Correlation Between Peak VO₂ And LVEF In Patients With CHF

Objective To analyze the correlation between Peak VO₂ and left ventricular ejection fraction（LVEF）in patients with chronic heart failure,and to explore the clinical value and safety of Peak VO₂ in evaluating cardiac function in patients with chronic heart failure.Methods Cardiac Dalian port hospital rehabilitation center randomly selected 100patients since July 2016 to January 2019 patients with previous confirmed coronary heart disease who met the diagnostic criteria for chronic heart failure were included in the heart failure group,the New York heart association（NYHA）cardiac function class Ⅰ-Ⅱ,clinical symptoms in patients with stable,conventional treatment of heart failure drugs.At the same time 100 cardiopulmonary function in hospital physical examination center of Dalian port normal subjects as control group.According to NYHA cardiac function classification,patients in the heart failure group were divided into two groups,namely NYHA cardiac function grade Ⅰ group（58 cases）and NYHA cardiac function grade Ⅱ group（42 cases）.Age,gender,height,weight,smoking history,drinking history,history of hypertension,history of diabetes mellitus,heart rate,systolic blood pressure,diastolic blood pressure,medication,blood creatinine and other clinical data of subjects in the heart failure group and the control group were collected to calculate body mass index（BMI）.All subjects performed cardiopulmonary exercise test with power bicycle as the exercise mode according to the treadmill exercise program of 10 watts per minute,completed the most symptomatic limited exercise,obtained the peak oxygen uptake,and recorded the main reason for the termination of cardiopulmonary exercise test to determine the peak oxygen uptake.Obey the normal distribution of measurement data with±s,,compares the single factor analysis of variance between groups.The measurement data of non-normal distribution were expressed by M（Q25-Q75）and the chi-square test was used for comparison between groups.The rate of counting data was expressed,and chi-square test was used for comparison between groups.Univariate anova was used to compare the Peak VO₂ and LVEF between the heart failure group and the control group.Similarly,one-way anova was used to compare the Peak VO₂and LVEF of patients in NYHA level Ⅰ group with those in NYHA level Ⅱ group.Pearson correlation analysis was used to examine the correlation between left ventricular ejection fraction and peak oxygen uptake in the heart failure group,and to explore whether peak oxygen uptake can be used to evaluate the condition of patients with chronic heart failure.To determine the main reasons for the termination of cardiopulmonary exercise test and their respective proportions,and to discuss the safety of cardiopulmonary exercise test to determine the peak oxygen uptake in patients with chronic heart failure.Results 1.There were no significant differences in age,gender and BMI between the heart failure group and the control group（P>0.05）.2.Peak VO₂ and LVEF were statistically different between the heart failure group and the control group（P<0.05）.3.Peak VO₂ was significantly different between NYHA group Ⅰ and NYHA group Ⅱ（P<0.05）,while LVEF was not significantly different（P>0.05）.4.Pearson correlation analysis showed that there was a correlation between peak oxygen uptake and left ventricular ejection fraction in the heart failure group（R=0.604,P<0.01）,and the correlation between peak oxygen uptake and left ventricular ejection fraction was higher after adjusting for age,gender and body mass index（R=0.668,P<0.01）.5.Reasons for the termination of cardiopulmonary exercise test to determine the peak oxygen uptake in the heart failure group included:fatigue in 53 cases（53%）,soreness in 3 cases（3%）,dyspnea in 19 cases（19%）,palpitations in 11 cases（11%）,and chest tightness in 14 cases（14%）.Ⅰn the control group,the main reasons for the termination of cardiopulmonary exercise test that measured the peak oxygen uptake were:fatigue in 88 cases（88%）,soreness in both lower limbs in 4 cases（4%）,and palpitations in 8 cases（8%）.Conclusions 1.There is a correlation between Peak VO₂ and LVEF in patients with chronic heart failure.Peak VO₂ can objectively and quantitatively evaluate the cardiac function of patients with chronic heart failure.2.Ⅰt is safe and feasible to measure the peak oxygen uptake by cardiopulmonary exercise test in patients with chronic heart failure.