Ethnic differences in the prognostic value of coronary artery calcification for all-cause mortality.

OBJECTIVES: The purpose of this study was to evaluate the prognostic value of coronary artery calcium (CAC), a known marker of subclinical atherosclerosis, in a large, ethnically diverse cohort of 14,812 patients for the prediction of all-cause mortality. BACKGROUND: Disparities in case fatality rates for heart disease among ethnic groups are well known. In 2001, rates of death from heart disease were 30% higher among African Americans (AA) than non-Hispanic whites (NHW). Some of this variability may be due to differing pathophysiological mechanisms and effects of underlying atherosclerosis. METHODS: Ten-year death rates from all causes (total deaths = 505) were compared using risk-adjusted Cox proportional hazards models in AA (n = 637), Hispanic (HS, n = 1,334), Asian (AS, n = 1,065), and NHW (n = 11,776) populations. RESULTS: Ethnic minority patients were generally younger (0.3 to 4 years), more often persons with diabetes (p < 0.0001), hypertensive (p < 0.0001), and female (p < 0.0001). The prevalence of CAC scores > or =100 was highest in NHW (31%) and lowest for HS (18%) (p < 0.0001). Overall survival was 96%, 93%, and 92% for AS, NHW, and HS, respectively, as compared with 83% for AA (p < 0.0001). When comparing prognosis by CAC scores in ethnic minorities as compared with NHW, relative risk ratios were highest for AA with CAC scores > or =400 exceeding 16.1 (p < 0.0001). Hispanics with CAC scores > or =400 had relative risk ratios from 7.9 to 9.0, whereas AS with CAC scores > or =1,000 had relative risk ratios 6.6-fold higher than NHW (p < 0.0001). CONCLUSIONS: Consistent with population evidence, AA with increasing burden of subclinical coronary artery disease were the highest-risk ethnic minority population. These data support a growing body of evidence noting substantial differences in cardiovascular risk by ethnicity.     

Racial differences among high-risk patients presenting with non-ST-segment elevation acute coronary syndromes (results from the SYNERGY trial)

Management and outcomes of patients with acute coronary syndromes (ACSs) may vary according to patient race and ethnicity. To assess racial differences in presentation and outcome in high-risk North American patients with non-ST-segment elevation (NSTE) ACS, we analyzed baseline racial/ethnic differences and all-cause death or nonfatal myocardial infarction (MI) in 6,077 white, 586 African-American, and 344 Hispanic patients through 30-day, 6-month, and 1-year follow-up. Frequencies of hypertension were 66% for whites, 83% for African-Americans, and 78% for Hispanics (overall p <0.001). Use of angiography was similar across groups. Use of percutaneous coronary intervention (46% for whites, 41% for African-Americans, and 45% for Hispanics, overall p = 0.046) and coronary artery bypass grafting (20% for whites, 16% for African-Americans, and 22% for Hispanics, overall p = 0.044) differed. African-American patients had significantly fewer diseased vessels compared with white patients (p = 0.0001). Thirty-day death or MI was 14% for whites, 10% for African-Americans, and 14% for Hispanics (overall p = 0.034). After adjustment for baseline variables, African-American patients had lower 30-day death or MI compared with white patients (odds ratio 0.73, 95% confidence interval 0.55 to 0.98). There were no differences in 6-month death or MI across racial/ethnic groups. In conclusion, baseline clinical characteristics differed across North American racial/ethnic groups in the SYNERGY trial. African-American patients had significantly better adjusted 30-day outcomes but similar 6-month outcomes compared with white patients.     

Ethnic differences in stressors, resources, and psychological outcomes of family caregiving: a meta-analysis

PURPOSE: We investigated ethnic differences in caregiver background variables, objective stressors, filial obligations beliefs, psychological and social resources, coping processes, and psychological and physical health. DESIGN AND METHODS: We used a meta-analysis to integrate the results of 116 empirical studies. RESULTS: Ethnic minority caregivers had a lower socioeconomic status, were younger, were less likely to be a spouse, and more likely to receive informal support. They provided more care than White caregivers and had stronger filial obligations beliefs than White caregivers. Asian-American caregivers, but not African-American and Hispanic caregivers, used less formal support than non-Hispanic White caregivers. Whereas African-American caregivers had lower levels of caregiver burden and depression than White caregivers, we found that Hispanic and Asian-American caregivers were more depressed than their White non-Hispanic peers. However, all groups of ethnic minority caregivers reported worse physical health than Whites. Observed ethnic differences in burden and depression were influenced by study characteristics, such as the type of illness of the care recipient and the representativeness of the sample. IMPLICATIONS: The results suggest that more specific theories are needed to explain differential effects of ethnic minority groups of caregivers. Intervention needs vary, in part, between ethnic groups of caregivers.     

