HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Figures Only Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Related articles in JNM Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Takehana, K. Articles by Glover, D. K. Search for Related Content PubMed PubMed Citation Articles by Takehana, K. Articles by Glover, D. K.

Assessment of Residual Coronary Stenoses Using ^99mTc-N-NOET Vasodilator Stress Imaging to Evaluate Coronary Flow Reserve Early After Coronary Reperfusion in a Canine Model of Subendocardial Infarction

Experimental Cardiology Laboratory, Cardiovascular Division, Department of Medicine, University of Virginia, Charlottesville, Virginia

Reperfusion is often incomplete after recanalization therapy because of the presence of residual coronary stenoses. Detecting mild to moderate stenoses requires assessing coronary flow reserve with vasodilator stress. ^99mTc-(N-ethoxy-N-ethyl-dithiocarbamato)nitrido (N-NOET) is a viability-independent flow tracer and thus may be well suited for assessing coronary flow reserve in the acute phase of reperfusion. Methods: Twelve open-chest dogs underwent 60 min of total left anterior descending artery (LAD) occlusion followed by either full reperfusion (group 1; n = 4) or reperfusion through a residual critical stenosis (group 2; n = 8). ^99mTc-N-NOET was given during peak vasodilator stress 165 min after reperfusion, and initial and 60-min delayed images were acquired. Regional blood flow was assessed with radiolabeled microspheres. Results: Infarct size was similar in both groups (9% ± 2% vs. 8% ± 2% of left ventricle). Both initial (0.61 ± 0.02 vs. 0.73 ± 0.01; P < 0.01) and 60-min (0.67 ± 0.02 vs. 0.80 ± 0.01; P < 0.01) defect count ratios (LAD/left circumflex coronary artery [LCx]) differentiated between the 2 groups, reflecting the greater diminution in coronary flow reserve in group 2 dogs (LAD/LCx flow ratios = 0.37 ± 0.04 vs. 0.57 ± 0.09; P < 0.01). Interestingly, coronary flow reserve in the reperfused zone of group 1 was diminished despite the absence of a stenosis. Thus, the difference in ^99mTc-N-NOET uptake between the 2 groups was less than expected. Conclusion: In this canine myocardial infarction model with some coronary flow reserve preservation, ^99mTc-N-NOET imaging can detect residual coronary stenoses. However, with more prolonged occlusion resulting in more severe endothelial or microvascular dysfunction, it may be difficult to distinguish varying degrees of vessel patency using any coronary flow reserve technique.

Key Words: coronary flow reserve • myocardial infarction • ^99mTcN-NOET

Related articles in JNM:

^99mTc-N-NOET Imaging for Myocardial Perfusion: Can It Offer More Than We Already Have?

Daniel Fagret, Catherine Ghezzi, and Gérald Vanzetto
JNM 2001 42: 1395-1396. [Full Text]  

This article has been cited by other articles:

				A. Boschi, L. Uccelli, C. Bolzati, A. Duatti, N. Sabba, E. Moretti, G. Di Domenico, G. Zavattini, F. Refosco, and M. Giganti Synthesis and Biologic Evaluation of Monocationic Asymmetric 99mTc-Nitride Heterocomplexes Showing High Heart Uptake and Improved Imaging Properties J. Nucl. Med., May 1, 2003; 44(5): 806 - 814. [Abstract] [Full Text] [PDF]

				D. Fagret, C. Ghezzi, and G. Vanzetto 99mTc-N-NOET Imaging for Myocardial Perfusion: Can It Offer More Than We Already Have? J. Nucl. Med., September 1, 2001; 42(9): 1395 - 1396. [Full Text] [PDF]