The Factors Affecting Visit-to-visit Heart Rate Variability In Patients With Coronary Heart Disease And Stent Implantation

Background:Previous investigations have showed that elevated resting heart rate（RHR）is associated with mortality.However,RHR differs in persons,different status,and different time points.Maybe some parameters are needed to evaluate the changes of RHR.Visit-to-visit heart rate variability（HRV）can reflect the fluctuation of RHR over a long period.Recently,epidemiologic investigations had shown that visit-to-visit HRV was associated with the risk of myocardial infarction,cardiovascular and all-cause mortality.However,seldom studies were regarding of the factors affecting visit-to-visit HRV.Objective:The present study was aimed to study the influencing factors of visit-to-visit HRV in coronary heart disease（CHD）patients after stent implantation.Methods:A total of 152 CHD patients（91 males,61females;aged63.2±7.0 years）were included to receive stent implantation from march to may in 2019.All the patients were followed up weekly in the outpatient department,and parameters[including RHR,LVEF,NT-pro BNP,high-sensitivity C-reactive protein（hs-CRP）,etc]were recorded for 4 weeks.Visit-to-visit HRV was calculated,and the study population was divided into three groups based on it(1^st tertile,2^nd tertile,and 3^rd tertile).The baseline characteristics were compared among groups.Linear regression analysis was performed to study the relationship between variables and visit-to-visit HRV.Results:The levels of hs-CRP in the 3^rd and 2^nd tertile of the study population were significantly higher than the 1^st tertile（5.3±2.5 mg/L vs.3.5±1.7mg/L vs.1.5±1.0 mg/L;P<0.001）.Univariate correlation analysis indicated that visit-to-visit HRV had a strong relationship with age（correlation coefficient 0.479,P<0.001）,hs-CRP（correlation coefficient 0.801,P<0.001）,and RHR（correlation coefficient 0.482,P<0.001）.Multiple-adjusted linear regression analysis also showed that visit-to-visit HRV was related with age（partial regression coefficient 0.101,P<0.001）,hs-CRP（partial regression coefficient 0.902,P<0.001）,and RHR（partial regression coefficient 0.112,P<0.001）.Visit-to-visit HRV was significantly higher in patients aged≥65 years.A strongly positive linear relationship was found between hs-CRP and visit-to-visit HRV（R²=0.640;P<0.001）.Moreover,RHR also had a linear relationship with visit-to-visit HRV（R²=0.233;P<0.001）.Conclusion:1.Age,RHR and hs-CRP are associated with visit-to-visit HRV in CHD patients after stent implantation.2.Visit-to-visit HRV is increasing due to aging,especially when patients older than 65 years;Visit-to-visit HRV is increasing due to higher hs-CRP levels,and has a strong linear relationship with hs-CRP;Visit-to-visit HRV is increasing due to higher RHR level,and had a linear relationship with visit-to-visit HRV.