Nano- and micro-patterning biotemplated magnetic CoPt arrays

Patterned thin-films of magnetic nanoparticles (MNPs) can be used to make: surfaces for manipulating and sorting cells, sensors, 2D spin-ices and high-density data storage devices. Conventional manufacture of patterned magnetic thin-films is not environmentally friendly because it uses high temperatures (hundreds of degrees Celsius) and high vacuum, which requires expensive specialised equipment. To tackle these issues, we have taken inspiration from nature to create environmentally friendly patterns of ferromagnetic CoPt using a biotemplating peptide under mild conditions and simple apparatus. Nano-patterning via interference lithography (IL) and micro-patterning using micro-contact printing (μCP) were used to create a peptide resistant mask onto a gold surface under ambient conditions. We redesigned a biotemplating peptide (CGSGKTHEIHSPLLHK) to self-assemble onto gold surfaces, and mineralised the patterns with CoPt at 18 °C in water. Ferromagnetic CoPt is biotemplated by the immobilised peptides, and the patterned MNPs maintain stable magnetic domains. This bioinspired study offers an ecological route towards developing biotemplated magnetic thin-films for use in applications such as sensing, cell manipulation and data storage.

Quality and age of shallow groundwater in the Bakken Formation production area, Williston Basin, Montana and North Dakota

The quality and age of shallow groundwater in the Bakken Formation production area were characterized using data from 30 randomly distributed domestic wells screened in the upper Fort Union Formation. Comparison of inorganic and organic chemical concentrations to health based drinking-water standards, correlation analysis of concentrations with oil and gas well locations, and isotopic data give no indication that energy-development activities affected groundwater quality. It is important, however, to consider these results in the context of groundwater age. Most samples were recharged before the early 1950s and had 14C ages ranging from <1000 to >30,000 years. Thus, domestic wells may not be as well suited for detecting contamination associated with recent surface spills as shallower wells screened near the water table. Old groundwater could be contaminated directly by recent subsurface leaks from imperfectly cemented oil and gas wells, but horizontal groundwater velocities calculated from 14C ages imply that the contaminants would still be less than 0.5 km from their source. For the wells sampled in this study, the median distance to the nearest oil and gas well was 4.6 km. Because of the slow velocities, a long-term commitment to groundwater monitoring in the upper Fort Union Formation is needed to assess the effects of energy development on groundwater quality. In conjunction with that effort, monitoring could be done closer to energy-development activities to increase the likelihood of early detection of groundwater contamination if it did occur.

Does cardiovascular phenotype explain the association between diabetes and incident heart failure? The Strong Heart Study

BACKGROUND AND AIMS

Diabetes remains a predictor of incident heart failure (HF), independent of intercurrent myocardial infarction (MI) and concomitant risk factors. Initial cardiovascular (CV) characteristics, associated with incident heart failure (HF) might explain the association of diabetes with incident HF.

METHODS AND RESULTS

Participants to the 2nd Strong Heart Study exam, without prevalent HF or coronary heart disease, or glomerular filtration rate <30 mL/min/1.73 m(2), were analyzed (n = 2757, 1777 women, 1278 diabetic). Cox regression of incident HF (follow-up 8.91 ± 2.76 years) included incident MI censored as a competing risk event. Acute MI occurred in 96 diabetic (7%) and 84 non-diabetic participants (6%, p = ns). HF occurred in 156 diabetic (12%) and in 68 non-diabetic participants (5%; OR = 2.89, p < 0.001). After accounting for competing MI and controlling for age, gender, BMI, systolic blood pressure, smoking habit, plasma cholesterol, antihypertensive treatment, heart rate, fibrinogen and C-reactive protein, incident HF was predicted by greater LV mass index, larger left atrium, lower systolic function, greater left atrial systolic force and urinary albumin/creatinine excretion. Risk of HF was reduced with more rapid LV relaxation and anti-hypertensive therapy. Diabetes increases hazard of HF by 66% (0.02 < p < 0.001). The effect of diabetes could be explained by the level of HbA1c.

CONCLUSIONS

Incident HF occurs more frequently in diabetes, independent of intercurrent MI, abnormal LV geometry, subclinical systolic dysfunction and indicators of less rapid LV relaxation, and is influenced by poor metabolic control. Identification of CV phenotype at high-risk for HF in diabetes should be advised.

Cost-effectiveness of lower targets for blood pressure and low-density lipoprotein cholesterol in diabetes: the Stop Atherosclerosis in Native Diabetics Study (SANDS)

BACKGROUND

The Stop Atherosclerosis in Native Diabetics Study (SANDS) reported cardiovascular benefit of aggressive versus standard treatment targets for both low-density lipoprotein cholesterol (LDL-C) and blood pressure (BP) in diabetic individuals.

OBJECTIVE

In this analysis, we examined within trial cost-effectiveness of aggressive targets of LDL-C ≤70 mg/dL and systolic BP ≤115 mmHg versus standard targets of LDL-C ≤100 mg/dL and systolic BP ≤130 mmHg.

DESIGN

Randomized, open label blinded-to-endpoint 3-year trial.

DATA SOURCES

SANDS clinical trial database, Quality of Wellbeing survey, Centers for Medicare and Medicaid Services, Wholesale Drug Prices.

TARGET POPULATION

American Indians ≥ age 40 years with type 2 diabetes and no previous cardiovascular events.

TIME HORIZON

April 2003 to July 2007.

PERSPECTIVE

Health payer.

INTERVENTIONS

Participants were randomized to aggressive versus standard groups with treatment algorithms defined for both.

OUTCOME MEASURES

Incremental cost-effectiveness.

RESULTS OF BASE-CASE ANALYSIS

Compared with the standard group, the aggressive group had slightly lower costs of medical services (-$116) but a 54% greater cost for BP medication ($1,242) and a 116% greater cost for lipid-lowering medication ($2,863), resulting in an increased cost of $3,988 over 3 years. Those in the aggressively treated group gained 0.0480 quality-adjusted life-years (QALY) over the standard group. When a 3% discount rate for costs and outcomes was used, the resulting cost per QALY was $82,589.

RESULTS OF SENSITIVITY ANALYSIS

The use of a 25%, 50%, and 75% reduction in drug costs resulted in a cost per QALY of $61,329, $40,070, and $18,810, respectively.

LIMITATIONS

This study was limited by use of a single ethnic group and by its 3-year duration.

CONCLUSIONS

Within this 3-year study, treatment to lower BP and LDL-C below standard targets was not cost-effective because of the cost of the additional medications required to meet the lower targets. With the anticipated availability of generic versions of the BP and lipid-lowering drugs used in SANDS, the cost-effectiveness of this intervention should improve. Published by Elsevier Inc on behalf of the National Lipid Association.

Acute myocardial infarction quality of care: the Strong Heart Study

OBJECTIVES

Evaluate the quality of care provided patients with acute myocardial infarction and compare with similar national and regional data.

DESIGN

Case series.

SETTING

The Strong Heart Study has extensive population-based data related to cardiovascular events among American Indians living in three rural regions of the United States.

PARTICIPANTS

Acute myocardial infarction cases (72) occurring between 1/1/2001 and 12/31/2006 were identified from a cohort of 4549 participants.

