Global strategy for asthma management and prevention: GINA executive summary

Asthma is a serious health problem throughout the world. During the past two decades, many scientific advances have improved our understanding of asthma and ability to manage and control it effectively. However, recommendations for asthma care need to be adapted to local conditions, resources and services. Since it was formed in 1993, the Global Initiative for Asthma, a network of individuals, organisations and public health officials, has played a leading role in disseminating information about the care of patients with asthma based on a process of continuous review of published scientific investigations. A comprehensive workshop report entitled "A Global Strategy for Asthma Management and Prevention", first published in 1995, has been widely adopted, translated and reproduced, and forms the basis for many national guidelines. The 2006 report contains important new themes. First, it asserts that "it is reasonable to expect that in most patients with asthma, control of the disease can and should be achieved and maintained," and recommends a change in approach to asthma management, with asthma control, rather than asthma severity, being the focus of treatment decisions. The importance of the patient-care giver partnership and guided self-management, along with setting goals for treatment, are also emphasised.

Outcomes for COPD pharmacological trials: from lung function to biomarkers

The American Thoracic Society/European Respiratory Society jointly created a Task Force on "Outcomes for COPD pharmacological trials: from lung function to biomarkers" to inform the chronic obstructive pulmonary disease research community about the possible use and limitations of current outcomes and markers when evaluating the impact of a pharmacological therapy. Based on their review of the published literature, the following document has been prepared with individual sections that address specific outcomes and markers, and a final section that summarises their recommendations.

Efficacy of antiseptic-impregnated central venous catheters in preventing catheter-related bloodstream infection: a meta-analysis

CONTEXT

Central venous catheters impregnated with chlorhexidine and silver sulfadiazine have recently been introduced for the prevention of catheter-related infections. However, there remains some uncertainty regarding the efficacy of these catheters because of conflicting reports in the literature.

OBJECTIVE

To evaluate the efficacy of chlorhexidine-silver sulfadiazine-impregnated central venous catheters in the prevention of catheter-related bloodstream infection.

DATA SOURCES

Studies identified from a computerized search of the MEDLINE database from January 1966 to January 1998, reference lists of identified articles, and queries of principal investigators and the catheter manufacturer.

STUDY SELECTION

Randomized trials comparing chlorhexidine-silver sulfadiazine-impregnated central venous catheters with nonimpregnated catheters were included. The outcomes assessed were catheter colonization and catheter-related bloodstream infection confirmed by catheter culture.

DATA EXTRACTION

Twelve studies met the inclusion criteria for catheter colonization and included a total of 2611 catheters. Eleven studies with a total of 2603 catheters met the inclusion criteria for catheter-related bloodstream infection. Most patients in these studies were from groups considered to be at high risk for catheter-related infections. Summary statistics were calculated using Mantel-Haenszel methods under a fixed-effects model.

DATA SYNTHESIS

The summary odds ratio for catheter colonization was 0.44 (95% confidence interval [CI], 0.36-0.54; P<.001), indicating a significant decrease in catheter colonization associated with impregnated catheters. The studies examining the outcome of primary interest, catheter-related bloodstream infection, had a summary odds ratio of 0.56 (95% CI, 0.37-0.84; P = .005).

CONCLUSIONS

Central venous catheters impregnated with a combination of chlorhexidine and silver sulfadiazine appear to be effective in reducing the incidence of both catheter colonization and catheter-related bloodstream infection in patients at high risk for catheter-related infections.

The health economics of asthma and rhinitis. I. Assessing the economic impact

As new health care strategies compete with existing ones for limited resources, the health care system and its providers are beginning to turn to health economic analyses to help inform choices in the delivery of care. This 2-part review examines the current health economic literature for asthma and rhinitis. This first installment of the review focuses on studies that characterize the economic burden of asthma and rhinitis and examines how resources are allocated to the care of persons with asthma and rhinitis. In 1998, asthma in the United States accounted for an estimated 12.7 billion dollars annually. Similarly, in 1994, allergic rhinitis was estimated to cost 1.2 billion dollars. Most of the costs for these conditions are attributed to direct medical expenditures, with medications emerging as the single largest cost component. Indirect costs also represent an important social effect. While cost-of-illness studies help to characterize the economic burden, comparative health economic studies evaluate the value of new and existing strategies for clinical care. The second part of this review will explore how comparative studies have contributed to understanding how to best diagnose and treat asthma and allergic rhinitis.

