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Biomedical subjects

Roger S Blumenthal

Publications and source records attributed to Roger S Blumenthal.

At least 37 records · Page 2Linked to original sources
PubMed2006

Aspirin and clopidogrel resistance.

Despite aspirin's and clopidogrel's proven benefit in reducing cardiovascular (CV) events, recurrent CV events still occur in patients receiving antiplatelet therapy. Many of these patients are resistant or only partially responsive to the antiplatelet effects of aspirin and clopidogrel, as determined by standard platelet assays. However, current clinical guidelines do not support routine screening for aspirin or clopidogrel resistance, in part because determination of the most appropriate screening test has not been established. This review attempts to (1) describe the phenomena of clinical aspirin and clopidogrel resistance (ie, treatment failure), (2) discuss the complexity of defining and identifying aspirin and clopidogrel resistance, (3) identify factors that may be responsible for aspirin and clopidogrel resistance, (4) outline several standard platelet function assays and their limitations, and (5) describe potential new antiplatelet therapies that may benefit aspirin- or clopidogrel-resistant patients.

Aspirin↗
PubMed2005

Comprehensive coronary risk determination in primary prevention: an imaging and clinical based definition combining computed tomographic coronary artery calcium score and national cholesterol education program risk score.

Cardiovascular disease (CVD) is the leading cause of mortality and a major cause of morbidity. Coronary heart disease (CHD) accounts for nearly half of all CVD deaths. Currently estimation of risk in primary prevention is based on the Framingham risk equations, which inputs traditional risk factors and is helpful in predicting the development of CHD in asymptomatic individuals. However many individuals suffer events in the absence of established risk factors for atherosclerosis and broad based population risk estimations may have little precision when applied to a given individual. To meet the challenge of CHD risk assessment, several tools have been developed to identify atherosclerotic disease in its preclinical stages. This paper aims to incorporate information from coronary artery calcification (CAC) scoring from a computed tomographic "heartscan" (using Electron Beam Tomography (EBT) as the validated prototype) along with current Framingham risk profiling in order to refine risk on an absolute scale by combining imaging and clinical data to affect a more comprehensive calculation of absolute risk in a given individual. For CAC scores above the 75th percentile but <90th percentile, 10 years is added to chronological age, and for CAC scores above the 90th percentile, 20 years is added to current chronological age. Among those in whom a positive CAC score is the norm such as older individuals (men> or =55 years, women> or =65 years) a CAC = 0 will result in an age point score corresponding to the age-group whose median CAC score is zero i.e., 40-44 years for men and 55-59 years for women. The utilization of CAC scores allows the inclusion of sub-clinical disease definition into the context of modifiable risk factors as well as identifies high-risk individuals requiring aggressive treatment.

Aged↗
PubMed2005

Increased level of cardiorespiratory fitness blunts the inflammatory response in metabolic syndrome.

OBJECTIVE: The presence of metabolic syndrome is associated with a higher degree of inflammation. We sought to assess whether the higher levels of cardiorespiratory fitness attenuate the levels of inflammation in people with metabolic syndrome. RESEARCH DESIGN AND METHODS: We studied 449 consecutive asymptomatic men (47+/-7 years) who underwent a maximal treadmill exercise test according to the Bruce protocol. Cardiorespiratory fitness was divided into tertiles based on metabolic equivalents (METs). White blood cells (WBC) (x10(9) cells/L) count was used as marker of inflammation. RESULTS: In our study population, 23% of the participants had the metabolic syndrome. The WBC count increased (p < 0.0001 for trend) with increasing number of risk factors for metabolic syndrome; however there was an inverse relationship (p < 0.0001 for trend) with increasing tertiles of fitness (6.47 cells x 10(9) cells/L for lowest tertile and 5.7 x 10(9) cells/L for highest tertile). Multiple linear regression analyses demonstrated that as compared to individuals with no MS risk factor, the WBC count remained significantly higher in men with metabolic syndrome in first tertile (regression coefficient: 1.2, 95% CI 0.4-2.0, p = 0.003) and second tertile (regression coefficient: 0.61, 95% CI 0.4-2.0, p = 0.02) of cardiorespiratory fitness, respectively. However, in the highest tertile of fitness no increase in level of WBC count was observed with increasing metabolic syndrome risk factors. CONCLUSION: Our findings suggest that in people with metabolic syndrome an increased level of physical fitness might exert its beneficial effect via attenuating inflammation.

