What Does ISCHEMIA Mean for Interventional Cardiology?

By Cari Wade Gervin
Tuesday, December 1, 2020

The multi-year study showed medication and lifestyle changes are as effective as invasive procedures.

At the end of last March, The New England Journal of Medicine published the long-awaited results of the International Study of Comparative Health Effectiveness with Medical and Invasive Approaches (ISCHEMIA).

The trial, which followed over 5,000 patients with stable ischemic heart disease for years, ultimately found that conservative treatment with medication and lifestyle changes had virtually the same results as more invasive treatments like stenting and bypass surgeries. However, patients with regular angina did show improvement in quality of life.

“Taken together, the quality of life and clinical results suggest that there is no need for invasive procedures in patients without symptoms,” said David Maron, MD, Director of the Stanford Prevention Research Center at Stanford University and the study’s lead author and principal investigator, at the time of the study’s release. “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.”

Could New Guidelines Lead to Savings?

The ISCHEMIA results had formally been announced in November 2019 at the American Heart Association Scientific Sessions, prompting immediate discussion in journals. Although the study’s actual publication was partially overshadowed by the onset of the COVID-19 pandemic, the ongoing debate in interventional cardiology has continued.

The American Heart Association is reviewing whether to incorporate the findings into its treatment guidelines. Dr. Maron has estimated that if cardiology practices change and asymptomatic, stable patients don’t receive surgical treatment unless needed later on, the healthcare system could save $500 million per year.

“That’s a back of the envelope calculation — it’s probably significantly more — but if we just stopped doing PCI on asymptomatic patients, it would be a huge saving,” Dr. Maron told Cardiovascular Research Foundation’s TCTMD.

Controversy Remains

Not everyone agrees that ISCHEMIA results should result in less intervention. In addition to the improved quality of life after stents or bypass for patients with angina, the rate of heart attacks and other cardiac events after four years was 2.2% lower for participants who underwent invasive procedures.

Some cardiologists have said this seems to show that the procedures are worth it, especially given how hard it is for many patients to stick to lifestyle changes. A June 2020 article in the Journal of Invasive Cardiology also questioned whether the study had used a faulty algorithm to guide revascularization based on stress testing, affecting the results.

The next phase, ISCHEMIA EXTEND, is in the planning process. The study will follow many or the original participants for up to 10 years to investigate further mortality outcomes.