OUTCOME MEASURES

The proportion of cases that were provided standard quality of care therapy, as defined by the Healthcare Financing Administration and other national organizations.

RESULTS

The provision of quality services, such as administration of aspirin on admission and at discharge, reperfusion therapy within 24 hours, prescription of beta blocker medication at discharge, and smoking cessation counseling were found to be 94%, 91%, 92%, 86% and 71%, respectively. The unadjusted, 30 day mortality rate was 17%.

CONCLUSION

Despite considerable challenges posed by geographic isolation and small facilities, process measures of the quality of acute myocardial infarction care for participants in this American Indian cohort were comparable to that reported for Medicare beneficiaries nationally and within the resident states of this cohort.

Safety and feasibility of achieving lower systolic blood pressure goals in persons with type 2 diabetes: the SANDS trial

The Stop Atherosclerosis in Native Diabetics Study (SANDS) was a randomized open-label clinical trial in type 2 diabetics designed to examine the effects of intensive reduction of blood pressure, aggressive vs standard goals (< or =115/75 mm Hg vs < or =130/80 mm Hg), and low-density lipoprotein (LDL) cholesterol on the composite outcome of change in carotid intimal-medial thickness and cardiovascular events. The study demonstrated that in conjunction with a lower LDL cholesterol target of 70 mg/dL, aggressive systolic blood pressure-lowering resulted in a reduction in carotid intimal-medial thickness and left ventricular mass without measurable differences in cardiovascular events. The blood pressure treatment algorithm included renin-angiotensin system blockade, with other agents added if necessary. The authors conclude that both standard and more aggressive systolic blood pressure reduction can be achieved with excellent safety and good tolerability in patients with type 2 diabetes mellitus.

PREVENTION OF ATHEROSCLEROSIS WITH LDL-C LOWERING - LIPOPROTEIN CHANGES AND INTERACTIONS: THE SANDS STUDY

BACKGROUND: Lowering low-density lipoprotein cholesterol (LDL-C) with statins reduces atherosclerosis. LDL and high-density lipoprotein (HDL) are commonly measured by their cholesterol content, but non-HDL cholesterol, LDL particle number (LDL-P), or total apolipoprotein B (apoB) may better predict cardiovascular risk. Few studies have examined relations among lipoprotein levels and composition before and after interventions to lower LDL-C and non-HDL-C. OBJECTIVE: To measure changes in carotid artery intimal media thickness (CIMT) and lipid concentration and composition during 36 months of statin therapy. METHODS: Analyses were conducted on 418 diabetic individuals, with complete data and no prior cardiovascular events, who were randomized to aggressive (AG) versus standard (STD) treatment for LDL-C, non-HDL-C, and systolic blood pressure (SBP) as part of the Stop Atherosclerosis in Native Diabetics Study (SANDS). RESULTS: The AG group achieved average LDL-C and non-HDL-C of 71mg/dL and 100mg/dL and a decrease in CIMT. No significant interactions were observed between treatment effect and initial levels of LDL-C, non-HDL-C, HDL-C, triglycerides, apoB, or LDL-P. Decreases in LDL-C (p<.005) and non-HDL-C (p<.001) were independently correlated with CIMT regression in the AG group. Changes in apoB and LDL-P showed borderline correlations with CIMT regression (p=.07 and p=.09). CONCLUSIONS: In diabetic adults with no prior cardiovascular events, treatment to current targets for lipids and SBP reduces atherosclerosis progression and when more aggressive targets are met, atherosclerosis regresses. The aggressive targets for LDL-C and non-HDL-C appeared to be the main determinants of CIMT regression and were more predictive of this outcome than changes in LDL-P or apoB.

Incidence and risk factors for stroke in American Indians: the Strong Heart Study

BACKGROUND

There are few published data on the incidence of fatal and nonfatal stroke in American Indians. The aims of this observational study were to determine the incidence of stroke and to elucidate stroke risk factors among American Indians.

METHODS AND RESULTS

This report is based on 4549 participants aged 45 to 74 years at enrollment in the Strong Heart Study, the largest longitudinal, population-based study of cardiovascular disease and its risk factors in a diverse group of American Indians. At baseline examination in 1989 to 1992, 42 participants (age- and sex-adjusted prevalence proportion 1132/100 000, adjusted to the age and sex distribution of the US adult population in 1990) had prevalent stroke. Through December 2004, 306 (6.8%) of 4507 participants without prior stroke suffered a first stroke at a mean age of 66.5 years. The age- and sex-adjusted incidence was 679/100 000 person-years. Nonhemorrhagic cerebral infarction occurred in 86% of participants with incident strokes; 14% had hemorrhagic stroke. The overall age-adjusted 30-day case-fatality rate from first stroke was 18%, with a 1-year case-fatality rate of 32%. Age, diastolic blood pressure, fasting glucose, hemoglobin A(1c,) smoking, albuminuria, hypertension, prehypertension, and diabetes mellitus were risk factors for incident stroke.

CONCLUSIONS

Compared with US white and black populations, American Indians have a higher incidence of stroke. The case-fatality rate for first stroke is also higher in American Indians than in the US white or black population in the same age range. Our findings suggest that blood pressure and glucose control and smoking avoidance may be important avenues for stroke prevention in this population.

Effect of lower targets for blood pressure and LDL cholesterol on atherosclerosis in diabetes: the SANDS randomized trial

CONTEXT

Individuals with diabetes are at increased risk for cardiovascular disease (CVD), but more aggressive targets for risk factor control have not been tested.

OBJECTIVE

To compare progression of subclinical atherosclerosis in adults with type 2 diabetes treated to reach aggressive targets of low-density lipoprotein cholesterol (LDL-C) of 70 mg/dL or lower and systolic blood pressure (SBP) of 115 mm Hg or lower vs standard targets of LDL-C of 100 mg/dL or lower and SBP of 130 mm Hg or lower.

DESIGN, SETTING, AND PARTICIPANTS

A randomized, open-label, blinded-to-end point, 3-year trial from April 2003-July 2007 at 4 clinical centers in Oklahoma, Arizona, and South Dakota. Participants were 499 American Indian men and women aged 40 years or older with type 2 diabetes and no prior CVD events.

INTERVENTIONS

Participants were randomized to aggressive (n=252) vs standard (n=247) treatment groups with stepped treatment algorithms defined for both.

MAIN OUTCOME MEASURES

Primary end point was progression of atherosclerosis measured by common carotid artery intimal medial thickness (IMT). Secondary end points were other carotid and cardiac ultrasonographic measures and clinical events.

RESULTS

Mean target LDL-C and SBP levels for both groups were reached and maintained. Mean (95% confidence interval) levels for LDL-C in the last 12 months were 72 (69-75) and 104 (101-106) mg/dL and SBP levels were 117 (115-118) and 129 (128-130) mm Hg in the aggressive vs standard groups, respectively. Compared with baseline, IMT regressed in the aggressive group and progressed in the standard group (-0.012 mm vs 0.038 mm; P < .001); carotid arterial cross-sectional area also regressed (-0.02 mm(2) vs 1.05 mm(2); P < .001); and there was greater decrease in left ventricular mass index (-2.4 g/m(2.7) vs -1.2 g/m(2.7); P = .03) in the aggressive group. Rates of adverse events (38.5% and 26.7%; P = .005) and serious adverse events (n = 4 vs 1; P = .18) related to blood pressure medications were higher in the aggressive group. Clinical CVD events (1.6/100 and 1.5/100 person-years; P = .87) did not differ significantly between groups.

