This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Vanzetto, G. Articles by Beller, G. A. Search for Related Content PubMed PubMed Citation Articles by Vanzetto, G. Articles by Beller, G. A. Related Collections Nuclear cardiology and PET

(Circulation. 2000;101:2424.)
© 2000 American Heart Association, Inc.

Basic Science Reports

^99mTc-N-NOET Myocardial Uptake Reflects Myocardial Blood Flow and Not Viability in Dogs With Reperfused Acute Myocardial Infarction

Gérald Vanzetto, MD, PhD; David K. Glover, ME; Mirta Ruiz, MD; Dennis A. Calnon, MD; Roberto Pasqualini, PhD; Denny D. Watson, PhD; George A. Beller, MD

From the Experimental Cardiology Laboratory, Cardiovascular Division, Department of Medicine, University of Virginia Health Sciences Center, Charlottesville, Va, and Cis-bio international, Gif sur Yvette, France (R.P.).

Correspondence to David K. Glover, ME, Cardiovascular Division, Department of Medicine, Box 500, Medical Center, University of Virginia Health Sciences Center, Charlottesville, VA 22908. E-mail dglover{at}virginia.edu

Background—N-Ethoxy-N-ethyl-dithiocarbamato-nitrido-^99mTc (^99mTc-N-NOET) is a new neutral lipophilic ^99mTc-labeled myocardial perfusion agent with a high first-pass extraction fraction and delayed redistribution kinetics after transient ischemia comparable to what is observed with ²⁰¹Tl. It is unknown whether the uptake of this tracer reflects myocardial viability or just reperfusion flow in the setting of a reperfused myocardial infarction.

Methods and Results—In 13 anesthetized open-chest dogs, the left anterior descending coronary artery was occluded for 180 minutes, followed by 180 minutes of reperfusion. ²⁰¹Tl and ^99mTc-N-NOET were injected after either 60 (group 1, n=9) or 175 (group 2, n=4) minutes of reperfusion. Myocardial blood flow was measured by radioactive microspheres, and ²⁰¹Tl and ^99mTc-N-NOET tissue activities were determined by gamma-well counting. Normalized myocardial blood flow in the central infarct zone fell from 0.80±0.03 (SEM) and 0.89±0.01 at baseline to 0.18±0.04 and 0.13±0.02 during the occlusion in groups 1 and 2, respectively. Normalized ²⁰¹Tl activity in these segments was 0.39±0.04 and 0.43±0.04 and reflected myocardial viability rather than reperfusion flow (P<0.001). Normalized ^99mTc-N-NOET activity in the same segments was 0.84±0.08 and 0.64±0.03, respectively (P<0.01 versus ²⁰¹Tl; P=NS versus reperfusion flow) and more accurately reflected reperfusion flow (0.99±0.17 and 0.70±0.04) than residual viability.

Conclusions—The myocardial uptake of ^99mTc-N-NOET reflects reperfusion myocardial blood flow and not viability in a canine model of reperfused acute myocardial infarction. The clinical use of early ^99mTc-N-NOET imaging to assess the success of coronary reperfusion in patients with acute myocardial infarction should be investigated.

Key Words: radioisotopes • myocardial infarction • thallium • technetium

This article has been cited by other articles:

				L. M. Riou, S. Unger, M.-C. Toufektsian, M. Ruiz, D. D. Watson, G. A. Beller, and D. K. Glover Effects of Increased Lipid Concentration and Hyperemic Blood Flow on the Intrinsic Myocardial Washout Kinetics of 99mTcN-NOET J. Nucl. Med., July 1, 2003; 44(7): 1092 - 1098. [Abstract] [Full Text] [PDF]

				L. M. Riou, C. Ghezzi, G. Vanzetto, A. Broisat, J.-P. Mathieu, R. Bontron, R. Pasqualini, and D. Fagret Verapamil Does Not Inhibit 99mTcN-NOET Uptake In Situ in Normal or Ischemic Canine Myocardium J. Nucl. Med., June 1, 2003; 44(6): 981 - 987. [Abstract] [Full Text] [PDF]

				K. Takehana, G. A. Beller, M. Ruiz, F. D. Petruzella, D. D. Watson, and D. K. Glover 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 J. Nucl. Med., September 1, 2001; 42(9): 1388 - 1394. [Abstract] [Full Text] [PDF]