How PET is transforming cardiac nuclear imaging

"There's a recognition that vascular dysfunction, both in the large epicardial vessels and in the small vasculature of the heart, is responsible for perhaps two-thirds of the symptoms that the angiogram does not provide us a clear explanation for why the patient has chest pain or dyspnea. We couldn't do that with SPECT, but now we can do that with PET," Di Carli, who is also the editor-in-chief of the Journal of Nuclear Cardiology, explained. "PET has changed the practice of nuclear medicine in general and I think it is going to revitalize the practice of cardiology that allows a unique tool that allows us to understand the disease in ways we couldn't do with SPECT."

Flurpiridaz is a game-changer for accessibility

One major development fueling PET’s growth is the recent approval of flurpiridaz F-18, sold by GE Healthcare under the trade name Flyrcado. It is the first new myocardial perfusion PET tracer in more than 20 years and can be distributed like standard SPECT unit doses, removing the logistical and financial barriers posed by the costly rubidium generators used in many centers with PET. He said this is a game-changer because it enables centers with PET systems for oncology to start doing low volumes of cardiac scans with these pre-ordered doses per patient.

At the America Society of Nuclear Cardiology (ASNC) meeting in September, the expansion of PET was a major talking point. There is now interest in the technology from practices of all types and sizes. 

"It was exciting to see it was not just the large research academic centers, but now it is the regular private practice doctors who say they want to integrate PET into their practice," Di Carli explained.  

PET quantification drives better outcomes

Quantitative PET is not only more precise, it is increasingly supported by clinical evidence. Di Carli pointed to the recent CENTURY trial, led by Lance Gould and published in the European Heart Journal, which demonstrated that PET-guided management strategies—especially those emphasizing medical therapy—reduced mortality and myocardial infarction rates.[1]

"They showed that PET-guided interventions, particularly on medical therapy, were quite successful in lowering a patient's risk. So they use PET to select who needs revascularization, a very small percentage. But then the myocardial flow assessment reassured patients entering the randomization that it was safe to actually engage in intensive medical therapy. And that led to reduction in mortality, reduction in myocardial infarction. So now not only the guidelines, but the evidence is sort of pointing us into a new era for profusion imaging moving away from SPECT," Di Carli said.

Guidelines endorse PET as a preferred modality

Reflecting the growing body of data, major professional societies, including the American College of Cardiology, American Heart Association, and European Society of Cardiology, now explicitly recommend PET as the preferred imaging modality for patients with suspected or known coronary disease when available. These guidelines also emphasize the importance of quantitative flow measurement as part of the interpretation process.