Stanford analysis shows little difference in risk rates for angioplasty, bypass procedures

October 15, 2007

STANFORD, Calif. - Patients with heart disease who undergo coronary angioplasty have an equivalent risk of death and heart attack as patients who undergo coronary bypass surgery, according to Stanford University School of Medicine researchers. The analysis is the largest comparison of bypass surgery and angioplasty, two of the most common major medical procedures performed in North America.

The researchers also found that the survival rates for bypass surgery and angioplasty were similar for patients with diabetes, refuting previous reports that angioplasty was associated with a significantly higher risk of death among diabetic patients.

"It is reassuring that the long-term safety of these two procedures is roughly the same," said senior author Mark Hlatky, MD, professor of health research and policy and of cardiovascular medicine. "Patients and their doctors can have a more informed discussion about which procedure should be done, based on other outcomes that are important to the patient."

The study, which was funded by the Agency for Healthcare Research and Quality and conducted by the Stanford-UCSF Evidence-based Practice Center, will be published in the Oct. 16 advance online issue of Annals of Internal Medicine.

Two types of medical interventions are available to patients with coronary artery disease, which affects about 15 million Americans. One is bypass surgery, in which surgeons take a healthy blood vessel from another part of the body to create a detour around the blocked part of the coronary artery. The other is angioplasty, in which a tiny balloon is used to open a blocked artery; a mesh tube called a stent is often inserted to hold open the artery after the procedure.

Bypass surgery is the preferred treatment for patients with blockages in three arteries, while angioplasty is typically used for those patients with single-vessel disease. Patients with heart disease between these extremes are candidates for either procedure, but Hlatky said it's not always clear which is the best treatment choice.

To gain a better understanding of the differences between the two procedures, Hlatky and his colleagues analyzed data from 23 randomized clinical trials that compared treatments for patients with mid-range coronary disease. The studies involved nearly 10,000 patients in Europe and the United States; 4,944 patients were randomly assigned to surgery and 5,019 patients were randomly assigned to angioplasty.

After reviewing the data, the researchers determined that the procedural survival rate for the two was virtually the same - 98.2 percent for bypass surgery and 98.9 percent for angioplasty. Bypass surgery was, however, associated with a small but significantly greater risk of stroke within 30 days of the procedure.

Long-term survival rates were comparable, with about 90 percent of patients living five years after either procedure, as was the risk of post-procedure heart attack. About 12 percent of surgery patients and 10.9 percent of angioplasty patients had a heart attack within five years.

The researchers also looked specifically at patients with diabetes, a key risk factor for coronary artery disease, and found no difference in survival rates between the two procedures. Hlatky said this was surprising, given the 1995 results from the Bypass Angioplasty Revascularization Investigation by the National Institutes of Health. The BARI study showed that diabetic patients who underwent bypass surgery had a higher five-year survival rate than those who had angioplasty.

"A lot of patients with diabetes were worried about angioplasty after the BARI finding came out," said Hlatky. "But after reviewing all the published data, we didn't see a significant difference in survival rates between these procedures."

Among the researchers' other findings, bypass surgery led to fewer repeat procedures - 9.8 percent of bypass patients had repeat procedures after five years, compared with 46.1 percent of patients who had angioplasty without a stent and 40.1 percent who had angioplasty with a stent. Bypass surgery was also found to be more effective than angioplasty in relieving chest pain known as angina.

Hlatky said once patients and doctors are sure there is no major difference in the risk of death and heart attacks between the two procedures, they can turn their attention to more subjective outcomes, such as control of angina, patient concern about major surgery or about a stent, and the chance of needing a second procedure. "In many ways, it makes the decision a little easier," he said.

The authors noted that their analysis did not include angioplasties involving stents coated with drugs that are released over time, which may reduce the chance that arteries will become clogged again. Because these drug-eluting stents are relatively new, clinical trials are still ongoing and have not yet been published. However, Hlatky said the comparative effectiveness of bypass surgery and drug-eluting stents should not differ dramatically from the findings of this study.
The lead author of the study is senior research scientist Dena Bravata, MD. Eight other Stanford researchers collaborated with Hlatky and Bravata on the study.

Stanford University Medical Center integrates research, medical education and patient care at its three institutions - Stanford University School of Medicine, Stanford Hospital & Clinics and Lucile Packard Children's Hospital at Stanford. For more information, please visit the Web site of the medical center's Office of Communication & Public Affairs at

Stanford University Medical Center

Related Diabetes Articles from Brightsurf:

New diabetes medication reduced heart event risk in those with diabetes and kidney disease
Sotagliflozin - a type of medication known as an SGLT2 inhibitor primarily prescribed for Type 2 diabetes - reduces the risk of adverse cardiovascular events for patients with diabetes and kidney disease.

Diabetes drug boosts survival in patients with type 2 diabetes and COVID-19 pneumonia
Sitagliptin, a drug to lower blood sugar in type 2 diabetes, also improves survival in diabetic patients hospitalized with COVID-19, suggests a multicenter observational study in Italy.

Making sense of diabetes
Throughout her 38-year nursing career, Laurel Despins has progressed from a bedside nurse to a clinical nurse specialist and has worked in medical, surgical and cardiac intensive care units.

Helping teens with type 1 diabetes improve diabetes control with MyDiaText
Adolescence is a difficult period of development, made more complex for those with Type 1 diabetes mellitus (T1DM).

Diabetes-in-a-dish model uncovers new insights into the cause of type 2 diabetes
Researchers have developed a novel 'disease-in-a-dish' model to study the basic molecular factors that lead to the development of type 2 diabetes, uncovering the potential existence of major signaling defects both inside and outside of the classical insulin signaling cascade, and providing new perspectives on the mechanisms behind insulin resistance in type 2 diabetes and possibly opportunities for the development of novel therapeutics for the disease.

Tele-diabetes to manage new-onset diabetes during COVID-19 pandemic
Two new case studies highlight the use of tele-diabetes to manage new-onset type 1 diabetes in an adult and an infant during the COVID-19 pandemic.

Genetic profile may predict type 2 diabetes risk among women with gestational diabetes
Women who go on to develop type 2 diabetes after having gestational, or pregnancy-related, diabetes are more likely to have particular genetic profiles, suggests an analysis by researchers at the National Institutes of Health and other institutions.

Maternal gestational diabetes linked to diabetes in children
Children and youth of mothers who had gestational diabetes during pregnancy are at increased risk of diabetes themselves, according to new research published in CMAJ (Canadian Medical Association Journal).

Two diabetes medications don't slow progression of type 2 diabetes in youth
In youth with impaired glucose tolerance or recent-onset type 2 diabetes, neither initial treatment with long-acting insulin followed by the drug metformin, nor metformin alone preserved the body's ability to make insulin, according to results published online June 25 in Diabetes Care.

People with diabetes visit the dentist less frequently despite link between diabetes, oral health
Adults with diabetes are less likely to visit the dentist than people with prediabetes or without diabetes, finds a new study led by researchers at NYU Rory Meyers College of Nursing and East Carolina University's Brody School of Medicine.

Read More: Diabetes News and Diabetes Current Events is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to