Preclinical TSPO Ligand PET to Visualize Human Glioma Xenotransplants: A Preliminary Study

Current positron emission tomography (PET) imaging biomarkers for detection of infiltrating gliomas are limited. Translocator protein (TSPO) is a novel and promising biomarker for glioma PET imaging. To validate TSPO as a potential target for molecular imaging of glioma, TSPO expression was assayed in a tumor microarray containing 37 high-grade (III, IV) gliomas. TSPO staining was detected in all tumor specimens. Subsequently, PET imaging was performed with an aryloxyanilide-based TSPO ligand, [¹⁸F]PBR06, in primary orthotopic xenograft models of WHO grade III and IV gliomas. Selective uptake of [¹⁸F]PBR06 in engrafted tumor was measured. Furthermore, PET imaging with [¹⁸F]PBR06 demonstrated infiltrative glioma growth that was undetectable by traditional magnetic resonance imaging (MRI). Preliminary PET with [¹⁸F]PBR06 demonstrated a preferential tumor-to-normal background ratio in comparison to 2-deoxy-2-[¹⁸F]fluoro-D-glucose ([¹⁸F]FDG). These results suggest that TSPO PET imaging with such high-affinity radiotracers may represent a novel strategy to characterize distinct molecular features of glioma growth, as well as better define the extent of glioma infiltration for therapeutic purposes.

Multi-institutional validation of a preoperative scoring system which predicts survival for patients with glioblastoma

Glioblastoma is the most common and aggressive type of primary brain tumor in adults. Average survival is approximately 1 year, but individual survival is heterogeneous. Using a single institutional experience, we have previously identified preoperative factors associated with survival and devised a prognostic scoring system based on these factors. The aims of the present study are to validate these preoperative factors and verify the efficacy of this scoring system using a multi-institutional cohort. Of the 334 patients in this study from three different institutions, the preoperative factors found to be negatively associated with survival in a Cox analysis were age >60 years (p<0.0001), Karnofsky Performance Scale score ≤80 (p=0.03), motor deficit (p=0.02), language deficit (p=0.04), and periventricular tumor location (p=0.04). Patients possessing 0-1, 2, 3, and 4-5 of these variables were assigned a preoperative grade of 1, 2, 3, and 4, respectively. Patients with a preoperative grade of 1, 2, 3, and 4 had a median survival of 17.9, 12.3, 10, and 7.5 months, respectively. Survival of each of these grades was statistically significant (p<0.05) in log-rank analysis. This grading system, based only on preoperative variables, may provide patients and physicians with prognostic information that may guide medical and surgical therapy before any intervention is pursued.

Segmentation of malignant gliomas through remote collaboration and statistical fusion

PURPOSE

Malignant gliomas represent an aggressive class of central nervous system neoplasms. Correlation of interventional outcomes with tumor morphometry data necessitates 3D segmentation of tumors (typically based on magnetic resonance imaging). Expert delineation is the long-held gold standard for tumor segmentation, but is exceptionally resource intensive and subject to intrarater and inter-rater variability. Automated tumor segmentation algorithms have been demonstrated for a variety of imaging modalities and tumor phenotypes, but translation of these methods across clinical study designs is problematic given variation in image acquisition, tumor characteristics, segmentation objectives, and validation criteria. Herein, the authors demonstrate an alternative approach for high-throughput tumor segmentation using Internet-based, collaborative labeling.

METHODS

In a study of 85 human raters and 98 tumor patients, raters were recruited from a general university campus population (i.e., no specific medical knowledge), given minimal training, and provided web-based tools to label MRI images based on 2D cross sections. The labeling goal was characterized as to extract the enhanced tumor cores on T1-weighted MRI and the bright abnormality on T2-weighted MRI. An experienced rater manually constructed the ground truth volumes of a randomly sampled subcohort of 48 tumor subjects (for both T1w and T2w). Raters' taskwise individual observations, as well as the volume wise truth estimates via statistical fusion method, were evaluated over the subjects having the ground truth.

