioeconomic status. Advances in detecting and understanding interactions between genetic susceptibility and modifiable risk factors should lead to improvements in prevention and treatment. However, working with families can be difficult. In the United States, families are usually small, are often widely dispersed, and may not be intact. Family histories may be unknown, affected relatives may be dead, and secular trends mask similarities among generations. Many exposures occur outside the home, and families change over time. Ethical, legal, and social issues arise when dealing with families. Nevertheless, opportunities are missed when research, clinical practice, and prevention focus on individual patients. Greater emphasis on families is needed to reduce the burden of CHD.

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.