Comparing heart disease treatments

The study compared conservative and invasive approaches to treating heart disease. apomares / E+ via Getty Images

Coronary artery disease is the most common type of heart disease. It’s caused by narrowed arteries that reduce blood flow to the heart. Affecting about 18 million Americans, it is the leading cause of death in the United States. Symptoms can vary, but some people don’t have any symptoms at all. They may not know they have heart disease until they experience chest pain, a heart attack, or sudden cardiac arrest.

To determine the best approach to help reduce these outcomes, the International Study of Comparative Health Effectiveness with Medical and Invasive Approaches (ISCHEMIA) study followed more than 5,000 patients with stable, moderate to severe heart disease for a median of about 3 years. The trial compared a conservative treatment approach to an invasive treatment strategy. The study was funded in part by NIH’s National Heart, Lung, and Blood Institute (NHLBI). Results were published online on March 30, 2020, in the New England Journal of Medicine.

Participants were randomly assigned to receive either the conservative medical therapy (unless their symptoms worsened) or medical therapy and an invasive intervention. The conservative treatment strategy involved medications to control blood pressure, cholesterol, and angina (chest discomfort caused by inadequate blood to the heart), along with counseling about diet and exercise. The invasive strategy involved medications and counseling, as well as coronary procedures performed soon after patients recorded an abnormal stress test.

By the end of the 5-year trial, the death rates between the two groups were similar. Among people who had invasive procedures, 145 died, compared with 144 who received medication alone. The overall rate of disease-related events differed slightly. Among those who took medication alone, 352 experienced an event such as heart attack, compared with 318 who had invasive procedures.

A companion paper showed that, among patients with angina, those in the invasive treatment group showed greater improvement in angina-related symptoms, physical function, and quality of life than those in the conservative treatment group.

“ISCHEMIA showed an impressive, sustained improvement in patients’ symptoms, function and quality of life with an invasive strategy for up to four years of follow-up,” says Dr. John Spertus at Saint Luke’s Mid America Heart Institute in Kansas City, MO. “However, this benefit was only observed in roughly two-thirds of those who had angina at baseline, and no benefit was seen in those who had no symptoms.”

“Taken together, the quality of life and clinical results suggest that there is no need for invasive procedures in patients without symptoms,” says Dr. David Maron of Stanford University. “For those with angina, our results show it is just as safe to begin treating with medication and lifestyle change, and then if symptoms persist, discuss invasive treatment options.”

Two other companion papers looked at people who also had chronic kidney disease. Heart disease is the leading cause of death for these patients, and they’re at higher risk of complications from invasive treatments. This population showed similar risks of death and heart attack for the invasive and conservative treatments. There were no differences in quality of life measures, either, even for those participants with angina symptoms.