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Dual combination therapy with a phosphodiesterase-5 inhibitor (PDE5i) and endothelin receptor antagonist is recommended for most patients with intermediate-risk pulmonary arterial hypertension (PAH). The RESPITE and REPLACE studies suggest that switching from a PDE5i to a soluble guanylate cyclase (sGC) activator may provide clinical improvement in this situation. The optimal approach to escalation or transition of therapy in this or other scenarios is not well defined. We developed an expert consensus statement on the transition to sGC and other treatment escalations and transitions in PAH using a modified Delphi process. The Delphi process used a panel of 20 physicians with expertise in PAH. Panelists answered three questionnaires on the management of treatment escalations and transitions in PAH. The initial questionnaire included open-ended questions. Later questionnaires consolidated the responses into statements that panelists rated on a Likert scale from -5 (strongly disagree) to +5 (strongly agree) to determine consensus. The Delphi process produced several consensus recommendations. Escalation should be considered for patients who are at high risk or not achieving treatment goals, by adding an agent from a new class, switching from oral to parenteral prostacyclins, or increasing the dose. Switching to a new class or within a class should be considered if tolerability or other considerations unrelated to efficacy are affecting adherence. Switching from a PDE5i to an SGC activator may benefit patients with intermediate risk who are not improving on their present therapy. These consensus-based recommendations may be helpful to clinicians and beneficial for patients when evidence-based guidance is unavailable.

The existing coverage criteria for home noninvasive ventilation (NIV) do not recognize the diversity of hypoventilation syndromes and advances in technologies. This document summarizes the work of the hypoventilation syndromes Technical Expert Panel working group. The most pressing current coverage barriers identified were: (1) overreliance on arterial blood gases (particularly during sleep); (2) need to perform testing on prescribed oxygen; (3) requiring a sleep study to rule out OSA as the cause of sustained hypoxemia; (4) need for spirometry; (5) need to show bilevel positive airway pressure (BPAP) without a backup rate failure to qualify for BPAP spontaneous/timed; and (6) qualifying hospitalized patients for home NIV therapy at the time of discharge. Critical evidence support for changes to current policies includes randomized controlled trial evidence and clinical practice guidelines. To decrease morbidity and mortality by achieving timely access to NIV for patients with hypoventilation, particularly those with obesity hypoventilation syndrome, we make the following key suggestions: (1) given the significant technological advances, we advise acceptance of surrogate noninvasive end-tidal and transcutaneous Pco2 and venous blood gases in lieu of arterial blood gases; (2) not requiring Pco2 measures while on prescribed oxygen; (3) not requiring a sleep study to avoid delays in care in patients being discharged from the hospital; (4) remove spirometry as a requirement; and (5) not requiring BPAP without a backup rate failure to approve BPAP spontaneous/timed. The overarching goal of the Technical Expert Panel is to establish pathways that improve clinicians' management capability to provide Medicare beneficiaries access to appropriate home NIV therapy. Adoption of these proposed suggestions would result in the right device, for the right type of patient with hypoventilation syndromes, at the right time.

This document summarizes suggestions of the central sleep apnea (CSA) Technical Expert Panel working group. This paper shares our vision for bringing the right device to the right patient at the right time. For patients with CSA, current coverage criteria do not align with guideline treatment recommendations. For example, CPAP and oxygen therapy are recommended but not covered for CSA. On the other hand, bilevel positive airway pressure (BPAP) without a backup rate may be a covered therapy for OSA, but it may worsen CSA. Narrow coverage criteria that require near elimination of obstructive breathing events on CPAP or BPAP in the spontaneous mode, even if at poorly tolerated pressure levels, may preclude therapy with BPAP with backup rate or adaptive servoventilation, even when those devices provide demonstrably better therapy. CSA is a dynamic disorder that may require different treatments over time, sometimes switching from one device to another; an example is switching from BPAP with backup rate to an adaptive servoventilation with automatic end-expiratory pressure adjustments, which may not be covered. To address these challenges, we suggest several changes to the coverage determinations, including: (1) a single simplified initial and continuing coverage definition of CSA that aligns with OSA; (2) removal of hypoventilation terminology from coverage criteria for CSA; (3) all effective therapies for CSA should be covered, including oxygen and all PAP devices with or without backup rates or servo-mechanisms; and (4) patients shown to have a suboptimal response to one PAP device should be allowed to add oxygen or change to another PAP device with different capabilities if shown to be effective with testing.