RESULTS

Individual raters were able to reliably characterize (with >0.8 dice similarity coefficient, DSC) the gadolinium-enhancing cores and extent of the edematous areas only slightly more than half of the time. Yet, human raters were efficient in terms of providing these highly variable segmentations (less than 20 s per slice). When statistical fusion was used to combine the results of seven raters per slice for all slices in the datasets, the 3D agreement of the fused results with expertly delineated segmentations was on par with the inter-rater reliability observed between experienced raters using traditional 3D tools (approximately 0.85 DSC). The cumulative time spent per tumor patient with the collaborative approach was equivalent to that with an experienced rater, but the collaborative approach could be achieved with less training time, fewer resources, and efficient parallelization.

CONCLUSIONS

Hence, collaborative labeling is a promising technique with potentially wide applicability to cost-effective manual labeling of medical images.

Temporal trends in ischemic and hemorrhagic strokes in Northern Italy: results from the cardiovascular monitoring unit in Northern Italy population-based register, 1998-2004

BACKGROUND

We compared rates and case fatality from a population-based stroke register in Northern Italy between 1998 and 2004 to assess changes over time and to evaluate changes in case diagnosis and management.

METHODS

The WHO Multinational Monitoring of Trends and Determinants in Cardiovascular Disease criteria were used to identify suspected fatal or nonfatal events occurring among residents 35-74 years of age. Data on in-hospital treatments, symptoms and diagnostic tools were extracted. Out-of-hospital deaths were also investigated. The annual average relative change (ARC) in death rate, attack rate and case fatality were derived from Poisson models.

RESULTS

Death rates due to ischemic stroke (IS) decreased [men: ARC -12.7, 95% confidence interval (CI) -21.3 to -3.2; women: ARC -14.0, 95% CI -23.3 to -3.5]. These reductions are attributable to decreases in case fatality; attack rates of nonfatal IS increased (men: ARC 3.6, 95% CI 0.5-6.7; women: ARC 4.1, 95% CI 0.0-8.2). IS patients showed a higher prevalence of dyslipidemia and hypertension and underwent MRI more frequently in 2004. Both findings may explain the increased proportions of less severe cases. Case fatality and attack rates for hemorrhagic strokes (HS) were stable, with an observed increased prevalence of patients under anticoagulant/antiplatelet treatments.

CONCLUSIONS

In this low-IS-incidence population, death rates decreased substantially during the investigated period. More accurate diagnostic tools increase the probability of detecting less severe cases. HS remains a frequently fatal disease with a stable incidence.

COLLABORATIVE LABELING OF MALIGNANT GLIOMA

Malignant gliomas represent an aggressive class of central nervous system neoplasms which are often treated by maximal surgical resection. Herein, we seek to improve the methods available to quantify the extent of tumors as seen on magnetic resonance imaging using Internet-based, collaborative labeling. In a study of clinically acquired images, we demonstrate that teams of minimally trained human raters are able to reliably characterize the gadolinium-enhancing core and edema tumor regions (Dice ≈ 0.9). The collaborative approach is highly parallel and efficient in terms of time (the total time spent by the collective is equivalent to that of a single expert) and resources (only minimal training and no hardware is provided to the participants). Hence, collaborative labeling is a very promising new technique with potentially wide applicability to facilitate cost-effective manual labeling of medical imaging data.

