Study results show bypass surgery extends lives of patients with heart failure
April 4, 2016 - 1:36 PM
Scientists funded by the National Heart, Lung, and Blood Institute
(NHLBI) of the National Institutes of Health have found that a greater
number of patients with coronary artery disease may benefit from
coronary artery bypass graft (CABG) surgery than previously thought.
CABG — a surgical procedure to help improve blood flow to the heart
by bypassing arteries clogged with cholesterol plaques — was thought to
be too risky for patients with the long-term effects of coronary artery
disease: left ventricular dysfunction (when the left side of the heart
is unable to pump normally) and heart failure. Studies of the safety and
effectiveness of CABG in the 1970s excluded most patients with these
two conditions. The procedure was typically used to relieve angina, or
“With limited data showing any benefit for patients with left
ventricular dysfunction and heart failure, physicians and patients were
less likely to engage in such an invasive, and thus risky, procedure as
CABG for diagnosis and treatment,” said lead author Eric J. Velazquez,
MD, FACP, FACC, FASE, FAHA, of Duke University Medical Center. “Patients
with these conditions largely received medical therapy alone and had
Dr. Velazquez and his team conducted a five-year global, randomized
controlled clinical trial, called the Surgical Treatment for Ischemic
Heart Failure (STICH) study, and a five-year extension study (STICHES (link is external)),
to evaluate whether CABG plus guideline-directed medical therapy had a
durable benefit over medical therapy alone for patients with coronary
artery disease and left ventricular dysfunction. The researchers found
that CABG added to medical therapy led to significantly lower rates of
death and hospitalization among patients with coronary artery disease,
left ventricular dysfunction, and heart failure.
“Our results usher in a new era in the treatment of coronary artery
disease because we now have evidence that with CABG and medical therapy,
there is a 16 percent reduction in the risk of death from any cause
over 10 years,” Dr. Velazquez said.
He added that there is also a median survival benefit of nearly a
year and a half, and that he and his team saw that the addition of CABG
to medical therapy prevented a death from any cause for every 14
patients they treated. Their data further suggest that the reduction in
the risk of death could be even greater in real-world practice.
“Conducting this trial was critically important to determine in a
scientifically rigorous study that CABG improves survival for
individuals with coronary artery disease and compromised left
ventricular function,” said NHLBI Director Gary H. Gibbons, MD. “The
current 10-year follow-up provides new important insights about patient
subgroups that are more likely to benefit from CABG as compared to
medical therapy alone. As such, we now have a solid evidence base to
inform patient care and the future development of clinical practice
Dr. Velazquez noted that the results are particularly important
because the prevalence of left ventricular dysfunction and heart failure
is expected to increase to approximately 8 million individuals by 2030
in the U.S. alone. The increase in the projected prevalence is a result
of advances in the management of cardiovascular disease and its risk
factors, increasingly transforming coronary artery disease into a
chronic disease with long-term effects such as left ventricular
dysfunction and heart failure.
George Sopko, MD, MPH, the program director in NHLBI’s Division of
Cardiovascular Sciences who administered the study grant, added that
this investigation, published in The New England Journal of Medicine
(April 2016), is one of only a few cardiovascular trials with 10 years
of follow-up and with approximately 98 percent of the patients followed
throughout the study period.
“It is unusual to have this quality of follow-up for so long,” said
Dr. Sopko. “It speaks to the rigor of the results.” He added that the
results are very generalizable, as the study included a diverse patient
population spread across 22 countries and various health systems.
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