[Residual activity or defect reversibility on stress-redistribution-reinjection 201T1 SPECT: which is the better marker of myocardial viability?].
Although both residual T1 activity and defect reversibility are used as a marker of myocardial viability on stress-redistribution-reinjection T1 (T1-RI) imaging, it is not yet fully understood which marker better predicts reversible dysfunction after revascularization. The aim of this study was to assess the comparative efficacies of these criteria for prediction of functional recovery after revascularization. Twenty-five patients (LVEF 41%) who underwent successful revascularization were studied with T1-RI SPECT and gated blood pool scintigraphy before revascularization. The gated blood pool study was repeated at mean 2 months after revascularization. The left ventricular myocardium was divided into 9 segments and the mean regional activities were calculated for each segment. In this study, two independent criteria were used as a viability index; (A) the presence of residual T1 activity (> 50% of peak) on the final image (reinjection image), (B) reversible defect (> 10% increase on the subsequent images) or normal T1 uptake (> 80% of peak) on the initial image. Functional recovery occurred in 51 of 88 dysfunctional segments. The presence of residual T1 activity was a highly sensitive (96%) but poorly specific (35%) marker of reversible dysfunction, while a reversible defect or normal T1 uptake was a less sensitive (67%) but more specific (59%) predictor of functional recovery. In conclusion, defect reversibility provides unique information on myocardial viability which cannot be obtained by assessing residual T1 activity alone.
Fujino
S
S
Department of Cardiology, Fukui Prefectural Hospital.
Matsunari
I
I
Muramori
A
A
Saga
T
T
Ichiyanagi
K
K
D000368:Aged; D003327:Coronary Disease / Q000000981:diagnostic imaging* / Q000503:physiopathology; D005260:Female; D006321:Heart / Q000000981:diagnostic imaging*; D006801:Humans; D007267:Injections; D008297:Male; D009200:Myocardial Contraction; D009206:Myocardium / Q000473:pathology*; D013794:Thallium Radioisotopes; D014022:Tissue Survival; D015899:Tomography, Emission-Computed, Single-Photon
D013794:Thallium Radioisotopes