Collaborative Labeling of Malignant Glioma with WebMILL: A First Look

Malignant gliomas are the most common form of primary neoplasm in the central nervous system, and one of the most rapidly fatal of all human malignancies. They are treated by maximal surgical resection followed by radiation and chemotherapy. Herein, we seek to improve the methods available to quantify the extent of tumors using newly presented, collaborative labeling techniques on magnetic resonance imaging. Traditionally, labeling medical images has entailed that expert raters operate on one image at a time, which is resource intensive and not practical for very large datasets. Using many, minimally trained raters to label images has the possibility of minimizing laboratory requirements and allowing high degrees of parallelism. A successful effort also has the possibility of reducing overall cost. This potentially transformative technology presents a new set of problems, because one must pose the labeling challenge in a manner accessible to people with little or no background in labeling medical images and raters cannot be expected to read detailed instructions. Hence, a different training method has to be employed. The training must appeal to all types of learners and have the same concepts presented in multiple ways to ensure that all the subjects understand the basics of labeling. Our overall objective is to demonstrate the feasibility of studying malignant glioma morphometry through statistical analysis of the collaborative efforts of many, minimally-trained raters. This study presents preliminary results on optimization of the WebMILL framework for neoplasm labeling and investigates the initial contributions of 78 raters labeling 98 whole-brain datasets.

Safety and cost effectiveness of early discharge following microscopic trans-sphenoidal resection of pituitary lesions

Background:

Inpatient hospitalization following trans-sphenoidal resection of a pituitary neoplasm has traditionally involved a hospital stay of 2 days or more. It has been the policy of the senior pituitary neurosurgeon (GSA) since February 2008 to allow discharge home on postoperative day (POD) 1 if thirst mechanism is intact and the patient is tolerating oral hydration. The goal of this study was to evaluate the safety and cost-effectiveness of this practice.

Methods:

We reviewed the charts of 30 patients, designated the early discharge group, who consecutively underwent microscopic trans-sphenoidal resection from February 2008 to December 2009. We then reviewed the charts of 30 patients, designated the standard discharge group, who consecutively underwent trans-sphenoidal resection from May 2007 to February 2008 before discharge home on POD1 was considered an appropriate option. Safety and cost-effectiveness of the two patient groups were retrospectively evaluated.

Results

Patients in the early discharge group went home, on average, on POD 1.3. Following exclusion of two outliers, the average date of discharge of patients in the standard discharge group was POD 2.2. The policy of early discharge saved an average of $1,949 per patient-approximately 4% the total cost of the procedure. Trends toward decreased costs did not reach statistical significance. While no patient suffered any measurable morbidity as a result of early discharge home, 1 in 3 patients in the early discharge group required unscheduled postoperative re-evaluation-a figure significantly higher than the standard discharge group.

Conclusions:

At a dedicated pituitary center with the resources to closely monitor outpatient endocrinological and postsurgical issues, early discharge home following trans-sphenoidal surgery is a safe option that is associated with an increase in the number of unscheduled postoperative visits and a trend toward lower costs.

Hemostatic factors and subclinical brain infarction in a community-based sample: the ARIC study

BACKGROUND

Previous data are conflicting as to whether imbalance between hemostatic factors is associated with clinical strokes. We evaluated the association between hemostatic factor levels and subclinical lacunar infarcts in a nested sample from a subset of the Atherosclerosis Risk in Communities (ARIC) cohort.

METHODS

196 cases without clinical strokes had lacunar infarcts by MRI, and 214 controls without radiographic infarcts were frequency-matched by age group and sex. Logistic regression models were fitted to assess the association between levels of hemostatic markers and case status.

RESULTS

In age-, race- and sex-adjusted models, von Willebrand factor (vWF) and D-dimer were positively associated with case status, with odds ratios for the highest vs. lowest tertile of 2.0 (95% CI 1.2-3.6) for vWF and 1.76 (95% CI 1.02-3.0) for D-dimer. Plasminogen had nonsignificant inverse associations with presence of silent lacunar infarcts.

CONCLUSIONS

vWF and D-dimer were positively associated, and plasminogen was nonsignificantly inversely associated with subclinical radiographic infarct. Further studies on the role of these hemostatic factors in the development of silent lacunar infarcts may help elucidate the mechanisms behind this injury and may even point to potential targets for future intervention.

