RESUMO
Objective:To investigate the characteristics of cardiopulmonary exercise testing, and to explore the clinical value of midregional pro-atrial natriuretic peptide(MR-proANP)in elderly heart failure(HF)patients with preserved ejection fraction(HFpEF).Methods:A total of 56 elderly HFpEF patients with New York Heart Association(NYHA)cardiac function class Ⅱ-Ⅲ at our hospital from January 2019 to June 2019 were successively recruited into the HF group, and 49 healthy individuals who took health examinations during the same period were enrolled as the control group.All subjects underwent cardiopulmonary exercise testing.Plasma was collected at rest before exercise for the measurement of MR-proANP and N-terminal B-type natriuretic peptide(NT-proBNP).Results:NT-proBNP and MR-proANP levels were higher in the HF group than in the control group[375(236-541)ng/L vs.31(22-130)ng/L, 78(52-215)pmol/L vs.14(10-23)pmol/L, P<0.05]. MR-proANP levels were higher in HF patients with NHYA class Ⅲ(n=23)than in HF patients with NHYA class Ⅱ(n=33)[228(121-436)pmol/L vs.60(50-92)pmol/L, χ2=0.256, P<0.01], while NT-proBNP levels showed no significant difference between the two subgroups[375(245-743)ng/L vs.382(220-540)ng/L, χ2=10.949, P>0.05]. Compared with the control group, the anaerobic threshold, peak exercise oxygen consumption(peak VO 2), peak VO 2 as percentage of predicted value(peak VO2%pred)and peak oxygen pulse were lower in the HF group( P<0.05), and VE/VCO 2 slope was higher in the HF group( P<0.05). Pearson analysis showed that MR-proANP and NT-proBNP were negatively correlated with anaerobic threshold, peak VO 2, peak VO 2%pred, and peak oxygen pulse( P<0.05), and positively correlated with the VE/VCO 2 slope( P<0.05). MR-proANP had the highest correlation with peak VO 2( r=0.791). Conclusions:Compared with healthy subjects, exercise tolerance and oxygen uptake capacity are lower in elderly HFpEF patients, indicating that their cardiopulmonary reserve function is reduced, .Plasma levels of MR-proANP can reflect the state of cardiac function in HFpEF patients with NYHA class Ⅱ~Ⅲ and can better evaluate the condition of patients.