The economic burden of COPD

COPD is one of the leading causes of morbidity and mortality worldwide and imparts a substantial economic burden on individuals and society. Despite the intense interest in COPD among clinicians and researchers, there is a paucity of data on health-care utilization, costs, and social burden in this population. The total economic costs of COPD morbidity and mortality in the United States were estimated at $23.9 billion in 1993. Direct treatments for COPD-related illness accounted for $14.7 billion, and the remaining $9.2 billion were indirect morbidity and premature mortality estimated as lost future earnings. Similar data from another US study suggest that 10% of persons with COPD account for > 70% of all medical care costs. International studies of trends in COPD-related hospitalization indicate that although the average length of stay has decreased since 1972, admissions per 1,000 persons per year for COPD have increased in all age groups > 45 years of age. These trends reflect population aging, smoking patterns, institutional factors, and treatment practices.

A large-scale North American study of fungal isolates from nails: the frequency of onychomycosis, fungal distribution, and antifungal susceptibility patterns

BACKGROUND

Onychomycosis, a fungal infection of the nail bed, is responsible for up to 50% of nail disorders. Although several surveys have been conducted in different parts of the world, there have been no multicenter epidemiologic surveys of onychomycosis in North America.

OBJECTIVE

A 12-center study was undertaken to (1) determine the frequency of onychomycosis, (2) identify organisms recovered from the nails, and (3) determine the antifungal susceptibility of isolates.

METHODS

A total of 1832 subjects participated in this study and completed a comprehensive questionnaire, and nail clippings were collected for potassium hydroxide examination and culturing.

RESULTS

The frequency of onychomycosis, as defined by the presence of septate hyphae on direct microscopy and/or the recovery of a dermatophyte, was found to be 13.8%. In general, the dermatophyte isolates were susceptible to the antifungals tested.

CONCLUSION

Because of the limited number of large-scale studies, the baseline incidence is not firmly established. However, the higher frequency of onychomycosis in this study may confirm the suspected increase in incidence of disease in North America.

Emotional functioning in eating disorders: attentional bias, emotion recognition and emotion regulation

BACKGROUND

Interpersonal processes, anxiety and emotion regulation difficulties form a key part of conceptual models of eating disorders (EDs), such as anorexia nervosa (AN) and bulimia nervosa (BN), but the experimental findings to support this are limited.

METHOD

The Reading the Mind in the Eyes task, the Difficulties in Emotion Regulation Scale (DERS) and a computerized pictorial (angry and neutral faces) Stroop task were administered to 190 women [50 with AN, 50 with BN and 90 healthy controls (HCs)].

RESULTS

Those with an ED showed attentional biases to faces in general (medium effect), but specifically to angry faces over neutral faces (large effect) compared to HCs. The ED group also reported significantly higher emotion regulation difficulties (large effect) than HCs. There was a small difference between the ED and HC groups for the emotion recognition task (small-medium effect), particularly in the restricting AN (RAN) group. Depression and attentional bias to faces significantly predicted emotion regulation difficulties in a regression model.

CONCLUSIONS

The data provide support for conceptualizations of EDs that emphasize the role of emotional functioning in the development and maintenance of EDs. Further research will concentrate on exploring whether these findings are state or trait features of EDs.

