Impact of the research: Although bilateral phrenic nerve stimulation did not increase the proportion of successful weaning from mechanical ventilation compared to the standard of care, it resulted in substantial improvements in inspiratory pressure generation capacity without major safety issues. In the absence of previous clinical data, these findings suggest that diaphragm pacing could be effective in mitigating diaphragm dysfunction in patients difficult to wean from mechanical ventilation. Author contributions:The academic authors (MD, MGDA, TS) wrote the first draft of the manuscript and verified the underlying data. All authors critically reviewed and approved the manuscript and are accountable its accuracy and integrity. Dr Martin Dres had full access to all the data in the study and takes full responsibility for the integrity of the data and the accuracy of the data analysis. Teresa Nelson conducted and is responsible for the data analysis. Support:The study was funded by Lungpacer Medical Inc, PA, USA.

No abstract

BACKGROUND: In patients with pulmonary arterial hypertension who have an insufficient response to oral or inhaled therapies, current guidelines recommend the use of parenteral prostacyclin analogues, although the efficacy of this approach is unknown. METHODS: This retrospective multicenter study evaluated patients with pulmonary arterial hypertension who received intravenous treprostinil as an add-on therapy. The risk at baseline and follow-up (6−12 months after the initiation of treprostinil) was classified as low, intermediate, or high according to current recommendations. The outcome was measured as transplant-free survival after the initiation of treprostinil therapy. RESULTS: A total of 126 patients were analyzed, almost all of them pre-treated with combinations of other pulmonary arterial hypertension medications. Before the initiation of intravenous treprostinil, 2 (2%) patients had a low-risk profile; 100 (79%), an intermediate-risk profile; and 24 (19%), a highrisk profile. At follow-up, 24 (19%) patients were classified as low-risk. These patients had a 5-year transplant-free survival rate >90%. In contrast, patients who remained at intermediate or high risk had transplant-free survival rates of 76%, 43%, and 28% at 1, 3, and 5 years, respectively. Failure to reach a low risk at follow-up was an independent predictor of transplant-free survival (hazard ratio, 9.25; 95% confidence interval, 1.20−71.60; p = 0.033 1). CONCLUSIONS: Risk assessment at 6−12 months after the initiation of add-on intravenous treprostinil in patients with an insufficient response to nonparenteral treatments allows the prediction of transplantfree survival over the ensuing years. Achieving a low-risk profile is associated with excellent outcomes, whereas mortality is high in patients who remain at intermediate or high risk.

<b><i>Introduction:</i></b> Chronic obstructive pulmonary disease (COPD) is one of the most common chronic diseases associated with high mortality. Previous studies suggested a prognostic role for peak oxygen uptake (VO₂peak) assessed during cardiopulmonary exercise testing (CPET) in patients with COPD. However, most of these studies had small sample sizes or short follow-up periods, and despite their relevance, CPET parameters are not included in the Global Initiative for Chronic Obstructive Lung Disease (GOLD) tool for assessment of severity. <b><i>Objectives:</i></b> We therefore aimed to assess the prognostic value of CPET parameters in a large cohort of outpatients with COPD. <b><i>Methods:</i></b> In this retrospective, multicentre cohort study, medical records of patients with COPD who underwent CPET during 2004–2017 were reviewed and demographics, smoking habits, GOLD grade and category, exacerbation frequency, dyspnoea score, lung function measurements, and CPET parameters were documented. Relationships with survival were evaluated using Kaplan-Meier analysis, Cox regression, and receiver operating characteristic (ROC) curves. <b><i>Results:</i></b> Of a total of 347 patients, 312 patients were included. Five-year and 10-year survival probability was 75% and 57%, respectively. VO₂peak significantly predicted survival (hazard ratio: 0.886 [95% confidence interval: 0.830; 0.946]). The optimal VO₂peak threshold for discrimination of 5-year survival was 14.6 mL/kg/min (area under ROC curve: 0.713). Five-year survival in patients with VO₂peak &#x3c;14.6 mL/kg/min versus ≥ 14.6 mL/kg/min was 60% versus 86% in GOLD categories A/B and 64% versus 90% in GOLD categories C/D. <b><i>Conclusions:</i></b> We confirm that VO₂peak is a highly significant predictor of survival in COPD patients and recommend the incorporation of VO₂peak into the assessment of COPD severity.

No abstract