Author + information
- Received August 3, 1982
- Revision received November 2, 1982
- Accepted November 5, 1982
- Published online March 1, 1983.
- Robert S. Gibson, MD*,
- Denny D. Watson, PhD,
- George J. Taylor, MD, FACC,
- Ivan K. Crosby, MD,
- Harry L. Wellons, MD,
- Nina D. Holt, BS, RN and
- George A. Beller, MD, FACC
- ↵*Address for reprints: Robert S. Gibson, MD, Box 158, Medical Center, University of Virginia, Charlottesville, Virginia 22908.
Because thallium-201 uptake relates directly to the amount of viable myocardium and nutrient blood flow, the potential for exercise scintigraphy to predict response to coronary revascularization surgery was investigated in 47 consecutive patients. All patients underwent thallium-201 scintigraphy and coronary angiography at a mean (± standard deviation) of 4.3 ±3.1 weeks before and 7.5 ± 1.6 weeks after surgery. Thallium uptake and washout were computer-quantified and each of six segments was defined as normal, showing total or partial redistribution or a persistent defect. Persistent defects were further classified according to the percent reduction in regional thallium activity; PD25-50denoted a 25 to 50% constant reduction in relative thallium activity and PD> 50denoted a greater than 50% reduction. Of 82 segments with total redistribution before surgery, 76 (93%) showed normal thallium uptake and washout postoperatively, versus only 16 (73%) of 22 with partial redistribution (probability [p] = 0.01). Preoperative ventriculography revealed that 95% of the segments with total redistribution had preserved wall motion, versus only 74% of those with partial redistribution (p = 0.01). Of 42 persistent defects thought to represent myocardial scar before surgery, 19 (45%) demonstrated normal perfusion postoperatively. Of the persistent defects that showed improved thallium perfusion postoperatively, 75% had normal or hypokinetic wall motion before surgery, versus only 14% of those without improvement (p < 0.001). Whereas 57% of the persistent defects that showed a 25 to 50% decrease in myocardial activity demonstrated normal thallium uptake and washout postoperatively, only 21 % of the persistent defects with a decrease in myocardial activity greater than 50% demonstrated improved perfusion after surgery (p = 0.02).
Thus, preoperative quantitative thallium-201 scintigraphy appears useful in predicting response to revascularization surgery, and some persistent defects may revert to normal thallium uptake after surgery. Importantly, the preoperative distinction between viable and nonviable myocardium can be reasonably established by quantitating the amount of persistent reduction in thallium uptake and correlating this with preoperative wall motion.
This study was supported in part by Grant HL-26205 from the National Heart, Lung, and Blood Institute, Department of Health and Human Services, Bethesda, Maryland
- Received August 3, 1982.
- Revision received November 2, 1982.
- Accepted November 5, 1982.
- American College of Cardiology Foundation