Systematically missing confounders in individual participant data meta-analysis of observational cohort studies

One difficulty in performing meta-analyses of observational cohort studies is that the availability of confounders may vary between cohorts, so that some cohorts provide fully adjusted analyses while others only provide partially adjusted analyses. Commonly, analyses of the association between an exposure and disease either are restricted to cohorts with full confounder information, or use all cohorts but do not fully adjust for confounding. We propose using a bivariate random-effects meta-analysis model to use information from all available cohorts while still adjusting for all the potential confounders. Our method uses both the fully adjusted and the partially adjusted estimated effects in the cohorts with full confounder information, together with an estimate of their within-cohort correlation. The method is applied to estimate the association between fibrinogen level and coronary heart disease incidence using data from 154 012 participants in 31 cohorts.† Copyright © 2009 John Wiley & Sons, Ltd.

The cardiovascular risk factor profile in the study area Augsburg. Results from the first MONICA survey 1984/85

The main objective of the first survey was the investigation of the prevalence and distribution of hypertension, hypercholesterolemia and cigarette smoking in the study area. The data-collection phase lasted from October 1984 to May 1985. A two-stage cluster sample of 5312 persons of German nationality was drawn from a population of 282,279 inhabitants, aged 25-64. The data were gathered through interview, physical examination and self-administered questionnaire. A response of 79% was achieved. Sixteen percent of men and 10% of women had high blood pressure (BP) values (greater than or equal to 160/95 mmHg). Only 16% of male and 34% of female hypertensives had controlled BP values. The prevalence of hypercholesterolemia (greater than or equal to 6.72 mmol/L = greater than or equal to 260 mg/dl) was 26% in men and 22% in women. Forty percent of men and 22% of women reported they were current cigarette smokers. Among participants, aged 25-44, cigarette smoking was the most prevalent risk factor in men and women. Thirty-seven percent of men and 52% of women, aged 25-64, had none of the three major risk factors.

Neighborhood of residence and incidence of coronary heart disease

BACKGROUND

Where a person lives is not usually thought of as an independent predictor of his or her health, although physical and social features of places of residence may affect health and health-related behavior.

METHODS

Using data from the Atherosclerosis Risk in Communities Study, we examined the relation between characteristics of neighborhoods and the incidence of coronary heart disease. Participants were 45 to 64 years of age at base line and were sampled from four study sites in the United States: Forsyth County, North Carolina; Jackson, Mississippi; the northwestern suburbs of Minneapolis; and Washington County, Maryland. As proxies for neighborhoods, we used block groups containing an average of 1000 people, as defined by the U.S. Census. We constructed a summary score for the socioeconomic environment of each neighborhood that included information about wealth and income, education, and occupation.

RESULTS

During a median of 9.1 years of follow-up, 615 coronary events occurred in 13,009 participants. Residents of disadvantaged neighborhoods (those with lower summary scores) had a higher risk of disease than residents of advantaged neighborhoods, even after we controlled for personal income, education, and occupation. Hazard ratios for coronary events in the most disadvantaged group of neighborhoods as compared with the most advantaged group--adjusted for age, study site, and personal socioeconomic indicators--were 1.7 among whites (95 percent confidence interval, 1.3 to 2.3) and 1.4 among blacks (95 percent confidence interval, 0.9 to 2.0). Neighborhood and personal socioeconomic indicators contributed independently to the risk of disease. Hazard ratios for coronary heart disease among low-income persons living in the most disadvantaged neighborhoods, as compared with high-income persons in the most advantaged neighborhoods were 3.1 among whites (95 percent confidence interval, 2.1 to 4.8) and 2.5 among blacks (95 percent confidence interval, 1.4 to 4.5). These associations remained unchanged after adjustment for established risk factors for coronary heart disease.

CONCLUSIONS

Even after controlling for personal income, education, and occupation, we found that living in a disadvantaged neighborhood is associated with an increased incidence of coronary heart disease.

Occupational risk factors for mortality from stomach and lung cancer among rubber workers: an analysis using internal controls and refined exposure assessment

OBJECTIVES

To determine occupational risk factors for stomach and lung cancer among workers in the German rubber industry.