Health status disparities in ethnic minority patients with rheumatoid arthritis: a cross-sectional study

OBJECTIVE: To examine disparities in disability, pain, and global health between Caucasian (n = 4294) and African American (n = 283) and Caucasian and Hispanic (n = 153) patients with rheumatoid arthritis (RA). METHODS: Patients were from 9 Arthritis, Rheumatism, and Aging Medical Information System databanks. Cross-sectional data were derived from the Health Assessment Questionnaire. Staged multivariate analysis of covariance was used to explore roles of possible contributing factors (age, sex, education, disease duration, number of comorbid conditions, and treatment) to ethnic minority disparities. RESULTS: The cohort was 91% Caucasian and 76% female. Caucasians were significantly older than African Americans and Hispanics (62 vs 56 and 55 yrs; both p < 0.0001 from Caucasians), better educated (13 vs 12 and 12 yrs; both p < 0.0001 from Caucasians), and had their RA longer (16 vs 13 and 15 yrs; p < 0.01 for African Americans). Unadjusted disability scores were statistically indistinguishable, but pain was worse in both ethnic groups (p < 0.01), and global health worse in Hispanics (p < 0.05). After adjustment for covariates, African Americans had the poorest outcomes in all 3 measures, although only pain in African Americans (p < 0.05) was statistically different from Caucasians. CONCLUSION: Results of this exploratory study suggest that in a relatively similar cohort of patients with RA, minority health disparities exist. Both ethnic groups had poorer outcomes for all 3 measures than Caucasians after adjustment. Additional study and longitudinal research with larger numbers of patients are needed to improve our understanding of these differences and to assess potential causal roles.     

Independent contribution of myocardial perfusion defects to exercise capacity and heart rate recovery for prediction of all-cause mortality in patients with known or suspected coronary heart disease

OBJECTIVES: The goal of this study was to determine the value of thallium201 single photon emission computed tomography (SPECT) imaging for prediction of all-cause mortality when considered along with functional capacity and heart rate recovery. BACKGROUND: Myocardial perfusion defects identified by thallium201 SPECT imaging are predictive of cardiac events. Functional capacity and heart rate recovery are exercise measures that also have prognostic implications. METHODS: We followed 7,163 consecutive adults referred for symptom-limited exercise thallium SPECT (mean age 60 +/- 10, 25% women) for 6.7 years. Using information theory, we identified a probable best model relating nuclear findings to outcome to calculate a prognostic nuclear score. RESULTS: There were 855 deaths. Intermediate- and high-risk prognostic nuclear scores were noted in 28% and 10% of patients. Compared with those with low-risk scans, patients with an intermediate-risk score were at increased risk for death (14% vs. 9%, hazard ratio: 1.67, 95% confidence interval [CI]: 1.44 to 1.95, p < 0.0001), while those with high-risk scores were at greater risk (24%, hazard ratio: 2.98, 95% CI: 2.49 to 3.56, p < 0.0001). In multivariable analyses that adjusted for clinical characteristics, functional capacity and heart rate recovery, an intermediate-risk nuclear score remained predictive of death (adjusted hazard ratio: 1.50, 95% CI: 1.28 to 1.76, p < 0.0001), as did a high-risk score (adjusted hazard ratio: 2.76, 95% CI: 2.13 to 2.56, p < 0.0001). Impaired functional capacity and decreased heart rate recovery provided additional prognostic information. CONCLUSIONS: Myocardial perfusion defects detected by thallium SPECT imaging are independently predictive of long-term all-cause death, even after accounting for exercise capacity, heart rate recovery and other potential confounders.     

