Cardiac Rubidium-82 Positron Emission Tomography as an 'Area at Risk' Marker. Comparison to the Gold Standard, Cardiac SPECT

Introduction: Determination of the area at risk (AaR) is essential in assessing myocardial salvage, which is an important surrogate marker when assessing new cardioprotective strategies. Single-photon emission computed tomography (SPECT) is considered the gold standard for measuring these parameters, however, it is logistically challenging and requires tracer injection prior to revascularization. Hypothesis: We hypothesized that Rubidium (Rb)-82 Positron Emission Tomography (PET) can determine the AaR in myocardial infarction after the initial treatment with percutaneous coronary intervention. Methods: Twelve patients with ST-elevation myocardial infarction were prospectively enrolled and prior to revascularization injected with Tc-99m-Sestamibi and after revascularization underwent cardiac SPECT imaging followed by cardiac Rb-82 PET. Quantitation of perfusion defect from both PET and SPECT was determined by an automated algorithm with a threshold of <50 % of normal counts considered as AaR and estimated ...