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Highlights of NHLBI-Supported Research Presented at American Heart Association's Scientific Sessions

For Immediate Release:
November 17, 2009, 10:00 AM EST

Findings shared on new strategies to control hypertension, link between air pollution and measures of vascular tone, comparison of surgical strategies to treat a heart defect in newborns

New education strategies for better controlling hypertension and research suggesting a possible link between short-term and long-term exposure to air pollution and increased risk of constricted blood vessels are among the research highlights from studies supported by the National Heart, Lung, and Blood Institute (NHLBI) at the American Heart Association's 2009 Scientific Sessions in Orlando held Nov. 14–18.  Other NHLBI-supported studies to be presented focus on the detection of fat in the tissue layer surrounding the heart, and a comparison of surgical strategies to treat a heart defect in newborns. The NHLBI is part of the National Institutes of Health.

News stories are embargoed until papers are presented, time of news event, or 4 p.m. Eastern time, whichever occurs first. To reach NHLBI spokespeople, call the NHLBI Communications Office at 301-496-4236.

Study reveals mixed results comparing surgical methods for ventricle lesions. (Embargoed until 4 p.m. EST, Sunday, Nov. 15) Babies born with one working ventricle (lower chamber of the heart) instead of the standard two ventricles require a series of operations to optimize heart function, and are at high risk of medical problems and death. At a featured research session, Pediatric Heart Network investigators will announce the results of a unique study involving 555 infants that compared two approaches in current use for the initial surgery, known as the Norwood procedure, in newborns. The trial is the first to directly compare the two approaches and is the first North American multi-center, randomized surgical trial in infants with congenital heart defects. The traditional method uses a modified Blalock-Taussig shunt (MBTS), which connects the aorta (the main artery that carries oxygen-rich blood pumped from the left side of the heart out to the body) to the pulmonary artery (the major blood vessel that carries blood pumped from the right side of the heart to the lungs to pick up a fresh supply of oxygen). The alternative method connects the working right ventricle to the pulmonary artery. Surgeons performed the Norwood Procedure using one of the two shunt strategies. Results indicate advantages and disadvantages for both techniques. At 12 months after surgery, 64 percent of infants survived with the MBTS method without the need for a heart transplant, as compared to 74 percent with the other method. After two years, 62 percent of infants treated with the MBTS method survived without the need of a heart transplant as compared to 68 percent with the other method, a difference that is not statistically significant. The results will help develop evidence-based surgical approaches for this group of newborns. NHLBI Spokesperson: Gail Pearson, M.D., Sc.D. Study Investigator: Richard G. Ohye, M.D., University of Michigan Congenital Heart Center, Ann Arbor, Mich. Dr. Ohye can be reached at (734) 936-4978 or ohye@umich.edu. Further information about this trial (NCT00115934) can be found at www.clinicaltrials.gov.

ACE inhibitor therapy fails to help growth rate or ventricular function in infants with single ventricles. (Embargoed until 4 p.m. EST, Sunday, Nov. 15) At a featured research session on Sunday, investigators in the NHLBI-funded Pediatric Heart Network will report the results of the largest randomized trial conducted to date to assess a treatment for infants with single ventricle physiology, a complex form of congenital heart disease in which either the left or right ventricle (lower chamber) of the heart does not develop properly in utero. The main treatment is surgical: affected infants require one or more major surgical procedures during the first year of life, and experience a high rate of complications and death despite sophisticated treatment strategies. One of the common complications is heart failure, which is when the heart cannot pump blood at its normal capacity, and a slow growth rate. Based on data in adults as well as results of small studies of children with heart failure, angiotensin converting enzyme, also known as ACE, inhibitor therapy is common in many pediatric cardiac centers, but has never been tested systematically. ACE inhibitor therapy blocks an enzyme that leads to blood vessel constriction. In this study involving 230 infants, those treated with the ACE inhibitor enalapril were found to have no better growth rates or ventricular function at 14 months of age than infants treated with placebo. Infants in the enalapril and placebo groups registered similar results in a scoring system based on weight for age. With these latest results, researchers must now search for new options to help treat infants with this congenital heart defect. NHLBI Spokesperson: Gail Pearson, M.D., Sc.D.   Study Investigator: Daphne T. Hsu, M.D., Division Chief, Pediatric Cardiology, Children's Hospital at Montefiore, can be reached at 917-842-5965 or dhsu@montefiore.org. Further information about this trial (NCT00113087) can be found at www.clinicaltrials.gov.

