Abstract 17595: Comparison of Absolute Stress Perfusion and Perfusion Reserve for Detection of Significant Coronary Artery Disease
Objectives: Coronary perfusion reserve (CPR), a ratio of stress and rest perfusion, has been widely used with many imaging techniques to detected significant coronary artery disease (CAD). Recently it has become possible to quantify myocardial perfusion in absolute terms, but the value of absolute stress perfusion alone for detection of significant CAD in the clinical practice remains to be studied. We wanted to compare coronary perfusion reserve (CPR) and absolute perfusion parameters in the detection of CAD.
Methods: 104 patients (64 males, mean age 64 years) with moderate (30–70%) pretest likelihood of CAD were enrolled. Regional myocardial blood flow (MBF) was measured using PET with O-15-water at rest and during adenosine (140 ug/min) stress using validated quantitative model and software. All patients subsequently underwent invasive coronary angiography. Hemodynamically significant stenosis was defined as >50% of luminal narrowing (in borderline cases intracoronary FFR <0.80 confirmed hemodynamic significance). All analysis were done blinded and a ROC analysis was performed to compare the accuracies of CPR, MBF and also the absolute MBF increase by adenosine.
Results: Absolute MBF was comparable at rest (1.0±0.3 vs. 1.0±0.2 ml/g/min), but markedly lower at stress in the presence than absence of significant stenosis (1.8±0.6 vs. 3.5±1.0 ml/g/min, p<0.001). The PPV, NPV, sensitivity and specificity of stress MBF alone for significant stenosis were 74%, 98%, 95% and 90%, respectively, with optimal cut-off value of 2.4 ml/min/g (AUC 0.95). The absolute increase of MBF by adenosine resulted also in accurate results (93% sensitivity and 86% specificity when using 1.5 ml/min/g as a cut-off ; AUC 0.95). PPV, NPV, sensitivity and specificity of CPR were 65%, 94%, 81% and 87% with optimal cut-off value of 2.5 (AUC 0.90).
Conclusions: The absolute quantification of stress perfusion provides alone more accurate diagnosis of significant CAD than perfusion reserve. Also the increase of MBF between stress and rest in absolute terms works better than the reserve. The results indicate that quantification of myocardial perfusion in absolute terms is useful and provides additional clinical information.
- © 2010 by American Heart Association, Inc.