929-63 Dobutamine Stress Cine Magnetic Resonance Imaging versus PET for Detection of Myocardial Viability

Abstract

To identify viable myocardium before coronary revascularization, we prospectively submitted eleven patients (60 ± 7 yrs; 11 M) with previous Q-wave myocardial infarction to 18 FDG-Positon Emission Tomography and low-dose (5 to 10 μg/kg/min) dobutamine cine-MRI. 18 FDG uptake > 60% was considered indicative of viable tissue. Ouantitation of systolic wall thickening/thinning (SW) was performed by use of a computer software allowing automatic detection of epicardial and endocardial outlines, at rest and under 5, 7.5 and 10 μg/kg/min of dobutamine. Heart slices of both 18 FDG-PET scans and dobutamine cine-MRI were divided in 8 segments, matched and analyzed byobservers blinded to clinical data. Sixty-five segments were considered viable by 18 FDG-PET; in this subgroup, rest SW thickening averaged 47 ± 5% and improved by 43 ± 8% under low-dose dobutamine. In the remaining 23 segments considered non viable by PET. rest SW thickening averaged 14 ± 7% * ( * p < 0.05 vs viable segment group) and further worsened by –13 ± 8% * during low-dose dobutamine stress ( * p < 0.05 versus viable segment group). Positive predictive value of low-dose dobutamine stress cine-MRI for assessment of myocardial viability was 84%. These data suggest that quantitative assessment of regional wall motion by dobutamine cine-MRI may help discriminate viable from non viable myocardium as defined by 18 FDG-Positon Emission Tomography.