No significant cardiovascular differences between liberal and restrictive blood transfusion strategies in surgical hip repair patients. (Embargoed until 8 a.m. EST, Monday, Nov. 16) Patients undergoing hip fracture repair surgery may become anemic after surgery and require blood transfusions. Patients treated by a restrictive transfusion strategy had no significant differences in cardiovascular outcomes compared to similar patients treated with a liberal blood transfusion strategy, according to late-breaking clinical findings from Jeffrey L. Carson, M.D., of the University of Medicine and Dentistry of New Jersey's Robert Wood Johnson Medical School in New Brunswick, N.J. The study involved 2,016 patients, primarily women (75 percent) with a mean age of 81, who had surgery to repair a hip fracture. Some patients received transfusions as soon as their hemoglobin, proteins in the blood that carry iron, levels fell below 10 grams per deciliter (g/dL). Other patients were given blood transfusions only when symptomatic or if their hemoglobin levels dropped below 8 g/dL, a more restrictive strategy. For patients in the liberal transfusion strategy group, 4.3 percent of patients had a heart attack, unstable angina, or died in the hospital; whereas, 5.2 percent of patients on the restrictive transfusion arm had either a heart attack, unstable angina, or died in the hospital, a difference that was not statistically significant. Although anemia occurs in most patients with hip fracture, many of whom are women, the data emerging from the analysis of this study indicate that transfusion in the absence of symptoms is not always required. Appropriate use of blood transfusions assures more efficient use of the Nation's blood supply. NHLBI Spokesperson: Simone Glynn M.D., MPH. Study Investigator: Jeffrey L. Carson, M.D., University of Medicine and Dentistry of New Jersey's Robert Wood Johnson Medical School. Dr. Carson can be reached at (732) 235-7122 or carson@umdnj.edu. Further information about this trial (NCT00071032) can be found at www.clinicaltrials.gov.

Air pollution impacts blood-vessel health. (Embargoed until 2 p.m. EST, Monday, Nov. 16.)Results from the Multi-Ethnic Study of Atherosclerosis (MESA) and Air Pollution Study confirm that air pollution appears to have short- and long-term ill effects on the health and resiliency of blood vessels. The researchers used ultrasound-guided measurements of blood-vessel diameter and responsiveness in 3,501 people participating in the ongoing MESA study, a long-term population-based study of ethnically diverse Americans in six urban U.S. regions. The researchers recorded air pollution levels in these locales the day before the blood vessel measurements were taken and estimated annual exposure to fine particulate air pollution. The results link long-term exposure to air pollution with both forearm-artery narrowing and a reduced ability of these arteries to adjust to normal changes in blood flow. In contrast, short-term exposure to air pollution only appeared to affect artery-narrowing. The study suggests that both types of changes may be early cardiovascular disease risk factors affected by the environment. NHLBI spokesperson: Diane Bild, M.D. Study investigator: Joel D. Kaufman, M.D., University of Washington, Seattle. Contact Dr. Kaufman at 206-669-7014 or joelk@u.washington.edu. Further information about this trial (NCT00005487) can be found at www.clinicaltrials.gov.

Fat deposits near the heart linked to clogged arteries. (Embargoed until 4 p.m. EST, Monday, Nov 16.) Along with abdominal fat, fat deposits near the heart itself (pericardial fat), have been associated with cardiovascular disease, diabetes and metabolic syndrome. Metabolic syndrome is the name for a group of risk factors linked to overweight and obesity that increase the risk of heart disease, diabetes, and stroke. Researchers discovered that pericardial fat alone was associated with clogged arteries (detected by magnetic resonance imaging), independent of other known risk factors such as high blood pressure and smoking. The results suggest that pericardial fat may be involved in the development of atherosclerosis, or hardening of the arteries. The study involved 94 male participants in the ongoing Multi-Ethnic Study of Atherosclerosis (MESA) study, a long-term population-based study of ethnically diverse Americans in six urban U.S. regions. NHLBI spokesperson: Diane Bild, M.D. Study investigator: Cuilian Miao, M.D., Johns Hopkins University Medical Center. Dr. Miao can be reached at 443-248-1014 or cmiao2@jhmi.edu.

Combination of physician and patient intervention best lowers blood pressure. (Embargoed until 10 a.m. EST, Tuesday, November 17.)  Despite widely publicized hypertension treatment guidelines for physicians and lifestyle recommendations for patients, blood pressure control rates remain low.  Researchers from Duke University who conducted the Hypertension Improvement Project (HIP) tested physician and patient intervention methods in community-based primary care clinics.  A total of 32 physicians and 574 patients participated in the study.  Physician intervention techniques included Internet-based training (before patient intervention began), followed by self-monitoring and quarterly feedback reports for 18 months.  Patient intervention practices included 20 weekly group counseling sessions focused on weight loss, a hypertension-controlling diet, exercise, and reduced sodium intake, followed by 12 brief monthly phone contacts.  After six months, those who received both physician and patient intervention methods experienced the largest impact with a decrease in systolic blood pressure of 9.7 mmHg.  The systolic blood pressure of those patients who received only physician intervention decreased 5.3 mmHg; the systolic blood pressure of those who had only patient intervention decreased 7.1 mmHg.     However, the added benefit of the combined intervention did not persist 12 months after the period of intense patient intervention. Notably, at 18 months more than 70 percent of patients were at goal blood pressure in all study groups (compared with approximately 60 percent at baseline). Future research should focus on increasing the magnitude of the effect in each individual component and sustainability of the interaction between an informed patient and a proactive practice team.  NHLBI spokesperson: Paula T. Einhorn, M.D., M.S.  HIP Investigator: Laura P. Svetkey, M.D., Duke University.  Contact Dr. Svetkey at svetk001@mc.duke.edu.

To interview NHLBI spokespeople identified in these highlights, call (301) 496-4236 or e-mail nhlbi_news@nhlbi.nih.gov. On November 14 and 15, call (301) 496-5449 and leave a message. Your call will be returned.