A new perspective on concepts of asthma severity and control

Concepts of asthma severity and control are important in the evaluation of patients and their response to treatment but the terminology is not standardised and the terms are often used interchangeably. This review, arising from the work of an American Thoracic Society/European Respiratory Society Task Force, identifies the need for separate concepts of control and severity, describes their evolution in asthma guidelines and provides a framework for understanding the relationship between current concepts of asthma phenotype, severity and control. "Asthma control" refers to the extent to which the manifestations of asthma have been reduced or removed by treatment. Its assessment should incorporate the dual components of current clinical control (e.g. symptoms, reliever use and lung function) and future risk (e.g. exacerbations and lung function decline). The most clinically useful concept of asthma severity is based on the intensity of treatment required to achieve good asthma control, i.e. severity is assessed during treatment. Severe asthma is defined as the requirement for (not necessarily just prescription or use of) high-intensity treatment. Asthma severity may be influenced by the underlying disease activity and by the patient's phenotype, both of which may be further described using pathological and physiological markers. These markers can also act as surrogate measures for future risk.

Incidence and long-term cost of steroid-related side effects after renal transplantation

Corticosteroids are an essential component of most immunosuppressive regimens currently used in renal transplantation because of their efficacy in reducing acute rejection and improving graft survival. Steroids, however, are associated with numerous side effects that lead to increased patient morbidity and mortality. The incidence and economic cost of steroid-related side effects have not been quantitatively assessed. Thus, based on a systematic review of the published literature, we estimated the incidence of steroid-related hypertension (15%), posttransplantation diabetes mellitus (10%), peripheral fractures (2% per year), avascular necrosis of the hip (8%), and cataracts (22%). In addition, we estimated that approximately 5% of patients who have cataracts or avascular necrosis of the hip require surgery. We used these literature-based estimates in a model to project the costs of treating side effects over a 10-year posttransplantation time frame for a 50-patient cohort that represented an average-sized renal transplant center. Steroid-induced hypertension and its complications were the most expensive side effect ($93,900), followed closely by posttransplantation diabetes ($89,700) and avascular necrosis of the hip ($61,700). Cataracts and peripheral bone fractures were less costly ($16,300 and $4,300, respectively). The cumulative projected 10-year cost of all side effects for the 50-patient cohort was $265, 900, or $5,300 per transplant patient. Steroid-related side effects add to the long-term cost of medical care of renal transplant recipients. These costs provide a rationale for further investigation of steroid-sparing immunosuppression protocols.

Systemic inhibition of tumor growth and tumor metastases by intramuscular administration of the endostatin gene

Tumors require ongoing angiogenesis to support their growth. Inhibition of angiogenesis by production of angiostatic factors should be a viable approach for cancer gene therapy. Endostatin, a potent angiostatic factor, was expressed in mouse muscle and secreted into the bloodstream for up to 2 weeks after a single intramuscular administration of the endostatin gene. The biological activity of the expressed endostatin was demonstrated by its ability to inhibit systemic angiogenesis. Moreover, the sustained production of endostatin by intramuscular gene therapy inhibited both the growth of primary tumors and the development of metastatic lesions. These results demonstrate the potential utility of intramuscular delivery of an antiangiogenic gene for treatment of disseminated cancers.

Trends in the cost of illness for asthma in the United States, 1985-1994

BACKGROUND

During the past decade, there have been notable changes in asthma prevalence, morbidity, and mortality. In this same time period, there have also been important national efforts to increase asthma awareness and improve asthma care.

OBJECTIVE

The purpose of this study was to examine the changes in US cost of illness for asthma during the 10-year period from 1985-1994.

METHODS

The study was a two-period (1985 and 1994), cross-sectional, cost-of-illness analysis. Cost estimates were based on US population and health care survey data available from the National Center for Health Statistics.

RESULTS

The total US costs of asthma for 1994 were $10.7 billion. On the basis of 1985 estimates adjusted to 1994 dollars, total asthma costs increased by 54.1% and direct medical expenditures increased by 20.4% during the 10-year period. In 1985, hospital inpatient care represented the largest component cost of direct medical expenditures (44.6%). Hospital inpatient costs decreased to 29.5% of direct medical expenditures in 1994, primarily because of shorter lengths of stay, as opposed to a decrease in the total number of admissions. In 1994, medications represented the largest component cost of direct medical expenditures (40.1%, up from 30.0% in 1985). The largest component increase in indirect costs was due to loss of work. On the basis of adjusted dollars, estimated costs per affected person with asthma declined by 3.4% (decrease of 15.5% for children and an increase of 2.9% for persons 18 years and older) during this time period.

