Independent at heart: persistent association of altitude with ischaemic heart disease mortality after consideration of climate, topography and built environment.

BACKGROUND Living at higher altitude was dose-dependently associated with lower risk of ischaemic heart disease (IHD). Higher altitudes have different climatic, topographic and built environment properties than lowland regions. It is unclear whether these environmental factors mediate/confound the association between altitude and IHD. We examined how much of the altitude-IHD association is explained by variations in exposure at place of residence to sunshine, temperature, precipitation, aspect, slope and distance to main road. METHODS We included 4.2 million individuals aged 40-84 at baseline living in Switzerland at altitudes 195-2971 m above sea level (ie, full range of residence), providing 77 127 IHD deaths. Mortality data 2000-2008, sociodemographic/economic information and coordinates of residence were obtained from the Swiss National Cohort, a longitudinal, census-based record linkage study. Environment information was modelled to residence level using Weibull regression models. RESULTS In the model not adjusted for other environmental factors, IHD mortality linearly decreased with increasing altitude resulting in a lower risk (HR, 95% CI 0.67, 0.60 to 0.74) for those living >1500 m (vs<600 m). This association remained after adjustment for all other environmental factors 0.74 (0.66 to 0.82). CONCLUSIONS The benefit of living at higher altitude was only partially confounded by variations in climate, topography and built environment. Rather, physical environment factors appear to have an independent effect and may impact on cardiovascular health in a cumulative way. Inclusion of additional modifiable factors as well as individual information on traditional IHD risk factors in our combined environmental model could help to identify strategies for the reduction of inequalities in IHD mortality.

The care of adults with congenital heart disease across the globe: Current assessment and future perspective

The number of adults with congenital heart disease (CHD) has increased markedly over the past few decades as a result of astounding successes in pediatric cardiac care. Nevertheless, it is now well understood that CHD is not cured but palliated, such that life-long expert care is required to optimize outcomes. All countries in the world that experience improved survival in CHD must face new challenges inherent to the emergence of a growing and aging CHD population with changing needs and medical and psychosocial issues. Founded in 1992, the International Society for Adult Congenital Heart Disease (ISACHD) is the leading global organization of professionals dedicated to pursuing excellence in the care of adults with CHD worldwide. Recognizing the unique and varied issues involved in caring for adults with CHD, ISACHD established a task force to assess the current status of care for adults with CHD across the globe, highlight major challenges and priorities, and provide future direction. The writing committee consisted of experts from North America, South America, Europe, South Asia, East Asia, and Oceania. The committee was divided into subgroups to review key aspects of adult CHD (ACHD) care. Regional representatives were tasked with investigating and reporting on relevant local issues as accurately as possible, within the constraints of available data. The resulting ISACHD position statement addresses changing patterns of worldwide epidemiology, models of care and organization of care, education and training, and the global research landscape in ACHD.

Transition from adolescence to adulthood in congenital heart disease - Many roads lead to Rome

More than 90% of children born with heart defects reach adulthood. They continue to require specialized medical care. In most countries, their care has to be transferred from the pediatric care environment to specialized adult clinics. This transfer of care usually occurs at a time when adolescents become young adults. Supporting adolescents and emerging adults with congenital heart disease through transition has been recognized as an important task of their treating teams in recent years. An environment where adolescents feel welcome and where education and patient participation are fostered is crucial. For an optimal transition process, patients, their families and all health care providers need to be involved. Different models for transition programs have emerged, depending on local policies and resources. The authors offer insight into established transition programs in Bern and Zurich, Switzerland. Advantages and challenges of different models of care and transition programs are presented.

Thyroid function within the normal range and risk of coronary heart disease: an individual participant data analysis of 14 cohorts

IMPORTANCE Some experts suggest that serum thyrotropin levels in the upper part of the current reference range should be considered abnormal, an approach that would reclassify many individuals as having mild hypothyroidism. Health hazards associated with such thyrotropin levels are poorly documented, but conflicting evidence suggests that thyrotropin levels in the upper part of the reference range may be associated with an increased risk of coronary heart disease (CHD). OBJECTIVE To assess the association between differences in thyroid function within the reference range and CHD risk. DESIGN, SETTING, AND PARTICIPANTS Individual participant data analysis of 14 cohorts with baseline examinations between July 1972 and April 2002 and with median follow-up ranging from 3.3 to 20.0 years. Participants included 55,412 individuals with serum thyrotropin levels of 0.45 to 4.49 mIU/L and no previously known thyroid or cardiovascular disease at baseline. EXPOSURES Thyroid function as expressed by serum thyrotropin levels at baseline. MAIN OUTCOMES AND MEASURES Hazard ratios (HRs) of CHD mortality and CHD events according to thyrotropin levels after adjustment for age, sex, and smoking status. RESULTS Among 55,412 individuals, 1813 people (3.3%) died of CHD during 643,183 person-years of follow-up. In 10 cohorts with information on both nonfatal and fatal CHD events, 4666 of 48,875 individuals (9.5%) experienced a first-time CHD event during 533,408 person-years of follow-up. For each 1-mIU/L higher thyrotropin level, the HR was 0.97 (95% CI, 0.90-1.04) for CHD mortality and 1.00 (95% CI, 0.97-1.03) for a first-time CHD event. Similarly, in analyses by categories of thyrotropin, the HRs of CHD mortality (0.94 [95% CI, 0.74-1.20]) and CHD events (0.97 [95% CI, 0.83-1.13]) were similar among participants with the highest (3.50-4.49 mIU/L) compared with the lowest (0.45-1.49 mIU/L) thyrotropin levels. Subgroup analyses by sex and age group yielded similar results. CONCLUSIONS AND RELEVANCE Thyrotropin levels within the reference range are not associated with risk of CHD events or CHD mortality. This finding suggests that differences in thyroid function within the population reference range do not influence the risk of CHD. Increased CHD risk does not appear to be a reason for lowering the upper thyrotropin reference limit.

