The role of pulmonary function in patients with heart failure and preserved ejection fraction: Looking beyond chronic obstructive pulmonary disease

Background The prognostic value of chronic obstructive pulmonary disease (COPD) as a comorbidity in heart failure has been well documented. However, the role of pulmonary function indices in patients with heart failure and preserved ejection fraction (HFpEF) remains to be elucidated. Methods Subjects with HFpEF received pulmonary function tests and echocardiogram. Total lung capacity (TLC), residual volume (RV), forced expiratory flow rate between 25% and 75% of vital capacity (FEF25-75), forced expiratory volume in the 1(st)second (FEV1), forced vital capacity (FVC), and vital capacity (VC) were measured. Echocardiographic indices, including pulmonary artery systolic pressure (PASP), the ratio of early ventricular filling flow velocity to the septal mitral annulus tissue velocity (E/e'), and left ventricular mass (LVM), were recorded. National Death Registry was linked for the identification of mortality. Results A total of 1194 patients (72.4 +/- 13.2 years, 59% men) were enrolled. PASP, E/e' and LVM were associated with either obstructive (RV/TLC, FEV1 and FEF25-75) or restrictive (VC and TLC) ventilatory indices. During a mean follow-up of 23.0 +/- 12.8 months, 182 patients died. Subjects with COPD had a lower survival rate than those without COPD. While VC, FVC, RV/TLC, and FEV1 were all independently associated with all-cause mortality in patients without COPD, only FEF25-75 was predictive of outcomes in those with COPD. Conclusions The abnormalities of pulmonary function were related to the cardiac hemodynamics in patients with HFpEF. In addition, these ventilatory indices were independently associated with long-term mortality, especially in those without COPD.