Adult↗
PubMed2005

Ethnic differences of the presence and severity of coronary atherosclerosis.

BACKGROUND: Although cardiovascular risk factor levels are substantially different in Caucasians, African-American, Hispanics, and Asians, the relative rates of coronary heart disease in these groups are not consistent with these differences. The objective of the study is to assess the differences in the prevalence and severity of coronary artery calcification, as a measure of atherosclerosis, in these different ethnic groups. METHODS: Electron-beam tomography was performed in 16,560 asymptomatic men and women (Asians=1336, African-Americans=610, Hispanics=1256) aged >or=35 years referred by their physician for cardiovascular risk evaluation. The study population encompassed 70% males, aged 52+/-8 years. RESULTS: Caucasians were more likely to present with dyslipidemia (p<0.0001), while African-Americans and Hispanics had a higher prevalence of smoking, diabetes, and hypertension (all p<0.001). After adjustment for age, gender, risk factors, and treatment for hypercholesterolemia, compared with Caucasians, the relative risks for men having coronary calcification were 0.64 (95% CI: 0.48-0.86) in African-Americans, 0.88 (95% CI: 0.67-1.15) in Hispanics, and 0.66 (95% CI: 0.55-0.80) in Asians. After similar adjustments, the relative risks for women having coronary calcification, were 1.58 (95% CI: 1.13-2.19) for African-Americans, 0.84 (95% CI: 0.66-1.06) in Hispanics, and 0.71 (95% CI: 0.56-0.89) in Asian women. After adjusting for age and risk factors using multivariable analysis, African-American men were least likely to have any coronary calcium while African-American women had significantly higher OR of any calcification. Asian men and women had significantly lower OR of any calcification. There was no significant difference in prevalence or severity of atherosclerosis between Hispanics and Caucasians, in men or women. CONCLUSIONS: Our study results demonstrate significant difference in the presence as well as severity of calcification according to ethnicity, independent of atherosclerotic risk factors. Results from this study (physician referred) closely parallel the results from MESA (population based, measured risk factors). Ethnic specific data on the predictive value of differing coronary calcium scores are needed.

Black or African American↗
PubMed2005

Difference in atherosclerosis burden in different nations and continents assessed by coronary artery calcium.

We utilized coronary artery calcium scores (CACS) to assess differences in atherosclerosis burden between asymptomatic White populations living in continents with different cardiovascular disease rates. The similarities in the genetic pool between Brazilian and Portuguese Caucasian subjects offered an opportunity to assess the influence of environmental factors on the development of atherosclerosis. We reviewed CACS data from 17,563 individuals (12,378 men and 5169 women) collected in the USA (74% of the subjects), Brazil (15% of the subjects) and Portugal (11% of the subjects). CACS was absent in 80 and 88% of Portuguese men and women, compared with 46 and 62% and 33 and 59% of Brazilian and US counterparts (p<0.0001). Although the US subjects showed the lowest prevalence of risk factors they had a higher median (interquartile range) CACS than the Brazilian and the Portuguese cohorts: 4 (0;87), 1 (0;68) and 0 (0;0), respectively (p<0.0001). After adjusting for differences in age and cardiovascular risk factors, US men showed higher relative risk ratios of having any CACS than either Brazilian or Portuguese men. Brazilian and US women did not differ as far as risk of CACS although they demonstrated a greater risk than Portuguese women. In this study, significant differences in CACS were detected among three nations in different continents. The CACS differences paralleled the respective cardiovascular mortality rates.

Adult↗
PubMed2005

Detection of high-risk young adults and women by coronary calcium and National Cholesterol Education Program Panel III guidelines.