Incremental prognostic power of single-photon emission computed tomographic myocardial perfusion imaging in patients with known or suspected coronary artery disease

Noninvasive stress testing provides prognostic information in patients who have suspected coronary artery disease, but limited data are available on the incremental value of myocardial perfusion testing in high-risk patients. We studied 3,275 patients who underwent cardiac catheterization and single-photon emission computed tomographic (SPECT) perfusion imaging. Median follow-up was 3.1 years for death, cardiovascular death, and a composite of cardiovascular death or nonfatal myocardial infarction. Using Cox's proportional hazards regression models, we examined the relation of SPECT summed stress score (SSS) to each outcome. A 1-unit change in SSS was associated with increased risks of 4%, 7%, and 5% for death, cardiovascular death, and death or nonfatal myocardial infarction, respectively (all p <0.0001). To examine the prognostic utility of SPECT, after baseline adjustments, SSS and angiographic results provided incremental prognostic information for each outcome. Thus, SPECT SSS provides information beyond clinical and angiographic data in patients who have known or suspected coronary artery disease. This information may be useful for stratifying patients into multiple risk categories for future cardiovascular events and potentially guiding therapy.     

H. pylori infection and genotyping in patients undergoing upper endoscopy at inner city hospitals

Kings County Hospital (KCH), and St. John's Episcopal Hospital (SJH) are inner-city hospitals in New York City serving predominantly minority populations. Staten Island University Hospital (SIUH) serves a predominantly middle-class Caucasian population. We examined H. pylori (HP) infection in patients undergoing upper endoscopy at these hospitals. Two gastric biopsies were obtained from each patient. One biopsy was examined by histology or the rapid urease test for the presence of HP. The other was subjected to analysis by PCR to detect HP DNA and to identify putative HP virulence factors. Of 200 subjects, 54% were African-American, 10% were Hispanic, and 36% were Caucasian. HP infection rates in African-American, Hispanic, and Caucasian patients were 43%, 20%, and 11%, respectively. Many of the African-American patients are recent immigrants from the Caribbean Islands. In these patients, an inverse relationship was observed between HP infection and the number of years living in the United States. Higher levels of HP infection were observed in patients with duodenitis and peptic ulcer disease. With respect to HP virulence factors, the vacA s1b and m1 alleles, as well as the iceA2 allele were the predominant alleles expressed in HP-positive samples obtained from African-Americans. The cagA gene was detected in 81% of HP-positive samples. However, CagA positivity was not related to any specific gastrointestinal disorder. Our findings indicate that among several ethnic groups served by three hospitals, African-American patients have the highest rate of HP infection. Moreover, in African-American patients undergoing endoscopy: (1) HP infection was inversely related to the number of years the patients have been living in the USA; (2) HP infection rates were higher in patients diagnosed with duodenitis and peptic ulcer disease versus other disorders; (3) expression of the CagA gene was not associated with any specific gastroduodenal disorder; and (4) there was little allelic heterogeneity with respect to VacA and IceA subtypes. These findings suggest that inner-city African-Americans are more likely to be infected with HP and suffer from more serious gastroduodenal disorders than other ethnic groups.     

Infarct size determination by technetium 99m sestamibi single-photon emission computed tomography predicts survival in patients with chronic coronary artery disease

BACKGROUND: The prognostic value of infarct size quantification by technetium 99m sestamibi single-photon emission computed tomography (SPECT) in patients with chronic coronary artery disease (CAD) has not been established.Methods And Results Between September 1994 and May 1995, 1323 patients with known or suspected CAD were referred for perfusion imaging for clinical reasons and had infarct size determined by quantitative SPECT imaging. Patients underwent exercise stress (61%), pharmacologic stress (37%), and rest imaging (3%). Patients were excluded if they had cardiomyopathy, valvular heart disease, or myocardial infarction within 3 weeks of the SPECT study. There were 1224 patients who formed the study group. Follow-up was 94% complete at a median of 1.9 +/- 0.4 years. Sixty-five percent of patients had no measurable infarct. Among the patients with measurable infarcts, the mean infarct size by sestamibi imaging was 15.0% +/- 14.5% of the left ventricle (25% of infarcts /=19% of the left ventricle). By using stepwise regression analysis, age, diabetes, and hypercholesterolemia were all clinical predictors of overall death (P <.05). For cardiac death, only age and diabetes were significant. After adjusting for these clinical variables, infarct size remained an independent predictor of overall death (P =. 001) and survival free of cardiac death (P =.0002). However, when first-pass left ventricular ejection fraction was added to the models, infarct size was no longer significant. CONCLUSIONS: Infarct size determination by SPECT (99m)Tc sestamibi can predict subsequent death in patients with chronic CAD, although ejection fraction appears to have greater prognostic value.     

