How Can PET Cardiac Stress Testing Prevent Invasive Procedures? Merrill Stewart, MD

Captions were auto-generated.

Cardiac positron emission tomography (PET) stress testing is emerging as a more accurate tool for assessing coronary artery disease (CAD), helping to reduce the need for invasive diagnostic procedures that may offer little to no clinical benefit, especially for patients with stable disease.

In an interview with The American Journal of Managed Care^® (AJMC^®), Merrill H. Stewart, MD, director of nuclear cardiology and noninvasive and critical care cardiologist at Ochsner Health, explained how cardiac PET offers advantages over both older nuclear imaging techniques and traditional invasive methods. He emphasized that PET stress testing stands out as the most sensitive and specific noninvasive modality available for evaluating obstructive CAD, surpassing single photon emission computed tomography and stress echocardiography in accuracy.

“[Fewer] people are going on to downstream testing as a result of cardiac PET stress testing,” Stewart said. “There are other types of modalities out there that, when you get an abnormal test, you might go on to do more invasive testing to learn that that test was actually a false positive. Cardiac PET stress testing is unique in that regard.”

CAD has been traditionally diagnosed and evaluated through invasive coronary angiography, in which catheters are threaded into the heart and dye is used to visually assess blockages. However, Stewart noted that this method primarily focuses on large arterial blockages and often fails to assess blood flow at the microscopic, cellular level, where he says the real determinants of ischemia and long-term outcomes lie.

Cardiac PET stress testing helps address this gap. By injecting a radiotracer and tracking blood flow into myocardial cells, clinicians can evaluate coronary perfusion more comprehensively. This technique allows physicians to assess coronary flow capacity and determine not only the presence of disease but also whether a patient would actually benefit from revascularization.

This level of physiological detail is important because, as Stewart pointed out in the interview, patients with stable CAD may not always benefit from stenting or surgery, especially if their body has developed natural bypass vessels. To date, no randomized trial has shown that treating stable blockages with invasive procedures reduces mortality.

Stewart, who also serves as program coordinator for Ochsner’s cardiology fellowship and medical director of the hospital’s on-site cyclotron facility, highlighted the broader institutional commitment to advanced cardiovascular imaging. By using PET technology to improve diagnostic precision, cardiology teams can offer more targeted interventions while reducing reliance on invasive testing in patients who are unlikely to benefit.