Author + information
- Received May 9, 1988
- Revision received June 10, 1988
- Accepted July 25, 1988
- Published online December 1, 1988.
- Hosen Kiat, MB, FRACP1,
- Daniel S. Berman, MD, FACC*,1,
- Jamshid Maddahi, MD, FACC1,
- Ling De Yang, MD1,
- Ken Van Train, BS1,
- Alan Rozanski, MD, FACC1 and
- John Friedman, MD, FACC1
- ↵*.Address for reprints:Daniel S. Berman, MD, Cedars-Sinai Medical Center, 8700 Beverly Boulevard, Los Angeles, California 90048.
Twenty-one patients were studied who underwent thallium-201 stress-redistribution single photon emission computed tomography (SPECT) both before and after coronary artery bypass grafting (n = 15) or transluminal coronary angioplasty (n = 6). All patients underwent thallium imaging 15 min, 4 h and late (18 to 72 h) after stress as part of the preintervention thallium-201 scintigram.
In a total of 201 tomographic myocardial segments with definite post-stress thallium-201 perfusion defects in which the relevant coronary arteries were subsequently successfully reperfused, the 4 h redistribution images did not predict the postintervention scintigraphic improvement: 67 (85%) of the 79 4 h reversible as well as 88 (72%) of the 122 4 h nonreversible segments improved (p = NS). The 18 to 72 h late redistribution images effectively subcategorized the 4 h nonreversible segments with respect to postinter- vention scintigraphic improvement: 70 (95%) of the 74 late reversible segments improved after intervention, whereas only 18 (37%) of the 48 late nonreversible segments improved (p < 0.0001).
The frequency of late reversible defects and the frequency of postrevascularization improvement of late nonreversible defects are probably overestimated by this study because of referral biases. The cardiac counts and target to background ratios from late redistribution studies resulted in satisfactory cardiac images for visual interpretation. For optimal assessment of the extent of viable myocardium by thallium-201 scintigraphic studies, late redistribution imaging should be performed when nonreversible defects are observed on 4 h redistribution images.
- Received May 9, 1988.
- Revision received June 10, 1988.
- Accepted July 25, 1988.
- American College of Cardiology Foundation