Prediction of cardiac death in hemodialysis patients by myocardial fatty acid imaging.

OBJECTIVES: The aim was to evaluate the potential of single-photon emission computed tomography (SPECT) to predict cardiac death in chronic hemodialysis patients using the iodinated fatty acid analogue iodine-123 123I-beta-methyl iodophenyl-pentadecanoic acid (BMIPP). BACKGROUND: We previously reported that BMIPP SPECT could detect asymptomatic coronary artery disease with high sensitivity in hemodialysis patients. METHODS: We prospectively enrolled 375 asymptomatic hemodialysis patients who had undergone dual SPECT using 123I-BMIPP and 201thallium (Tl) chloride. Patients who had a clinical history of myocardial infarction and/or coronary revascularization were excluded from the study. Uptake on SPECT images was graded in 17 segments on a 5-point scale (0 normal, 4 absent) and assessed as summed BMIPP or Tl scores. RESULTS: During a 3.6 +/- 1.0-year follow-up, 57 patients who had undergone coronary revascularization within 60 days of SPECT were excluded from the analysis. Among the remaining 318 patients (male/female: 170/148; 64 +/- 12 years of age), 50 died of cardiac events (acute myocardial infarction 22, congestive heart failure 17, cardiac sudden death 11). Stepwise Cox hazard analysis associated cardiac death with age (> or =70 years) and with severely abnormal BMIPP SPECT images (BMIPP summed scores > or =12: hazard ratio 21.894; p < 0.0001). Kaplan-Meier analysis showed that the cardiac death-free survival rates at 3 years were 61% and 98% in patients with BMIPP summed scores of > or =12 and <12, respectively. CONCLUSIONS: Severely impaired myocardial fatty acid metabolism, which might mainly reflect repetitive myocardial ischemia, can identify a high-risk group of cardiac death among hemodialysis patients.     

Characteristics of contemporary patients with hypertension and coronary artery disease

BACKGROUND: Despite a high prevalence of hypertension in the population with CAD, there are limited data describing the clinical characteristics and treatments, as well as their interrelations in these patients. This is particularly true for black and Hispanic patients who have been underrepresented in randomized CAD trials. HYPOTHESIS: There exist racial and ethnic differences that define the characteristics of patients with both coronary artery disease (CAD) and hypertension. METHODS: This report describes the characteristics of Caucasian, Hispanic, and black patients enrolled in the International Verapamil SR/trandolapril Study (INVEST), a prospective trial undertaken exclusively in patients with CAD and hypertension. RESULTS: In all, 10,925 Caucasian, 8,045 Hispanic, and 3,029 black patients are described. An abnormal angiogram or documented myocardial infarction was observed more frequently in Caucasian patients (73%), while angina pectoris was more prevalent in Hispanic patients (87%). Diabetes and left ventricular hypertrophy were most common in black patients (33 and 29%, respectively), while hypercholesterolemia and prior revascularization (coronary artery bypass graft or angioplasty) were most common in Caucasian patients (64 and 41%, respectively). More than 60% of Hispanic and black patients were women--a unique characteristic for randomized CAD trials. Comparing race/ethnic cohorts, there were significant differences for all characteristics. More than 80% of patients in all race/ethnic groups were receiving antihypertensive therapy; however, only fewer than 25% had controlled blood pressure according to guidelines from the sixth report of the Joint National Committee on Prevention, Detection, Evaluation and Treatment of High Blood Pressure. CONCLUSIONS: This high-risk population of hypertensive patients with CAD has been undertreated and does not have well-controlled BP. Race/ethnic differences were observed for clinical characteristics and medication use.     

