PET outperforms SPECT, CCTA in diagnosing coronary artery disease

Researchers have directly compared the performance of three noninvasive imaging methods for diagnosing myocardial ischemia—and they identified positron emission tomography (PET) as the most accurate.

The study—published online Aug. 16 in JAMA Cardiology—compared coronary computed tomography angiography (CCTA), single-photon emission tomography (SPECT) and PET.

“At present, European and US guidelines do not advocate for any specific noninvasive modality over another,” wrote research team, led by Ibrahim Danad, MD, with the department of cardiology at VU University Medical Center in Amsterdam, the Netherlands. “In this controlled clinical head-to-head comparative diagnostic performance study, PET demonstrated improved accuracy compared with CCTA and SPECT for the diagnosis of coronary ischemia, as measured by fractional flow reserve (FFR), in symptomatic patients with suspected coronary artery disease.”

The study population included 208 patients who had stable, new-onset chest pain and suspected CAD (76 women, 132 men, with a mean age of 58 years).  Patients all underwent CCTA, PET, and SPECT. Within two weeks after having those imaging tests, the patients underwent invasive coronary angiography and FFR measurements of all their coronary arteries. 

In addition to finding that diagnostic accuracy was highest for PET, compared with that of CCTA and SPECT, this study found no evidence to support the use of hybrid imaging methods, the use of CCTA with either SPECT or PET, even though some other investigators have promoted such a double-barreled approach.

Not only does a combined approach not enhance diagnostic accuracy, they said but the widespread use of CCTA along with SPECT or PET would also result in increased radiation exposure to patients.