Detection of restenosis after percutaneous transluminal coronary angioplasty using the exercise treadmill test and technetium 99m-sestamibi scintigraphy.

Background: The detection of myocardial ischemia after percutaneous transluminal coronary angioplasty (PTCA) is important because 30-50 per cent of the patients will develop restenosis within 6 months. Symptoms of chest pain and exercise stress test (EST) have shown to be less sensitive for detection of ischemia than exercise Technetium-99m Sestamibi (Tc-99m MIBI). The purpose of this study was to compare the sensitivity and specificity of chest pain, EST and Tc-99m MIBI with coronary angiography (CAG).
Method: Tc-99m MIBI with SPECT imaging was performed at months 1, 3 and 6 and CAG was repeated 6 months after successful PTCA. Earlier Tc-99m MIBI and CAG were performed in patients with recurrent angina pectoris or suspected restenosis.
Results: Forty six patients (M 29, F 17) who had undergone successful angioplasty were prospectively enrolled. Their mean age was 61 +/- 19 yrs. Eighty eight lesions (LAD63%, LCX34%, RCA19%) were performed. Lesion characteristics were type A in 9 per cent, type in B 30 per cent and type C in 61 per cent. Fifty four per cent of PTCA were performed for single vessel disease and 46 per cent for multivessel disease. The mean duration of time between PTCA and follow-up CAG was 6.1 +/- 2.7 months. We detected restenosis from CAG in 58 per cent of the cases. The Tc-99m MIBI had higher sensitivity to detect restenosis than anginal pain (85.0% vs 39.4% p < 0.005) or EST (85.0% vs 63.6% p < 0.05) when compared with CAG. The overall accuracy of Tc-99m MIBI for the detection of restenosis was 80 per cent.
Conclusion: Tc-99m MIBI with SPECT imaging constitutes a better means than symptoms or exercise test to detect restenosis after successful coronary angioplasty.