CONCLUSIONS

Reducing LDL-C and SBP to lower targets resulted in regression of carotid IMT and greater decrease in left ventricular mass in individuals with type 2 diabetes. Clinical events were lower than expected and did not differ significantly between groups. Further follow-up is needed to determine whether these improvements will result in lower long-term CVD event rates and costs and favorable risk-benefit outcomes.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00047424.

The Ratio of Mitral Deceleration Time to E-wave Velocity and Mitral Deceleration Slope Outperform Deceleration Time Alone in Predicting Cardiovascular Outcomes: The Strong Heart Study

BACKGROUND

The deceleration time of early mitral inflow (E) is shortened by left ventricular chamber stiffening and prolonged by impaired relaxation. For any given rate of deceleration of early mitral inflow, a higher E-wave velocity (E) is associated with a longer deceleration time. It is not known whether deceleration time normalized for E-velocity or its inverse (deceleration slope) better predicts cardiovascular (CV) events compared with deceleration time or E-velocity alone.

METHODS

We compared the prognostic value of deceleration time, E-velocity, deceleration time/E-velocity, and deceleration slope in 3102 American Indian participants in the Strong Heart Study, free of clinical CV disease and documented atrial fibrillation, in predicting fatal and nonfatal CV events.

RESULTS

During a mean of 8.5 +/- 2.4 years, there were 637 fatal and nonfatal CV events. After adjustment for traditional CV risk factors, deceleration time/E-velocity (adjusted hazard ratio [HR], 1.09; 95% confidence interval [CI], 1.00-1.18; P = .04 for every 0.89 msec/[cm/s] [1 + standard deviation {SD}] increase) and deceleration slope (HR, 0.91; 95% CI, 0.82-1.00; P = .01 for every 91 msec [1 + SD] increase) predicted CV events, whereas deceleration time and E-velocity did not. When participants with restrictive-type filling (n = 74) were removed from the analysis, deceleration time/E-velocity (HR, 1.10; 95% CI, 1.01-1.20; P = .03 for every 0.89 msec/[cm/s] [1 + SD] increase) and deceleration slope (HR, 0.64; 95% CI, 0.36-0.91; P = .01 for every 91 msec [1 + SD] increase) predicted CV events even more strongly.

CONCLUSION

In a large population-based sample with high prevalences of hypertension and diabetes, free of prevalent CV disease, deceleration time/E-velocity and deceleration slope predict CV events, whereas their components (deceleration time and E-velocity) do not. This suggests normalization of deceleration time for E-velocity or using its inverse (deceleration slope) more precisely captures prognostically significant prolongation of deceleration than does deceleration time alone.

Utility of the myocardial performance index in a population with high prevalences of obesity, diabetes, and hypertension: the strong heart study

INTRODUCTION

The myocardial performance index (MPI) introduced by Tei, a Doppler-derived echocardiographic measure that reflects both left ventricular (LV) systolic and diastolic function, has been shown to have prognostic value in several clinical settings, including myocardial infarction and congestive heart failure. There are scant data on the correlates and prognostic value of MPI in a population without overt cardiovascular (CV) disease.

METHODS

We investigated clinical and physiologic correlates of MPI, as assessed from echocardiographic Doppler recordings in 1,862 American Indian participants free of coronary or valvular disease or LV systolic dysfunction in the population-based strong heart study (SHS). We then assessed the prognostic value of MPI for incident CV events, including nonfatal stroke, coronary heart disease, congestive heart failure, and CV death.

RESULTS

The study population was 59 +/- 8 years old (66% women); 48% had diabetes, 44% hypertension, and 54% were obese. In univariable analyses, MPI (mean = 0.24 +/- 0.17) showed significant negative associations with creatinine clearance, C-reactive protein (CRP), LV ejection fraction (EF), mitral valve E- and A-wave velocities, cardiac index (CI), stroke index (SI) and stroke index/pulse pressure (SI/PP), and significant positive associations with serum creatinine and total peripheral resistance index (TPRI) (all P < 0.05). There were no significant associations of MPI with hypertension or diabetes status, systolic or diastolic blood pressure, body mass index, hemoglobin A1C or LV mass. After adjusting for age, sex, diabetes, and hypertension, MPI remained weakly but significantly correlated with CRP, EF, CI, SI, SI/PP, mitral E- and A-wave velocities, and TPRI. MPI did not predict fatal and nonfatal CV events (risk ratio 1.06 per unit MPI, 95% C.I. 0.56-2.04; P = 0.85) at a mean follow-up of 7.1 +/- 2.2 years.

CONCLUSIONS

In a population-based sample of adults with high prevalence of diabetes, hypertension, and obesity but without overt CV disease, MPI has weak associations with clinical and physiologic determinants of cardiac function. Moreover, MPI does not provide prognostic information for CV events in this population. Though conceptually attractive as a global measure of cardiac function, MPI has limited utility in a high-risk population without clinical CV disease.

Prevalence and Prognostic Significance of Wall-Motion Abnormalities in Adults Without Clinically Recognized Cardiovascular Disease

Background— Left ventricular wall motion (WM) abnormalities have recognized prognostic significance in patients with coronary or other heart diseases; however, whether abnormal WM predicts adverse events in adults without overt cardiovascular disease has not been assessed. Our objective was to determine whether echocardiographic WM abnormalities predict subsequent cardiovascular events in a population-based sample.

Methods and Results— Participants (n=2864, mean age 60±8 years, 64% women) without clinically evident cardiovascular disease in the second Strong Heart Study examination who had complete echocardiographic WM assessment were studied. Echocardiographic assessment revealed that 5% of participants (n=140) had focal hypokinesia, and 1.5% (n=42) had WM abnormalities. Relationships between WM abnormalities and fatal and nonfatal cardiovascular events (including myocardial infarction, stroke, coronary artery disease, and heart failure; n=554) and cardiovascular death (n=182) during 8±2 years follow-up were examined. In Cox regression, after adjustment for age, gender, waist/hip ratio, systolic blood pressure, and diabetes mellitus, segmental WM abnormalities were associated with a 2.5-fold higher risk of cardiovascular events and a 2.6-fold higher risk of cardiovascular death (both P <0.0001). In similar multivariable models, global WM abnormalities were associated with a 2.4-fold higher risk of cardiovascular events ( P =0.001) and a 3.4-fold higher risk of cardiovascular death ( P =0.003).

Conclusions— Echocardiographic left ventricular WM abnormalities in adults without overt cardiovascular disease are associated with 2.4- to 3.4-fold higher risks of cardiovascular morbidity and mortality, independent of established risk factors.

Prognostic impact of metabolic syndrome by different definitions in a population with high prevalence of obesity and diabetes: the Strong Heart Study

OBJECTIVE

This study analyzed which definition of the metabolic syndrome is more predictive of cardiovascular events in both diabetic and nondiabetic members of a population-based sample.