The current national coverage determinations (NCDs) for noninvasive ventilation for patients with thoracic restrictive disorders, COPD, and hypoventilation syndromes were formulated in 1998. New original research, updated formal practice guidelines, and current consensus expert opinion have accrued that are in conflict with the existing NCDs. Some inconsistencies in the NCDs have been noted, and the diagnostic and therapeutic technology has also advanced in the last quarter century. Thus, these and related NCDs relevant to bilevel positive airway pressure for the treatment of OSA and central sleep apnea need to be updated to ensure the optimal health of patients with these disorders. To that end, the American College of Chest Physicians organized a multisociety (American Thoracic Society, American Academy of Sleep Medicine, and American Association for Respiratory Care) effort to engage experts in the field to: (1) identify current barriers to optimal care; (2) highlight compelling scientific evidence that would justify changes from current policies incorporating best evidence and practice; and (3) propose suggestions that would form the basis for a revised NCD in each of these 5 areas (thoracic restrictive disorders, COPD, hypoventilation syndromes, OSA, and central sleep apnea). The expert panel met during a 2-day virtual summit in October 2020 and subsequently crafted written documents designed to achieve provision of "the right device to the right patient at the right time." These documents have been endorsed by the participating societies following peer review and publication in CHEST and will be used to inform efforts to revise the current NCDs.

This document summarizes the work of the CPAP and bilevel PAP therapy for OSA Technical Expert Panel working group. For positive airway pressure (PAP) therapy, the most pressing current coverage barriers identified were: an insufficient symptom list describing all potential symptoms in patients with mild OSA; the 4 h per night of PAP usage requirement to keep the device; the additional sleep studies requirement to re-qualify for PAP or supplemental oxygen; and the inability to use telehealth visits for follow-up visits. Critical evidence supports changes to current policies and includes: symptom list inadequate to cover all scenarios based on updated clinical practice guidelines; published evidence that 2 h per night of PAP use can result in benefit to quality of life and other metrics; the costs of another sleep study not justified for all nonadherent patients or for supplemental oxygen due to other types of assessment currently available; and the remarkable success and acceptance of telehealth visits. To achieve optimal access for patients on PAP therapy, we make the following key suggestions: removing symptom criteria for mild OSA; reduce continued coverage criteria to > 2 h per night; eliminate the need for a sleep study to re-qualify if nonadherent or for new Centers for Medicare & Medicaid Services beneficiaries already on and adherent to PAP therapy; allow telehealth visits for documenting benefit and adherence; and allow PAP reports and domiciliary oximetry to qualify for supplemental oxygen with PAP if needed. This paper shares our best vision for bringing the right device to the right patient at the right time.

This document summarizes the work of the COPD Technical Expert Panel working group. For patients with COPD, the most pressing current coverage barriers identified were onerous diagnostic requirements focused on oxygenation (rather than ventilation) and difficulty obtaining bilevel devices with backup rate capabilities. Because of these difficulties, many patients with COPD were instead sometimes prescribed home mechanical ventilators. Critical evidence supports changes to current policies, including randomized controlled trial evidence suggesting a mortality benefit from bilevel positive airway pressure with backup rate and updated clinical practice guidelines from the American Thoracic Society as well as the European Respiratory Society. To achieve optimal access to noninvasive ventilation for patients with COPD, we make the following key recommendations: (1) removal of the need for overnight oximetry testing; (2) the ability to initiate therapy using bilevel devices with backup rate capability; and (3) increased duration of time to meet adherence criteria (ie, a second 90-day trial period) in those patients actively engaged in their care. Clear guidelines based on medical necessity are also included for patients who require initiation of or switch to a home mechanical ventilator. Adoption of these proposed recommendations would result in the right device, for the right type of patient with COPD, at the right time. Finally, we emphasize the need for adequate clinical support during initiation and maintenance of home noninvasive ventilation in such patients.

The existing coverage criteria for noninvasive ventilation (NIV) do not recognize the benefits of early initiation of NIV for those with thoracic restrictive disorders and do not address the unique needs for daytime support as the patients progress to ventilator dependence. This document summarizes the work of the thoracic restrictive disorder Technical Expert Panel working group. The most pressing current coverage barriers identified were: (1) delays in implementing NIV treatment; (2) lack of coverage for many nonprogressive neuromuscular diseases; and (3) lack of clear policy indications for home mechanical ventilation (HMV) support in thoracic restrictive disorders. To best address these issues, we make the following key recommendations: (1) given the need to encourage early initiation of NIV with bilevel positive airway pressure devices, we recommend that symptoms be considered as a reason to initiate therapy even at mildly reduced FVCs; (2) broaden CO2 measurements to include surrogates such as transcutaneous, end-tidal, or venous blood gas; (3) expand the diagnostic category to include phrenic nerve injuries and disorders of central drive; (4) allow a bilevel positive airway pressure device to be advanced to an HMV when the vital capacity is < 30% or to address severe daytime respiratory symptoms; and (5) provide additional HMV when the patient is ventilator dependent with use > 18 h per day. Adoption of these proposed recommendations would result in the right device, at the right time, for the right type of patients with thoracic restrictive disorders.

