Background: Hybrid positron emission tomography (PET) myocardial perfusion imaging (MPI) with computed tomography (CT) allows the incorporation of coronary artery calcium (CAC) into the clinical protocol. We aimed to determine whether the combined analysis of MPI and CAC could improve the diagnostic accuracy of PET MPI in prediction of obstructive coronary artery disease (CAD).
Methods and Results: Consecutive patients (N=152, mean age 69±12 years) without prior CAD, referred to 82Rb PET MPI followed by invasive coronary angiography (mean time difference 14 days), were studied. Myocardial perfusion was quantified automatically for left anterior descending (LAD), left circumflex (LCX) and right coronary artery (RCA) territories as an ischemic total perfusion deficit (ITPD) for 456 vessels. Global and per-vessel CAC Agatston scores were calculated. Obstructive CAD was defined as ≥ 50% stenosis of left main stem and ≥ 70% stenosis in LAD, LCX and RCA. Logistic regression and 10-fold cross validation were used to derive and validate the combined ITPD/CAC scores.
Results: In the prediction of per-vessel obstructive CAD, the receiver operating characteristics area under curve for combined per-vessel ITPD/CAC score was higher, 0.85 [95% CI: 0.81-0.89] as compared with standalone ITPD AUC 0.81 [95% CI: 0.76-0.85] and CAC score 0.73 [95% CI: 0.68-0.78], P
Conclusions: Combined automatically derived per-vessel ITPD with per-vessel CAC score improves accuracy of 82Rb PET MPI for detection of obstructive CAD.