OBJECTIVES: The purpose of this study was to investigate the classification of cardiovascular risk in young individuals and women according to the National Cholesterol Education Program (NCEP) guidelines across a continuum of coronary calcium scores (CCS). BACKGROUND: Current NCEP guidelines might underestimate cardiovascular risk in young individuals and women. METHODS: The study population consisted of 1,611 asymptomatic individuals (67% men, mean age: 53 +/- 10 years) who presented to a single electron beam tomography facility for coronary artery calcium screening. Participants were categorized into low-risk (n = 738, 46%), intermediate-risk (n = 583, 36%), moderately high-risk (n = 263, 16%), and high-risk (n = 27, 2%) according to the NCEP Panel III guidelines. RESULTS: Absence of calcium, CCS of 0 to 99 (mild), 100 to 399 (moderate), and > or =400 (severe), was observed in 572 (35%), 707 (44%), 192 (12%), and 140 (9%) of the patients, respectively. A high CCS percentile (> or =75th percentile) was present in 426 (26%) individuals. Overall, 59% and 78% of participants with CCS > or =400 and CCS > or =75th percentile were not identified as high risk and candidates for pharmacotherapy on the basis of NCEP categories. Furthermore, women as well as young individuals were less likely to be considered candidates for pharmacotherapy compared with men and older individuals in each CCS category. CONCLUSIONS: The NCEP guidelines seem to underestimate cardiovascular risk in young asymptomatic individuals and women. For these individuals, assessment of plaque burden might provide incremental value to global risk assessment.

Aged↗
PubMed2005

Enhanced risk assessment in asymptomatic individuals with exercise testing and Framingham risk scores.

BACKGROUND: National Cholesterol Education Program Adult Treatment Panel III (ATP III) guidelines recommend the use of Framingham risk scores (FRS) for cardiovascular assessment of asymptomatic individuals. We hypothesized that risk prediction could be improved with 2 non-ECG exercise test measures, exercise capacity (metabolic equivalents, or METs) and heart rate recovery (HRR). METHODS AND RESULTS: An asymptomatic cohort with baseline treadmill tests (n=6126; 46% women, FRS <20%) was followed up prospectively for 20 years. Individuals with low (median or less) HRR or METs experienced 91% of all cardiovascular disease (CVD) deaths (225/246). After FRS adjustment, low HRR and METs individually were highly significant predictors of CVD death, but low HRR and METs together were associated with substantially higher risk (adjusted hazard ratio compared with high HRR/high METs for women 8.51, 95% CI 3.65 to 19.84; for men, 3.53, 95% CI 2.03 to 6.15; P<0.001 for both). At 10-year follow-up, FRS-adjusted CVD death risk associated with low HRR/low METs was less than at 20 years but remained significant (women 3.83, 95% CI 1.09 to 13.47, and men 2.70, 95% CI 1.11 to 6.55). The application of HRR/METs information to FRS assessment identified those at high risk (>0.5% annual CVD mortality) in half of women with FRS 6% to 9% and 10% to 19% and just under half of men with FRS 10% to 19%. Low HRR/low METs was also associated with an increased relative risk of CVD death in individuals with low-risk FRS (FRS <6% in women and <10% in men), but absolute CVD mortality rates were low in this subgroup. CONCLUSIONS: Exercise testing may be a useful adjunct for clinical risk assessment in asymptomatic women with FRS 6% to 19% and men with FRS 10% to 19%.

Adult↗
PubMed2005

Visualizing coronary calcium is associated with improvements in adherence to statin therapy.