BackgroundRare genetic variants cause pulmonary arterial hypertension, but the contribution of common genetic variation to disease risk and natural history is poorly characterised. We tested for genome-wide association for pulmonary arterial hypertension in large international cohorts and assessed the contribution of associated regions to outcomes.MethodsWe did two separate genome-wide association studies (GWAS) and a meta-analysis of pulmonary arterial hypertension. These GWAS used data from four international case-control studies across 11 744 individuals with European ancestry (including 2085 patients). One GWAS used genotypes from 5895 whole-genome sequences and the other GWAS used genotyping array data from an additional 5849 individuals. Cross-validation of loci reaching genome-wide significance was sought by meta-analysis. Conditional analysis corrected for the most significant variants at each locus was used to resolve signals for multiple associations. We functionally annotated associated variants and tested associations with duration of survival. All-cause mortality was the primary endpoint in survival analyses.FindingsA locus near SOX17 (rs10103692, odds ratio 1·80 [95% CI 1·55-2·08], p=5·13 × 10-15) and a second locus in HLA-DPA1 and HLA-DPB1 (collectively referred to as HLA-DPA1/DPB1 here; rs2856830, 1·56 [1·42-1·71], p=7·65 × 10-20) within the class II MHC region were associated with pulmonary arterial hypertension. The SOX17 locus had two independent signals associated with pulmonary arterial hypertension (rs13266183, 1·36 [1·25-1·48], p=1·69 × 10-12; and rs10103692). Functional and epigenomic data indicate that the risk variants near SOX17 alter gene regulation via an enhancer active in endothelial cells. Pulmonary arterial hypertension risk variants determined haplotype-specific enhancer activity, and CRISPR-mediated inhibition of the enhancer reduced SOX17 expression. The HLA-DPA1/DPB1 rs2856830 genotype was strongly associated with survival. Median survival from diagnosis in patients with pulmonary arterial hypertension with the C/C homozygous genotype was double (13·50 years [95% CI 12·07 to >13·50]) that of those with the T/T genotype (6·97 years [6·02-8·05]), despite similar baseline disease severity.InterpretationThis is the first study to report that common genetic variation at loci in an enhancer near SOX17 and in HLA-DPA1/DPB1 is associated with pulmonary arterial hypertension. Impairment of SOX17 function might be more common in pulmonary arterial hypertension than suggested by rare mutations in SOX17. Further studies are needed to confirm the association between HLA typing or rs2856830 genotyping and survival, and to determine whether HLA typing or rs2856830 genotyping improves risk stratification in clinical practice or trials.FundingUK NIHR, BHF, UK MRC, Dinosaur Trust, NIH/NHLBI, ERS, EMBO, Wellcome Trust, EU, AHA, ACClinPharm, Netherlands CVRI, Dutch Heart Foundation, Dutch Federation of UMC, Netherlands OHRD and RNAS, German DFG, German BMBF, APH Paris, INSERM, Université Paris-Sud, and French ANR.

BACKGROUND: This study assessed the clinical effects of a ventilatory assist (VA) device in addition to supplemental O2 (VA+O2) on exercise endurance in subjects with severe to very severe COPD managed with long-term oxygen therapy (LTOT). METHODS: This was a crossover clinical feasibility study of the effects of VA+O2 in subjects with severe to very severe COPD managed with LTOT (N = 15). At visit 1, physiologic measures were obtained, and subjects were tested on the cycle ergometer with VA. Peak work rate and flow for continuous supplemental O2/VA+O2 were established. At visit 2, subjects exercised at a constant work rate of 80% peak work rate to maximum endurance after allocation to VA+O2 or O2. Cardiorespiratory variables, work rate, and dyspnea were included to define potential clinical benefits of VA+O2. Data were analyzed using a linear mixed model. RESULTS: Fifteen subjects with COPD (mean ± SD, age 67.9 ± 9.0 y, FEV1 0.89 ± 0.35 observed) completed the study. Exercise duration in minutes was significantly longer with VA+O2 versus O2 (least squares mean [standard error], 12.0 [2.0] vs 6.2 [2.0], P = .01). VA+O2 versus O2 was also associated with significantly greater isotime improvements in Borg dyspnea scores (3.6 [0.5] vs 5.7 [0.5], P < .001), SpO2 (96.9 [0.9] vs 91.4 [0.9], P < .001), leg fatigue scores (3.8 [0.6] vs 5.2 [0.6], P = .008), and breathing frequency (22.8 [0.9] vs 25.8 [0.9] breaths/min, P = .01). There were no differences in heart rate. CONCLUSIONS: In symptomatic subjects with severe to very severe COPD, VA+O2 significantly increased exercise time and improved dyspnea, SpO2, breathing frequency, and leg fatigue versus O2 alone [ABSTRACT FROM AUTHOR]