RESEARCH DESIGN AND METHODS

A 10-year, longitudinal follow-up of the Strong Heart Study cohort has been evaluated. The analysis included 3,945 participants (2,384 female) with complete data (1,700 with diabetes and 1,468 with arterial hypertension) for evaluation of metabolic syndrome. Those with prevalent cardiovascular disease were excluded (n = 287, of whom 127 were female). Prevalence of metabolic syndrome was assessed based on the World Health Organization (WHO), the National Cholesterol Education Program Adult Treatment Panel (NCEP ATP) III, and International Diabetes Federation (IDF) definitions. The main outcome was 10-year incidence of combined fatal and nonfatal cardiovascular events, including stroke, coronary heart disease, and congestive heart failure.

RESULTS

Fatal and nonfatal cardiovascular events occurred in 1,120 participants. After adjusting for age, sex, and diabetes, metabolic syndrome by all definitions was significantly associated with higher incidence of cardiovascular events (all P < 0.0001). In nondiabetic individuals, incident cardiovascular event rates were about 30-40% higher in those with metabolic syndrome, without a significant difference among definitions (0.03 < P < 0.001), and remained significant in WHO and NCEP ATP III definitions even after further adjustment for obesity, hypertension, and low HDL cholesterol. In the diabetic group, metabolic syndrome risk for cardiovascular events was greatest using the WHO definition (P < 0.002 vs. other models).

CONCLUSIONS

In individuals without diabetes, metabolic syndrome is associated with incident cardiovascular disease, especially with WHO and NCEP ATP III definitions. Metabolic syndrome also predicts higher cardiovascular event rates in diabetic participants, a prediction that is greatest using the WHO definition.

Usefulness of quantitative assessment of electrocardiographic ST depression for predicting new-onset heart failure in American Indians (from the Strong Heart Study)

The qualitative electrocardiographic strain pattern of ST depression (STD) and T-wave inversion is strongly associated with coronary heart disease and left ventricular hypertrophy and is an independent predictor of new-onset heart failure in hypertensive participants. However, whether quantitative measures of STD in the lateral precordial leads predict new heart failure is unclear. Digital electrocardiograms were examined in 2,059 American-Indian participants in the second Strong Heart Study examination with no history of heart failure. The absolute magnitude of ST segment deviation was measured using computer to the nearest 5 microV in leads V(5) and V(6). During 5.7 +/-1.4 years of follow-up, heart failure developed in 77 participants (3.7%). Participants who developed heart failure had greater STD in leads V(5) or V(6) (-11 +/- 35 vs 12 +/- 27 microV; p <0.001) than those who did not. In univariate Cox analyses, STD was a significant predictor of new heart failure, with each 10-microV greater STD associated with a 31% greater risk of heart failure (hazard ratio [HR] 1.31, 95% confidence interval [CI] 1.24 to 1.39). Increasing STD grouped according to quartiles was strongly associated with the development of heart failure, with stepwise increasing risk of heart failure compared with the lowest quartile of STD for the second (HR 2.39, 95% CI 0.77 to 7.40), third (HR 3.01, 95% CI 1.00 to 9.08), and fourth quartiles of STD (HR 9.06, 95% CI 3.26 to 25.16). In Cox multivariate analyses controlling for age, gender, diabetes, coronary heart disease, albuminuria, and other baseline risk factors, STD remained a significant predictor of incident heart failure (HR 1.22, 95% CI 1.13 to 1.32 per 10-muV increment in STD; p <0.001). In conclusion, increasing STD in lateral precordial leads is strongly associated with increased risk of developing heart failure independent of other risk factors for new heart failure.

Central pressure more strongly relates to vascular disease and outcome than does brachial pressure: the Strong Heart Study

Brachial blood pressure is predictive of cardiovascular outcome; however central pressure may better represent the load imposed on the coronary and cerebral arteries and thereby bear a stronger relationship to vascular damage and prognosis. Relations of brachial and central pressures to carotid artery hypertrophy (intimal-medial thickness and vascular mass), extent of atherosclerosis (plaque score), and incident cardiovascular events were examined in the Strong Heart Study. Central pressures were calculated using radial applanation tonometry. Among 3520 participants, central and brachial pulse pressures were more strongly related to vascular hypertrophy and extent of atherosclerosis than were systolic pressures. Central pulse pressure was more strongly related to all 3 arterial measures than was brachial pulse pressure (r=0.364 versus 0.309 for plaque score; P<0.001 for comparison of Spearman correlation coefficient; r=0.293 versus 0.249 for intimal-medial thickness; P<0.002; r=0.320 versus 0.289 for vascular mass; P<0.05). Among the 2403 participants free of clinical cardiovascular disease at baseline, 319 suffered fatal or nonfatal cardiovascular events during mean follow-up of 4.8+/-1.3 years. After adjustment for age, gender, current smoking, body mass index, cholesterol:HDL ratio, creatinine, fibrinogen, diabetes, and heart rate, central pulse pressure predicted cardiovascular events more strongly than brachial pulse pressure (hazards ratio=1.15 per 10 mm Hg, chi(2)=13.4, P<0.001 versus hazards ratio=1.10, chi(2)=6.9, P=0.008). In conclusion, noninvasively-determined central pulse pressure is more strongly related to vascular hypertrophy, extent of atherosclerosis, and cardiovascular events than is brachial blood pressure. These findings support prospective examination of use of central blood pressure as a treatment target in future trials.

Prediction of coronary heart disease in a population with high prevalence of diabetes and albuminuria: the Strong Heart Study

BACKGROUND

The present article presents equations for the prediction of coronary heart disease (CHD) in a population with high rates of diabetes and albuminuria, derived from data collected in the Strong Heart Study, a longitudinal study of cardiovascular disease in 13 American Indian tribes and communities in Arizona, North and South Dakota, and Oklahoma.

METHODS AND RESULTS

Participants of the Strong Heart Study were examined initially in 1989-1991 and were monitored with additional examinations and mortality and morbidity surveillance. CHD outcome data through December 2001 showed that age, gender, total cholesterol, low-density lipoprotein (LDL) cholesterol, high-density lipoprotein cholesterol, smoking, diabetes, hypertension, and albuminuria were significant CHD risk factors. Hazard ratios for ages 65 to 75 years, hypertension, LDL cholesterol > or = 160 mg/dL, diabetes, and macroalbuminuria were 2.58, 2.01, 2.44, 1.66, and 2.11 in men and 2.03, 1.69, 2.17, 2.26, and 2.69 in women, compared with ages 45 to 54 years, normal blood pressure, LDL cholesterol <100 mg/dL, no diabetes, and no albuminuria. Prediction equations for CHD and a risk calculator were derived by gender with the use of Cox proportional hazards model and the significant risk factors. The equations provided good discrimination ability, as indicated by a c statistic of 0.70 for men and 0.73 for women. Results from bootstrapping methods indicated good internal validation and calibration.

CONCLUSIONS

A "risk calculator" has been developed and placed on the Strong Heart Study Web site, which provides predicted risk of CHD in 10 years with input of these risk factors. This may be valuable for diverse populations with high rates of diabetes and albuminuria.

