Myocardial salvage after ST-segment-elevation myocardial infarction: comparison between prasugrel and clopidogrel in the presence or absence of high-residual platelet reactivity

Optimized gated a SPECT-derived myocardial salvage index: its prognostic significance in predicting major adverse cardiac events following acute myocardial infarction percussion

PURPOSE

Estimate myocardial salvage index (MSI) using a single-gated Single-Photon Emission Computed Tomography (SPECT) myocardial perfusion imaging (GSMPI) early after percutaneous coronary intervention (PCI) in patients with acute myocardial infarction (AMI) and compare its predictive value with the traditional method especially for post-PCI left ventricular ejection fraction (LVEF) improvement and major adverse cardiac events (MACEs).

METHODS

GSMPI was performed in 62 patients with AMI early after PCI (3-10 days). The MSI and the conventional parameters were obtained, including total perfusion deficit, LVEF, peak ejection rate (PER), and peak filling rate (PFR). The new calculation method (scoring evaluation method means the extent of abnormality is the percentage of the total scores of abnormal segments divided by the sum of the maximum scores of all myocardial segments using 4-point and 5-point scale semi-quantitative scoring method) and the reference method (number evaluation method means the extent of abnormality is the percentage of the number of abnormal segments divided by the total number of myocardial segments) were applied to acquire the MSI. We compared the predictive ability of the 2 methods based on the area under the receiver operating characteristic curve for LVEF improvement 6 months after PCI using MSI. The Kaplan-Meier method was used for depicting survival curves for predicting MACEs by the 2 methods. Cox proportional-hazards regression was applied to confirm the independent predictors of MACEs.

RESULTS

The MSI obtained by the new method indicated stronger prognostic significance in LVEF improvement [area under the curve (AUC): 0.793, 95% confidence interval (CI) 0.620-0.912, P < .001] compared with the reference method (AUC: 0.634, 95%CI 0.452-0.792, P = .187). Delong's test revealed a statistically significant difference in AUCs between the 2 methods (P < .05, 95%CI 0.003-0.316). The diagnostic value of the scoring evaluation method was higher than that of the number evaluation method. The Cox prevalence of MACEs was substantially higher in the < median MSI group than in the ≥ median MSI group (hazard ratio: 0.172; 95% CI 0.041-0.724; P < .05] using the new method, whereas no considerable differences were observed between the 2 groups using the reference method (P = .12). Further, the multivariate Cox regression analysis revealed that MSI was an independent indicator for predicting MACEs (P < .05).

CONCLUSION

The MSI obtained from a simple GSMPI early after PCI, using the scoring evaluation method, was a reliable prognostic indicator for predicting LVEF improvement and MACEs in AMI. It remarkably improved the prognostic value compared with the previous reference methods.

Effects of Clopidogrel Rehabilitation on Cardiac Protein Kinase C, Cardiac Heat Shock Protein 70, and CI in MIRI Rat Model

In order to investigate the effects of clopidogrel rehabilitation on the levels of cardiac protein kinase C (PKC), cardiac heat shock protein 70 (HSP70), and cardiac index (CI) in rats with myocardial ischemia-reperfusion injury (MIRI), sixty Wistar rats are randomly divided into three groups (sham operation group, model group, and clopidogrel group), with 20 rats in each group. The clopidogrel group is given clopidogrel by gavage, and the sham operation group and the model group are given the same amount of normal saline by gavage. The experimental results show that compared with the model group, the clopidogrel group has clear horizontal lines and cell edema. The myocardial infarction rate, creatine kinase-MB (CK-MB), and malondialdehyde (MDA) of the model group and clopidogrel group in the control sham operation group significantly increase.