In this double-blind, randomized, placebo-controlled trial, sotatercept increased the exercise capacity of patients with pulmonary arterial hypertension.
Some patients with COVID-19 who have recovered from the acute infection after experiencing only mild symptoms continue to exhibit persistent exertional limitation that often is unexplained by ...conventional investigative studies.
What is the pathophysiologic mechanism of exercise intolerance that underlies the post-COVID-19 long-haul syndrome in patients without cardiopulmonary disease?
This study examined the systemic and pulmonary hemodynamics, ventilation, and gas exchange in 10 patients who recovered from COVID-19 and were without cardiopulmonary disease during invasive cardiopulmonary exercise testing (iCPET) and compared the results with those from 10 age- and sex-matched control participants. These data then were used to define potential reasons for exertional limitation in the cohort of patients who had recovered from COVID-19.
The patients who had recovered from COVID-19 exhibited markedly reduced peak exercise aerobic capacity (oxygen consumption VO
) compared with control participants (70 ± 11% predicted vs 131 ± 45% predicted; P < .0001). This reduction in peak VO
was associated with impaired systemic oxygen extraction (ie, narrow arterial-mixed venous oxygen content difference to arterial oxygen content ratio) compared with control participants (0.49 ± 0.1 vs 0.78 ± 0.1; P < .0001), despite a preserved peak cardiac index (7.8 ± 3.1 L/min vs 8.4±2.3 L/min; P > .05). Additionally, patients who had recovered from COVID-19 demonstrated greater ventilatory inefficiency (ie, abnormal ventilatory efficiency VE/VCO
slope: 35 ± 5 vs 27 ± 5; P = .01) compared with control participants without an increase in dead space ventilation.
Patients who have recovered from COVID-19 without cardiopulmonary disease demonstrate a marked reduction in peak VO
from a peripheral rather than a central cardiac limit, along with an exaggerated hyperventilatory response during exercise.
Mitochondrial DNA (mtDNA) is a critical activator of inflammation and the innate immune system. However, mtDNA level has not been tested for its role as a biomarker in the intensive care unit (ICU). ...We hypothesized that circulating cell-free mtDNA levels would be associated with mortality and improve risk prediction in ICU patients.
Analyses of mtDNA levels were performed on blood samples obtained from two prospective observational cohort studies of ICU patients (the Brigham and Women's Hospital Registry of Critical Illness BWH RoCI, n = 200 and Molecular Epidemiology of Acute Respiratory Distress Syndrome ME ARDS, n = 243). mtDNA levels in plasma were assessed by measuring the copy number of the NADH dehydrogenase 1 gene using quantitative real-time PCR. Medical ICU patients with an elevated mtDNA level (≥3,200 copies/µl plasma) had increased odds of dying within 28 d of ICU admission in both the BWH RoCI (odds ratio OR 7.5, 95% CI 3.6-15.8, p = 1×10(-7)) and ME ARDS (OR 8.4, 95% CI 2.9-24.2, p = 9×10(-5)) cohorts, while no evidence for association was noted in non-medical ICU patients. The addition of an elevated mtDNA level improved the net reclassification index (NRI) of 28-d mortality among medical ICU patients when added to clinical models in both the BWH RoCI (NRI 79%, standard error 14%, p<1×10(-4)) and ME ARDS (NRI 55%, standard error 20%, p = 0.007) cohorts. In the BWH RoCI cohort, those with an elevated mtDNA level had an increased risk of death, even in analyses limited to patients with sepsis or acute respiratory distress syndrome. Study limitations include the lack of data elucidating the concise pathological roles of mtDNA in the patients, and the limited numbers of measurements for some of biomarkers.
Increased mtDNA levels are associated with ICU mortality, and inclusion of mtDNA level improves risk prediction in medical ICU patients. Our data suggest that mtDNA could serve as a viable plasma biomarker in medical ICU patients.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Pulmonary hypertension (PH) is a deadly vascular disease with enigmatic molecular origins. We found that vascular extracellular matrix (ECM) remodeling and stiffening are early and pervasive ...processes that promote PH. In multiple pulmonary vascular cell types, such ECM stiffening induced the microRNA-130/301 family via activation of the co-transcription factors YAP and TAZ. MicroRNA-130/301 controlled a PPARγ-APOE-LRP8 axis, promoting collagen deposition and LOX-dependent remodeling and further upregulating YAP/TAZ via a mechanoactive feedback loop. In turn, ECM remodeling controlled pulmonary vascular cell crosstalk via such mechanotransduction, modulation of secreted vasoactive effectors, and regulation of associated microRNA pathways. In vivo, pharmacologic inhibition of microRNA-130/301, APOE, or LOX activity ameliorated ECM remodeling and PH. Thus, ECM remodeling, as controlled by the YAP/TAZ-miR-130/301 feedback circuit, is an early PH trigger and offers combinatorial therapeutic targets for this devastating disease.
