Task Force on Research in Epidemiology and Prevention of Cardiovascular Diseases: A Revisit

Claude Lenfant, MD
(Published in the May 1, 1996, issue of Circulation)

In December 1994, the executive summary of the report of the National Heart, Lung, and Blood Institute (NHLBI) Task Force on Research in Epidemiology and Prevention of Cardiovascular Diseases appeared in this column. Now, a little over a year later, I want to take the opportunity to describe our progress on implementation of the report's recommendations, which were summarized into eight priority areas. Highlighted under each area are examples of NHLBI-initiated programs either implemented or in the process of being implemented since the Task Force began its deliberations in FY 1992. The programs, some of which relate to more than one priority area, are expected to provide valuable information for future epidemiology and prevention research.

Prevention of Adverse Lifestyles and Related Risk Factors

The NHLBI Cholesterol Awareness Surveys were re-administered in the fall of 1994. The public survey component was the fourth to track changes in public attitudes and practices relating to cholesterol since the inception of the National Cholesterol Education Program (NCEP). It found that substantially more Americans have had a blood cholesterol test, have been told their cholesterol level by a health-care provider, and know their cholesterol level than was the case 5 years ago. The companion survey of physicians found that most routinely order cholesterol tests for new patients, assess LDL and HDL levels, and initiate dietary and drug treatment at levels recommended by the NCEP. The survey also identified areas for continuing education, and its data will be used for interim evaluation of progress toward DHHS Healthy People 2000 cholesterol objectives. It is being conducted in collaboration with the Food and Drug Administration.

Specialized Centers of Research (SCORs) in Ischemic Heart Disease in Blacks, begun in FY 1995, focus on the expression of heart disease in blacks through use of modern methods and interdisciplinary approaches to molecular biology, cellular and organ physiology, and clinical medicine. Research emphasizes three themes, i.e., diabetic heart disease, microvascular disease, and sudden death. The Activity Counseling Trial was implemented in FY 1994 to develop and evaluate the effectiveness of various intervention approaches delivered in health-care settings to increase and maintain habitual physical activity and cardiorespiratory fitness among sedentary men and women at elevated risk of coronary heart disease (CHD).

Control of High Blood Pressure and Other Established Cardiovascular Disease (CVD) Risk Factors

ALLHAT is the acronym for the Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial, a practice-based evaluation of antihypertensive pharmacological treatment to determine if the combined incidence of nonfatal myocardial infarction and CHD death differs between diuretic-based and three alternative antihypertensive pharmacological treatments. It will also determine, in a subset of older adult patients, if lowering serum cholesterol with a HMG CoA reductase inhibitor reduces all-cause mortality. ALLHAT was initiated in 1993 and is being conducted in conjunction with the Department of Veterans Affairs.

A new NHLBI SCOR program, Molecular Genetics of Hypertension, begins this year. This collaborative network of closely interacting, multiproject SCORs will identify and map genes responsible for hypertension in humans and animals and undertake mechanistic studies to clarify the role of specific genetic mutations in development and maintenance of high blood pressure.

Another program, Genetic Determinants of High Blood Pressure, was begun in FY 1995 to establish networks for research collaborations aimed at discovering the major genetic determinants of high blood pressure. A special feature is sharing technology, skills, data, and biological materials.

The Angiogenesis and Remodeling in the Microvasculature program begins in FY 1996 and focuses on molecular, cellular, and physiological mechanisms involved in the processes of angiogenesis and remodeling in the microvasculature, particularly related to coronary insufficiency or hypertension.

Reduction of CVD Events, Disability, and Death Associated With Socioeconomic Differences

Despite improvements in the treatment and control of hypertension in recent years, blacks continue to experience higher morbidity and mortality from hypertension, and to develop the disease earlier in life than whites. The NHLBI-initiated demonstration and education research program Improving Hypertensive Care for Inner-City Minorities was initiated in 1993. Its goals are to develop and to evaluate for feasibility, acceptability, and effectiveness, methods to maintain therapy and control of hypertension for diagnosed individuals. The NHLBI sponsored a major conference, Socioeconomic Status (SES) and Cardiovascular Health and Disease, in November 1995 to assess the state of knowledge, identify information ready for transfer to health care professionals and the public, and develop future research recommendations. A significant achievement was compilation of national SES data for participants to discuss during the meeting. The conference report will be widely disseminated and its recommendations will serve to guide the Institute's future directions in this important area.

The clinical trial Enhancing Recovery in Coronary Heart Disease Patients began in FY 1995. It is determining the effects of psychosocial interventions on morbidity and mortality in CHD patients. Interventions include psychosocially supportive and educational strategies designed to assist recovery from myocardial infarction in patients who are at high risk, defined by depression, social isolation, or a perception of lack of support from family and friends.

Prevention of Hypertension, Dyslipidemia, Smoking, and Atherosclerosis Beginning in Youth The NHLBI recently announced its interest in receiving grant applications for research to study specimens of human tissues collected in the Pathological Determinants of Atherosclerosis in Youth and in the Risk Factors in Early Human Atherogenesis programs. The specimens are suitable for use to investigate cellular and molecular factors that may be implicated in the initiation and progression of atherosclerotic lesions in humans between 15 and 34 years of age.

PATHWAYS, initiated in 1993, is a randomized clinical trial for the primary prevention of obesity in pre-adolescent American Indians. It is school-based and includes a curriculum focused on healthful eating habits and an increase in physical activity. The project is currently in a 3-year planning and feasibility phase which, if successful, will be followed by a full-scale study that may last an additional 6 years.