CONCLUSION

Although the US costs of asthma increased during the 1985-1994 time period, estimated costs per person with asthma demonstrated a modest decline. These findings may represent a combination of reductions in hospital lengths of stay and increasing prevalence of persons with low consumption of asthma-related health care resources. In examining the component costs, it is unclear whether these changes can be attributed to the many local, regional, and national efforts aimed at controlling untoward asthma outcomes during the 1985-1994 time period.

The medical cost of undiagnosed sleep apnea

Obstructive sleep apnea is an under-diagnosed, but common disorder with serious adverse consequences. Cost data from the year prior to the diagnosis of sleep-disordered breathing in a consecutive series of 238 cases were used to estimate the potential medical cost of undiagnosed sleep apnea and to determine the relationship between the severity of sleep-disordered breathing and the magnitude of medical costs. Among cases, mean annual medical cost prior to diagnosis was $2720 versus $1384 for age and gender matched controls (p<0.01). Regression analysis showed that the reciprocal of the apnea hypopnea index among cases was significantly related to log-transformed annual medical costs after adjusting for age, gender, and body mass index (p<0.05). We conclude that patients with undiagnosed sleep apnea had considerably higher medical costs than age and sex matched individuals and that the severity of sleep-disordered breathing was associated with the magnitude of medical costs. Using available data on the prevalence of undiagnosed moderate to severe sleep apnea in middle-aged adults, we estimate that untreated sleep apnea may cause $3.4 billion in additional medical costs in the U.S. Whether medical cost savings occur with treatment of sleep apnea remains to be determined.

Remodeling of an acellular collagen graft into a physiologically responsive neovessel

Surgical treatment of vascular disease has become common, creating the need for a readily available, small-diameter vascular graft. However, the use of synthetic materials is limited to grafts larger than 5-6 mm because of the frequency of occlusion observed with smaller-diameter prosthetics. An alternative to synthetic materials would be a biomaterial that could be used in the design of a tissue-engineered graft. We demonstrate that a small-diameter (4 mm) graft constructed from a collagen biomaterial derived from the submucosa of the small intestine and type I bovine collagen has the potential to integrate into the host tissue and provide a scaffold for remodeling into a functional blood vessel. The results obtained using a rabbit arterial bypass model have shown excellent hemostasis and patency. Furthermore, within three months after implantation, the collagen grafts were remodeled into cellularized vessels that exhibited physiological activity in response to vasoactive agents.

Phylogenetics of flowering plants based on combined analysis of plastid atpB and rbcL gene sequences

Following (1) the large-scale molecular phylogeny of seed plants based on plastid rbcL gene sequences (published in 1993 by Chase et al., Ann. Missouri Bot. Gard. 80:528-580) and (2) the 18S nuclear phylogeny of flowering plants (published in 1997 by Soltis et al., Ann. Missouri Bot. Gard. 84:1-49), we present a phylogenetic analysis of flowering plants based on a second plastid gene, atpB, analyzed separately and in combination with rbcL sequences for 357 taxa. Despite some discrepancies, the atpB-based phylogenetic trees were highly congruent with those derived from the analysis of rbcL and 18S rDNA, and the combination of atpB and rbcL DNA sequences (comprising approximately 3000 base pairs) produced increased bootstrap support for many major sets of taxa. The angiosperms are divided into two major groups: noneudicots with inaperturate or uniaperturate pollen (monocots plus Laurales, Magnoliales, Piperales, Ceratophyllales, and Amborellaceae-Nymphaeaceae-Illiciaceae) and the eudicots with triaperturate pollen (particularly asterids and rosids). Based on rbcL alone and atpB/rbcL combined, the noneudicots (excluding Ceratophyllum) are monophyletic, whereas in the atpB trees they form a grade. Ceratophyllum is sister to the rest of angiosperms with rbcL alone and in the combined atpB/rbcL analysis, whereas with atpB alone, Amborellaceae, Nymphaeaceae, and Illiciaceae/Schisandraceae form a grade at the base of the angiosperms. The phylogenetic information at each codon position and the different types of substitutions (observed transitions and transversions in the trees vs. pairwise comparisons) were examined; taking into account their respective consistency and retention indices, we demonstrate that third-codon positions and transitions are the most useful characters in these phylogenetic reconstructions. This study further demonstrates that phylogenetic analysis of large matrices is feasible.