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•Matrix remodeling induces YAP/TAZ-miR-130/301 early in pulmonary hypertension (PH)•YAP/TAZ-miR-130/301 promotes matrix remodeling via a mechanoactive feedback loop•Such matrix remodeling drives pulmonary vascular activation and cellular crosstalk•Pharmacologic modulation of this circuit ameliorates matrix remodeling and PH
Bertero et al. establish vascular matrix remodeling as an early, pervasive driver of pulmonary hypertension (PH) controlled by mechanoactive feedback from YAP/TAZ-microRNA-130/301 in multiple cell types. Inhibition of this circuit ameliorated matrix remodeling and PH, thus introducing promising cooperative therapies to treat this disease.
Inflammatory cytokine interleukin (IL)-6 is elevated in the serum and lungs of patients with pulmonary artery hypertension (PAH). Several animal models of PAH cite the potential role of inflammatory ...mediators. We investigated role of IL-6 in the pathogenesis of pulmonary vascular disease. Indices of pulmonary vascular remodeling were measured in lung-specific IL-6–overexpressing transgenic mice (Tg) and compared to wild-type (Tg) controls in both normoxic and chronic hypoxic conditions. The Tg mice exhibited elevated right ventricular systolic pressures and right ventricular hypertrophy with corresponding pulmonary vasculopathic changes, all of which were exacerbated by chronic hypoxia. IL-6 overexpression increased muscularization of the proximal arterial tree, and hypoxia enhanced this effect. It also reproduced the muscularization and proliferative arteriopathy seen in the distal arteriolar vessels of PAH patients. The latter was characterized by the formation of occlusive neointimal angioproliferative lesions that worsened with hypoxia and were composed of endothelial cells and T-lymphocytes. IL-6–induced arteriopathic changes were accompanied by activation of proangiogenic factor, vascular endothelial growth factor, the proproliferative kinase extracellular signal-regulated kinase, proproliferative transcription factors c-MYC and MAX, and the antiapoptotic proteins survivin and Bcl-2 and downregulation of the growth inhibitor transforming growth factor-β and proapoptotic kinases JNK and p38. These findings suggest that IL-6 promotes the development and progression of pulmonary vascular remodeling and PAH through proproliferative antiapoptotic mechanisms.
Pulmonary hypertension (PH) is known to complicate various forms of interstitial lung disease (ILD), including idiopathic pulmonary fibrosis, the interstitial pneumonias and chronic hypersensitivity ...pneumonitis. Pathogenesis of PH-ILD remains incompletely understood, and probably has overlap with other forms of pre-capillary pulmonary hypertension. PH-ILD carries a poor prognosis, and is associated with increased oxygen requirements, and a decline in functional capacity and exercise tolerance. Despite most patients having mild-moderate pulmonary hypertension, more severe pulmonary hypertension and signs of right heart failure are observed in a subset of cases. Clinical suspicion and findings on pulmonary function, computed tomography and echocardiography are often the initial steps towards diagnosis. Definitive diagnosis is obtained by right heart catheterisation demonstrating pre-capillary pulmonary hypertension. Drugs approved for pulmonary arterial hypertension have been investigated in several randomised controlled trials in PH-ILD patients, leading to discouraging results until the recent INCREASE study. This review provides an overview of the current understanding, approach to diagnosis and recent advances in treatment.
