Prognostic value of exercise stress ^99mTc-MIBI SPECT myocardial perfusion imaging in patients suspected of coronary artery disease and LVEF> 45%

Objective To assess the predicting value of exercise stress 99m-technetium myocardial perfusion single-photon emission computed tomography (MPS, SPECT) for major adverse cardiovascular events (MACEs) in patients suspected of coronary artery disease (CAD) and LVEF> 45%. Methods Patients who were suspected of CAD admitted to Beijing Friendship Hospital from June 2013 to March 2016 were enrolled in this study. All patients had undergone exercise ^99mTc-sestamibi MPS for evaluation of ischemia, then were divided into two groups according to summed stress score (SSS): SSS 0-7 group and SSS≥8 group. The patients were followed up by telephone to record the occurrence of MACEs. Results A total of 295 patients were enrolled, 243 patients (male/female 133/110) were in SSS 0-7 group and 52 (male/female 40/12) were in SSS ≥ 8 group. Compared with SSS 0-7 score group, SSS ≥8 score group had higher proportion of males, typical symptoms of angina pectoris, history of myocardial infarction and abnormal wall motion (All P< 0.05), greater echocardiographic left ventricular end diastolic diameter and left ventricular end systolic diameter (All P< 0.05), and lower left ventricular ejection fraction (P=0.000). The incidence of MACEs in SSS 0-7 score group was 16% (n=39), versus 25% (n=13) in SSS≥8 score group, with no significant difference (P=0.124).There was no statistically significant difference in the incidences of cardiac death, non-fatal myocardial rehospitalization infarction, rehospitalization for angina pectoris, and revascularization between the two groups. The cumulative survival rate was lower in SSS≥8 group compared with SSS 0-7 group by Kaplan-Meier curve (P=0.042). The incidence of cardiac events (including cardiac death and non-fatal myocardial infarction) of SSS 0-7 group was 1%, which was 2% in SSS≥8 group. Conclusion Exercise myocardial perfusion imaging can be applied for evaluating cardiovascular risk of patients suspected of myocardial ischemia andLVEF> 45%. MPI indicates that SSS≥8 is an indication of revascularization therapy.