Correlation Between Noninvasive Hemodynamic Parameters And Reduced Cardiogenic Exercise Tolerance In Middle-aged And Elderly Patients With Stage A And B Heart Failure

Objective:We aimed to find some clinical factors associated with reduced cardiogenic exercise tolerance in middle-aged and elderly patients with stage A and B heart failure and investigate the relationship between noninvasive hemodynamic parameters and reduced cardiogenic exercise tolerance.Methods:In this study,one hundred ninety-seven patients with stage A and stage B heart failure were enrolled sequentially.The study subjects were divided into the exercise tolerance normal group（ETN）and the exercise tolerance reduced group（ETD）,based on the weight-corrected peak oxygen uptake(Peak Vo₂≥20 ml·kg^-1·min^-1)measured by the CPET.The two groups were compared and differences in general clinical data,CPET values,transthoracic color Doppler ultrasonography measures,and hemodynamic parameters were noted.Results:In comparison to the ETN group,the ETD group had larger percentages of women,co-morbidity,age,body mass index（BMI）,and B-type natriuretic peptide（BNP）as well as higher rates of ACEI/ARB and beta-blocker usage（P<0.05）.In CPET parameters,arterial-venous oxygenation difference（AVO₂diff）at rest was similar in both groups（P>0.05）.And in the ETD group,the percentage of chronotropic incompetence（CI）was greater,the peak O₂pulse was considerably lower,and the breath reserve（BR）was significantly higher（P<0.05）.Only the left ventricular mass index（LVMI）and median left ventricular mass/left ventricular end-diastolic volume（LVM/LVEDV）were larger（1.72 g/ml vs 1.61 g/ml）in the ETD group compared to the ETN group（P<0.05）among cardiac structure and function measures.Among hemodynamic parameters,the ETD group was significantly different from the ETN group in peak pulmonary valve antegrade velocity（PV max）,early mitral flow peak velocities to mitral annular mean velocities（E/e’）,brachial pulse pressure（b PP）,systemic vascular resistance index（SVRI）,total arterial compliance index（TACI）,left ventricular relaxation time constant（Tau）,and LVEDV index（LVEDVI）/E/e’（P<0.05）.After adjusting for confounding variables,a linear regression analysis revealed that sex,age,BMI,co-morbidity,Beta-blocker,CI,PV max,and LVEDVI/E/e’were distinct factors of exercise tolerance（P<0.05）,adjusted for R²=0.506.Reduced exercise tolerance was analyzed using logistic regression,and LVMI,PV max,and LVEDVI/E/e’were independent factors after adjusting for confounding factors（P<0.05）.The OR values of LVMI,PV max and LVEDVI/E/e’were1.033（95%CI:1.009 to 1.057,P=0.006）,0.757（95%CI:0.602 to 0.953,P=0.018）and 0.682（95%CI:0.533 to 0.874,P=0.002）.And the regression model（Model）was established,adjusted R²=0.433.And ROC curve analysis of LVMI,PV max,LVEDVI/E/e’and Model to predict reduced exercise tolerance showed that the AUC for the Model was 0.838（95%CI 0.783 to 0.894,P<0.0001）,with a sensitivity of 82.4%and a specificity of 73.0%,while the AUC for LVEDVI/E/e’was 0.666（95%CI 0.590 to0.742,P<0.0001）,with a 38.2%sensitivity and a better specificity of 89.8%.The areas under the curves for LVMI and PV max were 0.615 and 0.611,respectively（P<0.01）.Also,LVEDVI/E/e’had the best correlation with Peak Vo₂（r=0.368,P<0.0001）.LVMI and PV max were（r=﹣0.227,P=0.001）and（r=0.209,P=0.003）,respectively.To further verify the association between LVEDVI/E/e’and exercise intolerance,grouping of subjects by optimal cut-off value（6.513）,and the group with LVEDVI/E/e’>6.513showed better exercise performance,lower exercise intolerance compared with LVEDVI/E/e’<6.513（P<0.05）.Conclusions:Reduced exercise tolerance is associated with early hemodynamic alterations（abnormal cardiac diastole and increased arterial load）.An index of left ventricular compliance（LVEDVI/E/e’）at rest may serve as a noninvasive marker for identification of carefully reduced cardiogenic exercise tolerance in patients with stage A and B heart failure.