Dysregulation of vascular stiffness and cellular metabolism occurs early in pulmonary hypertension (PH). However, the mechanisms by which biophysical properties of the vascular extracellular matrix ...(ECM) relate to metabolic processes important in PH remain undefined. In this work, we examined cultured pulmonary vascular cells and various types of PH-diseased lung tissue and determined that ECM stiffening resulted in mechanoactivation of the transcriptional coactivators YAP and TAZ (WWTR1). YAP/TAZ activation modulated metabolic enzymes, including glutaminase (GLS1), to coordinate glutaminolysis and glycolysis. Glutaminolysis, an anaplerotic pathway, replenished aspartate for anabolic biosynthesis, which was critical for sustaining proliferation and migration within stiff ECM. In vitro, GLS1 inhibition blocked aspartate production and reprogrammed cellular proliferation pathways, while application of aspartate restored proliferation. In the monocrotaline rat model of PH, pharmacologic modulation of pulmonary vascular stiffness and YAP-dependent mechanotransduction altered glutaminolysis, pulmonary vascular proliferation, and manifestations of PH. Additionally, pharmacologic targeting of GLS1 in this model ameliorated disease progression. Notably, evaluation of simian immunodeficiency virus-infected nonhuman primates and HIV-infected subjects revealed a correlation between YAP/TAZ-GLS activation and PH. These results indicate that ECM stiffening sustains vascular cell growth and migration through YAP/TAZ-dependent glutaminolysis and anaplerosis, and thereby link mechanical stimuli to dysregulated vascular metabolism. Furthermore, this study identifies potential metabolic drug targets for therapeutic development in PH.
In participants with pulmonary arterial hypertension, 24 weeks of sotatercept resulted in a significantly greater reduction from baseline in pulmonary vascular resistance than placebo. This report ...characterises the longer-term safety and efficacy of sotatercept in the PULSAR open-label extension. We report cumulative safety, and efficacy at months 18-24, for all participants treated with sotatercept.
PULSAR was a phase 2, randomised, double-blind, placebo-controlled study followed by an open-label extension, which evaluated sotatercept on top of background pulmonary arterial hypertension therapy in adults. Participants originally randomised to placebo were re-randomised 1:1 to sotatercept 0.3 or 0.7 mg·kg
(placebo-crossed group); those initially randomised to sotatercept continued the same sotatercept dose (continued-sotatercept group). Safety was evaluated in all participants who received ≥1 dose of sotatercept. The primary efficacy endpoint was change from baseline to months 18-24 in pulmonary vascular resistance. Secondary endpoints included 6-min walk distance and functional class. Two prespecified analyses, placebo-crossed and delayed-start, evaluated efficacy irrespective of dose.
Of 106 participants enrolled in the PULSAR study, 97 continued into the extension period. Serious treatment-emergent adverse events were reported in 32 (30.8%) participants; 10 (9.6%) reported treatment-emergent adverse events leading to study discontinuation. Three (2.9%) participants died, none considered related to study drug. The placebo-crossed group demonstrated significant improvement across primary and secondary endpoints and clinical efficacy was maintained in the continued-sotatercept group.
These results support the longer-term safety and durability of clinical benefit of sotatercept for pulmonary arterial hypertension.
Right ventricular (RV) dysfunction is associated with shortened life expectancy in heart failure with preserved ejection fraction (HFpEF). The contribution of pulmonary vascular dysfunction to RV ...dysfunction in HFpEF is not well understood.
We investigated rest and exercise invasive pulmonary hemodynamics, ventilation, and gas exchange in 67 patients with HFpEF (of whom 28 had an abnormal pulmonary vascular response during exercise referred to as HFpEF+PVR group and 39 had a normal pulmonary vascular response during exercise referred to as HFpEF group) and in 21 matched control subjects.
Both groups of patients with HFpEF had a markedly decreased peak oxygen consumption (Vo
), decreased oxygen delivery, and impaired chronotropic response. Single beat analysis of RV pressure waveforms was used to compute the end-systolic elastance (Ees) and pulmonary arterial elastance (Ea). Right ventricular-pulmonary artery (RV-PA) coupling was measured as the ratio of Ees/Ea. Exercise was associated with a preserved Ees response but a decreased Ees/Ea in patients with HFpEF with a normal PVR response, indicating partially preserved RV contractile reserve. In HFpEF+PVR, exercise-induced increase in Ees was markedly reduced, resulting in decreased Ees/Ea and RV-PA uncoupling. Patients with HFpEF+PVR with an exercise-induced decrease in Ees/Ea had lower pulmonary artery compliance, lower peak Vo
, and lower stroke volume than patients with HFpEF.
We conclude that RV-PA uncoupling is common in HFpEF and is caused by both intrinsic RV contractile impairment and afterload mismatch. Resting and dynamic RV-PA uncoupling in HFpEF is driven by an increase in RV pulsatile rather than resistive afterload. However, with the additive effects of increased RV resistive afterload, RV-PA uncoupling worsens dynamically during exercise.
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