Hypertension Management in Minority Communities: A Clinician Survey

BACKGROUND: Rates of blood pressure (BP) control are lower in minority populations compared to whites. OBJECTIVE: As part of a project to decrease health-related disparities among ethnic groups, we sought to evaluate the knowledge, attitudes, and management practices of clinicians caring for hypertensive patients in a predominantly minority community. DESIGN/PARTICIPANTS: We developed clinical vignettes of hypertensive patients that varied by comorbidity (type II diabetes mellitus, chronic renal insufficiency, coronary artery disease, or isolated systolic hypertension alone). We randomly assigned patient characteristics, e.g., gender, age, race/ethnicity, to each vignette. We surveyed clinicians in ambulatory clinics of the 4 hospitals in East/Central Harlem, NY. MEASUREMENTS: The analysis used national guidelines to assess the appropriateness of clinicians' stated target BP levels. We also assessed clinicians' attitudes about the likelihood of each patient to achieve adequate BP control, adhere to medications, and return for follow-up. RESULTS: Clinicians' target BPs were within 2 mm Hg of the recommendations 9% of the time for renal disease patients, 86% for diabetes, 94% for isolated systolic hypertension, and 99% for coronary disease. BP targets did not vary by patient or clinician characteristics. Clinicians rated African-American patients 8.4% (p = .004) less likely and non-English speaking Hispanic patients 8.1% (p = .051) less likely than white patients to achieve/maintain BP control. CONCLUSIONS: Clinicians demonstrated adequate knowledge of recommended BP targets, except for patients with renal disease. Clinicians did not vary management by patients' sociodemographics but thought African-American, non-English-speaking Hispanic and unemployed patients were less likely to achieve BP control than their white counterparts.     

Ethnic differences in the place of death of elderly hospice enrollees

Elderly minorities are more likely to die in inpatient settings than their Caucasian counterparts. It is not known whether this difference is due to cultural preferences for place of death or decreased access to hospice. This analysis examines ethnic differences in the place of death of elderly hospice patients. Using data from a large, national hospice provider, elderly (> or = 65) African-American, Hispanic, and Caucasian decedents admitted to hospice between January 1, 2000, and December 31, 2003, were identified. Of the 115,854 eligible decedents, 78.3% were Caucasian, 10.7% African American, and 11% Hispanic. Hispanics and African Americans were more likely to die in inpatient hospice settings than Caucasians (38.5%, 38.5%, and 32%, respectively). After adjustment for demographic and hospice use variables, older African Americans had higher odds than older Caucasians of dying in an inpatient hospice setting than a nursing home (odds ratio (OR)=1.12, 95% confidence interval (CI)=1.07-1.19). However, African-American ethnicity was not a significant predictor of death in an inpatient setting versus home (OR=1.03, 95% CI=0.97-1.08)). Hispanics had lower odds than Caucasians of death in an inpatient hospice setting than at home (OR=0.88, 95% CI=0.84, 0.93) and higher odds of death in an inpatient setting than a nursing home (OR=1.45, 95% CI=1.37-1.53). Admission to hospice reduces but does not eliminate ethnic differences in place of death. Further research should examine the effect of individual and cultural preferences for place of death on decisions to enroll in hospice.     

Cardiovascular disease risk stratification with stress single-photon emission computed tomography technetium-99m tetrofosmin imaging in patients with the metabolic syndrome and diabetes mellitus

The metabolic syndrome represents a constellation of risk factors caused by insulin resistance, dyslipidemia, hypertension, and obesity, resulting in elevated coronary disease risk. From a multicenter prospective registry of 7,849 patients, the relation among the metabolic syndrome, diabetes, and risk stratification with stress technetium-99m tetrofosmin single photon-emission computed tomography (SPECT) was evaluated. The percentage of stress myocardial defects was calculated as < or = 5%, 5.1% to 10%, 10.1% to 15%, and > 15%. A Cox proportional-hazards model was used to estimate cardiovascular death or myocardial infarction (n = 752). Of 7,849 patients, 42% had the metabolic syndrome. Patients with the metabolic syndrome had an 84% 2-year event-free survival rate, lower than patients with normal metabolic status (p <0.0001). In patients with the metabolic syndrome, the percentage of moderate to severely abnormal SPECT findings ranged from 11% to 44% for those with 3 to 5 risk factors for the metabolic syndrome. There was an additive relation between the number of risk factors for the metabolic syndrome and the extent and severity of abnormalities in SPECT findings (p <0.0001). Patients with 5 risk factors for the metabolic syndrome were at the greatest risk, with hazard ratios from 7.8- to 14.1-fold for mild to severely abnormal SPECT findings. For diabetic patients requiring combined oral and insulin therapy, relative risk ratios increased from 15 to 21.4 for patients with > 5% to > 15% stress myocardial perfusion defects. In conclusion, cardiovascular prognosis is affected by the degree of metabolic dysfunction, and stress-induced reductions in myocardial perfusion provide an accurate means for near-term risk stratification.     

