Value Of MPV、PDW And SSema4D In Predicting Severity And Prognosis Of Acute Coronary Syndrome

Platelet plays an important role in the process of acute coronary syndrome(ACS). The mean platelet volume(MPV) and platelet distribution width(PDW) can reflect the degree of platelet activation and be related with the function of platelet. Platelets express semaphorin4D(Sema4D), Sema4 D is involved in the formation of atherosclerosis by regulating thrombosis. Risk stratification of Patients with ACS is critical for the treatment. GRACE risk score system has been demonstrated to be good for risk stratification, optimizing the treatment, contributing better prognosis.Part1 The role of platelet volume index in evaluating the severity and prognosis of acute myocardial infarctionObjectives:To investigate the dynamic changes of MPV and PDW,and explore the role in the prognosis of patients with acute myocardial infarction.Methods:This retrospective cohort study included 312 patients diagnosed with AMI during 2012-2014 in Soochow University First Hospital. MPV and PDW was measured serially from admission to day-7 after AMI. The relationship between PDW MPV and GRACE risk score was further investigated.Results: In the STEMI group, the patients were younger, and with higher proportions of hyperlipidemia and smoking,patients in STEMI were observed a greater risk of dead during hospitalization, compared to NSTEMI. In the high PDW group,the proportions of congestion heart failure 、 cardiogenic shock and Killip IV were higher. PDW was significantly associated with mortality of in-hospital、one-year mortality and the risk of reinfarction in one year(ρs=0.69,P<0.001;ρs=0.68,P<0.001;ρs=0.70,P<0.001). MPV was significantly associated with one-year mortality(ρs=0.30,P=0.02).Conclusions: PDW was related to the severity of AMI, could predict the risk of in-hospital mortality、one-year mortality and reinfarction,, it was helpful to screen out the high-riskpatients, so as to make more suitable treatment, and improve the prognosis of patients.Part2 The relationship between s Sema4 D and clinical characteristic of ACSObjectives:To determinate the expression of s Sema4 D of patients with ACS and the relationship between s Sema4 D and ACS, investigate the correlation between s Sema4 D and PDW or MPV.Methods:The serum s Sema4 D of ACS cohort was detected by using ELISA assay, the ACS cohort included 70 patients with STEMI、20 patients with NSTEMI and 10 patients with UA. Differential expression of s Sema4 D was compared between ACS subgroup, levels of s Sema4 D during preoperative and postoperative of STEMI were also studied. Correlation between s Sema4 D and MPV、PDW in patients with STEMI was further analyzed.Results: Expression of sSema4 D in male patients was significantly higher than that in female patients(P=0.017). Expression of s Sema4 D in ACS was higher compared to control group(P<0. 021). Also expression of s Sema4 D in STEMI and NSTEMI group was higher(P<0.001 vs P=0.015). The expression of s Sema4 D in UA group was higher than that in the control group, but there was no statistically significant difference between them. s Sema4 D levels significantly decreased at the first day after emergency PCI in STEMI group. The expression of s Sema4 D in patients with STEMI was significant correlated with PDW(ρs=0.557,P<0.001), and moderate correlated with MPV(ρs =0.324,P=0.002), no significance correlation was observed between s Sema4 D and platelet count(ρs =-0.165,P=0.115).Conclusions: Expression of s Sema4 D was elevated in patients with ACS,there was difference among all types of ACS. After coronary revascularization, the s Sema4 D level of STEMI decreased. The expression of s Sema4 D was correlated to platelet activation, which suggested that s Sema4 D may serve as a new marker for monitoring ACS risk.Part3 The validation of GRACE risk model in Soochow patients with AMIObjective: To validate the GRACE risk score system of STEMI and NSTEMI in Soochow area.Methods: A total of 312 patients with STEMI and NSTEMI were identified and the GRACE risk score were calculated for each patient. The validity of the model was assessed with discrimination, calibration and decision curve analysis.Results: GRACE risk score demonstrated good discrimination(c-index 0.720, 95%CI 0.607-0.833) The calibration plot demonstrated that the risk was underestimated for low risk cohorts. Decision curve analysis showed that GRACE risk score system was suitable for all the patients enrolled in the validation cohorts.Conclusions: GRACE risk score could make a good risk stratification of ACS subgroup(STEMI and NSTEMI) in Soochow area. Furthermore it was beneficial for stratifying, making individualized treatment and improving the prognosis. At present, the calibration ability of GRACE risk score system should be improved, validating with larger sample size of the risk stratification system was necessary.