Research in the Physical Activity and Cardiopulmonary Health program, initiated in FY 1995, focuses on dose-effect relationships and determinants in adolescents; dose for prevention of CHD in adults; relationship to respiratory health in children, adolescents, and adults with asthma; and relationship to respiratory health for children, adolescents, and adults with cystic fibrosis.

Gene-Nutrient Interactions in the Pathogenesis of Congenital Heart Defects was implemented in FY 1995. Its objective is to study the relationships between genes and nutrients, such as vitamin A, in the etiology and prevention of congenital cardiovascular malformations and to elucidate the molecular mechanisms involved.

Improvement in Population-Wide Prevention Strategies

The NIH Consensus Development Conference on Physical Activity and Cardiovascular Health, held December 1995, recommended that all children and adults set a goal of accumulating at least 30 minutes of moderate-intensity physical activity on most, and preferably all, days of the week. Moderate-intensity activities include brisk walking, cycling, swimming, home repair, and yard work. Those who currently meet these standards may derive additional health and fitness benefits by becoming more physically active or including more vigorous activity. Conferees noted that additional research is needed to improve understanding of optimal levels of physical activity.

In FY 1993, the National High Blood Pressure Education Program published the Working Group Report on the Primary Prevention of Hypertension. The report calls for a population strategy whereby Americans are encouraged to reduce their sodium intake, exercise more regularly, limit alcohol consumption, and achieve and maintain a healthy weight in an effort to prevent the onset of hypertension. The NHLBI has incorporated a multiple risk factor strategy into its community-based outreach programs, and has launched new, intensive efforts in black and Latino communities. Another particularly important effort is directed toward women, i.e., fact sheets titled Hormone Replacement Therapy and Heart Disease: The PEPI (Postmenopausal Estrogen/Progestin Interventions) Trial and So You Have Heart Disease. Copies are available from the NHLBI Information Center at (301) 592-8573.

In order to help prevent overweight and increase physical activity, as well as favorably modify other CVD risk factors, the Cardiovascular Health Promotion Project has devised a two-part plan to encourage adoption of heart healthy behaviors among America's children and their families. Its components are (a) a community outreach partnership program that includes community programs and media promotions emphasizing physical activity, along with nutrition; and (b) the translation and dissemination of NHLBI-supported intervention programs related to CVD prevention in children and youth.

Clarification of Insulin-Glucose-Atherosclerosis Association

The Institute's Insulin, Insulin Resistance and Cardiovascular Disease study was renewed in FY 1995. Its objective is to continue to collect longitudinal data on insulin and insulin resistance as independent CVD risk factors and on other recognized CVD risk factors.

Also in FY 1995, the NHLBI initiated the program Etiology of Excess Cardiovascular Disease in Diabetes Mellitus. Its goal is to understand how the presence of diabetes increases CVD risk. Special emphasis is placed on the relative importance of hyperglycemia versus other CVD risk factors associated with glucose intolerance in the pathogenesis of the accelerated macrovascular disease in diabetic patients.

Development of Technical Resources and Improved Measurement Techniques

A new program, Culturally Appropriate Hypertension Risk Factor Assessment, was approved by the National Heart, Lung, and Blood Advisory Council in October 1995 to design and develop valid and culturally appropriate interviews or questionnaires to assess specific risk factors (e.g., diet, smoking, physical activity, and stress) related to hypertension. These instruments are intended for use in epidemiologic studies in black and other minority populations. This program was also recommended by the NHLBI Working Group on Research in CHD in Blacks.

Expansion of Research Training Programs The NHLBI began its support of the Training Workshop in Cardiovascular Epidemiology in 1981. The workshop was initially established in 1974 to provide an introduction to epidemiology, biometry, and preventive cardiology for health professionals interested in CVD epidemiology and prevention. More than 470 participants have received this postgraduate training. In 1989, the NHLBI ensured participation by minorities in the 2-week workshop through opportunities for recruitment and support; in 1993, 32 percent (9) of the 28 participants were from minority groups. The workshop is supported through a grant for continuing education training.

The NHLBI Vascular Disease Academic Award was initiated in FY 1995 to stimulate development of diagnostic and therapeutic skills in clinical management of patients with a wide variety of vascular diseases, promote professional development of awardees, and enable awardee institutions to develop programs in vascular medicine.

The objective of the new NHLBI Multidisciplinary Course in Genetics of Heart, Lung, and Blood Diseases is to provide an intensive introduction to the uses of molecular genetic approaches to the understanding of genetic and nongenetic determinants of complex cardiovascular, lung, and blood diseases.

Other Activities Since the inception of the Task Force, the Institute has renewed four of its major epidemiological studies. The well-known Framingham Heart Study continues to follow its cohort of men and women who were aged 30 to 62 years when the study was initiated in 1948.

The Coronary Artery Risk Development in Young Adults (CARDIA) study is measuring CHD risk factors in black and white young men and women who were aged 18 to 30 years when the project began in 1981. CARDIA also seeks to identify lifestyle changes during the critical years of transition from adolescence to young adulthood to middle age that influence CHD risk.

The Atherosclerosis Risk in Communities (ARIC) study is examining a large cohort of women and men, aged 45 to 64 years at the start of the study in 1985, in four communities, one of which has a large black population. A wide range of suspected and established risk factors are under investigation. ARIC is also providing estimates of trends in the incidence of hospitalized myocardial infarction and CHD death.

The Cardiovascular Health Study is looking at CVD risk factors in women and men who were aged 65-90 years when the study began in 1988. It addresses the critical need for data about prognostic characteristics, effects of medical care, and ultimate outcomes of CVD in the elderly population.

The examples of programs described above emphasize the Institute's interaction with and reliance upon a cadre of scientific advisors who provide their time and expertise in support of the Institute's activities. We appreciate all their efforts and will continue to take their advice seriously.