VE/VCO2 slope in cardiopulmonary exercise testing was associated with left ventricular diastolic dysfunction in patients with reduced ejection fraction

Abstract

Abstract Background Heart failure with reduced ejection fraction (EF) was well-known as a poor prognosis. VE/VCO2 slope and peak oxygen uptake (VO2) by cardiopulmonary exercise testing (CPET) is a useful parameter for predicting cardiovascular disease prognosis. Furthermore, though there are some reports that CPET parameters are associated with indicators of diastolic dysfunction, each of these indicators has some limitations. Recently, recommendations for the evaluation of left ventricular diastolic function by echocardiography were reported from the ASE/EACVI. However, there are no reports to examine the association between exercise tolerance indices and diastolic dysfunction based on these recommended variables. Purpose To examine the relationship between CPET parameters and diastolic dysfunction using the recommendation from ASE/EACVI in cardiovascular diseases patients with reduced EF Methods We recruited 214 patients who performed both CPET and echocardiography. EF<50% was 115 patients. All patients underwent 0W warm-up and 10W ramp on an upright electrical bicycle ergometer. We defined peak VO2<14 ml/min/kg as low peak VO2, and VE/VCO2>34 as high VE/VCO2 slope. Diastolic dysfunction was assessed using the recommendations for the evaluation of diastolic function by ASE/EACVI. We used this recommendation algorithm to estimate grading LV diastolic function in patients with depressed LVEF. Grading 3 shows the most severe diastolic dysfunction. Results Mean age was 55±15 years old, and the portion of women was 30%. The portion of Grading 3 diastolic dysfunction was 18%. In univariable logistic regression analysis for diastolic dysfunction, Log BNP, and high VE/VCO2 slope were significantly associated with diastolic dysfunction. In multivariable logistic regression analysis, each Model, LogBNP and high VE/VCO2 slope were independent factors for severe diastolic dysfunction [adjusted age and sex, Model 1: LogBNP (OR 2.42, CI 1.44-4.05, p<0.001), low PeakVO2. Model2: LogBNP (OR 2.23, CI 1.31-3.78, p=0.003), high VE/VCO2 slope (OR 3.30, CI 1.06-10.3, p=0.039)]. We performed receiver operating characteristics (ROC) curve analysis on the ability of BNP, and VE/VCO2 slope. The area under the ROC curve (AUC) for BNP was 0.77, with the discriminating sensitivity and specificity at 0.67 and 0.86, respectively (cut-off value 234 pg/mL). On the other hand, the AUC for the high VE/VCO2 slope was 0.75, with the discriminating sensitivity and specificity at 0.81 and 0.67, respectively (cut-off value 30). Conclusion In patients with depressed EF, high VE/VCO2 slope was significantly associated with diastolic dysfunction assessed by the recommendations from the ASE/EACVI.