UNLABELLED: The pathophysiological significance of 99mTc-MIBI uptake at rest for assessing myocardial viability in patients with coronary artery disease (CAD) is still controversial. Therefore, we studied the relationship of 99mTc-MIBI uptake at rest and preserved or absent uptake of 18FDG as assessed with PET in 111 consecutive patients after overnight withdrawal of their antianginal medication. METHODS: Each ventricle was evaluated in 13 segments derived from 25 regions of interest (ROIs) in short-axis cuts and 18FDG uptake was normalized to the intraindividual normal reference ROI (ROI with maximal = 100% 99mTc-MIBI uptake). Segments with a normalized 18FDG uptake > 70% were defined as viable while segments with a 18FDG uptake < 50% were defined as nonviable. RESULTS: Five to 11% of segments with 99mTc-MIBI uptake at rest < or = 30% of peak activity were viable and 80%-84% nonviable. Of moderate to severe 99mTc-MIBI defects at rest (31%-70% of peak), 13%-61% were viable. Segmental 99mTc-MIBI uptake and normalized 18FDG uptake were linearly correlated (r = 0.61, n = 1443, p < 0.001). In segments revealing severely reduced 99mTc-MIBI uptake (< or = 50% of peak) the correlation was considerably lower (r = 0.44, n = 295, p < 0.001). CONCLUSIONS: In patients with CAD, 99mTc-MIBI uptake underestimates myocardial viability in comparison to 18FDG-PET. Myocardial 99mTc-MIBI uptake therefore appears to reflect myocardial blood flow rather than myocardial viability. Patients with moderate and severe 99mTc-MIBI defects at rest may benefit from additional metabolic PET imaging prior to final therapeutic decisions.
UNLABELLED: The pathophysiological significance of 99mTc-MIBI uptake at rest for assessing myocardial viability in patients with coronary artery disease (CAD) is still controversial. Therefore, we studied the relationship of 99mTc-MIBI uptake at rest and preserved or absent uptake of 18FDG as assessed with PET in 111 consecutive patients after overnight withdrawal of their antianginal medication. METHODS: Each ventricle was evaluated in 13 segments derived from 25 regions of interest (ROIs) in short-axis cuts and 18FDG uptake was normalized to the intraindividual normal reference ROI (ROI with maximal = 100% 99mTc-MIBI uptake). Segments with a normalized 18FDG uptake > 70% were defined as viable while segments with a 18FDG uptake < 50% were defined as nonviable. RESULTS: Five to 11% of segments with 99mTc-MIBI uptake at rest < or = 30% of peak activity were viable and 80%-84% nonviable. Of moderate to severe 99mTc-MIBI defects at rest (31%-70% of peak), 13%-61% were viable. Segmental 99mTc-MIBI uptake and normalized 18FDG uptake were linearly correlated (r = 0.61, n = 1443, p < 0.001). In segments revealing severely reduced 99mTc-MIBI uptake (< or = 50% of peak) the correlation was considerably lower (r = 0.44, n = 295, p < 0.001). CONCLUSIONS: In patients with CAD, 99mTc-MIBI uptake underestimates myocardial viability in comparison to 18FDG-PET. Myocardial 99mTc-MIBI uptake therefore appears to reflect myocardial blood flow rather than myocardial viability. Patients with moderate and severe 99mTc-MIBI defects at rest may benefit from additional metabolic PET imaging prior to final therapeutic decisions.
Authors: David S Fieno; Louise E J Thomson; Piotr Slomka; Aiden Abidov; John D Friedman; Guido Germano; Daniel S Berman Journal: J Nucl Cardiol Date: 2007-01 Impact factor: 5.952
Authors: M J Cramer; E E van der Wall; W Jaarsma; J F Verzijlbergen; M G Niemeyer; A H Zwinderman; E K Pauwels Journal: J Nucl Cardiol Date: 1996 Sep-Oct Impact factor: 5.952