The efficacy of silver alloy-coated urinary catheters in preventing urinary tract infection: a meta-analysis

PURPOSE

Indwelling urinary catheters are implicated in most cases of nosocomial urinary tract infection. Silver-coating of catheters may reduce the risk of these infections; however, trials have provided mixed results. We performed a meta-analysis to estimate the effectiveness of silver-coated urinary catheters.

SUBJECTS AND METHODS

Published or unpublished articles were sought using MEDLINE, reference review, and correspondence with original authors, catheter manufacturers, and experts. Trials using silver-coated urinary catheters in the treatment group and uncoated urinary catheters in the control group were included. Bacteriuria, as evaluated by urine culture, was the outcome variable used to indicate urinary tract infection. Summary odds ratios (OR) and 95% confidence intervals (CI) were calculated using Mantel-Haenszel methods with a fixed-effects model.

RESULTS

Of 117 reports retrieved, eight trials with a total of 2,355 patients satisfied inclusion criteria. The summary OR for urinary tract infection was 0.59 (95% CI, 0.42 to 0.84) indicating a significant benefit in the patients receiving silver-coated catheters. A test of heterogeneity, however, indicated that the odds ratios varied significantly among studies. Silver alloy catheters (OR = 0.24; 95% CI, 0.11 to 0.52) were significantly more protective against bacteriuria than silver oxide catheters (OR = 0.79; 95% CI, 0.56 to 1.10).

CONCLUSIONS

This meta-analysis clarifies discrepant results among trials of silver-coated urinary catheters by revealing that silver alloy catheters are significantly more effective in preventing urinary tract infections than are silver oxide catheters. Though silver alloy urinary catheters cost about $6 more than standard urinary catheters, they may be worth the extra cost since catheter-related infection is a common cause of nosocomial infection and bacteremia.

The costs of treating COPD in the United States

STUDY OBJECTIVES

COPD affects millions of people in the United States. The purpose of this study was to describe the medical resource use and costs incurred by persons with COPD in the United States in 1987.

DESIGN

Data for this study were derived from the 1987 National Medical Expenditure Survey. A societal perspective was adopted for this analysis.

PATIENTS OR PARTICIPANTS

All persons > or = 40 years old with resource use or expenditures for chronic bronchitis, emphysema, or nonspecific chronic airway obstruction were included in this study.

RESULTS

Mean per-person direct medical expenditures among persons with COPD were $6,469 (1987 US dollars), about 25% of which was COPD related. Approximately 68% of direct medical expenditures in persons with COPD were for inpatient hospitalization.

CONCLUSIONS

COPD causes a large societal burden of illness that is expected to increase. This study provides a valuable foundation and historical measure against which to compare other estimates.

Chordal cutting: a new therapeutic approach for ischemic mitral regurgitation

BACKGROUND

Mitral regurgitation (MR) conveys adverse prognosis in ischemic heart disease. Because such MR is related to increased leaflet tethering by displaced attachments to the papillary muscles (PMs), it is incompletely treated by annular reduction. We therefore addressed the hypothesis that such MR can be reduced by cutting a limited number of critically positioned chordae to the leaflet base that most restrict closure but are not required to prevent prolapse. This was tested in 8 mitral valves: a porcine in vitro pilot with PM displacement and 7 sheep with acute inferobasal infarcts studied in vivo with three-dimensional (3D) echo to quantify MR in relation to 3D valve geometry.

