Statement from Elizabeth G. Nabel, M.D.,
Director, National Heart, Lung, and Blood Institute on New
Findings on the Role of Inflammation in Prevention of Coronary
Heart Disease
This year, about 450,000 Americans will die of coronary heart
disease — the leading cause of death for both men and women.
Although we have made great strides in preventing and treating
heart disease, we continue to explore the complex mechanisms involved
in cardiovascular disease, and we are eager to refine risk assessment
tools and preventive strategies to reduce the incidence of heart
attack and stroke.
New results from three studies being presented at the American
Heart Association (AHA) Scientific Sessions in New Orleans and
published in scientific journals today provide the strongest evidence
to date that a simple blood test for high-sensitivity C-reactive
protein (hsCRP) is a useful marker for cardiovascular disease.
Importantly, a much-anticipated study demonstrates for the first
time that hsCRP levels in the blood can be used to guide treatment
decisions to effectively lower the risk of heart attacks, stroke,
and death. Together, these studies show great promise in helping
clinicians better identify and treat individuals at risk for cardiovascular
disease – potentially saving millions more lives.
For years, growing evidence has suggested that inflammation plays
a strong role in developing cardiovascular disease, especially
atherosclerosis, or hardening of the arteries. HsCRP is one of
the most widely studied markers of inflammation in cardiovascular
disease.
But, whether measuring hsCRP adds any measurable value for predicting
risk for cardiovascular disease independent of traditional risk
factors, such as age, blood cholesterol levels, blood pressure,
diabetes, and smoking has been a topic of great debate. Further,
it has been uncertain whether hsCRP levels can be used to improve
treatment decisions.
Two studies supported by the National Heart, Lung, and Blood Institute
(NHLBI) show that adding hsCRP levels to assess risk of a first
heart attack or stroke in middle-aged or older adults improves
accuracy over the traditional assessment tools by between 5 percent
and 14 percent. The information proved to be especially valuable
in reclassifying the risk of heart disease and stroke among individuals
considered to be at intermediate risk (10 percent to 20 percent
risk of having a heart attack within 10 years) by traditional methods.
Using data from the 3006 participants in NHLBI's Framingham Heart
Offspring Study, Peter W. F. Wilson, M.D., of Emory University
in Atlanta and colleagues from NHLBI, Boston University, and Tufts
USDA Nutrition Center in Boston found that using hsCRP levels to
assess risk provided a more accurate risk assessment over traditional
risk scores among people otherwise considered at intermediate risk.
The researchers suggest a two-stepped approach to assessing risk — using
traditional risk scores first, then adding hsCRP levels to those
found to be at intermediate risk — to guide clinical decisions.
These results are published online today in Circulation Cardiovascular
Quality and Outcomes.
In the second study, researchers used data from 10,724 men in
the Physicians Health Study-II to prospectively develop the Reynolds
Risk Score for Men, which adds hsCRP levels and parental history
of early heart disease to traditional risk factors to assess men's
risk. The new assessment tool was significantly more accurate than
traditional risk factors alone in the study population. The report,
by Paul Ridker, MD, of Brigham and Women's Hospital and Harvard
Medical School in Boston, and colleagues, is published online in
the journal Circulation today and will be presented Tuesday
at the AHA Scientific Sessions. Previous work in the NHLBI-funded
Women’s Health Study led to the development of a comparable Reynolds
Risk Score for women last year.
The third hsCRP study results released today are from JUPITER
(the Justification for Use of statins in Prevention: an Intervention
Trial Evaluating Rosuvastatin), an international randomized clinical
trial to test the effectiveness of treating individuals with high
levels of hsCRP. Dr. Ridker and his colleagues demonstrate for
the first time that a strategy of treatment decisions based upon
hsCRP levels in otherwise healthy individuals significantly improves
outcomes.
The study of 17,802 apparently healthy men and women was stopped
early on March 30 after about 2 years because of the strong positive
results. The researchers found that a daily dose of a commonly
used statin, rosuvastatin (Crestor), reduced the risk of heart
attack, stroke, and death by nearly half (44 percent) in individuals
with high levels of hsCRP (2.0 mg/L or higher) but with normal
or low levels of LDL (130mg/dL or lower). The treatment reduced
LDL cholesterol by 50 percent and hsCRP by 37 percent. Supported
by AstraZeneca, U.S., the study was presented today at the AHA
Scientific Sessions and appears online in the New England Journal
of Medicine (November 20, 2008, print issue).
These studies expand our understanding of the role of inflammation
in detecting early signs of cardiovascular disease and identifying
adults who are at risk for heart attack or stroke. These findings
suggest that adding hsCRP levels to traditional risk factors could
identify millions more adults for whom treatment with statins appears
to lower the risk of heart attack.
Many clinicians now offer hsCRP testing to their patients, but
until now the value of hsCRP levels to treatment decisions, especially
in adults with desirable cholesterol levels, was unclear. As with
any medical discovery, however, broadly adopting a new approach
to detect or treat a condition should first be critically tested,
preferably through large-scale event-based randomized clinical
trials like JUPITER, and proven to bear greater benefits than risks,
including costs.
As part of the NHLBI strategic plan, we have engaged an expert
panel to review and update the scientific evidence regarding the
assessment and management of cardiovascular risk factors. Today’s
findings will be part of the rigorous scientific review to distill
the scientific evidence and generate an evidence-based, comprehensive,
set of clinical guidelines for primary care practitioners to help
adult patients reduce their risk for cardiovascular disease.
In the meantime, however, we must not lose sight of the essential
truth of what we already know to prevent heart disease: Cholesterol
still counts, and we have proven ways to lower it and lessen its
impact. The value of following a heart-healthy eating plan, being
physically active, maintaining a healthy weight, and not smoking
cannot be overestimated. And, statins can significantly reduce
the risk of heart attack in those at high risk.
Let us continue to use our current knowledge as well as apply
new discoveries based on solid evidence to take action for the
betterment of individual and public health.
Resources:
What is Coronary Artery Disease?, http://www.nhlbi.nih.gov/health/dci/Diseases/Cad/CAD_WhatIs.html
NHLBI Workshop Report, July 10-11, 2006: C-Reactive Protein:
Basic and Clinical Research Needs, http://www.nhlbi.nih.gov/meetings/workshops/crp/report.htm
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related to the causes, prevention, diagnosis, and treatment of
heart, blood vessel, lung, and blood diseases; and sleep disorders.
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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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