METHODS

A cohort of all male German rubber workers (n = 11,633) who had been employed for at least one year in one of five study plants and who were alive and actively employed or retired on 1 January 1981 was followed for mortality from 1 January 1981 through December 1991. A subcohort of n = 8,933 workers who were hired after 1 January 1950 was defined to focus on working conditions in the more recent rubber industry. Work histories were reconstructed using routinely documented 'cost centre codes' and classified into six work areas as well as subgroups of some work areas. The work areas are: 1. preparation of materials, 2. production of technical rubber goods, 3. production of tyres, 4. storage and dispatch, 5. maintenance, 6. others. Standardized mortality ratios (SMR) and Cox proportional hazards models were calculated for each of the work areas (>1 year of employment in the respective work area). Hazard rate ratios were adjusted for age (time marker) and stratified for year of hire (1950-1959, > or =1960) and years of employment in the respective work area (1-9 years, > or =10 years); years of employment were lagged 10 years to account for latency.

RESULTS

Compared to the national reference population mortality from cancer of stomach (observed 44, SMR = 117; 95% CI: 85-157) and lung (observed 154, SMR = 123; 95% CI: 104-144) was slightly increased. Using internal controls we observed excess deaths from stomach cancer in work area 1 (relative risk [RR] = 2.3; 95% CI: 1.2-4.2) and from lung cancer in work areas 1 (RR = 1.7; 95% CI: 1.2-2.3), 2 (RR = 1.5; 95% CI: 1.1-2.1), and 3 (RR = 1.3; 95% CI: 0.9-1.8). On the basis of cumulative years of employment an exposure response relationship was observed for mortality from both cancer sites among a subcategory of work area 1: weighing and mixing. Increased risks were also seen for lung cancer among workers employed in production of technical rubber goods.

CONCLUSION

Our results support an association between an excess mortality from stomach and lung cancer and employment in early production stages of rubber manufacturing, especially weighing and mixing. This may point to an aetiologic role of asbestos or carbon black. For stomach cancer additional risk factors, e.g. exposure to dust and talc, deserve further investigation. The results of the present study do not support a causal role of nitrosamines for stomach or lung cancer.

An occupational cohort mortality study of women in the German rubber industry: 1976 to 1991

Few previous studies of workers in the rubber industry have focused on women. We examined patterns of mortality among 2871 women employed in one of five German rubber plants for at least 1 year on or after January 1, 1976, and observed through December 31, 1991. All-causes mortality was near that expected (standardized mortality ratio [lsqbSMR], 101; 95% confidence interval [CI], 87 to 118), but cancer mortality was decreased (SMR, 90; 95% CI, 70 to 115). Nevertheless, excesses were observed for mortality from stomach cancer (SMR, 156; 95% CI, 63 to 322), lung cancer (SMR, 140; 95% CI, 56 to 289), and lymphatic system cancers (SMR, 175; 95% CI, 48 to 448). Stronger associations were observed among sub-cohorts defined by time period hired. Despite limited numbers of deaths, modest excesses of mortality due to specific cancers were observed and are consistent with previous studies.

Comparison of medical care and survival of hospitalized patients with acute myocardial infarction in Poland and the United States

Few studies have evaluated between-country differences in medical care and survival after acute myocardial infarction, and none have compared the US with countries from Eastern Europe. Comparable data from the US (Atherosclerosis Risk in Communities Study [US-ARIC]) and Poland (Multinational Monitoring of Trends and Determinants in Cardiovascular Disease project [Pol-MONICA]) were developed. From 1987 through 1993, a total of 3,694 patients were hospitalized with acute myocardial infarction events in the 2 Pol-MONICA communities and 4,801 in the 4 US-ARIC communities. Patients in the US-ARIC were 1.7 times more likely to be treated in a coronary care unit and received cardiac procedures, calcium channel blockers, and thrombolytic agents significantly more often than patients in the Pol-MONICA. The use of antiplatelet agents, nitrates, angiotensin-converting enzyme inhibitors, and beta blockade agents was similar in both countries. Case fatality (28-day) rates after hospitalized acute myocardial infarction were nearly identical (men, 7% in Pol-MONICA vs 6% in US-ARIC; women, 9% in Pol-MONICA vs 8% in US-ARIC). However, when fatal coronary heart disease events not associated with a hospitalized myocardial infarction were included, the US-ARIC rates were less than half than those seen in Pol-MONICA. Substantial differences in treatment of hospitalized acute myocardial infarction between countries did not translate into a survival advantage for patients reaching clinical attention. Differences in case severity, arising from the high out-of-hospital coronary death rate in Poland may play an important role in this finding.

