Safety and Effectiveness of Selexipag in Pediatric Pulmonary Hypertension: A Retrospective Multi-Center Cohort Study.

OBJECTIVE: To describe the safety and effectiveness of treating pediatric patients who have pulmonary arterial hypertension (PAH) with selexipag in a real-world, multi-center cohort, given that data supporting its use in pediatric PAH are sparse. STUDY DESIGN: We report a multi-center, retrospective, cohort study of children with PAH treated with selexipag. Demographic and clinical variables were extracted from the medical records. Clinical parameters were analyzed at 3 timepoints: pre-selexipag, 3-12 months post-selexipag, and >12 months follow-up. RESULTS: Eighty-seven patients were included, 32 received selexipag as add-on to background therapy, and 55 transitioned from another prostanoid. Median starting and final doses were 4.7 and 28.5 µg/kg/dose BID, respectively. Add-on patients demonstrated improved indexed pulmonary to systemic vascular resistance ratio after selexipag initiation (PVRi/SVRi, 0.62v0.53, p=0.034) with a lower average mean pulmonary artery pressure (MPAP, 46v39 mmHg, p=NS), and oxygen consumption (VO2 max 27.8v30.9 mL/kg/min, p=NS). Transition patients demonstrated stable MPAP (47v45 mmHg, p=NS) and a lower mean PVRi (10.9v8.2 Wood units*m2, p=NS) but late functional worsening in some with VO2 max decreased at follow-up (26.0v19.5 ml/kg/min). Side effects were noted in 40% of the cohort but prompted discontinuation in only 2%. CONCLUSIONS: In a large, multi-center cohort, the oral prostacyclin agonist selexipag demonstrates favorable tolerability and effectiveness. Add-on patients demonstrated early hemodynamic improvement. Transition patients demonstrated early stability with risk of late functional worsening, highlighting the importance of ongoing monitoring.

Prostacyclin Synthase Deficiency Leads to Exacerbation or Occurrence of Endothelium-Dependent Contraction and Causes Cardiovascular Disorders Mainly via the Non-TxA2 Prostanoids/TP Axis.

BACKGROUND: Prostaglandin I2 synthesized by endothelial COX (cyclooxygenase) evokes potent vasodilation in some blood vessels but is paradoxically responsible for endothelium-dependent constriction (EDC) in others. Prostaglandin I2 production and EDC may be enhanced in diseases such as hypertension. However, how PGIS (prostaglandin I2 synthase) deficiency affects EDC and how this is implicated in the consequent cardiovascular pathologies remain largely unknown. METHODS: Experiments were performed with wild-type, Pgis knockout (Pgis-/-) and Pgis/thromboxane-prostanoid receptor gene (Tp) double knockout (Pgis-/-Tp-/-) mice and Pgis-/- mice transplanted with unfractionated wild-type or Cox-1-/- bone marrow cells, as well as human umbilical arteries. COX-derived prostanoids were measured by high-performance liquid chromatography-mass spectrometry. Vasomotor responses of distinct types of arteries were assessed by isometric force measurement. Parameters of hypertension, vascular remodeling, and cardiac hypertrophy in mice at different ages were monitored. RESULTS: PGF2α, PGE2, and a trace amount of PGD2, but not thromboxane A2 (TxA2), were produced in response to acetylcholine in Pgis-/- or PGIS-inhibited arteries. PGIS deficiency resulted in exacerbation or occurrence of EDC ex vivo and in vivo. Endothelium-dependent hyperpolarization was unchanged, but phosphorylation levels of eNOS (endothelial nitric oxide synthase) at Ser1177 and Thr495 were altered and NO production and the NO-dependent relaxation evoked by acetylcholine were remarkably reduced in Pgis-/- aortas. Pgis-/- mice developed high blood pressure and vascular remodeling at 16 to 17 weeks and subsequently cardiac hypertrophy at 24 to 26 weeks. Meanwhile, blood pressure and cardiac parameters remained normal at 8 to 10 weeks. Additional ablation of TP (TxA2 receptor) not only restrained EDC and the downregulation of NO signaling in Pgis-/- mice but also ameliorated the cardiovascular abnormalities. Stimulation of Pgis-/- vessels with acetylcholine in the presence of platelets led to increased TxA2 generation. COX-1 disruption in bone marrow-derived cells failed to affect the development of high blood pressure and vascular remodeling in Pgis-/- mice though it largely suppressed the increase of plasma TxB2 (TxA2 metabolite) level. CONCLUSIONS: Our study demonstrates that the non-TxA2 prostanoids/TP axis plays an essential role in mediating the augmentation of EDC and cardiovascular disorders when PGIS is deficient, suggesting TP as a promising therapeutic target in diseases associated with PGIS insufficiency.

A Comparison of the Anticoagulation Efficacy and Safety of Epoprostenol to Heparin and Citrate in Children Receiving Continuous Renal Replacement Therapy.