Prevalence and prognostic value of perfusion defects detected by stress technetium-99m sestamibi myocardial perfusion single-photon emission computed tomography in asymptomatic patients with diabetes mellitus and no known coronary artery disease

Coronary artery disease (CAD) is the leading cause of morbidity and mortality in diabetics. Early diagnosis of CAD and identification of high-risk subgroups, followed by appropriate therapy, may therefore enhance survival. This study sought to determine the value of stress myocardial perfusion single-photon emission computed tomography (SPECT) with technetium-99m sestamibi to detect perfusion defects and predict cardiac events in asymptomatic diabetics. One hundred eighty asymptomatic diabetics without known CAD who underwent 2-day stress technetium-99m sestamibi SPECT were followed up for 36 +/- 18 months. End points were defined as hard (myocardial infarction or cardiac death) or total events (myocardial infarction, cardiac death, or late revascularization). Logistic regression analysis evaluated clinical variables, type of stress, exercise treadmill test (ETT), and SPECT as predictors of end points. Perfusion defects were found in 26% of patients (15% reversible, 6% mixed, and 5% fixed). Clinical or ETT variables were not associated with perfusion defect type or with hard events. However, male gender predicted total events (chi-square 3.3; p = 0.01). An abnormal SPECT significantly increased the risk of hard events (chi-square 5.4; p = 0.001) and total events (chi-square 7.4; p = 0.0001). Extensive defects determined the highest risk of total events (chi-square 18.8; p = 0.0001). Event rates increased according to SPECT: 2% of hard events per year and 5% of total events per year in patients with normal SPECT versus 9% per year and 38% per year, respectively, in those with abnormal SPECT. Importantly, a normal SPECT identified a relatively low-risk subgroup of patients. Thus, stress technetium-99m sestamibi SPECT was useful in evaluating asymptomatic diabetics for the presence of CAD, and effectively risk-stratified this population.     

Prognostic significance of myocardial imaging with iodine-123 beta-methyl-p-iodophenyl-pentadecanoic acid in patients with angina pectoris

OBJECTIVES: To assess the clinical significance of iodine-123 beta-methyl-p-iodophenyl-pentadecanoic acid(BMIPP) single photon emission computed tomography(SPECT), the predictive value of BMIPP imaging in patients with angina pectoris was evaluated. METHODS: One hundred seventy-four patients who underwent BMIPP imaging in our institution were aged 61.8 +/- 11 years. One hundred thirty-five patients had stable angina and 39 had unstable angina at the time of examination. Patients with previous myocardial infarction or myocardial disorders were excluded. Early and delayed images were acquired in BMIPP SPECT, and the images were analyzed visually. Cardiac events were classified into hard and soft events: the former consisted of cardiac death and nonfatal myocardial infarction, and the latter included coronary revascularization and heart failure. RESULTS: The findings of BMIPP imaging were normal in 82 patients and abnormal in 92. During follow-up of 15.5 +/- 9.5 months, hard events were observed in 4 patients and soft events in 53. In patients with normal BMIPP imaging, soft events were observed in nine patients, but no hard event was encountered. Furthermore, in patients with both normal BMIPP and stress thallium imagings, no cardiac event was observed during 2 years. In contrast, 4 hard events and 44 soft events occurred in patients with abnormal BMIPP imaging. Patients with abnormal BMIPP imaging had a higher incidence of soft events than those with normal BMIPP imaging, regardless of the type of angina(16/62 vs 3/73, p < 0.0005 for stable angina; 28/30 vs 6/9, p < 0.0001 for unstable angina). CONCLUSIONS: The finding of BMIPP imaging correlates well with the mid-term prognosis of patients with angina pectoris. Since BMIPP SPECT is performed without stress to the patient, this imaging modality is important in evaluating patients with stable or unstable angina.     

Incremental cost-effectiveness of exercise echocardiography vs. SPECT imaging for the evaluation of stable chest pain.

