Relação da Função Pulmonar e da Força Inspiratória com Capacidade Aeróbica e com Prognóstico na Insuficiência Cardíaca

Background Spirometry is underused in heart failure (HF) and the extent to which each defect associates with exercise capacity and prognosis is unclear.Objective To determine the distinct relationship of continuous %predicted FVC (ppFVC) and FEV₁/FVC with: 1) maximal inspiratory pressure (MIP), left ventricular ejection fraction (LVEF), exercise performance; and 2) prognosis for the composite of cardiovascular death, heart transplantation or left ventricular assist device implant.Methods A cohort of 111 HF participants (AHA stages C/D) without diagnosed pneumopathy, spirometry, manovacuometry and maximum cardiopulmonary test. The association magnitudes were verified by linear and Cox (HR; 95% CI) regressions, age/sex adjusted. A p<0.05 was considered significant.Results Age was 57±12 years, 60% men, 64% in NYHA III. Every 10%-point increase in FEV₁/FVC [β 7% (95% CI: 3–10)] and ppFVC [4% (2-6)] associated with ventilatory reserve (VRes), however only ppFVC associated with MIP [3.8 cmH₂O (0.3-7.3)], LVEF [2.1% (0.5-3.8)] and VO₂peak [0.5 mL/kg/min (0.1–1.0)], accounting for age/sex. In 2.2 years (mean), 22 events occurred, and neither FEV₁/FVC (HR 1.44; 95% CI: 0.97–2.13) nor ppFVC (HR 1.13; 0.89–1.43) was significantly associated with the outcome. Only in the LVEF ≤50% subgroup (n=87, 20 events), FEV₁/FVC (HR 1.50; 1.01–2.23), but not ppFVC, was associated with greater risk.Conclusions In chronic HF, reduced ppFVC associated with lower MIP, LVEF, VRes and VO₂peak, but no distinct poorer prognosis over 2.2 years of follow-up. Distinctively, FEV₁/FVC was associated only with VRes, and, in participants with LVEF ≤50%, FEV₁/FVC reduction proportionally worsened prognosis. Therefore, FEV₁/FVC and ppFVC add supplementary information regarding HF phenotyping.