|Highlights of NHLBI-Supported Research Presented at American Heart Association's Scientific Sessions
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
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 email@example.com.
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 firstname.lastname@example.org.
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 email@example.com
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 firstname.lastname@example.org.
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 email@example.com.
To interview NHLBI spokespeople identified in these highlights, call (301) 496-4236 or e-mail firstname.lastname@example.org. On November 14 and 15, call (301) 496-5449 and leave a message. Your call will be returned.
Part of the National Institutes of Health, the National Heart, Lung, and Blood Institute (NHLBI) plans, conducts, and supports research related to the causes, prevention, diagnosis, and treatment of heart, blood vessel, lung, and blood diseases; and sleep disorders. The Institute also administers national health education campaigns on women and heart disease, healthy weight for children, and other topics. NHLBI press releases and other materials are available online at: www.nhlbi.nih.gov.
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