PACIFIC: PET superior to other modalities for diagnosis of myocardial ischemia

In a head-to-head comparison of noninvasive imaging modalities, PET was more accurate than coronary CT angiography or single-photon emission CT at diagnosing myocardial ischemia.

Hybrid modalities combining functional and anatomical assessments offered no additional accuracy beyond the capabilities of PET, researchers reported at the European Society of Cardiology Congress.

For the PACIFIC study, researchers analyzed 208 patients with suspected CAD from a single center. All patients first underwent coronary CTA, PET and SPECT imaging before being sent to the catheterization laboratory for fractional flow reserve measurements.

By FFR, 44.2% of patients had CAD of hemodynamic significance, Ibrahim Danad, MD, from VU University Medical Center, Amsterdam, and colleagues found.

Results of PET, SPECT, coronary CTA, hybrid SPECT/coronary CTA and hybrid PET/coronary CTA were compared with the gold standard of FFR.

For diagnosis of myocardial ischemia compared with the gold standard, PET was more accurate than coronary CTA (85% vs. 74%; P < .01) and SPECT (85% vs. 77%; P < .01), Danad and colleagues found.

Sensitivity was 87% for PET, 90% for coronary CTA and 57% for SPECT, while specificity was 84% for PET, 60% for coronary CTA and 94% for SPECT, according to the researchers.

Hybrid SPECT/coronary CTA (76%) and hybrid PET/coronary CTA (84%) did not improve accuracy compared with PET, but increased false negatives and decreased false positives (P < .001), according to Danad and colleagues.

“This study’s findings are novel and, to our knowledge, represent the first of its kind to evaluate diagnostic performance of noninvasive imaging modalities against a widely considered reference standard for functionally significant CAD,” Danad said in a press release. “The results will definitely spark further research. There is always a lot of discussion whether we need to choose SPECT or PET as the initial functional test for our patients. I think that we need to invest more in clinical PET imaging, which will be the future. It is more convenient for patients in terms of time, accuracy and radiation dose.” – by Erik Swain

Reference:

Danad I, et al. Hot Line: Coronary artery disease and imaging. Presented at: European Society of Cardiology Congress; Aug. 27-31, 2016; Rome.

Disclosure: Danad reports no relevant financial disclosures.

Editor’s Note: This article was updated on Sept. 2, 2016 to correct data about specificity.