Poor Relationship Between Exercise Capacity and Spirometric Measurements in Patients With More Symptomatic Heart Failure

In aged-matched controls with no MSHD, spirometric variables (FEV1/FVC) explain 18% to 25% of the variance in pV˙O2, and 16% to 18% of the variance in patients with NYHA class I-II symptoms. As symptoms worsen, the influence of spirometric variables on peak exercise capacity diminishes, and there is no such relation in the NYHA class III-IV patients.