Cardiac procedure use following acute myocardial infarction among American Indians

BACKGROUND

The prevalence of coronary heart disease is rising among American Indians (AIs), but there is limited evidence describing processes of care for AI with acute myocardial infarction (AMI). We compared rates of cardiac catheterization, percutaneous coronary intervention (PCI), and coronary artery bypass graft (CABG) surgery between AI and whites with AMI.

METHODS

Using data from the Nationwide Inpatient Sample and the Indian Health Service National Patient Information Reporting System, we identified 2511 AI and 316,526 whites older than 30 years admitted with AMI during 1998 to 2001. Comparisons of cardiac procedure use between AI and whites were performed after adjusting for comorbid conditions and after stratifying by geographic region.

RESULTS

American Indians were less likely than whites to undergo cardiac catheterization and PCI in 3 of 4 geographic regions, with the largest difference occurring in the West South Central region (OR 0.32, 95% CI 0.24 to 0.43 for catheterization; OR 0.43, 95% CI 0.31 to 0.57 for PCI). American Indians were less likely than whites to undergo CABG surgery among diabetic patients (OR 0.48, 95% CI 0.32-0.73), but not among nondiabetic patients (OR 0.90, 95% CI 0.72-1.12). There were no differences in rates of PCI and CABG surgery between AIs and whites among those receiving cardiac catheterization.

CONCLUSIONS

Differences in the performance of coronary procedures are concentrated in western regions of the United States and are especially related to access to cardiac catheterization. Future studies are indicated to elucidate the mechanisms of these differences in care and their impact on clinical outcomes.

Coronary heart disease risk equivalence in diabetes depends on concomitant risk factors

OBJECTIVE

Diabetes has been defined as a coronary heart disease (CHD) risk equivalent, and more aggressive treatment goals have been proposed for diabetic patients.

RESEARCH DESIGN AND METHODS

We studied the influence of single and multiple risk factors on the 10-year cumulative incidence of fatal and nonfatal CHD and cardiovascular disease (CVD) in diabetic and nondiabetic men and women, with and without baseline CHD or CVD, in a population (n = 4,549) with a high prevalence of diabetes.

RESULTS

In both sexes, diabetes increased the risk for CHD (hazard ratio 1.99 and 2.93 for men and women, respectively). Diabetic men and women had a 10-year cumulative incidence of CHD of 25.9 and 19.1%, respectively, compared with 57.4 and 58.4% for nondiabetic men and women with previous CHD. The pattern was similar when only fatal events were considered. Diabetic individuals with one or two risk factors had a 10-year cumulative incidence of CHD that was only 1.4 times higher than that of nondiabetic individuals (14%). However, the 10-year incidence of CHD in diabetic subjects with multiple risk factors was >40%, and the incidence of fatal CHD was higher in these subjects than in nondiabetic subjects with previous CHD. Data for CVD showed similar patterns, as did separate analyses by sex.

CONCLUSIONS

Our results and comparisons with other available data show wide variation in the rate of CHD in diabetes, depending on the population and existing risk factors. Most individuals had a 10-year cumulative incidence >20%, but only those with multiple risk factors had a 10-year cumulative incidence that was equivalent to that of patients with CHD. Until more data are available, it may be prudent to consider targets based on the entire risk factor profile rather than just the presence of diabetes.

Mitral Annular Calcification, Aortic Valve Sclerosis, and Incident Stroke in Adults Free of Clinical Cardiovascular Disease

Background and Purpose— Mitral annular calcification (MAC) and aortic valve (AV) sclerosis have each been linked to cardiovascular disease. Whether MAC and AV sclerosis are risk factors for stroke independent of other echocardiographic or laboratory predictors has not been established. We evaluated the relationship between MAC, AV sclerosis, and first stroke events in a population-based cohort.

Methods— Our study cohort consisted of 2723 American Indians participating in the Strong Heart Study who were free of prevalent cardiovascular disease. Participants underwent standardized clinical, echocardiographic, and laboratory evaluation, and incident stroke was ascertained using validated methods.

Results— During a median follow-up of 7 years, 86 strokes occurred. Age- and sex-adjusted incidence rates of stroke were significantly increased for MAC (rate ratio [RR], 3.12; 95% CI, 1.77 to 5.25) but not for AV sclerosis (RR, 1.15; 95% CI, 0.45 to 2.49). MAC was also associated with a reduced time to first stroke events after adjustment for clinical variables and the inflammatory markers C-reactive protein and fibrinogen (hazard ratio [HR], 2.42; 95% CI, 1.39 to 4.21) or the echocardiographic covariates left ventricular hypertrophy and left atrial enlargement (HR, 1.89; 95% CI, 1.04 to 3.41). Individuals with and without AV sclerosis showed no significant difference in stroke-free survival in unadjusted analyses ( P =0.698). Crossing of the survival curves precluded multivariable analysis using Cox models.

Conclusions— In this cohort of American Indians without clinical cardiovascular disease, the presence of MAC, but not AV sclerosis, proved to be a strong risk factor for incident stroke after extensive adjustment for other predictors. Individuals exhibiting MAC may benefit from aggressive risk factor modification, but this will require further investigation.

Cardiovascular health among American Indians and Alaska Natives: successes, challenges, and potentials

With low rates of the risk factors for cardiovascular disease as recently as 40 years ago, the rates of cardiovascular disease (CVD) in American Indians and Alaska Natives were exceedingly low. Despite recent large-scale efforts to eliminate health disparities in ethnic and minority populations, the impact among American Indian and Alaska Natives to date has been relatively limited. Indeed, over the past several decades the incidence and prevalence of cardiovascular risk factors has risen significantly, including the development of an epidemic of diabetes. Evidence suggests that these higher rates of cardiovascular risk factors, including tobacco abuse, diabetes, high blood pressure, and elevated cholesterol levels, may be placing an inordinate burden of cardiovascular disease on the American Indian and Alaska Native population. The rates of heart disease and stroke among American Indians and Alaska Natives are now higher than in the general U.S. population as well as in U.S. whites. Recent evaluations suggest that these rates are also higher than among other ethnic or racial populations in the United States. Additionally, American Indians and Alaska Natives have been found to have a substantially higher proportion of premature death from heart disease when compared with other ethnic and racial populations. A number of recent prevention initiatives and focused clinical efforts are making promising strides toward reduced disparities in cardiovascular health with primordial, primary, and secondary cardiovascular prevention efforts along with enhanced early identification and therapeutic intervention for more favorable cardiovascular outcomes in the future. In order to reach our goals of heart-healthy and stroke-free American Indians and Alaska Natives, implementation of an aggressive, reasonably resourced, systemic plan of coordinated health promotion, risk reduction, and disease control efforts are necessary, with appropriate policy and legislative support.

Repolarization Abnormality for Prediction of All-Cause and Cardiovascular Mortality in American Indians: The Strong Heart Study

BACKGROUND

Analysis of electrocardiographic (ECG) repolarization abnormality using QTc interval and principal component analysis (PCA) of the T-wave vector predict all-cause and cardiovascular (CV) mortality. Novel descriptors of T-wave morphology have been suggested as measures of repolarization heterogeneity and adverse prognosis. However, whether these T-wave descriptors provide prognostic information beyond QTc and the PCA ratio has not been examined.