BACKGROUND: Many patients lack motivation to control cardiovascular risk factors and clinicians have long sought ways to activate apathetic patients. Despite significant and consistent data on the benefits of lipid-lowering agents to reduce cardiovascular events, adherence and utilization of these agents remains low. We evaluated whether visualization of coronary calcium would positively affect patients' adherence rates. METHODS: We evaluated patients who underwent electron beam tomography (EBT) coronary calcium evaluation at least 1 year prior with a survey questioning them about health behaviors. Patients filled out baseline and follow-up questionnaires relating to lifestyle modifications, including statin utilization, diet, exercise, tobacco cessation and vitamin/antioxidant utilization. RESULTS: The study population consisted of 505 individuals on statin therapy on baseline who were followed for a mean of 3 +/- 2 years. Overall the statin compliance was lowest (44%) among those with CAC score in the first quartile (0-30), whereas 91% of individuals with baseline CAC score in the fourth quartile (>or= 526) adhered to statin therapy. In multivariable analysis, after adjusting for cardiovascular risk factors, age, and gender, higher baseline CAC scores were strongly associated with adherence to statin therapy. CONCLUSIONS: In addition to risk stratification for the asymptomatic person, patients visualizing coronary artery calcium may improve utilization and adherence to lipid-lowering therapy. Outcome studies and randomized trials need to be done to quantify the true value and cost-effectiveness of this approach.

Calcinosis↗
PubMed2005

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.

Adult↗
PubMed2005

Diets and cardiovascular disease: an evidence-based assessment.

With rising obesity, despite low-fat diet recommendations, there is an increased interest in weight loss and alternative dietary approaches for cardiovascular health. Physicians must have an understanding of the literature to better counsel their patients about diets and cardiovascular disease. This review examines several dietary approaches to cardiovascular health and evaluates the available scientific evidence regarding these diets.

Cardiovascular Diseases↗
PubMed2005

Relation of serum uric acid with metabolic risk factors in asymptomatic middle-aged Brazilian men.

This study in 352 asymptomatic middle-aged Brazilian men demonstrated that serum uric acid increases linearly with an increasing number (0 to >/=3) of metabolic risk factors (5.78 +/- 1.1, 6.14 +/- 1.0, 6.27 +/- 1.1, and 6.79 +/- 1.3, p <0.001). In patients who had >/=3 metabolic risk factors, there was a higher prevalence of serum uric acid in the highest quartile (7.2 to 10.3 mg/dl) than in the lowest quartile (2.6 to 5.4 mg/dl, 35% vs 12%, p <0.001). Mean serum levels of uric acid were higher in those who had an abnormal ratio of >/=3 for triglyceride to high-density lipoprotein (suggesting insulin resistance) than in those who had a normal ratio (6.6 +/- 1.2 vs 5.87 +/- 1 mg/dl, p <0.001).

Adult↗
PubMed2005

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.

Adult↗
PubMed2005

Relation of family history of premature coronary heart disease and metabolic risk factors to risk of coronary arterial calcium in asymptomatic subjects.

We studied 6,141 consecutive, asymptomatic, nondiabetic patients who underwent electron beam tomography and explored the interaction between metabolic risk factors (RFs) and premature family history (FH) of coronary heart disease (CHD) in predicting the presence and severity of coronary arterial calcium (CAC). In the presence of >2 metabolic RFs, patients with a positive FH of premature CHD had a significantly higher prevalence of any CAC, CAC >/=100, and CAC >/=75th age-gender percentile than those without a FH of CHD. Our study demonstrated that a familial propensity to subclinical atherosclerosis interacts with the presence of >/=2 metabolic RFs, magnifying the risks for those exposed to both.

Calcinosis↗
PubMed2005

Opportunity for intervention to achieve American Heart Association guidelines for optimal lipid levels in high-risk women in a managed care setting.

BACKGROUND: The American Heart Association (AHA) recently established evidence-based recommendations for cardiovascular disease (CVD) prevention in women, including lipid management. This study evaluated optimal lipid-level attainment and treatment patterns on the basis of these guidelines in high-risk women in a managed care setting. METHODS AND RESULTS: We conducted a historical prospective cohort analysis of a 1.1-million-member, integrated, managed-care database. Eligible high-risk women were those with evidence of previous CVD or risk equivalent who had a full lipid panel available between October 1, 1999, and September 30, 2000; were naive to lipid therapy; and had a minimum of 12 months health plan eligibility preindex and postindex lipid panel. Optimal lipid levels were defined as LDL cholesterol (LDL-C) <100 mg/dL, HDL cholesterol (HDL-C) >50 mg/dL, non-HDL-C <130 mg/dL, and triglycerides <150 mg/dL. Laboratory values and lipid pharmacotherapy were assessed longitudinally over the postindex follow-up (up to 36 months). A total of 8353 high-risk women (mean age, 66+/-14 years) with a mean follow-up of 27+/-8 months were included. Only 7% attained optimal combined lipid levels initially, and this increased to 12% after 36 months. Lipid-modifying therapy was initiated in 32% of patients, including 35% of women with LDL-C > or =100 mg/dL and 15% with LDL-C <100 mg/dL. CONCLUSIONS: Among high-risk women, few attained the AHA's standards for all lipid fractions, and only one third received recommended drug therapy, highlighting significant opportunities to apply evidence-based recommendations to manage lipid abnormalities in high-risk women.