AIMS: Technological advances in cardiac imaging have led to dramatic increases in test utilization and consumption of a growing proportion of cardiovascular healthcare costs. The opportunity costs of strategies favouring exercise echocardiography or SPECT imaging have been incompletely evaluated. METHODS AND RESULTS: We examined prognosis and cost-effectiveness of exercise echocardiography (n = 4884) vs. SPECT (n = 4637) imaging in stable, intermediate risk, chest pain patients. Ischaemia extent was defined as the number of vascular territories with echocardiographic wall motion or SPECT perfusion abnormalities. Cox proportional hazard models were employed to assess time to cardiac death or myocardial infarction (MI). Total cardiovascular costs were summed (discounted and inflation-corrected) throughout follow-up. A cost-effectiveness ratio < Dollars 50,000 per life year saved (LYS) was considered favourable for economic efficiency. The risk-adjusted 3-year death or MI rates classified by extent of ischaemia were similar, ranging from 2.3 to 8.0% for echocardiography and from 3.5 to 11.0% for SPECT (model chi2 = 216; P < 0.0001; interaction P = 0.24). Cost-effectiveness ratios for echocardiography were < Dollars 20,000/LYS when the annual risk of death or MI was < 2%. However, when yearly cardiac event rate were > 2%, cost-effectiveness ratios for echocardiography vs. SPECT were in the range of Dollars 66,686-Dollars 419,522/LYS. For patients with established coronary disease (i.e. > or = 2% annual event risk), SPECT ischaemia was associated with earlier and greater utilization of coronary revascularization (P < 0.0001) resulting in an incremental cost-effectiveness ratio of Dollars 32,381/LYS. CONCLUSION: Health care policies aimed at allocating limited resources can be effectively guided by applying clinical and economic outcomes evidence. A strategy aimed at cost-effective testing would support using echocardiography in low-risk patients with suspected coronary disease, whereas those higher risk patients benefit from referral to SPECT imaging.     

SPECT Imaging for Detecting Coronary Artery Disease and Determining Prognosis by Noninvasive Assessment of Myocardial Perfusion and Myocardial Viability

Basic knowledge of active and passive transport mechanisms for concentrating monovalent cations in myocardial cells led to the investigation of the application of radioisotopes of potassium, thallium, rubidium, and ammonia to the in vivo noninvasive assessment of regional myocardial perfusion and viability utilizing gamma camera or positron emission tomographic (PET) imaging technology. Subsequently, technetium-99m (Tc-99m)-labeled isonitriles (sestamibi and tetrofosmin), which bind to mitochondrial membranes, emerged as superior imaging agents with single photon emission tomography (SPECT) imaging. When any of these imaging agents are injected intravenously during either exercise or pharmacologic stress, myocardial defects in tracer uptake represent either abnormal regional flow reserve or myocardial scar reflecting of coronary artery disease (CAD). The major clinical indications for stress SPECT or PET myocardial perfusion imaging are for detection of CAD as the cause of chest pain and risk stratification for prognostication. Patients with normal stress myocardial perfusion scans have an excellent prognosis with <1.0% annual rate future annual death or nonfatal infarction. The greater the extent and severity of ischemic perfusion defects (defects seen on stress images but improve on resting images), the greater the subsequent death or infarction rate during follow-up. Rest imaging alone is performed for determination of myocardial viability in patients with CAD and severe left ventricular dysfunction. Myocardial segments showing >50% uptake compared to normal uptake have a better long-term outcome with revascularization than with medical therapy with enhanced left ventricular function and improved survival. Other applications of SPECT imaging include the evaluation of cardiac sympathetic function, assessment of myocardial metabolism in health and disease, and molecular imaging of coronary atherosclerosis and myocardial stem cell therapy.     

Ethnic differences in the frequency of ENPP1/PC1 121Q genetic variant in the Dallas Heart Study cohort