METHODS AND RESULTS

In all 8 valves, PM displacement restricted leaflet closure, with anterior leaflet angulation at the basal chord insertion, and mild-to-moderate MR. Cutting the 2 central basal chordae reversed this without prolapse. In vivo, MR increased from 0.8+/-0.2 to 7.1+/-0.5 mL/beat after infarction and then decreased to 0.9+/-0.1 mL/beat with chordal cutting (P<0.0001); this paralleled changes in the 3D leaflet area required to cover the orifice as dictated by chordal tethering (r(2)=0.76).

CONCLUSIONS

Cutting a minimum number of basal chordae can improve coaptation and reduce ischemic MR. Such an approach also suggests the potential for future minimally invasive implementation.

Cost-effectiveness of antiseptic-impregnated central venous catheters for the prevention of catheter-related bloodstream infection

CONTEXT

A recent randomized controlled trial and meta-analysis indicated that central venous catheters impregnated with an antiseptic combination of chlorhexidine and silver sulfadiazine are efficacious in reducing the incidence of catheter-related bloodstream infection (CR-BSI); however, the ultimate clinical and economic consequences of their use have not been formally evaluated.

OBJECTIVE

To estimate the incremental clinical and economic outcomes associated with the use of antiseptic-impregnated vs standard catheters.

DESIGN

Decision analytic model using data from randomized controlled trials, meta-analyses, and case-control studies, as well as safety data from the US Food and Drug Administration.

SETTING AND PATIENTS

A hypothetical cohort of hospitalized patients at high risk for catheter-related infections (eg, patients in intensive care units, immunosuppressed patients, and patients receiving total parenteral nutrition) requiring use of a central venous catheter.

INTERVENTION

Short-term use (2-10 days) of chlorhexidine-silver sulfadiazine-impregnated multilumen central venous catheters and nonimpregnated catheters.

MAIN OUTCOME MEASURES

Expected incidence of CR-BSI and death attributable to antiseptic-impregnated and standard catheter use; direct medical costs for both types of catheters.

RESULTS

In the base-case analysis, use of antiseptic-impregnated catheters resulted in a decrease in the incidence of CR-BSI of 2.2% (5.2% for standard vs 3.0% for antiseptic-impregnated catheters), a decrease in the incidence of death of 0.33% (0.78% for standard vs 0.45% for antiseptic-impregnated), and a decrease in costs of $196 per catheter used ($532 for standard vs $336 for antiseptic-impregnated). The decrease in CR-BSI ranged from 1.2% to 3.4%, the decrease in death ranged from 0.09% to 0.78%, and the costs saved ranged from $68 to $391 in a multivariate sensitivity analysis.

CONCLUSION

Our analyses suggest that use of chlorhexidine-silver sulfadiazine-impregnated central venous catheters in patients at high risk for catheter-related infections reduces the incidence of CR-BSI and death and provides significant saving in costs. Use of these catheters should be considered as part of a comprehensive nosocomial infection control program.

Conditioned flavor preferences in young children

In this experiment 11 children participated in a series of 8 pairs of conditioning trials in order to investigate the hypothesis that children could form conditioned flavor preferences based on caloric density. Unfamiliar drink flavors were used in these trials, and the drinks were either high in caloric density (155 kcal/150 ml) or low (less than 5 kcal/150 ml). Caloric density was altered by the addition of low glucose maltodextrin. Each child always had the same caloric density/flavor pairing throughout the conditioning trials. Each trial pair included one high and one low density preload, followed by ad lib consumption. These conditioning trials substituted for the children's regularly scheduled morning snack four days per week, one trial per day. Conditioning trials were given as a series of two-part snacks, consisting of fixed volumes of initially unfamiliar drinks, followed by the opportunity to eat a variety of foods ad lib. Two measures, obtained before and after conditioning, provided evidence for the formation of conditioned flavor preferences: 1) preference assessments, and 2) two-flavor choice tests. In addition, the ad lib consumption data indicated that the children were responsive to the caloric density manipulation, by consistently eating more following the low than the high density drink. The potential contribution of such acquired flavor preferences to the reduction of neophobia is discussed.