Prevalence of Subclinical Rheumatic Heart Disease in Eastern Nepal

Importance: Although rheumatic heart disease has been nearly eradicated in high-income countries, 3 in 4 children grow up in parts of the world where it is still endemic. Objectives: To determine the prevalence of clinically silent and manifest rheumatic heart disease as a function of age, sex, and socioeconomic status and to estimate age-specific incidence. Design, Setting, and Participants: In this school-based cross-sectional study with cluster sampling, 26 schools in the Sunsari district in Eastern Nepal with 5467 eligible children 5 to 15 years of age were randomly selected from 595 registered schools. After exclusion of 289 children, 5178 children were enrolled in the present study from December 12, 2012, through September 12, 2014. Data analysis was performed from October 1, 2014, to April 15, 2015. Exposures: Demographic and socioeconomic characteristics were acquired in a standardized interview by means of a questionnaire customized to the age of the children. A focused medical history was followed by a brief physical examination. Cardiac auscultation and transthoracic echocardiography were performed by 2 independent physicians. Main Outcomes and Measures: Rheumatic heart disease according to the World Heart Federation criteria. Results: The median age of the 5178 children enrolled in the study was 10 years (interquartile range, 8-13 years), and 2503 (48.3%) were female. The prevalence of borderline or definite rheumatic heart disease was 10.2 (95% CI, 7.5-13.0) per 1000 children and increased with advancing age from 5.5 (95% CI, 3.5-7.5) per 1000 children 5 years of age to 16.0 (95% CI, 14.9-17.0) in children 15 years of age, whereas the mean incidence remained stable at 1.1 per 1000 children per year. Children with rheumatic heart disease were older than children without rheumatic heart disease (median age [interquartile range], 11 [9-14] years vs 10 [8-13] years; P = .03), more commonly female (34 [64.2%] vs 2469 [48.2%]; P = .02), and more frequently went to governmental schools (40 [75.5%] vs 2792 [54.5%]; P = .002). Silent disease (n = 44) was 5 times more common than manifest disease (n = 9). Conclusions and Relevance: Rheumatic heart disease affects 1 in 100 schoolchildren in Eastern Nepal, is primarily clinically silent, and may be more common among girls. The overall prevalence and the ratio of manifest to subclinical disease increase with advancing age, whereas the incidence remains stable at 1.1 per 1000 children per year. Early detection of silent disease may help prevent progression to severe valvular damage.

The illness narratives of Hispanic American women with coronary heart disease (CHD): An ethnographic approach

Purpose. To provide a descriptive representation of the illness narratives described by Hispanic American women with CHD. ^ Design. Focused ethnographic design. ^ Setting. One outpatient general medicine clinic, one nurse-managed health promotion clinic, and informants' homes in a large metropolitan city located in southeast Texas. ^ Sample. Purposeful sampling from two different sites resulted in 17 interviews being conducted with 14 informants. ^ Method. Focused ethnographic techniques were employed in the designation of participants for the study, data collection, analysis and re-presentation. Audiotaped interviews and fieldwork were transcribed verbatim and analyzed through an iterative process of data reduction, data display, drawing conclusions and verification. ^ Findings. The developing conceptual framework that emerged from the data is labeled after the overarching experience described by informants, the experience of Embodied Exhaustion. Embodied Exhaustion, as described in this study, refers to an ongoing, dynamic, indeterminate experience of mind-body exhaustion resulting from a complex constellation of biologic, psychological and social distresses occurring over the life course. The experience consists of three categories: Taking Care of Others, Wearing Down and Hurting Hearts. Two stabilizing forces were identified: Collective Self and Believing in God. ^ Conclusions. The findings of this study emphasize the importance of framing all research, theory and practice targeting Hispanic women with CHD within a sociocentric paradigm. Nursing is challenged to provide care that extends beyond the physical body of the patient to include the social context of illness, especially the family. ^

Association between glycemic index and glycemic load and the risk of incident coronary heart disease among whites and African Americans with and without type 2 diabetes: The Atherosclerosis Risk in Communities study