METHODS AND RESULTS

Predictive values of QTc, PCA, and novel ECG variables characterizing the T-wave loop were assessed in 1,729 American Indian participants in the first Strong Heart Study exam. T-loop morphology was quantified by the ratio of the second to first eigenvalues of the T-wave vector (PCA ratio), T-loop area (TLA) projected onto the dominant vector plane, T-wave morphology dispersion (TMD) and by the sum of the squares of the fourth to eighth eigenvalues, the T-wave residuum (TWR). After mean follow-up of 4.8 +/- 0.8 years, there were 183 deaths from all causes, including 51 CV deaths. In univariate Cox analyses, prolonged QTc, increased PCA ratio, TLA, TMD, and TWR were significant predictors of all-cause and CV mortality (P < 0.001). In multivariate Cox analyses adjusting for demographic and clinical risk factors for mortality, increased PCA ratio (chi-square = 7.9, P = 0.005) and TWR (chi-square = 5.3, P = 0.022) remained significant predictors of CV mortality and increased QTc (chi-square = 12.1, P < 0.001) and TWR (chi-square = 6.0, P = 0.014) of all-cause mortality. Addition of TWR to the model with clinical variables and the PCA ratio for CV mortality and to the model with clinical variables and prolonged QTc for all-cause mortality increased prognostic value of each model (increase in overall chi-square from 287.5 to 301.9 and from 221.5 to 230.3, respectively).

CONCLUSION

Novel descriptors of T-wave complexity provide additional prognostic information beyond QTc and PCA ratio for prediction of all-cause and CV mortality.

C-Reactive Protein and Electrocardiographic ST-Segment Depression Additively Predict Mortality

OBJECTIVES

This study was designed to examine whether high-sensitivity C-reactive protein (CRP) and electrocardiographic (ECG) ST-segment depression (STD) have additive utility for predicting cardiovascular disease (CVD) death and all-cause death (ACD).

BACKGROUND

C-reactive protein, a marker of systemic inflammation, and ECG STD, an index of myocardial ischemia and hypertrophy, independently predict mortality.

METHODS

Electrocardiograms and CRP levels were examined in 2,155 American Indian participants in the second Strong Heart Study examination. ST-segment depression >/=50 microV (n = 127) and CRP >7.0 mg/l (defining the upper quartile of CRP levels, n = 540) were considered abnormal.

RESULTS

After 5.2 +/- 1.2 years follow-up there were 95 CVD deaths and 310 ACD. In univariate Cox analyses, the combination of CRP and ECG STD improved risk stratification compared to either alone, with the presence of both CRP >7.0 and ECG STD associated with a 7.7-fold increased risk of CVD death (95% confidence interval [CI] 3.3 to 18.2) and a 6.5-fold increased risk of ACD (95% CI 4.1 to 10.3). After adjustment for age, gender, and relevant risk factors, the combination of high CRP and STD remained predictive of CVD death and ACD, with the presence of both abnormal CRP and STD associated with the highest risks of CVD death (hazard ratio [HR] 3.2, 95% CI 1.1 to 10.5) and ACD (HR 3.9, 95% CI 2.1 to 7.2) and the presence of either high CRP or abnormal STD associated with intermediate risks of CVD death (HR 2.2, 95% CI 1.4 to 3.4) and ACD (HR 1.5, 95% CI 1.2 to 2.0).

CONCLUSIONS

The combination of ECG STD and CRP increases the risk of mortality, demonstrating the additive impacts of active inflammation and preclinical CVD on prognosis.

Combined Echocardiographic Left Ventricular Hypertrophy and Electrocardiographic ST Depression Improve Prediction of Mortality in American Indians

Echocardiographic left ventricular hypertrophy (Echo-LVH) and ST segment depression (STD) on the ECG have each been demonstrated to predict cardiovascular (CV) and all-cause (AC) mortality. However, the prognostic value of combining Echo-LVH and ECG-STD has not been examined. ECGs and echocardiograms were examined in 2193 American Indian participants in the second Strong Heart Study examination. STD was measured by computer and was considered abnormal if > or =50 microV. Echo-LVH was defined by indexed LV mass >116 g/m2 in men and >104 g/m2 in women. After a mean follow-up of 3.1+/-0.7 years, there were 57 CV and 169 AC deaths. In univariate Cox analyses, Echo-LVH (chi2=54.2 and chi2=68.5) and ECG-STD (chi2=35.9 and chi2=46.3, all P<0.001) predicted CV and AC mortality, respectively. The combination of Echo-LVH and ECG-STD improved risk stratification compared with either alone for both CV death (chi2=74.4, P<0.001) and AC death (chi2=102.0, P<0.001), with presence of both ECG-STD and Echo-LVH associated with the greatest risks. After adjustment for age, sex, and relevant risk factors, combined Echo-LVH and ECG-STD remained predictive of CV mortality (chi2=19.7, P<0.001) and AC mortality (chi2=24.9, P<0.001), with the presence of both Echo-LVH and ECG-STD associated with a 6.3-fold increased risk of CV death (95% CI: 2.8 to 14.2) and a 4.6-fold increased risk of AC mortality (95% CI: 2.5 to 8.5). ECG-STD and Echo-LVH additively increase the risk of both CV mortality and AC mortality. These findings support the value of combining Echo-LVH and ECG-STD to improve risk stratification. These findings require verification in other populations.

Electrocardiographic repolarization complexity and abnormality predict all-cause and cardiovascular mortality in diabetes: the strong heart study

Type 2 diabetes is associated with increased risk of cardiovascular (CV) and all-cause mortality. Although electrocardiographic measures of repolarization abnormality and complexity stratify risk in the general population, their prognostic value in diabetes has not been well characterized. Digital electrocardiogram (ECG) readings were acquired for 994 American Indians with type 2 diabetes. ST segment depression (STD) >/=50 micro V and rate-corrected QT interval (QTc) >460 ms were examined as measures of repolarization abnormality. The principal component analysis (PCA) of the ratio of the second to first eigenvalues of the T-wave vector (PCA ratio) (>32.0% in women and >24.6% in men) was examined as a measure of repolarization complexity on the ECG. After a mean follow-up of 4.7 +/- 1.0 years, there were 56 CV deaths and 155 deaths from all causes. In univariate analyses, STD, QTc, and the PCA ratio predicted CV and all-cause mortality. After multivariate adjustment for age, sex, and other risk factors, STD (hazard ratio 3.68, 95% CI 1.70-7.96) and PCA ratio (2.61, 1.33-5.13) remained predictive of CV mortality and both STD (2.36, 1.38-4.02) and QTc (2.03, 1.32-3.12) predicted all-cause mortality. Computerized ECG measures of repolarization abnormality and complexity predict CV and all-cause mortality in type 2 diabetes, supporting their use to identify high-risk individuals with diabetes.

Quantitative assessment of electrocardiographic strain predicts increased left ventricular mass: the Strong Heart Study

OBJECTIVES

This study was designed to examine the relation of computer-measured ST depression (STdep) in the lateral precordial leads to the presence of left ventricular hypertrophy (LVH).

BACKGROUND

Qualitative abnormalities of repolarization in the lateral precordial leads of the electrocardiogram, as manifested by the strain pattern of T-wave inversion and STdep, are markers for LVH and adverse prognosis. However, the independent relationship of increased left ventricular (LV) mass to quantitative measures of STdep in these leads remains unclear.

