Abstract | PURPOSE: Microcirculatory failure after reperfusion is clinically indicated to cause reperfusion injury whereas excessive intracellular calcium ion overload is experimentally proved as a key mechanism of reperfusion injury. We hypothesized that technetium-99m ((99m)Tc) pyrophosphate ( Tc-PYP) uptake in injured but viable infarct-related myocardium with preserved myocardial perfusion after reperfusion estimated by thallium-201 ((201)Tl) uptake would be associated with final functional recovery. METHODS: Dual- isotope Tc-PYP/(201)Tl single-photon emission computed tomography (SPECT) was performed 2 days after successful reperfusion therapy in patients with first acute myocardial infarction, and 50 patients (63 +/- 13 years old, female 22%) with preserved (201)Tl uptakes of > or = 50% in reperfused myocardium was followed for 1 month. Tc-PYP uptake was assessed as the heart-to-sternum (H/S) ratio. Two-dimensional echocardiography was also performed 2 days and 1 month after reperfusion to evaluate functional recovery. RESULTS: High Tc-PYP uptake, defined as the H/S ratio > or = 0.81, was predictive of chronic phase no functional recovery (73.7% in 14 of 19 patients with high uptake vs 16.1% in five of 31 patients without those, p < 0.0001). After adjustment for potential confounding variables, including electrocardiographic persistent ST segment elevation at 1 h after reperfusion, high Tc-PYP uptake remained independently predictive of no functional recovery with odds ratio of 8.7 (95% confidential interval = 2 to 38.7; p = 0.005). CONCLUSION: High Tc-PYP uptake in reperfused but viable infarct-related myocardium was a powerful predictor of no functional recovery, which may reflect excessive intracellular calcium ion overload caused by reperfusion injury. Tc-PYP/(201)Tl dual- isotope SPECT imaging can provide prognostic information after reperfusion.
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Authors | Yasushi Akutsu, Kyouichi Kaneko, Yusuke Kodama, Hui-Ling Li, Hideki Nishimura, Yuji Hamazaki, Jumpei Suyama, Akira Shinozuka, Takehiko Gokan, Youichi Kobayashi |
Journal | European journal of nuclear medicine and molecular imaging
(Eur J Nucl Med Mol Imaging)
Vol. 36
Issue 2
Pg. 230-6
(Feb 2009)
ISSN: 1619-7089 [Electronic] Germany |
PMID | 18787823
(Publication Type: Journal Article)
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Chemical References |
- Thallium Radioisotopes
- Technetium Tc 99m Pyrophosphate
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Topics |
- Humans
- Myocardial Infarction
(physiopathology, surgery)
- Myocardial Reperfusion Injury
(diagnostic imaging, metabolism, physiopathology)
- Recovery of Function
- Technetium Tc 99m Pyrophosphate
(metabolism)
- Thallium Radioisotopes
(metabolism)
- Tomography, Emission-Computed, Single-Photon
(methods)
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