Value of nuclein myocardial perfusion imaging in diagnosis of patients with coronary intermediate lesion and judgement of long-term prognosis

Objective To compare the consistency between myocardial perfusion imaging(MPI)and fraction of myocardial blood flow reserve(FFR)in the diagnosis of myocardial ischemia in patients with coronary intermediate lesion, and to analyze the long-term prognosis of patients with normal MPI and FFR value of 0.75~0.80 in gray area and those with FFR value above 0.80 undergoing no percutaneous coronary. Methods A retrospective analysis in clinical data of 30 patients with coronary intermediate lesion who underwent CAG and FFR detection was performed, and these patients all underwent MPI within two weeks before CAG. FFR values below 0.75 and less than 0.80 were used as the standard in judging myocardial ischemia, and the consistency between MPI and FFR was analyzed. The receiver operating characteristic curve(ROC)curve of the MPI's total integral summed differential score(SDS)was plotted. Twenty-two patients without PCI in CAG surgery were divided into guidance group(FFR value ranging from 0.75 to 0.80 and normal MPI Value, n=7)and control - group(FFR value over 8, n=15), follow-up lasted 51 to 82 months after surgery, with an average of(65.7±8.8)months. Major adverse heart events(MACE)including cardiac death, myocardial infarction, re-reconstruction of blood transport and the incidence of re-angina were observed. Results The agreement between MPI and FFR was good(Kappa=0.536)when FFR value was below 0.75, and the sensitivity, specificity, accuracy, negative predictive value, positive predictive value of MPI in the diagnosis of myocardial ischemia were 80.0%, 87.1%, 86.1%, 96.4% and 50.0%, respectively. The agreement between MPI and FFR was poor(Kappa=0.204)when FFR value was below 0.80, and the sensitivity, specificity, accuracy, negative predictive value, positive predictive value of MPI in the diagnosis of myocardial ischemia were 33.3%, 85.7%, 63.9%, 64.3% and 62.5%, respectively. There was no MACE event in the patients in the guidance group and the control group after operation, but angina pectoris occurred twice(28.6%)in former group and four times(26.7%)in latter group. Conclusion When FFR<0.75, MPI and FFR has good consistency in the diagnosis of myocardial ischemia. MPI has a certain clinical value in auxiliary diagnosis of coronary intermediate lesion patients with FFR value in gray region.