Detection of restenosis after Percutaneous Transluminal Coronary Angioplasty (PTCA) using the exercise treadmill test and technetium 99m-sestamibi scintigraphy

Abstract

BACKGROUND : The detection of myocardial ischemia after percutaneous balloon coronary angioplasty (PTCA) is important because 30-50% of the patients will develop restenosis in 6 months. Symptom of chest pain and exercise stress test (EST) have been shown to be less sensitive for detection restenosis after PTCA than Thallium-201 scintigraphy, but there are few reports regarding detection restenosis by using Tc-99m MIBI. The purpose of this study is to compare the sensitivity and specificity of chest pain, EST and exercise Tc-99m MIBI with coronary angiography (CAG) in post PTCA patients. Methods : Exercise Tc-99m MIBI with SPECT imaging was performed 1, 3 and 6 months and CAG was repeated at 6 months after successful PTCA. Earlier Tc-99m MIBI scan and CAG were done if the patients had recurrent angima pectoris. RESULTS : From November 1995 to February 1997, Forty-six patients (M29, F17) who underwent successful angioplasty were prospectively enrolled. Mean age was 61.3+_19 yrs. Eighty-eight lesions (LAD 63%, LCX 34%, RCA 19%) were performed. Lesion characteristics were type A in 9%, type B in 30% and type C in 65%. Fifty-four percent of PTCA were done for single vessel disease and forty-six percent for multivessel disease. Mean duration from PTCA to follow-up CAG was 6.1+_2.7 months. We detected 58% (27/46) case-restenosis from CAG. The sensitivity and specificity of angina pain, EST and Tc-99m MIBI compared with CAG were shown in the table. The overall accuracy of Tc-99m MIBI for detection of restenosis was 80%. Angina pain (sensitivity = 39.4%, specificity = 66.7%), EST sensitivity 63.6%, specificity = 66.7, and Tc 99m-MIBI (sensitivity 85.0*% specificity 72.0%). *p<0.05 versus EST and p<0.001 versus angina pain CONCLUSION : Tc-99m MIBI with SPECT imaging is a better tool for the detection of restenosis after coronary angioplasty.