Introduction: This study aimed to evaluate the prognostic significance of dynamic cadmium-zinc-telluride (CZT) cardiac-dedicated single photon emission computed tomography (SPECT)-derived myocardial flow reserve (MFR) in patients with suspected or confirmed coronary artery disease (CAD) and normal myocardial perfusion. Methods: A consecutive cohort of patients who completed dynamic myocardial perfusion imaging and routine myocardial perfusion imaging (MPI) using CZT cardiac-dedicated SPECT were selected and followed up for at least 24 months to determine the occurrence of major adverse cardiac events (MACEs). Patients were divided into groups with no MACEs and MACEs. Differences between the two groups in baseline characteristics, semiquantitative, and quantitative parameters were compared. Cox regression analysis was performed to identify predictive factors associated with MACEs. Kaplan-Meier survival curves were plotted, and log-rank tests were performed to compare the incidence of MACEs between the normal MFR group and the reduced MFR group. Results: A total of 369 patients with negative routine MPI results were included in this study, with an average age of 61.82±8.68 years (113 males and 256 females). The median follow-up duration was 30 months IQR (25, 34), during which 73 patients experienced MACEs. The incidence of MACEs was significantly higher in patients with reduced MFR than in those with normal MFR (P<0.05). Cox regression analysis identified reduced MFR as an independent predictor of MACEs (HR: 2.076, 95%CI: 1.174-3.669, P=0.012). The proportion of patients diagnosed with obstructive coronary artery disease (OCAD) was significantly higher in the MACE group compared to the no MACE group (P<0.05). Discussion: These findings provide critical clinical insights, particularly for patients in whom myocardial ischemia is not detected via traditional semiquantitative MPI analysis. CZT cardiac-dedicated SPECT, which enables quantitative assessment of myocardial blood flow, serves as a more precise tool for early CAD diagnosis and prognostic evaluation. This underscores the role of CZT cardiac-dedicated SPECT in assessing myocardial ischemia and prognosis among patients with negative conventional MPI, helping to identify high-risk individuals that conventional MPI may overlook. By leveraging CZT cardiac-dedicated SPECT to obtain absolute quantitative myocardial blood flow (MBF) and MFR, myocardial perfusion is quantified more accurately, thereby overcoming the limitations of traditional MPI and providing a more reliable basis for early clinical diagnosis and treatment. Conclusion: MFR measured with CZT cardiac-dedicated SPECT can effectively predict the prognosis of patients with suspected or confirmed CAD and normal MPI. Reduced MFR is significantly associated with a higher incidence of MACEs, and MFR reduction is an independent predictor of MACEs.
Wang et al. (Tue,) studied this question.