Incremental prognostic value of hybrid 15OH2O positron emission tomography–computed tomography: combining myocardial blood flow, coronary stenosis severity, and high-risk plaque morphology

AIMS: This study sought to determine the prognostic value of combined functional testing using positron emission tomography (PET) perfusion imaging and anatomical testing using coronary computed tomography angiography (CCTA)-derived stenosis severity and plaque morphology in patients with suspected coronary artery disease (CAD). METHODS AND RESULTS: In this retrospective study, 539 patients referred for hybrid 15OH2O PET-CT imaging because of suspected CAD were investigated. PET was used to determine myocardial blood flow (MBF), whereas CCTA images were evaluated for obstructive stenoses and high-risk plaque (HRP) morphology. Patients were followed up for the occurrence of all-cause death and non-fatal myocardial infarction (MI). During a median follow-up of 6.8 (interquartile range 4.8-7.8) years, 42 (7.8%) patients experienced events, including 23 (4.3%) deaths, and 19 (3.5%) MIs. Annualized event rates for normal vs. abnormal results of PET MBF, CCTA-derived stenosis, and HRP morphology were 0.6 vs. 2.1%, 0.4 vs. 2.1%, and 0.8 vs. 2.8%, respectively (P < 0.001 for all). Cox regression analysis demonstrated prognostic values of PET perfusion imaging hazard ratio (HR) 3.75 (1.84-7.63), P < 0.001, CCTA-derived stenosis HR 5.61 (2.36-13.34), P < 0.001, and HRPs HR 3.37 (1.83-6.18), P < 0.001 for the occurrence of death or MI. However, only stenosis severity HR 3.01 (1.06-8.54), P = 0.039 and HRPs HR 1.93 (1.00-3.71), P = 0.049 remained independently associated. CONCLUSION: PET-derived MBF, CCTA-derived stenosis severity, and HRP morphology were univariably associated with death and MI, whereas only stenosis severity and HRP morphology provided independent prognostic value.