12/30/2019 7:41:00 AM Study could impact treatment for coronary artery disease
Dear Doctor: I keep reading about stents, and how it turns out they're no better for blocked arteries than heart meds. How does something like that get decided?
Dear Reader: You're referring to the findings from a large international study that evaluated various medical interventions for patients with blocked coronary arteries.
Before we get into the study, we should first talk about coronary artery disease. This is a condition in which the vessels that supply the heart muscle with oxygen-rich blood become blocked. A substance called plaque -- which is made up of cholesterol, calcium, fat and other cells -- collects along the inner lining of the arteries and causes them to narrow. This limits the blood flow in the arteries, and, in some cases, can cut it off entirely. When the flow of oxygen-rich blood to the heart slows or stops, the results can range from chest pain, irregular heartbeat and shortness of breath, to heart attack, to an increased risk of stroke. Bits of the hardened plaque can also break free and cause blood clots, which can also limit or stop blood flow.
Coronary artery disease is the most common type of heart disease in the United States. According to the Centers for Disease Control and Prevention, it accounts for more than 370,000 deaths each year. It's a serious problem, and researchers have spent decades looking for solutions. These include bypass surgery and the use of stent intervention, which were evaluated in the study.
In bypass surgery, a surgeon uses a blood vessel taken from another part of the patient's body to route the flow of blood around the blocked artery. A less invasive option is the stent, which is a tiny mesh tube implanted into the artery via a long, flexible tube known as a catheter. The surgeon inserts the catheter into an artery in the arm or groin and then, with the help of a special X-ray machine, guides it through the blood vessels until it reaches the desired area. Once in place, the rigid stent physically opens and supports the artery walls, which allows normal blood flow.
The study you referenced, led by Stanford University and New York University, assessed the medical outcomes of more than 5,100 patients living with moderate to severe coronary artery disease. Researchers divided the study participants into two groups. One group underwent bypass surgery or received a stent. Participants in the other group were prescribed heart medication and instructed to make lifestyle changes, including regular exercise, a healthy diet and quitting smoking. Researchers then followed both groups for between 18 months and seven years, and tracked any cardiac events.
At the end of the study, researchers found that the surgical procedures proved more successful than medication alone at alleviating exercise-related chest pain. However, in the long run, they saw no difference between the two groups when it came to major coronary events, such as hospitalizations, heart attacks and death. In these instances, medication and lifestyle were as effective as surgical interventions. Whether these new findings help settle what has long been a fierce and sometimes contentious debate about treating coronary artery disease remains to be seen.
Eve Glazier, M.D., MBA, is an internist and associate professor of medicine at UCLA Health. Elizabeth Ko, M.D., is an internist and assistant professor of medicine at UCLA Health. Send your questions to firstname.lastname@example.org, or write: Ask the Doctors, c/o UCLA Health Sciences Media Relations, 10880 Wilshire Blvd., Suite 1450, Los Angeles, CA, 90024. Owing to the volume of mail, personal replies cannot be provided.