Genetic susceptibility modulates the impact of obesity on the risk for type 2 diabetes. One candidate gene predisposing to type 2 diabetes is ENPP1/PC1. A common polymorphism in this protein, K121Q, is associated with insulin resistance and increased susceptibility to type 2 diabetes in Caucasian, Afro-Caribbean, and South Asian populations. The goal of this study was to evaluate differences in the prevalence of the ENPP1 121Q variant in the Caucasian, African-American, and Hispanic populations in Dallas county and to establish a population-based estimate of gene variant prevalence for future investigations. We also evaluated the association between the ENPP1 121Q variant and diabetes. The Dallas Heart Study (DHS) is a multiethnic probability-based sample of the Dallas county population in which African-Americans were systematically oversampled so that the final sample was 50% African-Americans. We performed ENPP1/PC1 genotyping in 1038 non-Hispanic Whites (544 women, 494 men), 1815 African-Americans (1052 women and 763 men), and 597 Hispanics (347 women, 250 men). The frequency of ENPP1/PC1 K121Q was higher in both African-Americans (78.5%) and Hispanics (21.9%) than in the non-Hispanic White group (13.2%). The former two groups also have a higher prevalence of type 2 diabetes (African-Americans, 14.1%, and Hispanics, 11.7%) compared to non-Hispanic Whites (6.8%). Logistic regression analysis revealed significant interactions between the ENPP1 genotype, age, and body mass index within each ethnic group. After adjustment for these variables and their interactions, ENPP1 Q allele predicted diabetes when a recessive model was tested. Ethnic differences in ENPP1 121Q allele frequency may contribute to the increased susceptibility to type 2 diabetes observed in US minority groups.     

Race/ethnicity and outcomes following inpatient rehabilitation for hip fracture

BACKGROUND: Hip fracture results in severe and often permanent reductions in overall health and quality of life for many older adults. As the U.S. population grows older and more diverse, there is an increasing need to assess and improve outcomes across racial/ethnic cohorts of older hip fracture patients. METHODS: We examined data from 42,479 patients receiving inpatient rehabilitation for hip fracture who were discharged in 2003 from 825 facilities across the United States. Outcomes of interest included length of stay, discharge setting, and functional status at discharge and 3- to 6-month follow-up. RESULTS: Mean age was 80.2 (standard deviation [SD] = 8.0) years. A majority of the sample was non-Hispanic white (91%), followed by non-Hispanic black (4%), Hispanic (4%), and Asian (1%). After controlling for sociodemographic factors and case severity, significant (p <.05) differences between the non-Hispanic white and minority groups were observed for predicted lengths of stay in days (Asian: 1.1; 95% confidence interval [CI], 0.5-1.7; non-Hispanic black: 0.8; 95% CI, 0.6-1.1), odds of home discharge (Asian: 2.1; 95% CI, 1.6-2.8; non-Hispanic black: 2.0; 95% CI, 1.8-2.3; Hispanic: 1.9; 95% CI, 1.6-2.2), lower discharge Functional Independence Measure (FIM) ratings (non-Hispanic black: 3.6; 95% CI, 3.0-4.2; Hispanic: 1.6; 95% CI, 0.9-2.2 points lower), and lower follow-up FIM ratings (Hispanic: 4.4; 95% CI, 2.8-5.9). CONCLUSIONS: Race/ethnicity differences in outcomes were present in a national sample of hip fracture patients following inpatient rehabilitation. Recognizing these differences is the first step toward identifying and understanding potential mechanisms underlying the relationship between race/ethnicity and outcomes. These mechanisms may then be addressed to improve hip fracture care for all patients.     

99mTc-MIBI心肌灌注断层显像在冠心病冠状动脉内支架置入术的应用

目的 :应用硝酸甘油 (NTG)介入 ,单光子发射计算机断层显像 (SPECT)检查估测冠状动脉 (冠脉 )介入治疗前后存活心肌的大小、范围。方法 :对 42例冠心病患者行静息及NTG介入SPECT心肌显像检查 ,应用阅片计分法、极坐标靶心图定量分析法估测心肌活力。以 19例接受经皮腔内冠脉成形术 (PTCA)加冠脉内支架置入 (Stent)术后静息显像结果为“金标准” ,评价NTG介入显像对心肌活力检测效果。结果 :静息显像及NTG介入SPECT显像其不规则感兴趣区内放射性稀疏缺损面积、放射性计数、放射性异常计分差异有显著性意义 (t分别为 7.5 43、4.6 0 8、6 .76 2 ,均 P <0 .0 0 1)。静息显像检测出存活心肌为 5 6 .3% ,NTG介入显像为 6 9.6 %。NTG介入显像估测存活心肌准确率为阅片计分法 80 .9% ,定量分析法 90 .5 %。结论 :NTG介入SPECT检查可提高存活心肌检出率 ,为冠脉内支架置入术治疗提供客观依据