Assessment of myocardial perfusion reserve by czt camera compared to reference invasive microcirculation measurements

Abstract

Myocardial perfusion reserve (MPR) is a validated diagnostic and prognostic value by Positron Emission Tomography (PET) scans. However, PET availability stays limited in certain countries as France. Gamma cameras with cadmium-zinc telluride detector (CZT-SPECT) are more available and allow the evaluation of this MPR. However, there is no comparison of its results with the interventional diagnostic procedure. Twenty-seven patients with suspected of epicardial or microcirculatory coronary involvement were prospectively included. All patients benefited from an evaluation of the MPR by CZT SPECT as well as an interventional diagnostic procedure with measure of the Fractionnal Flow Reserve (FFR), coronary flow reserve (CRF) and index of microcirculation resistance (IMR). Correlation between MPR and CFR was measured and sensitivity and specificity to detect severe coronary microcirculation disease (CMVD) defined by FFR > 0.8, CFR < 2 and IMR > 25. Coronary angiography was performed in 27 patients, with a complete functional evaluation (FFR, CFR, IMR) on 33 vessels. Two patients had significant stenosis (50-90% stenosis and FFR < 0.8). MPR was correlate with CRF measurement ( r = 0.41; P = 0.017). The sensitivity and specificity per patient to detect severe CMVD were 71% and 65%, respectively. Sensitivity and specificity of MPR by territory were 87% and 76% respectively. MPR was correlated with CRF and presented satisfactory diagnostic performance to discriminate, in the absence of significant stenosis, patients free from patients with severe CMVD.