METHODS

Electrocardiograms and echocardiograms were examined in the second Strong Heart Study examination in 1,595 American Indian participants without evident coronary disease. The absolute magnitude of ST segment deviation above or below isoelectric baseline was measured by computer in leads V(5) and V(6), and participants were grouped according to gender-specific quartiles of maximal STdep. Left ventricular hypertrophy was defined by indexed LV mass >49.2 g/m(2.7) in men and >46.7 g/m(2.7) in women.

RESULTS

Increasing STdep was associated with older age, greater pulse pressure, serum fibrinogen levels and urinary albumin/creatinine ratios, and with stepwise increases in LV mass (145 +/- 28 vs. 150 +/- 33 vs. 156 +/- 36 vs. 164 +/- 43 g, p < 0.001), indexed LV mass (38.2 +/- 7.7 vs. 39.3 +/- 8.7 vs. 40.5 +/- 9.4 vs. 44.0 +/- 11.0 g/m(2.7), p < 0.001), and prevalence of LVH (11.6 vs. 19.1 vs. 21.5 vs. 31.2%, p < 0.001). After controlling for clinical differences, increasing STdep remained strongly associated with increased prevalence of LVH (p = 0.0001).

CONCLUSIONS

In the absence of evidence of coronary disease, increasing STdep in the lateral precordial leads is associated with increasing LV mass and increased prevalence of anatomic LVH.

The increasing incidence of coronary artery disease and cardiovascular risk factors among a Southwest Native American tribe: the White Mountain Apache Heart Study

BACKGROUND

Rates of cardiovascular disease and its risk factors seem to be increasing in American Indian populations, yet these changes have received little documentation.

OBJECTIVES

To evaluate incidence rates of coronary artery disease, acute myocardial infarction, and cardiac events during a 10-year period (1987-1996); to assess cardiac risk factors for an American Indian tribe in Arizona.

METHODS

A retrospective medical chart review was performed for tribal members from January 1, 1987-December 31, 1996. Patient records with even minor indications of coronary disease were reviewed independently by 2 cardiologists of the Native American Cardiology Program. Multiple databases were reviewed in an effort to find all diagnoses, and incidence rates were calculated and analyzed for increasing trends. Cardiac risk factors were assessed in a population convenience sample.

RESULTS

From 1987 through 1996, the number of incident cases increased from 3 to 18 for coronary artery disease, 1 to 10 for acute myocardial infarction, and 3 to 26 for cardiac events. Statistically significant increasing trends were calculated for each. Of our youthful convenience sample, 49% had 2 or more cardiac risk factors.

CONCLUSIONS

This study confirms increasing rates of coronary artery disease and its comorbidities in this American Indian population and demonstrates high prevalence of cardiovascular risk factors among tribal members without extant coronary disease. This suggests that coronary disease will likely continue to increase as this population ages. To prevent such increases, culturally appropriate, aggressive preventive interventions are needed.

The epidemiology of atherosclerosis and its risk factors among Native Americans

In the past, the rates of risk factors for atherosclerosis and cardiovascular disease (CVD) as well as the manifestations of coronary heart disease, stroke, and peripheral vascular disease in Native Americans have been relatively low compared to the general United States population. However, over the past several decades the rates of these CVD-associated risk factors have markedly increased with the concomitant development of a significant and alarming rise in the manifestations of atherosclerosis.

Principal component analysis of the T wave and prediction of cardiovascular mortality in American Indians: the Strong Heart Study

BACKGROUND

Increased QT interval dispersion (QTd) is a proposed ECG marker of vulnerability to ventricular arrhythmias and of cardiovascular (CV) mortality. However, principal component analysis (PCA) of the T-wave vector loop may more accurately represent repolarization abnormalities than QTd.

METHODS AND RESULTS

Predictive values of QTd and PCA were assessed in 1839 American Indian participants in the first Strong Heart Study examination. T-wave loop morphology was quantified by the ratio of the second to first eigenvalues of the T-wave vector by PCA (PCA ratio); QTd was quantified as the difference between maximum and minimum QT intervals. After 3.7+/-0.9 years mean follow-up, there were 55 CV deaths. In univariate analyses, an increased PCA ratio predicted CV mortality in women (chi2=7.8, P=0.0053) and men (chi2=9.5, P=0.0021). In contrast, increased QTd was a significant predictor of CV mortality in women (chi2=30.6, P<0.0001) but not in men (chi2=2.0, P=NS). In multivariate Cox analyses controlling for risk factors and rate-corrected QT interval, the PCA ratio remained a significant predictor of CV mortality in women (chi2=4.0 P=0.043) and men (chi2=6.4, P=0.011); QTd was a significant predictor in women only (chi2=11.0, P=0.0009). PCA ratios >90th percentile (32% in women and 24.6% in men) identified women with a 3.68-fold increased risk of CV mortality (95% CI, 1.54 to 8.83) and men with a 2.77-fold increased risk (95% CI, 1.18 to 6.49).

CONCLUSIONS

Abnormalities of repolarization measured by PCA of the T-wave loop predict CV death in men and women, supporting use of PCA for quantifying repolarization abnormalities.

Procainamide-induced psychosis: a case report and review of the literature

OBJECTIVE

To describe a case of procainamide-induced psychosis in an adult treated for atrial fibrillation.

CASE SUMMARY

A 45-year-old Native American woman developed acute psychosis within 72 hours of initiating procainamide for atrial fibrillation. Symptoms abated within 24 hours of discontinuing procainamide. Serum procainamide/N-acetylprocainamide concentrations were therapeutic throughout treatment. Sotalol was started without recurrence of symptoms.

DISCUSSION

Psychosis is a rare complication of treatment with procainamide, but the exact mechanism for this adverse event is not fully understood. Seven cases implicating procainamide as the cause of acute psychosis are reported in the literature. Cases of psychosis involving other antiarrhythmic agents have also been reported.

CONCLUSIONS

Healthcare personnel should be aware of this adverse event related to procainamide and other antiarrhythmic agents.

Arrhythmogenic right ventricular dysplasia in an American Indian woman

Arrhythmogenic right ventricular (RV) dysplasia consists of a dilatation of the right ventricle with a reduction of RV ejection fraction with fibrofatty replacement of the RV myocardium in the face of a well-preserved left ventricular systolic function. Arrhythmogenic RV dysplasia, which is a cause of sudden unexpected death, has been reported from many geographic areas, including the United States, Europe, and the Far East. This case report presents the first case of arrhythmogenic RV dysplasia in an American Indian (Native American) patient.

Rising tide of cardiovascular disease in American Indians. The Strong Heart Study

BACKGROUND

Although cardiovascular disease (CVD) used to be rare among American Indians, Indian Health Service data suggest that CVD mortality rates vary greatly among American Indian communities and appear to be increasing. The Strong Heart Study was initiated to investigate CVD and its risk factors in American Indians in 13 communities in Arizona, Oklahoma, and South/North Dakota.

