New Findings What is the central question of this study?The study aimed to establish a novel model to study the chronic obstructive pulmonary disease (COPD)‐related cardiopulmonary effects of dynamic hyperinflation in healthy subjects. What is the main finding and its importance?A model of expiratory resistance breathing (ERB) was established in which dynamic hyperinflation was induced in healthy subjects, expressed both by lung volumes and intrathoracic pressures. ERB outperformed existing methods and represents an efficacious model to study cardiopulmonary mechanics of dynamic hyperinflation without potentially confounding factors as present in COPD. Abstract Dynamic hyperinflation (DH) determines symptoms and prognosis of chronic obstructive pulmonary disease (COPD). The induction of DH is used to study cardiopulmonary mechanics in healthy subjects without COPD‐related confounders like inflammation, hypoxic vasoconstriction and rarefication of pulmonary vasculature. Metronome‐paced tachypnoea (MPT) has proven effective in inducing DH in healthy subjects, but does not account for airflow limitation. We aimed to establish a novel model incorporating airflow limitation by combining tachypnoea with an expiratory airway stenosis. We investigated this expiratory resistance breathing (ERB) model in 14 healthy subjects using different stenosis diameters to assess a dose–response relationship. Via cross‐over design, we compared ERB to MPT in a random sequence. DH was quantified by inspiratory capacity (IC, litres) and intrinsic positive end‐expiratory pressure (PEEPi, cmH2O). ERB induced a stepwise decreasing IC (means (95% CI): tidal breathing: 3.66 (3.45–3.88), ERB 3 mm: 3.33 (1.75–4.91), 2 mm: 2.05 (0.76–3.34), 1.5 mm: 0.73 (0.12–1.58) litres) and increasing PEEPi (tidal breathing: 0.70 (0.50–0.80), ERB 3 mm: 11.1 (7.0–15.2), 2 mm: 22.3 (17.1–27.6), 1.5 mm: 33.4 (3.40–63) cmH2O). All three MPT patterns increased PEEPi, but to a far lesser extent than ERB. No adverse events during ERB were noted. In conclusion, ERB was proven to be a safe and efficacious model for the induction of DH and might be used for the investigation of cardiopulmonary interaction in healthy subjects.
Background Targeted lung denervation (TLD) is a novel bronchoscopic therapy that disrupts parasympathetic pulmonary nerve input to the lung reducing clinical consequences of cholinergic hyperactivity. The AIRFLOW-1 study assessed safety and TLD dose in patients with moderate-to-severe, symptomatic COPD. This analysis evaluated the long-term impact of TLD on COPD exacerbations, pulmonary function, and quality of life over 3 years of follow up. Methods TLD was performed in a prospective, energy-level randomized (29 W vs 32 W power), multicenter study (NCT02058459). Additional patients were enrolled in an open label confirmation phase to confirm improved gastrointestinal safety after procedural modifications. Durability of TLD was evaluated at 1, 2, and 3 years post-treatment and assessed through analysis of COPD exacerbations, pulmonary lung function, and quality of life. Results Three-year follow-up data were available for 73.9% of patients (n = 34). The annualized rate of moderate to severe COPD exacerbations remained stable over the duration of the study. Lung function (FEV1, FVC, RV, and TLC) and quality of life (SGRQ-C and CAT) remained stable over 3 years of follow-up. No new gastrointestinal adverse events and no unexpected serious adverse events were observed. Conclusion TLD in COPD patients demonstrated a positive safety profile out to 3 years, with no late-onset serious adverse events related to denervation therapy. Clinical stability in lung function, quality of life, and exacerbations were observed in TLD treated patients over 3 years of follow up.
Background and Objectives: Patients with chronic obstructive pulmonary disease (COPD) are at increased risk for cardiovascular disease. This study aimed to investigate the relationship between pulmonary hyperinflation and baroreceptor reflex sensitivity (BRS), a surrogate for cardiovascular risk.Methods: 33 patients with COPD, free from clinical cardiovascular disease, and 12 healthy controls were studied. Participants underwent pulmonary function and non-invasive hemodynamic measurements. BRS was evaluated using the sequence method during resting conditions and mental arithmetic stress testing.Results: Patients with COPD had evidence of airflow obstruction [forced expiratory volume in 1 s predicted (FEV1%) 26.5 (23.3–29.1) vs. 91.5 (82.8–100.8); P < 0.001; geometric means (GM) with 95% confidence interval (CI)] and lung hyperinflation [residual volume/total lung capacity (RV/TLC) 67.7 (64.3–71.3) vs. 41.0 (38.8–44.3); P < 0.001; GM with 95% CI] compared to controls. Spontaneous mean BRS (BRSmean) was significantly lower in COPD, both during rest [5.6 (4.2–6.9) vs. 12.0 (9.1–17.6); P = 0.003; GM with 95% CI] and stress testing [4.4 (3.7–5.3) vs. 9.6 (7.7–12.2); P < 0.001; GM with 95% CI]. Stroke volume (SV) was significantly lower in the patient group [−21.0 ml (−29.4 to −12.6); P < 0.001; difference of the means with 95% CI]. RV/TLC was found to be a predictor of BRS and SV (P < 0.05 for both), independent of resting heart rate.Conclusion: We herewith provide evidence of impaired BRS in patients with COPD. Hyperinflation may influence BRS through alteration of mechanosensitive vagal nerve activity.
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