The economic burden of asthma in US children: estimates from the National Medical Expenditure Survey

BACKGROUND

Asthma is the leading chronic illness of childhood, is responsible for substantial pediatric morbidity, and has a significant impact on use of health resources.

OBJECTIVE

Our purpose was to assess the per capita impact of pediatric asthma on medical care utilization and total expenditures.

METHODS

A population-based national probability survey, the National Medical Expenditure Survey, was conducted in 1987 to determine the use and cost of health care services in the United States. We analyzed the responses for all children aged 1 to 17 years with (n = 667) and without (n = 6911) asthma. Children with asthma were identified with use of a population-based screening question. Frequency and cost of medications, ambulatory visits, emergency department care, and hospitalizations for all reasons, including asthma, were assessed.

RESULTS

The period prevalence of childhood asthma in 1987 was 8.8% and the treated prevalence (any asthma medications) was 4.0%. Forty-one percent of families with asthmatic children were classified as having no primary insurance. Children with asthma used substantially more services in all categories of care: 3.1 times as many prescriptions, 1.9 times as many ambulatory provider visits, 2. 2 times as many emergency department visits, and 3.5 times as many hospitalizations. Only 10.7% of children with asthma were defined as chronic users of medications. Children with asthma incurred an average of $1129 (SD $5310) per child per year in total health care expenditures compared with $468 (SD $2960) for children without asthma, a 2.8-fold difference.

CONCLUSION

Asthma has considerable impact on the use and costs of medical care services among US children. Data from the 1987 National Medical Expenditure Survey provide a useful baseline against which more recent, postguideline data should be compared.

Design of a new surgical approach for ventricular remodeling to relieve ischemic mitral regurgitation: insights from 3-dimensional echocardiography

BACKGROUND

Mechanistic insights from 3D echocardiography (echo) can guide therapy. In particular, ischemic mitral regurgitation (MR) is difficult to repair, often persisting despite annular reduction. We hypothesized that (1) in a chronic infarct model of progressive MR, regurgitation parallels 3D changes in the geometry of mitral leaflet attachments, causing increased leaflet tethering and restricting closure; therefore, (2) MR can be reduced by restoring tethering geometry toward normal, using a new ventricular remodeling approach based on 3D echo findings.

METHODS AND RESULTS

We studied 10 sheep by 3D echo just after circumflex marginal ligation and 8 weeks later. MR, at first absent, became moderate as the left ventricle (LV) dilated and the papillary muscles shifted posteriorly and mediolaterally, increasing the leaflet tethering distance from papillary muscle tips to the anterior mitral annulus (P<0.0001). To counteract these shifts, the LV was remodeled by plication of the infarct region to reduce myocardial bulging, without muscle excision or cardiopulmonary bypass. Immediately and up to 2 months after plication, MR was reduced to trace-to-mild as tethering distance was decreased (P<0.0001). LV ejection fraction, global LV end-systolic volume, and mitral annular area were relatively unchanged. By multiple regression, the only independent predictor of MR was tethering distance (r(2)=0.81).

CONCLUSIONS

Ischemic MR in this model relates strongly to changes in 3D mitral leaflet attachment geometry. These insights from quantitative 3D echo allowed us to design an effective LV remodeling approach to reduce MR by relieving tethering.

Extent, patterns, and burden of uncontrolled disease in severe or difficult-to-treat asthma

BACKGROUND

Characterization of uncontrolled asthma burden in a natural treatment setting can influence treatment recommendations and clinical practice. The objective was to characterize and compare the economic burden of severe or difficult-to-treat asthma in uncontrolled and controlled patients.

