Lung Hyperinflation Beyond COPD is Associated With Proxies of Systemic Fluid Overload and Functional Impairment in...

The role of hyperinflation in patients with heart failure (HF) remains poorly characterized. It may contribute to fluid overload (FO) and impaired cardiopulmonary function. We aimed to assess the relationship between hyperinflation and proxies of FO and functional capacity in patients with chronic HF.

In this prospective study, 144 stable ambulatory HF patients underwent body plethysmography for assessment of static hyperinflation. FO was evaluated using a combination of clinical examination, ultrasound imaging, and circulating markers. Functional capacity was assessed by distance walked in 6min (6MWT). The relationships between hyperinflation assessed by the inspiratory capacity/total lung capacity (IC/TLC) ratio and the endpoints were analyzed using multivariable logistic and linear regression models.

The mean age was 72.8±9.7 years, 108 (75%) were men, 125 (86.8%) had NYHA class II, 71 (49.3%) had preserved ejection fraction, and 46 (30.9%) had COPD (predominantly mild). The mean IC/TLC was 0.37±0.11. Lower IC/TLC was independently associated with several markers of systemic congestion, including jugular engorgement, venous renal congestion, and higher plasmatic levels of carbohydrate antigen 125, and shorter 6MWT. Risk of orthopnea, bendopnea, ultrasound pulmonary congestion, peripheral edema, and higher levels of NT-proBNP did not differ across IC/TLC. These associations remained significant after adjustment for COPD status and other confounders.

In ambulatory HF patients, lower IC/TLC, a proxy of hyperinflation, was associated with some clinical, imaging, and circulating proxies of FO, independent of COPD diagnosis. Additionally, lower IC/TLC identified patients with lower 6MWT.