Detection of coronary restenosis by exercise electrocardiography thallium-201 perfusion imaging and coronary angiography in asymptomatic patients after percutaneous transluminal coronary angioplasty

Noninvasive detection of restenosis in patients remaining asymptomatic afte r percutaneous transluminal coronary angioplasty (PTCA) remains a major cli nical problem. The value of exercise electrocardiography (ECG) and exercise -redistribution thallium-201 single-photon emission computed tomography (SP ECT) in detecting restenosis in such patients remains uncertain. Discordanc es between these tests and coronary angiography is a common situation. We s tudied 179 consecutive patients remaining asymptomatic after successful PTC A (208 vessels), who underwent 6 +/- 2 months of exercise EGG, SPECT, and c oronary angiography. We sought to assess the diagnostic value of the noninv asive tests compared with coronary angiography, and identify the determinan ts of discordances between the tests. Restenosis (diameter stenosis >50%) w as detected in 39% of patients and in 37% of vessels. The overall sensitivi ty, specificity, and accuracy for exercise ECG and SPECT in detecting reste nosis in individual vessels were, respectively, 53% versus 63% (p = 0.06), 59% versus 77% (p = 0.0001), and 57% versus 72% (p = 0.0001). On multivaria te analysis, positive exercise ECG was associated with higher heart rate re sponse (p = 0.02), incomplete revascularization (p = 0.004), and angiograph ic restenosis (p = 0.03), whereas positive SPECT was associated with incomp lete revascularization (p = 0.02), infarct-related artery PTCA (p = 0.01), and angiographic restenosis (p = 0.0001). Accuracies of the 2 tests were no t significantly different in patients with incomplete revascularization or PTCA of an infarct-related vessel. Overall, SPECT is more accurate than exe rcise ECG in detecting asymptomatic restenosis. Nevertheless, incomplete re vascularization and PTCA of on infarct-related artery could cause reversibl e perfusion defects regardless of restenosis, reducing the diagnostic value of SPECT in such patients. (C) 2000 by Excerpta Medica, Inc.