For people with stable coronary artery disease, stents and bypass surgery are no more effective at reducing rates of heart attack and death than lifestyle changes and medication alone, a recently published large-scale federally funded study shows.
The ISCHEMIA trial examined the efficacy of surgical intervention in patients with ischemic heart disease, also known as coronary artery disease. IHD occurs when plaque accumulates in the heart’s major blood vessels, reducing its blood flow. It is the most common type of heart disease in the United States and the leading cause of death worldwide, resulting in more than 9 million deaths annually.
ISCHEMIA authors first presented their research at the annual American Heart Association conference in November 2019, and the New England Journal of Medicine published the much-anticipated study in March 2020. A collaboration between researchers at NYU Langone Health and 15 other institutions, the trial followed 5,000 subjects with moderate to severe IHD. Participants were split into two groups: One group received only lifestyle counseling and medical therapy. The other group received stents or bypass surgery in addition to lifestyle counseling and medical therapy. After a median duration of four and a half years, researchers found no significant difference in rates of heart attack and death between the two groups.
Monica Aggarwal, MD, FACC, director of Integrative Cardiology and Prevention at the University of Florida, says she was not surprised by the results. “Many of us [cardiologists] who practice more conservatively believe that lifestyle modification and medications are better than [surgical] intervention, and this trial gave us validated information.”
Cardiologist Joel Kahn, MD, says the study is of “profound importance.” “[The ISCHEMIA study] should lead to a major reduction in the number of stents and bypass surgeries performed,” Kahn says. “The fact that a low saturated fat diet and exercise were goals of the conservative treatment group is validation of decades of lifestyle medicine and the work of Dean Ornish, MD, Nathan Pritikin, and other early pioneers in optimizing the treatment of heart disease with nonsurgical approaches.”
The ISCHEMIA researchers note that these findings do not apply to people having a heart attack or those with severe chest pain—cases in which emergency surgery may be indicated.
This is not the first study to conclude that surgical intervention should be used more sparingly for patients with stable cardiovascular disease: A 2017 study found stents were ineffective for chest pain.
Aggarwal notes that a lot of people mistakenly view surgical interventions as “no big deal.” “These are not benign procedures, by any means.” Aggarwal adds that while stents and catheterizations are relatively low-risk, any time a surgeon goes into the arteries, there is the potential for trauma or damage to the arteries. “Many people are getting these interventions that don’t need them, and that is what this study showed,” says Aggarwal.
For patients with stable ischemic heart disease, Aggarwal advises a combined approach of medical therapy and healthy lifestyle initiatives, including a whole-food, plant-based diet. “We have to remember that medications and lifestyle changes are complementary,” Aggarwal says.
“I have seen patients with stable ischemic heart disease whom I have treated with a whole-food, plant-based diet make marked improvements in symptoms and activity,” says Columbus Batiste, MD, chief of cardiology at Kaiser Permanente Riverside. “
A study presented at the 2017 AHA conference found that a plant-based diet was associated with a 42 percent reduction in the risk of heart failure among people without previously diagnosed heart disease or heart failure. A 2014 study of 198 patients with cardiovascular disease found that subjects who adopted a plant-based diet had a much lower rate of subsequent cardiac events compared with the subjects who did not adopt a plant-based diet.