Background: Patients with fibrotic interstitial lung disease (FILD) often experience gas exchange abnormalities and ventilatory limitations, resulting in reduced exercise capacity. High-flow nasal cannula (HFNC) oxygen therapy is a novel treatment, whose physiological beneficial effects have been demonstrated in various clinical settings. We hypothesized that HFNC oxygen therapy might be superior to conventional oxygen therapy for improving exercise capacity in FILD patients. Methods: We performed a prospective randomized controlled crossover trial with a high-intensity constant work-rate endurance test (CWRET) using HFNC (50 L/min, FiO₂ 0.5) and a venturi mask (VM) (15 L/min, FiO₂ 0.5) for oxygen delivery in FILD patients. The primary outcome variable was endurance time. The secondary outcome variables were SpO₂, heart rate, Borg scale (dyspnea and leg fatigue), and patient’s comfort. Results: Seven hundred and eleven patients were screened and 20 eligible patients were randomized. All patients completed the trial. The majority of patients were good responders to VM and HFNC compared with the baseline test (VM 75%; HFNC 65%). There was no significant difference in endurance time between HFNC and VM (HFNC 6.8 [95% CI 4.3–9.3] min vs VM 7.6 [95% CI 5.0–10.1] min, p = 0.669). No significant differences were found in other secondary endpoints. Subgroup analysis with HFNC good responders revealed that HFNC significantly extended the endurance time compared with VM (VM 6.4 [95%CI 4.5–8.3] min vs HFNC 7.8 [95%CI 5.8–9.7] min, p = 0.046), while no similar effect was observed in the VM good responders. Conclusions: HFNC did not exceed the efficacy of VM on exercise capacity in FILD, but it may be beneficial if the settings match. Further large studies are needed to confirm these findings. Trial registration: UMIN-CTR: UMIN000021901.

Pulmonary hypertension (PH) can develop in connective tissue disease associated interstitial lung disease (CTD-ILD), and contributes to increased morbidity and mortality. However, except for systemic sclerosis and mixed connective tissue disease, the impact of mean pulmonary arterial pressure (MPAP) on survival in CTD-ILD has not been sufficiently elucidated. We hypothesized that pulmonary arterial pressure may be a prognostic factor in CTD-ILDs regardless of the kind of CTD. We evaluated the survival impact of MPAP, which is measured using right heart catheterization, on survival of patients with CTD-ILD with various CTD backgrounds. We retrospectively analyzed data of consecutive CTD-ILD patients undergoing a pulmonary function test and right-heart-catheterization at the initial evaluation. We studied 74 patients (33 men and 41 women, mean age 62.8 ± 9.6, 24 with rheumatoid arthritis, 14 with systemic sclerosis, 14 with polymyositis/dermatomyositis, 11 with primary Sjögren’s syndrome, and 11 with other diagnoses). Six patients exhibited pulmonary hypertension (MPAP ≥ 25 mmHg), and 16 (21.6 %) had mild elevation of MPAP (≥20 mmHg). The mean MPAP was 17.2 ± 5.5 mmHg. We did not observe a significant difference in MPAP among various CTDs. A univariate Cox proportional hazard model showed that MPAP has a significant impact on survival, while the type of CTD did not contribute to survival in our cohort. A multivariate Cox proportional hazard model showed MPAP (HR = 1.087; 95 % CI 1.008–1.172; p = 0.030) to be the sole independent determinant of survival. Mild elevation of MPAP is relatively common in CTD-ILD patients with various CTD backgrounds. A higher MPAP at the initial evaluation was a significant independent predictor of survival in CTD-ILD. MPAP evaluation provides additional information on disease status and will help physicians predict mortality in CTD-ILD.

Molnupiravir (MOV) and nirmatrelvir/ritonavir (NMV/r) are efficacious oral antiviral agents for patients with the 2019 coronavirus (COVID-19). However, little is known about their effectiveness in older adults and those at high risk of disease progression. This retrospective single-center observational study assessed and compared the outcomes of COVID-19 treated with MOV and NMV/r in a real-world community setting. We included patients with confirmed COVID-19 combined with one or more risk factors for disease progression from June to October 2022. Of 283 patients, 79.9% received MOV and 20.1% NMV/r. The mean patient age was 71.7 years, 56.5% were men, and 71.7% had received ≥3 doses of vaccine. COVID-19-related hospitalization (2.8% and 3.5%, respectively; p = 0.978) or death (0.4% and 3.5%, respectively; p = 0.104) did not differ significantly between the MOV and NMV/r groups. The incidence of adverse events was 2.7% and 5.3%, and the incidence of treatment discontinuation was 2.7% and 5.3% in the MOV and NMV/r groups, respectively. The real-world effectiveness of MOV and NMV/r was similar among older adults and those at high risk of disease progression. The incidence of hospitalization or death was low.