Effect Of Influenza Vaccine On Prognosis And Cost-benefit Analysis Of Elderly Patients With Unstable Angina Pectoris

BackgroundCardiovascular disease is the leading cause of death in the world.Unstable angina pectoris,as a type of coronary heart disease,can rapidly develop to acute myocardial infarction or even death.Active control of controllable risk factors is an important measure to improve the prognosis of patients with unstable angina pectoris.A large number of studies have shown that influenza is a risk factor for cardiovascular adverse events.At present,it has become a consensus to recommend influenza vaccination for the elderly and patients with chronic diseases.However,the coverage rate of influenza vaccine in China is far lower than that recommended by the World Health Organization.There are few evidence-based studies on the potential benefits of influenza vaccine in elderly patients with unstable angina pectoris.Influenza vaccine has not been fully used in clinical practice,and the effectiveness of influenza vaccine has not been re-evaluated in practice.ObjectiveTo evaluate the effect of tetravalent influenza vaccination on the risk of all-cause death and cardiovascular adverse events in elderly patients with unstable angina pectoris,and analyze the cost-effectiveness.MethodUsing prospective observation and research method,we selected elderly patients with unstable angina pectoris who were hospitalized in a tertiary hospital in Xinxiang City from January to November 2018 as subjects.Patients were divided into vaccine group and control group according to whether they received tetravalent influenza vaccine between November 1 and December 14,2018.The basic clinical data of the patients were collected and followed up for 1 year.The incidences of death and cardiovascular adverse events were compared between the two groups,and the benefitcost was calculated.Multivariate Cox regression model was used to analyze the effect of tetravalent influenza vaccine on the prognosis of elderly patients with unstable angina pectoris.Result1.In this study,there was no significant difference in the baseline data between the two groups,with a total of 290,143 in the vaccine group,aged 73.17 ±5.90 years,accounting for 47.60%,and 147 in the control group,aged 72.52 ±5.64 years,accounting for 52.40%.2.The results of follow-up for 3 months and 6 months showed that there was no significant difference in mortality and cardiovascular adverse events hospitalization rate between the two groups.3.The results of follow-up for 9 months showed that there was no significant difference in mortality between the two groups.The hospitalization rates of cardiovascular adverse events(5.59% vs 12.24%),acute coronary syndrome(1.40%vs 6.12%)and heart failure(2.10% vs 7.48%)in the vaccine group were significantly lower than those in the control group.The benefit-cost ratio of influenza vaccination to reduce the hospitalization rate of cardiovascular adverse events was 2.65.4.The results of follow-up for 12 months showed that there was no significant difference in mortality between the two groups.The hospitalization rates of cardiovascular adverse events(6.30% vs 13.61%),acute coronary syndrome(1.40%vs 6.12%)and heart failure(2.10% vs 7.48%)in the vaccine group were significantly lower than those in the control group.The benefit-cost ratio of influenza vaccination to reduce the hospitalization rate of cardiovascular adverse events was 2.77.5.Multivariate Cox regression analysis showed that tetravalent influenza vaccination is a protective factor for cardiovascular adverse events in elderly patients with UA within one year(HR=0.44,95%CI:0.20~0.97,P=0.043),history of old myocardial infarction(HR=2.37,95%CI:1.11~5.57,P=0.047)and ejection fraction of left ventricle < 40%(HR=2.75,95%CI:1.29~5.87,P=0.009)were independent risk factors of cardiovascular adverse events in elderly patients with unstable anginapectoris within 1 year.Conclusion1.On the basis of optimized drug treatment,tetravalent influenza vaccination before influenza season can reduce the risk of hospitalization of cardiovascular adverse events,acute coronary syndrome and heart failure in elderly patients with unstable angina pectoris within one year,and improve clinical prognosis,which can be used as a cost-effective intervention.2.The history of old myocardial infarction and ejection fraction of left ventricle<40% were independent risk factors for cardiovascular adverse events in elderly patients with unstable angina pectoris within 1 year,and chronic obstructive pulmonary disease was an independent risk factor for hospitalization in patients with heart failure within 1 year.