Short-term Prognostic Value Of Heart Rate Variability In Patients With Acute Coronary Syndrome After PCI

Aim:Acute coronary syndrome(ACS)is a cardiovascular emergency with a high morbidity,which pathological basis is unstable changes of coronary atherosclerotic plaques.Those unstable changes can easily cause some vulnerable plaques to rupture or erode which would then break suddenly under the induction of certain conditions,resulting in the activation of the coagulation system,which ultimately interrupts the coronary blood supply.Current international clinical guidelines state that obstructed blood vessels should be recanalized in patients with ACS.Percutaneous Coronary Intervention(PCI)has proved its significant effect on recanalization of blocked blood vessels in patients with ACS after a large number of clinical verifications,and its recanalization rate is relatively high.However,it has been clinically found that some patients with ACS would undergo major adverse cardiac events(MACE)in a short term,even if PCI was performed to block the recanalization of the blood vessels,resulting in a poor prognosis of patients.Therefore,it is necessary to find a simple but accurate index to predict and diagnose high-risk ACS patients in order to reduce the probability of major adverse cardiac events after percutaneous coronary intervention in patients with ACS.At present,a great deal of experiments has found that many biomarkers can be used to predict the occurrence of MACE in patients with ACS.However,most of which have certain limitations in clinical application,so further researches and verifications are needed.Local myocardial necrosis in patients with will cause an evident increase in cardiac sympathetic nerve activity,which ultimately leads to severe malignant arrhythmias.At present,heart rate variability(HRV)indicators are often used clinically to assess the status of cardiac autonomic nerves.Therefore,this study combined PCI surgery and HRV indicators to explore the changes in HRV of patients with ACS after PCI and their role and value in short-term prognosis prediction,with a view to better clinical predict,diagnose and treat high-risk ACS patients and provide effective evidence.Methods:A retrospective analysis was conducted in 95 patients with ACS who were hospitalized in Coronary angiography(CAG)and PCI from June 2017 to February 2019 and they should be followed up for 3 months after PCI.The Gensini score of the severity of coronary lesions of each patient should be calculated according to the CAG results,and the patients were followed up during hospitalization and got regular follow-ups after.The clinical prognosis recorded within three months divided the patients into two groups: the first one was the uneventful group(62 cases): patients had no major adverse cardiac events(MACE)within 3 months after surgery;and the second one was the test group(33 cases): patients who had had MACE within 3 months after surgery.Afterwards,a 24-hour ambulatory electrocardiographic monitoring was performed on the two groups of patients within 72 hours after PCI by a dynamic electrocardiogram monitor.By comparing the standard deviation of the NN intervals(SDNN),the propotion derived by dividing NN50 by the total number of NN intervals(p NN50),the standard deviation of the average NN intervals(SDANN),very low frequency(VLF),low frequency(LF),high Frequency(HF)and other main parameters in HRV indicators between the experimental group and uneventful group,to analyze the correlation between HRV indicators and coronary Gensini scores of all patients,and apply Logistic regression analysis to predict the significance of HRV main indicators for the occurrence of MACE during the 3-month follow-up of patients with ACS.Results: Firstly,The SDNN,SDANN and LF of the experimental group were significantly higher than that of the uneventful group(P<0.05),while the p NN50 and HF of the experimental group were significantly lower than that of the uneventful group(P<0.05)and there was no significant difference in VLF(P> 0.05).Secondly,the HRV main parameters SDNN,SDANN,p NN50,HF and LF of all enrolled patients with ACS had no correlation with coronary Gensini score(P>0.05).Thirdly,the results of logistic regression analysis showed that SDANN and LF were all independent risk factors for the occurrence of MACE within 3 months of patients with ACS receiving PCI treatment.Conclusion:First of all,the main indicators of HRV in patients with ACS,SDNN,SDANN,PNN50,VLF,LF and HF,had no correlation with Gensini score.And,the main parameters of HRV SDANN and LF after PCI in ACS patients can be used as effective indicators for short-term prognosis prediction after operation for they can reflect the short-term prognosis outcome after operation.