METHODS AND RESULTS

A total of 4549 participants (1846 men and 2703 women 45 to 74 years old) who were seen at the baseline (1989 to 1991) examination were subjected to surveillance (average 4.2 years, 1991 to 1995), and 88% of those remaining alive underwent a second examination (1993 to 1995). The medical records of all participants were exhaustively reviewed to ascertain nonfatal cardiovascular events that occurred since the baseline examination or to definitively determine cause of death. CVD morbidity and mortality rates were higher in men than in women and were similar in the 3 geographic areas. Coronary heart disease (CHD) incidence rates among American Indian men and women were almost 2-fold higher than those in the Atherosclerosis Risk in Communities Study. Significant independent predictors of CVD in women were diabetes, age, obesity (inverse), LDL cholesterol, albuminuria, triglycerides, and hypertension. In men, diabetes, age, LDL cholesterol, albuminuria, and hypertension were independent predictors of CVD.

CONCLUSIONS

At present, CHD rates in American Indians exceed rates in other US populations and may more often be fatal. Unlike other ethnic groups, American Indians appear to have an increasing incidence of CHD, possibly related to the high prevalence of diabetes. In the general US population, the rising prevalence of obesity and diabetes may reverse the decline in CVD death rates. Therefore, aggressive programs to control diabetes and its risk factors are needed.

Vascular surgical society of great britain and ireland: limb salvage in the octogenarian

BACKGROUND: Critical limb ischaemia (CLI) presents a unique set of problems in the elderly patient. Foremost among these is the much greater likelihood of loss of independence and reduced quality of life if major amputation is required. For this reason it has been this unit's policy to attempt reconstructive vascular surgery in almost all cases of CLI. The outcome of this policy was examined. METHODS: All patients had surgery performed under one consultant and data were entered prospectively on to a database. RESULTS: Risk factors included diabetes (17 per cent), smoking (78 per cent) and ischaemic heart disease (31 per cent). Some 127 patients had either femoropopliteal (59), femorodistal (64) or popliteal-distal grafts (four) performed for limb-threatening ischaemia. Follow-up was performed at 3, 6 and 12 months and then at annual intervals until death. Seventeen of these patients required a subsequent major amputation, 12 at the below-knee and five at the above-knee level. Mean follow-up was 2 years. The perioperative mortality rate was 15 per cent, although eight of these patients were admitted with acute or chronic ischaemia. Cumulative graft secondary patency rate was 68 per cent at 4 years for vein grafts. Some 95 per cent of patients with patent grafts were independently mobile. CONCLUSION: Excellent results can be achieved for limb salvage with a relatively low morbidity in this group. Elderly patients with CLI do not live long and avoidance of amputation is particularly desirable in order to maximize the quality of their remaining life.

Accuracy of carotid duplex is laboratory specific and must be determined by internal audit

OBJECTIVE

To assess the accuracy of carotid duplex in a single vascular laboratory at the prediction of an angiographic 70% internal carotid artery stenosis.

DESIGN

A retrospective review of all patients who underwent both carotid duplex and angiography in a 1-year period at a vascular unit which participates in the ACST trial.

METHODS

Peak systolic velocity was used as a primary end-point in carotid duplex examinations with a PSV > 130 cm/s used as an indication for angiographic assessment. Biplanar arch aortography and selective carotid catheterisation were performed as indicated and diameter reduction calculated by the ECST method.

RESULTS

The sensitivity of 130 cm/s for the detection of a 70% stenosis was 96% and the specificity 67%. If a PSV of 250 cm/s were used the sensitivity would be only 37% and specificity 96%.

CONCLUSIONS

Applying duplex criteria from one centre to another is inappropriate. Laboratory specific audit of duplex and angiography is essential before deciding to abandon preoperative angiography for carotid disease.

Treatment of chronic iliac artery occlusions by means of percutaneous endovascular stent placement

PURPOSE

A retrospective evaluation of outcomes in patients with chronic iliac occlusions treated with insertion of metallic endovascular stents, without previous thrombolysis, on an intention-to-treat basis.

MATERIALS AND METHODS

Seventy-two patients with chronic iliac occlusion underwent attempted stent placement from either the ipsilateral or contralateral femoral artery. There were 49 men and 23 women. Mean age was 63.1 years (range, 39-88 years). A total of 89 stents were deployed in 67 patients. Follow-up was from 24 to 69 months (mean, 37.5 months).

RESULTS

Stents were successfully deployed in 67 patients (93%), with two early failures, giving a primary success rate of 90%. There were five significant and four insignificant procedural complications. There were four late failures (all within the first year) and four non-stent-related deaths.

CONCLUSION

Endovascular stent placement offers an alternative to surgery in the treatment of chronic iliac occlusions.

Impact of the New Deal on vascular surgical training

The rapid development and technological advances in vascular surgery have provided the impetus for the establishment of dedicated pure vascular surgical services. It remains unclear whether all vascular surgery will be provided by such units in the future or whether several district general hospitals will combine resources and provide dedicated vascular on-call rotas between surgeons on separate sites. Training in vascular surgery is also changing rapidly. A modular training scheme encompassing three levels of training has been recommended (1). Some of the training will only be performed in large training units, but there remains a requirement for general surgeons to be exposed to some vascular surgery during their training. The "New Deal' for junior doctors has imposed limits on the amount of hours worked during a week. Junior doctors should not on average be contracted for more than 72 hours a week or work more than 56 (2). The maximum on-call rota which fulfils these criteria is a 1 in 4 on-call with no early starts, late finishes and no prospective cover. Allowing for holidays, study leave, early starts and late finishes a 1 in 5 or 1 in 6 rota system is required. Implementation of the Calman report in higher specialist training would reduce the time spent in training at high specialist level to perhaps five years. In a modular training programme in vascular surgery there may be as little as one year Level II training spent in vascular surgery or perhaps two years if the candidate opted to have vascular surgery as their only sub-specialty. In an attempt to assess the impact of the New Deal and the Calman report on vascular surgical training we have assessed the exposure to vascular surgical procedure of hypothetical trainees on a 1 in 6 rota.

Effect of carotid endarterectomy on the ocular circulation and on ocular symptoms unrelated to emboli

OBJECTIVE

To evaluate haemodynamic changes in the ophthalmic artery and the retina following carotid endarterectomy and their effect on the pathophysiology of the eye.

DESIGN

Prospective study.

METHOD

Twenty-two consecutive patients with severe carotid stenosis underwent 23 carotid endarterectomies and one subclavian-carotid bypass. The following measurements were made preoperatively and 3 months after operation; Ophthalmic artery (OA) and retinal arteriole (RA) peak systolic velocity (PSV) and peak diastolic velocity (PDV), macular photostress recovery time, visual acuity, intraocular pressures, colour vision and visual fields testing.

RESULT

The RA PSV increased by 50% (p = 0.005) and PDV increased by 22% (p = 0.03). The OA PSV increased by 51% (p = 0.001). Macular photostress testing decreased from 58 s to 42 s (p = 0.001). Visual acuity improved in four and was unchanged in 13 eyes ipsilateral to the endarterectomy which had abnormal preoperative measurements. One patient experienced a dramatic increase in the ipsilateral intraocular pressure associated with visual deterioration. In two patients there was resolution of periorbital pain.

CONCLUSION

Our results demonstrate an increase in the PSV of the RA and OA following carotid surgery. There are pathophysiological changes in the eye, which accompany tight stenotic extracranial carotid artery disease and these may be influenced by carotid endarterectomy.