Several studies have examined the association between high glycemic index (GI) and glycemic load (GL) diets and the risk for coronary heart disease (CHD). However, most of these studies were conducted primarily on white populations. The primary aim of this study was to examine whether high GI and GL diets are associated with increased risk for developing CHD in whites and African Americans, non-diabetics and diabetics, and within stratifications of body mass index (BMI) and hypertension (HTN). Baseline and 17-year follow-up data from ARIC (Atherosclerosis Risk in Communities) study was used. The study population (13,051) consisted of 74% whites, 26% African Americans, 89% non-diabetics, 11% diabetics, 43% male, 57% female aged 44 to 66 years at baseline. Data from the ARIC food frequency questionnaire at baseline were analyzed to provide GI and GL indices for each subject. Increases of 25 and 30 units for GI and GL respectively were used to describe relationships on incident CHD risk. Adjusted hazard ratios for propensity score with 95% confidence intervals (CI) were used to assess associations. During 17 years of follow-up (1987 to 2004), 1,683 cases of CHD was recorded. Glycemic index was associated with 2.12 fold (95% CI: 1.05, 4.30) increased incident CHD risk for all African Americans and GL was associated with 1.14 fold (95% CI: 1.04, 1.25) increased CHD risk for all whites. In addition, GL was also an important CHD risk factor for white non-diabetics (HR=1.59; 95% CI: 1.33, 1.90). Furthermore, within stratum of BMI 23.0 to 29.9 in non-diabetics, GI was associated with an increased hazard ratio of 11.99 (95% CI: 2.31, 62.18) for CHD in African Americans, and GL was associated with 1.23 fold (1.08, 1.39) increased CHD risk in whites. Body mass index modified the effect of GI and GL on CHD risk in all whites and white non-diabetics. For HTN, both systolic blood pressure and diastolic blood pressure modified the effect on GI and GL on CHD risk in all whites and African Americans, white and African American non-diabetics, and white diabetics. Further studies should examine other factors that could influence the effects of GI and GL on CHD risk, including dietary factors, physical activity, and diet-gene interactions. ^

Systematic review of genetic risk score in coronary heart disease and other diseases

In order to better take advantage of the abundant results from large-scale genomic association studies, investigators are turning to a genetic risk score (GRS) method in order to combine the information from common modest-effect risk alleles into an efficient risk assessment statistic. The statistical properties of these GRSs are poorly understood. As a first step toward a better understanding of GRSs, a systematic analysis of recent investigations using a GRS was undertaken. GRS studies were searched in the areas of coronary heart disease (CHD), cancer, and other common diseases using bibliographic databases and by hand-searching reference lists and journals. Twenty-one independent case-control studies, cohort studies, and simulation studies (12 in CHD, 9 in other diseases) were identified. The underlying statistical assumptions of the GRS using the experience of the Framingham risk score were investigated. Improvements in the construction of a GRS guided by the concept of composite indicators are discussed. The GRS will be a promising risk assessment tool to improve prediction and diagnosis of common diseases.^

POLYCHOTOMOUS LOGISTIC REGRESSION ANALYSIS (HYPERTENSION, CORONARY HEART DISEASE)

The history of the logistic function since its introduction in 1838 is reviewed, and the logistic model for a polychotomous response variable is presented with a discussion of the assumptions involved in its derivation and use. Following this, the maximum likelihood estimators for the model parameters are derived along with a Newton-Raphson iterative procedure for evaluation. A rigorous mathematical derivation of the limiting distribution of the maximum likelihood estimators is then presented using a characteristic function approach. An appendix with theorems on the asymptotic normality of sample sums when the observations are not identically distributed, with proofs, supports the presentation on asymptotic properties of the maximum likelihood estimators. Finally, two applications of the model are presented using data from the Hypertension Detection and Follow-up Program, a prospective, population-based, randomized trial of treatment for hypertension. The first application compares the risk of five-year mortality from cardiovascular causes with that from noncardiovascular causes; the second application compares risk factors for fatal or nonfatal coronary heart disease with those for fatal or nonfatal stroke. ^

THE DECLINE OF ISCHEMIC HEART DISEASE MORTALITY IN TEXAS: HEALTH PLANNING IMPLICATIONS

This is a report on an empirical study of the decline of ischemic heart disease mortality in the State of Texas. The study period was from 1970 to 1977. The data was collected and analyzed at three different levels of analysis: state, health service area (HSA), and county. The study was designed to test five main hypotheses. They serve to test the role of the medical care system as a possible factor associated with the changing ischemic heart disease mortality trends.^ The principal findings of the study were that a reasonable relationship could be found between the number of emergency medical care personnel, the number of icu-ccu beds, the number of medical specialists and the percent of hospitals with icu-ccu and the decline in ischemic heart disease mortality for the State of Texas. However, non significant relationships were found between variables in the medical care system and ischemic heart disease mortality trends, at the health service area level of analysis. More specifically, the number of coronary care unit beds was found to be negatively correlated with the decline in ischemic heart disease mortality at the county level.^ While being limited in its scope, the study suggests that certain factors (emergency medical service, icu-ccu beds, percent of icu-ccu units, and medical specialists) have been shown to be associated with the observed decline in ischemic heart disease mortality. The study also suggests many avenues of future research that need to be explored. ^