Adult↗
PubMed2005

A simplified approach to the management of non-ST-segment elevation acute coronary syndromes.

CONTEXT: While current practice guidelines provide an evidence-based approach to management of acute coronary syndromes (ACS), application of the evidence by individual physicians has been suboptimal. OBJECTIVE: To assess and synthesize the evidence regarding optimal management of non-ST-segment elevation ACS (NSTE-ACS). DATA SOURCES: Systematic searches of peer-reviewed publications were performed in MEDLINE and the Cochrane Database from January 1990 through November 2004, with consultation by content experts. Search terms included antiplatelet therapy, antithrombotic therapy, angiotensin-converting enzyme inhibition, angiotensin receptor blockade, beta-blockade, hypertension, hyperlipidemia, cigarette smoking, diet, diabetes mellitus, exercise, myocardial ischemia, and coronary artery disease. STUDY SELECTION AND DATA EXTRACTION: Criteria for selection of studies included controlled study design, English language, and clinical pertinence. Data quality was based on the publishing journal and relevance to clinical management of NSTE-ACS. DATA SYNTHESIS: While outcomes of controlled studies support a comprehensive approach in the management of patients with NSTE-ACS, many physicians perceive existing guidelines as lengthy and complex. After risk stratification to identify those patients most likely to benefit from an early invasive vs early conservative strategy, a comprehensive management plan can be assembled through an "ABCDE" approach. The elements of this include "A" for antiplatelet therapy, anticoagulation, angiotensin-converting enzyme inhibition, and angiotensin receptor blockade; "B" for beta-blockade and blood pressure control; "C" for cholesterol treatment and cigarette smoking cessation; "D" for diabetes management and diet; and "E" for exercise. CONCLUSION: An "ABCDE" approach for the management of NSTE-ACS provides a practical and systematic means to implement evidence-based medicine into clinical practice.

Adrenergic beta-Antagonists↗
PubMed2005

Diabetes and progression of coronary calcium under the influence of statin therapy.

BACKGROUND: Coronary artery calcium (CAC) is a sensitive marker for the detection of coronary heart disease (CHD). Coronary artery calcification can be accurately quantified using electron beam tomography (EBT). We sought to evaluate the progression of atherosclerosis in asymptomatic persons with type 2 diabetes and measure the influence of statin therapy on CAC progression. METHODS: We evaluated 163 asymptomatic patients with type 2 diabetes (120 men, 43 women). Patients were physician referred and underwent 2 consecutive EBT scans at least 1 year apart. Demographic data, risk factors for CHD, and medication use were collected. Patients with symptoms or known CHD were excluded. RESULTS: The mean age was 65 +/- 10 years. The mean CAC score at baseline was 651 +/- 414. Only 9 (6%) of 163 of participants had scores of 0 at baseline. The time between scans averaged 27 +/- 15 months. Patients not treated with statins demonstrated a median annual increase in CAC progression of 20% (4%-44%), whereas statin-treated patients demonstrated increase of 10% (4%-25%) (P = .0001). Hemoglobin A 1c was weakly associated with CAC progression. CONCLUSIONS: Asymptomatic diabetic patients show a high prevalence of atherosclerosis based on high frequency of coronary calcification. Statin therapy induced a 50% reduction in the rate of CAC progression. As rapid CAC progression has been associated with coronary events, EBT may serve as a noninvasive method for following atherosclerosis and response to therapy.

Adult↗