Workplace risk factors for cancer in the German rubber industry: Part 2. Mortality from non-respiratory cancers

OBJECTIVES

To determine the mortality from non-respiratory cancers by work area among active and retired male workers of the German rubber industry.

METHODS

A cohort of 11,633 male German workers was followed up for mortality from 1 January 1981 to 31 December 1991. Cohort members were active (n = 7536) or retired (n = 4127) on 1 January 1981 and had been employed for at least one year in one of five study plants producing tyres or technical rubber goods. Work histories were reconstructed from routinely documented "cost centre codes" and classified into six categories: I preparation of materials; II production of technical rubber goods; III production of tyres; IV storage and dispatch; V general service; VI others. Standardised mortality ratios (SMRs) and 95% confidence intervals (95% CIs), controlling for age and calendar year and stratified by work area (employment in respective work area for at least one year) and time related variables (year of hire, lagged years of employment in work area) were calculated from national mortality rates as the reference.

RESULTS

Significant increases in mortality were found for pharyngeal cancer in work area IV (three deaths, SMR 486, 95% CI 101 to 1419), oesophageal cancer in work area III (11 deaths, SMR 227, 95% CI 114 to 407), and leukaemia in work areas I (11 deaths, SMR 216; 95% CI 108 to 387) and II (14 deaths, SMR 187; 95% CI 102 to 213). Furthermore, increased SMRs were found for stomach cancer in work area I (22 deaths, SMR 134; 95% CI 84 to 203), colon cancer in work area II (27 deaths, SMR 131, 95% CI 86 to 191), prostatic cancer in work area V (27 deaths, SMR 152, 95% CI 99 to 221), and bladder cancer in work areas IV (six deaths, SMR 253; 95% CI 93 to 551) and V (12 deaths, SMR 159, 95% CI 82 to 279). Mortality from cancer of the liver or gall bladder, pancreas and kidney, and from lymphomas was not substantially increased in any of the work areas.

CONCLUSIONS

Mortality from cancer of several sites was associated with specific work areas. Some of these associations have been reported previously. Future analyses of our study will have to determine the role of specific exposures in the aetiology of these cancers.

Workplace risk factors for cancer in the German rubber industry: Part 1. Mortality from respiratory cancers

OBJECTIVES

To determine the cancer specific mortality by work area among active and retired male workers in the German rubber industry.

METHODS

A cohort of 11,663 male German workers was followed up for mortality from 1 January 1981 to 31 December 1991. Cohort members were classified as active (n = 7536) or retired (n = 4127) as of 1 January 1981 and had been employed for at least one year in one of five study plants producing tyres or technical rubber goods. Work histories were reconstructed with routinely documented "cost centre codes" which were classified into six categories: I preparation of materials; II production of technical rubber goods; III production of tyres; IV storage and dispatch; V maintenance; and VI others. Standardised mortality ratios (SMRs) adjusted for age and calendar year and 95% confidence intervals (95% CIs), stratified by work area (employment in respective work area for at least one year) and time related variables (year of hire, lagged years of employment in work area), were calculated from national reference rates.

RESULTS

SMRs for laryngeal cancer were highest in work area I (SMR 253; 95% CI 93 to 551) and were significant among workers who were employed for > 10 years in this work area (SMR 330; 95% CI 107 to 779). Increased mortality rates from lung cancer were identified in work areas I (SMR 162; 95% CI 129 to 202), II (SMR 134; 95% CI 109 to 163), and V (SMR 131; 95% CI 102 to 167). Mortality from pleural cancer was increased in all six work areas, and significant excesses were found in work areas I (SMR 448; 95% CI 122 to 1146), II (SMR 505; 95% CI 202 to 1040), and V (SMR 554; 95% CI 179 to 1290).

