TY - JOUR
T1 - Baseline/postnitrate tetrofosmin SPECT for myocardial viability assessment in patients with postischemic severe left ventricular dysfunction
T2 - New evidence from MRI
AU - Giorgetti, Assuero
AU - Pingitore, Alessandro
AU - Favilli, Brunella
AU - Kusch, Annette
AU - Lombardi, Massimo
AU - Marzullo, Paolo
PY - 2005
Y1 - 2005
N2 - The aim of this study was to compare 99mTc-tetrofosm in SPECT with contrast-enhanced MRI (ceMRI), a new direct sign of myocardial fibrosis. Methods: We studied 21 patients (age, 60 ± 11 y; 19 male) with previous myocardial infarction and severe left ventricular dysfunction (ceMRI EF, 29% ± 6%). All patients underwent resting and postnitrate (intravenous isosorbide dinitrate) 99mTc-tetrofosmin gated SPECT as well as ceMRI. Scintigraphic analysis was performed using quantitative perfusion SPECT (QPS), providing the percentage radiotracer uptake and defect severity in a 20-segment model. Hyperenhancement was defined by the increase of ceMRI signal intensity 20 min after intravenous injection of gadolinium-diethylenetriaminepentaacetic acid and its regional extension as the percentage of the total segment area. Results: In ceMRI dysfunctional segments, the correlation between the extent of hyperenhancement and both 99mTc-tetrofosmin uptake and defect severity was significantly better after nitrate administration rather than at rest (P <0.0001). Using a ceMRI cutoff below 40%, 102 of 196 (52%) segments were viable, whereas 94 (48%) segments were not viable. According to receiver-operating characteristic curve analysis, diagnostic accuracies were higher for postnitrate 99mTc-tetrofosmin uptake as well as perfusion defect severity than using resting data (0.84 vs. 0.71, P <0.001; 0.89 vs. 0.76, P <0.001, respectively). Conclusion: After nitrate administration, 93mTc-tetrofosmin uptake and perfusion defect severity were closely related to ceMRI, demonstrating, in vivo, the existence of an inverse correlation between the transmural distribution of fibrosis and tracer delivery to the myocardium.
AB - The aim of this study was to compare 99mTc-tetrofosm in SPECT with contrast-enhanced MRI (ceMRI), a new direct sign of myocardial fibrosis. Methods: We studied 21 patients (age, 60 ± 11 y; 19 male) with previous myocardial infarction and severe left ventricular dysfunction (ceMRI EF, 29% ± 6%). All patients underwent resting and postnitrate (intravenous isosorbide dinitrate) 99mTc-tetrofosmin gated SPECT as well as ceMRI. Scintigraphic analysis was performed using quantitative perfusion SPECT (QPS), providing the percentage radiotracer uptake and defect severity in a 20-segment model. Hyperenhancement was defined by the increase of ceMRI signal intensity 20 min after intravenous injection of gadolinium-diethylenetriaminepentaacetic acid and its regional extension as the percentage of the total segment area. Results: In ceMRI dysfunctional segments, the correlation between the extent of hyperenhancement and both 99mTc-tetrofosmin uptake and defect severity was significantly better after nitrate administration rather than at rest (P <0.0001). Using a ceMRI cutoff below 40%, 102 of 196 (52%) segments were viable, whereas 94 (48%) segments were not viable. According to receiver-operating characteristic curve analysis, diagnostic accuracies were higher for postnitrate 99mTc-tetrofosmin uptake as well as perfusion defect severity than using resting data (0.84 vs. 0.71, P <0.001; 0.89 vs. 0.76, P <0.001, respectively). Conclusion: After nitrate administration, 93mTc-tetrofosmin uptake and perfusion defect severity were closely related to ceMRI, demonstrating, in vivo, the existence of an inverse correlation between the transmural distribution of fibrosis and tracer delivery to the myocardium.
KW - Contrast-enhanced MRI
KW - Gated SPECT
KW - Myocardial viability
KW - Nitrates
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M3 - Article
C2 - 16085584
AN - SCOPUS:25444531140
VL - 46
SP - 1285
EP - 1293
JO - Journal of Nuclear Medicine
JF - Journal of Nuclear Medicine
SN - 0161-5505
IS - 8
ER -