Journal of Nuclear Cardiology最新文献

Background: This study aims to assess the prognostic significance of myocardial blood flow (MBF) quantification parameters obtained through cadmium-zinc-telluride (CZT)-SPECT in post-percutaneous coronary intervention (PCI) acute myocardial infarction (AMI) patient population.

Methods: A prospective cohort comprising 144 AMI patients who underwent primary PCI was enrolled. All participants received PCI within 12 hours of AMI diagnosis and subsequently underwent cardiac-dedicated CZT-SPECT dynamic imaging within two weeks post-procedure. Quantitative MBF parameters, semiquantitative perfusion scores, and left ventricular functional parameters were collected. Major adverse cardiovascular events (MACEs) were defined as cardiovascular death, nonfatal myocardial infarction, nonfatal stroke, heart failure, late coronary revascularization, or hospitalization due to unstable angina.

Results: Over a median follow-up duration of 27 months (interquartile range [IQR]: 15-37), a total of 40 MACEs were observed. Stress MBF (sMBF) (P<0.001) and myocardial flow reserve (MFR) (P = 0.002) were significantly lower in patients with MACEs. Receiver operating characteristic analysis determined optimal prognostic thresholds: sMBF<1.39 (AUC: 0.67, 95% confidence interval [CI]: 0.58-0.76, sensitivity: 46.2%, specificity: 90.0%, P<0.001) and MFR<1.84 (AUC: 0.66, 95% CI: 0.57-0.75, sensitivity: 44.2%, specificity: 90.0%, P<0.01). Kaplan-Meier survival analysis demonstrated significantly diminished event-free survival in patients exhibiting impaired sMBF (log-rank = 14.67; P<0.0001) or MFR (log-rank = 12.98; P=0.0003).

Conclusions: CZT-SPECT MBF quantification provides substantial prognostic value for post-PCI AMI patients. Importantly, stress-induced sMBF and MFR were identified as independent predictors of MACEs, demonstrating enhanced diagnostic efficacy over traditional semiquantitative perfusion parameters.

Objectives: This study aims to establish lower reference values for myocardial blood flow (MBF) and myocardial flow reserve (MFR) measured by rubidium-82 (⁸²Rb) myocardial perfusion imaging (MPI) in patients at low risk for coronary artery disease (CAD).

Methods: This single-center study included 3,320 patients with very low risk of obstructive CAD who underwent dipyridamole ⁸²Rb PET MPI. Patients were grouped by biological sex and age (≤40, 41-50, 51-60, 61-70, 71-80, and ≥81 years). Lower reference limits were derived using the Hoffmann method.

Results: Rest MBF increased with age in females (r=0.104, p<0.001) and males (r=0.149, p<0.001), while stress MBF and MFR decreased with age in both females (r=-0.344, p<0.001; r=-0.440, p<0.001) and males (r=-0.371, p<0.001; r=-0.479, p<0.001). Females had significantly higher rest and stress MBF, and lower MFR than males (p<0.001). MFR lower reference limits were 2.14, 2.11, 1.94, 1.77, 1.57, and 1.38 for females and 2.05, 2.32, 1.97, 1.92, 1.56, and 1.28 for males across the six age groups. Stress MBF lower reference limits were 2.46, 2.34, 2.23, 2.04, 1.84, and 1.59 mL/min/g for females and 1.85, 1.88, 1.65, 1.56, 1.33, and 1.20 mL/g/min for males across the six age groups.

Conclusions: This study establishes sex- and age-specific lower reference limits for stress MBF and MFR in low-risk CAD patients. Females exhibited higher stress MBF and MFR than males, while both values declined with age in both sexes. These findings underscore the necessity of incorporating sex- and age-adjusted reference values when interpreting MBF and MFR in clinical practice.

Myocardial viability assessment can be valuable in the management of selected patients with moderate-to-severe ischemic cardiomyopathy. Among the viability imaging modalities, 18F-fluorodeoxyglucose positron emission tomography (18F-FDG PET) is a key tool for evaluating myocardial metabolic activity, helping to distinguish viable myocardium from scar tissue. Optimal metabolic preparation is crucial to enhance myocardial glucose uptake and ensure accurate imaging, particularly in diabetic patients with variable insulin resistance. This review presents a clinical case illustrating the role of 18F-FDG PET in myocardial viability assessment, explores different metabolic preparation protocols, and examines their clinical implications. The hyperinsulinemic euglycemic clamp (HEC) remains the most effective technique; however,alternative protocols, such as intravenous glucose loading with insulin, are increasingly utilized for their efficiency and practicality. A comparative analysis of these methods provides insight into their suitability for different patient populations. This review also emphasizes the importance of a standardized yet adaptable approach to metabolic preparation,considering individual patient factors and institutional resources. Emerging literature supporting optimized PET imaging protocols is highlighted to help guide clinical decision-making for revascularization in patients with moderate-to-severe ischemic cardiomyopathy.