CONCLUSION

A causal relation between the excess of pleural cancer and exposure to asbestos among rubber workers is plausible and likely. In this study, the pattern of excess of lung cancer parallels the pattern of excess of pleural cancer. This points to asbestos as one risk factor for the excess deaths from lung cancer among rubber workers. The study provides further evidence for an increased mortality from laryngeal cancer among workers in the rubber industry, particularly in work area I.

Population versus clinical view of case fatality from acute coronary heart disease: results from the WHO MONICA Project 1985-1990. Multinational MONItoring of Trends and Determinants in CArdiovascular Disease

BACKGROUND

The clinical view of case fatality (CF) from acute myocardial infarction (AMI) in those reaching the hospital alive is different from the population view. Registration of both hospitalized AMI cases and out-of-hospital coronary heart disease (CHD) deaths in the WHO MONICA Project allows both views to be reconciled. The WHO MONICA Project provides the largest data set worldwide to explore the relationship between CHD CF and age, sex, coronary event rate, and first versus recurrent event.

METHODS AND RESULTS

All 79,669 events of definite AMI or possible coronary death, occurring from 1985 to 90 among 5,725,762 people, 35 to 64 years of age, in 29 MONICA populations are the basis for CF calculations. Age-adjusted CF (percentage of CHD events that were fatal) was calculated across populations, stratified for different time periods, and related to age, sex, and CHD event rate. Median 28-day population CF was 49% (range, 35% to 60%) in men and 51% (range, 34% to 70%) in women and was particularly higher in women than men in populations in which CHD event rates were low. Median 28-day CF for hospitalized events was much lower: in men 22% (range, 15% to 36%) and in women 27% (range, 19% to 46%). Among hospitalized events CF was twice as high for recurrent as for first events.

CONCLUSIONS

Overall 28-day CF is halved for hospitalized events compared with all events and again nearly halved for hospitalized 24-hour survivors. Because approximately two thirds of 28-day CHD deaths in men and women occurred before reaching the hospital, opportunities for reducing CF through improved care in the acute event are limited. Major emphasis should be on primary and secondary prevention.

Gender, racial, and geographic differences in the performance of cardiac diagnostic and therapeutic procedures for hospitalized acute myocardial infarction in four states

This study compared rates of performance of cardiac procedures in relation to gender, race, and geographic location in patients hospitalized for myocardial infarction. The Atherosclerosis Risk in Communities (ARIC) study provides population data and standardized data collection methods. Hospital records of eligible people aged 35 to 74 years were abstracted in communities of 4 states in the United States: North Carolina, Mississippi, Maryland, and Minnesota. Between January 1987 and December 1991, 5,462 "definite" hospitalized patients with myocardial infarctions were identified. Women treated in nonteaching hospitals were less likely than men to have coronary angiography (odds ratio [OR] 0.7, 95% confidence interval [CI] 0.5 to 1.0), coronary artery bypass graft surgery (CABG) (OR 0.6, 95% CI 0.4 to 0.8), and thrombolytic therapy (OR 0.8, 95% CI 0.6 to 1.0), after controlling for age, race, severity of myocardial infarction, co-morbidity, and geographic area. Findings were similar in teaching hospitals. Blacks in the biracial communities were significantly less likely than whites to have coronary angiography, percutaneous transluminal coronary angioplasty, coronary artery bypass graft surgery, and thrombolytic therapy. After controlling for age, race, severity of myocardial infarction and co-morbidity, no consistent geographic differences were observed, except for Forsyth whites having the highest and Washington County the lowest odds for coronary angiography. Appropriate outcome measures would serve to evaluate the effect, if any, of the differences described on the ARIC population.