METHODS

Baseline patient data (age > or = 13 years; n = 3916) were obtained from The Epidemiology and Natural History of Asthma: Outcomes and Treatment Regimens study. Disease control was assessed using two approaches: (i) applying criteria for control based on the Gaining Optimal Asthma Control study, and (ii) using the Asthma Therapy Assessment Questionnaire (ATAQ) to identify the number of asthma control problems. Assessments were performed at baseline, and at months 12 and 24. Monetary values were assigned to productivity loss and medical resource use. Direct and indirect costs were aggregated over 24 months and compared using Student's t-test for continuous measures and chi-squared for categorical variables.

RESULTS

Throughout the study, most patients had uncontrolled asthma (83% uncontrolled; 16% inconsistent control; 1.3% controlled). Controlled patients experienced fewer work or school absences and less healthcare resource use than uncontrolled patients at all study time points. Using the multilevel ATAQ control score, asthma costs increased directly with the number of asthma control problems. Costs for uncontrolled patients were more than double those of controlled patients throughout the study (14,212 vs 6,452 US Dollars; adjusted to 2002 Dollars; P < 0.0001).

CONCLUSIONS

This study demonstrated that few severe or difficult-to-treat asthma patients achieved control over a 2-year period and the economic consequence of uncontrolled disease is substantial.

Children's food intake following drinks sweetened with sucrose or aspartame: time course effects

In two experiments, 2-5-year-old children's responsiveness to caloric density cues was examined. In a preloading protocol, consumption of fixed volumes of drinks (205 ml in Experiment 1; 150 ml in Experiment 2), sweetened with sucrose, aspartame, aspartame plus low glucose maltodextrin, or a water control, was followed by ad lib consumption from among a variety of foods. Caloric drinks had about 90 kcal in Experiment 1, 65 kcal in Experiment 2. The delay interval between the preload and the ad lib consumption was 0, 30 or 60 minutes. In Experiment 1, 24 4- and 5-year-old children participated in only one delay interval, while in Experiment 2, all 20 2- and 3-year-old children were seen in all conditions. Results revealed evidence of caloric compensation, but no evidence of preload x time delay interaction. In both experiments, aspartame also produced a significant suppression of intake relative to water, primarily due to the pattern at 30 min following the preload. Across conditions, the suppression following aspartame was usually significantly less than that produced by the caloric sweet drinks, providing evidence for postingestive effects. In Experiment 1, suppression of intake was related to the children's preferences for the foods, not to macronutrient content; consumption of nonpreferred foods was most suppressed. Consumption of sweetened drinks as long as 1 hour prior to eating suppressed food intake, and this common feeding practice may also reduce dietary variety.

Mood, anxiety and psychotic phenomena measure a common psychopathological factor

BACKGROUND

Psychotic phenomena are common in the general population but are excluded from diagnostic criteria for mild to moderate depression and anxiety despite their co-occurrence and shared risk factors. We used item response theory modelling to examine whether the co-occurrence of depressive, anxiety and psychotic phenomena is best explained by: (1) a single underlying factor; (2) two separate, uncorrelated factors; (3) two separate yet linked factors; or (4) two separate domains along with an underlying 'common mental distress' (CMD) factor. We defined where, along any latent continuum, the psychopathological items contributed most information.

METHOD

We performed a secondary analysis of cross-sectional, item-level information from measures of depression, anxiety and psychotic experiences in 6617 participants aged 13 years from the Avon Longitudinal Study of Parents and Children (ALSPAC) birth cohort and 977 participants aged 18 years from the ROOTS schools-based sample. We replicated results from one sample in the other and validated the latent factors against an earlier parental measure of mental state.

RESULTS

In both cohorts depression, anxiety and psychotic items were best represented as a bi-factor model with a single, unitary CMD factor on which psychotic items conveyed information about the more severe end (model 4); residual variation remained for psychotic items. The CMD factor was significantly associated with the prior parental measure.

CONCLUSIONS

Psychotic phenomena co-occur with depression and anxiety in teenagers and may be a marker of severity in a single, unitary dimension of CMD. Psychotic phenomena should be routinely included in epidemiological assessments of psychiatric morbidity, otherwise the most severe symptomatology remains unmeasured.