Clinical application of stress/rest myocardial perfusion imaging in the patients with 50 ％-75 ％ coronary stenosis / 中华核医学杂志

ABSTRACT

Objective To evaluate the clinical application of stress/rest MPI in the patients with 50％-75％ coronary artery stenosis.Methods The criteria for patient selection were that the patients should have at least one main coronary artery with stenosis more than 50％,and the maximal stenosis should be less than 75％ according to CAG.The stress/rest MPI was performed in 2 weeks before or after CAG.A total of 244 patients (178 males,66 females) with mean age (57 ± 10) years were included in this study.Symptom restriction stress test was used and stress MPI was performed 1 - 1.5 h after 99Tcm-MIBI (925 MBq)injection at the exercise peak.Rest MPI was performed within 48 - 72 h after stress MPI.Myocardial ischemia was diagnosed when there was a reduced uptake or even a defect in 2 different tomographic sections or in the same part of a myocardium in the continuous 2 slices.When there was an irreversible reduced uptake or defect,myocardial infarction was given as the final diagnosis.No reduced uptake or defect in all slices was shown as normal.The impact of MPI images on the selection for optimal clinical therapy plans was also discussed.X2 test was used for statistical analysis.Results A total of 340 coronary arteries with stenosis 50％ - 75％ were found by CAG.According to stress/rest MPI results,207 patients (84.8％)presented normal,33 had myocardial ischemia,3 had myocardial infarction,and 1 had both myocardial infarction and ischemia.In abnormal MPI images,there were 61 ischemic segments and 9 infarct segments,which were associated with 43 stenotic arteries (23 LAD,10 LCX,and 10 RCA).Patients were divided into 2 groups according to the results of MPIGroup 1 with normal MPI (207/244,84.8％ ) and Group 2 with abnormal MPI (37/244,15.2％ ).In Group 1,9 patients underwent coronary artery revascularization (PTCA or CABG),and the others had medical treatment.Eight patients had PTCA and 29 patients had medical treatment in Group 2.There was a statistically significant difference between the two groups ( X 2 =11.9,P =0.001 ).Conclusion Stress-rest MPI may be an effective method to evaluate ischemia degree for patients with 50％ -75％ coronary artery stenosis and a useful indicator for the individual treatment.