Cleveland
Clinic Study Finds Better Survival Rates With Bypass Surgery
Than Angioplasty in High-Risk Patients
People with severely
clogged coronary arteries coupled with other serious health problems
lived longer if they underwent surgery to bypass the blocked vessels
rather than less-invasive percutaneous procedures to reopen them, new
Cleveland Clinic research shows. Full results of the study will be published
in the May 18 issue of Circulation.*
For the study, Cleveland
Clinic researchers examined five-year mortality rates in a group of
patients with high-risk characteristics, such as coronary artery disease
in multiple vessels coupled with diabetes, high blood pressure or heart
failure.
Patients who had
percutaneous coronary interventions (PCI), such as angioplasty or stenting,
to reopen clogged arteries had mortality rates nearly two times greater
than did patients who had coronary artery bypass grafting (CABG) surgery,
after accounting for important differences in risk factors between the
two cohorts. CABG surgery restores blood flow to heart tissue by taking
a healthy vein or artery from the leg, arm, or chest and moving it outside
the heart to bypass the clogged coronary vessel.
The results were
somewhat surprising in light of recent technological and medical advancements
in PCI, which is considered significantly less invasive than open-heart
surgery, said Sorin J. Brener, M.D., first author of the Circulation
study.
“Bypass surgery
tended to have a greater benefit in the sickest patients,” said
Dr. Brener, a staff cardiologist at The Cleveland Clinic. “Surprising
results can be the most beneficial because they allow us to offer the
best treatment options to patients, especially when they are contrary
to conventional wisdom.”
Investigators reviewed
the medical records of more than 5,100 patients who had CABG and more
than 870 who had PCI. All patients were treated at The Cleveland Clinic
between 1995 and 1999. Although overall survival rates were not significantly
different between the two groups, researchers found important differences
after adjusting for certain risk factors — such as diabetes, hypertension,
smoking, body weight and other factors — to compare the groups
in-depth.
The one- and five-year
mortality rates (pre-adjustment) were 5 percent and 16 percent, respectively,
for the PCI treatment group, and 4 percent and 14 percent for the CABG
treatment group. After adjusting for additional risk factors, PCI was
associated with significantly higher death rates in all categories.
Study investigators
noted several points to consider in light of these findings. First,
operative mortality rates were significantly lower at The Cleveland
Clinic than the national average, which may affect applicability to
other centers. The Cleveland Clinic’s in-hospital mortality is
1.1 percent compared to 3.3 percent in the database of the Society of
Thoracic Surgeons, which includes data on more than 100,000 cardiovascular
surgeries. In addition, PCI is likely to be the better treatment for
lower-risk heart disease patients because of its shorter recovery time,
less-invasive nature and lower blood loss.
The Cleveland Clinic
Heart Center is the recognized world leader in the diagnosis and treatment
of cardiovascular disease. U.S. News & World Report has ranked The
Cleveland Clinic No. 1 in the nation for cardiac care each year since
1995 and among America’s Ten Best Hospitals each year since 1990.
Click
here to learn more about Coronary Artery Disease