Pulmonary hypertension (PH) pathogenesis is driven by inflammatory and metabolic derangements as well as glycolytic reprogramming. Induction of both interleukin 6 (IL6) and transglutaminase 2 (TG2) expression participates in human and experimental cardiovascular diseases. However, little is known about the role of TG2 in these pathologic processes. The current study aimed to investigate the molecular interactions between TG2 and IL6 in mediation of tissue remodeling in PH. A lung-specific IL6 over-expressing transgenic mouse strain showed elevated right ventricular (RV) systolic pressure as well as increased wet and dry tissue weights and tissue fibrosis in both lungs and RVs compared to age-matched wild-type littermates. In addition, IL6 over-expression induced the glycolytic and fibrogenic markers, hypoxia-inducible factor 1α, pyruvate kinase M2 (PKM2), and TG2. Consistent with these findings, IL6 induced the expression of both glycolytic and pro-fibrogenic markers in cultured lung fibroblasts. IL6 also induced TG2 activation and the accumulation of TG2 in the extracellular matrix. Pharmacologic inhibition of the glycolytic enzyme, PKM2 significantly attenuated IL6-induced TG2 activity and fibrogenesis. Thus, we conclude that IL6-induced TG2 activity and cardiopulmonary remodeling associated with tissue fibrosis are under regulatory control of the glycolytic enzyme, PKM2. [ABSTRACT FROM AUTHOR]

Group 5 pulmonary hypertension (PH) encompasses diverse diseases, with a few cases linking it to T-cell large granular lymphocytic (LGL) leukemia. We report a case of a 76-year-old woman, diagnosed with LGL leukemia and concomitant PH, treated with oral triple pulmonary arterial hypertension (PAH) therapy. She initially presented with dyspnea on exertion; evaluation revealed severe precapillary PH. Implementing cyclophosphamide for leukemia along with tadalafil and macitentan for PH led to sustained symptomatic and hemodynamic improvement for over 3 years. At that time, deterioration in PH prompted the addition of selexipag, resulting in sustained clinical improvement for an additional 5 years. This case exemplifies the potential for sustained benefits of PAH therapy in leukemia-associated PH and highlights the need for continued research on the mechanistic relationship between LGL leukemia and PH, with the hope of identifying new management strategies. [ABSTRACT FROM AUTHOR]

Pulmonary artery hypertension (PAH) patients exhibit elevated levels of inflammatory cytokines and infiltration of inflammatory cells in the lung. Concurrently, mutations of bmpr2, the gene encoding the type II receptor of bone morphogenetic proteins (BMP), are found in ∼75% of patients with familial PAH, but a possible nexus between increased inflammation and diminished BMP signaling has hitherto remained elusive. We previously showed that BMP4 triggers nuclear localization of the Myocardin-related transcription factor A (MRTF-A) in human pulmonary artery smooth muscle cells (PASMC), resulting in the induction of contractile proteins. Here we report the BMPR2-dependent repression of a set of inflammatory mediators in response to BMP4 stimulation of PASMC. Forced expression of MRTF-A precisely emulates the anti-inflammatory effect of BMP4, while MRTF-A depletion precludes BMP4-mediated cytokine inhibition. BMP4 and MRTF-A block signaling through NF-κB, the keystone of most pathways leading to inflammatory responses, at the level of chromatin recruitment and promoter activation. Moreover, MRTF-A physically interacts with RelA/p65, the NF-κB subunit endowed with a transcription activation domain. Interestingly, the MRTF-A-NF-κB interaction is mutually antagonistic: stimulation of NF-κB signaling by TNFα, as well as p65 overexpression, hinders MRTF-A activity and the expression of contractile genes. Thus, a molecular inhibitory pathway linking BMP4 signaling, activation of MRTF-A, and inhibition of NF-κB provides insights into the etiology of PAH and a potential focus of therapeutic intervention.