INTRODUCTION: Anticoagulants are used in continuous renal replacement therapy (CRRT) to prolong filter life. There are no prior investigations directly comparing epoprostenol to more commonly used forms of anticoagulation in children. Therefore, the primary aim of this study was to assess the efficacy and safety of epoprostenol as compared to heparin and citrate anticoagulation in a pediatric cohort. METHODS: We performed a retrospective analysis of all patients <18 years of age admitted to an academic quaternary care children's hospital from 2017-2022 who received epoprostenol, heparin, or citrate exclusively for CRRT anticoagulation. Efficacy was evaluated by comparing the hours to the first unintended filter change and the ratio of filters used to CRRT days. Safety was assessed by evaluating changes in platelet count and vasoactive-ionotropic score (VIS). RESULTS: Of 101 patients, 44 received epoprostenol (43.6%), 38 received heparin (37.6%), and 19 received citrate (18.8%). The first filter change was more commonly planned in patients receiving anticoagulation with epoprostenol (43%) as compared to citrate (11%) or heparin (29%) (p = 0.034). Of those patients where the first filter change was unintended (n = 33), there were greater median hours until the filter was replaced in those receiving epoprostenol (29) when compared to citrate (21) (p = 0.002) or heparin (18) (p = 0.003). There was a smaller median ratio of filters used to days on therapy in the patients that received epoprostenol (0.53) when compared to citrate (1) (p = 0.003) or heparin (0.75) (p = 0.001). For those receiving epoprostenol, there was no significant decrease in platelet count when comparing values prior to CRRT initiation through 7 days of therapy. There was no significant difference in VIS when comparing values prior to CRRT initiation through the first 2 days of CRRT. CONCLUSIONS: Epoprostenol-based anticoagulation is effective when compared to other anticoagulation strategies used in pediatric CRRT with a favorable side effect profile.

Pulmonary arterial hypertension: Navigating the pathways of progress in diagnosis, treatment, and patient care.

Pulmonary arterial hypertension (PAH) is a form of precapillary pulmonary hypertension caused by a complex process of endothelial dysfunction and vascular remodeling. If left untreated, this progressive disease presents with symptoms of incapacitating fatigue causing marked loss of quality of life, eventually culminating in right ventricular failure and death. Patient management is complex and based on accurate diagnosis, risk stratification, and treatment initiation, with close monitoring of response and disease progression. Understanding the underlying pathophysiology has enabled the development of multiple drugs directed at different targets in the pathological chain. Vasodilator therapy has been the mainstay approach for the last few years, significantly improving quality of life, functional status, and survival. Recent advances in therapies targeting dysfunctional pathways beyond endothelial dysfunction may address the fundamental processes underlying the disease, raising the prospect of increasingly effective options for this high-risk group of patients with a historically poor prognosis.

Elevated neutrophil extracellular traps in systemic sclerosis-associated vasculopathy and suppression by a synthetic prostacyclin analog.

OBJECTIVES: Neutrophils and neutrophil extracellular traps (NETs) contribute to the vascular complications of multiple diseases, but their role in systemic sclerosis (SSc) is understudied. We sought to test the hypothesis that NETs are implicated in SSc vasculopathy and that treatment with prostacyclin analogs may ameliorate SSc vasculopathy not only through vasodilation but also by inhibiting NET release. METHODS: Blood from 125 patients with SSc (87 diffuse cutaneous SSc and 38 limited cutaneous SSc) was collected at a single academic medical center. Vascular complications such as digital ulcers, pulmonary artery hypertension, and scleroderma renal crisis were recorded. The association between circulating NETs and vascular complications was determined using in vitro and ex vivo assays. The impact of the synthetic prostacyclin analog epoprostenol on NET release was determined. RESULTS: Neutrophil activation and NET release were elevated in patients with SSc-associated vascular complications compared to matched patients without vascular complications. Neutrophil activation and NETs positively correlated with soluble E-selectin and VCAM-1, circulating markers of vascular injury. Treatment of patients with digital ischemia with a synthetic prostacyclin analog boosted neutrophil cyclic AMP, which was associated with the blunting of NET release and reduced NETs in circulation. CONCLUSION: Our study demonstrates an association between NETs and vascular complications in SSc. We also identified the potential for an additional therapeutic benefit of synthetic prostacyclin analogs, namely to reduce neutrophil hyperactivity and NET release in SSc patients.

Practical management of oral treprostinil in patients with pulmonary arterial hypertension: Lessons from ADAPT, EXPEDITE, and expert consensus.

BACKGROUND: Oral treprostinil is a prostacyclin analogue approved to treat pulmonary arterial hypertension (PAH) by delaying disease progression and improving exercise capacity. Higher doses of oral treprostinil correlate with increased treatment benefit. Titrations may be challenging due to common side effects of prostacyclin-class therapies. STUDY DESIGN AND METHODS: The multicenter, prospective, real-world, observational ADAPT Registry study followed adult patients with PAH for up to 78 weeks after initiating oral treprostinil (NCT03045029). Dosing, titration, and transitions of oral treprostinil were at the discretion of the prescriber. Patient-reported incidence and treatment of common side effects were collected to understand side effect management and tolerability. Insights from literature and expert recommendations were added to provide a consolidated resource for oral treprostinil use. RESULTS: In total, 139 participants in ADAPT completed ≥1 weekly survey; (median age 60.0 years, 76 % female). Median treatment duration of oral treprostinil was 13.1 months. During early therapy (Months 1-5), 62 % (78/126) of patients reported headache and diarrhea, and 40 % (50/126) reported nausea. At Month 6, many patients who reported side effects during early therapy reported an improvement (61 % headache, 44 % diarrhea, 70 % nausea). Common side effect treatments, including acetaminophen, loperamide, and ondansetron, were effective. Approximately one-quarter of patients reporting the most common side effects were untreated at Month 6. CONCLUSION: Patient selection for, and initiation and titration of, oral treprostinil should be individualized and may include parenteral treprostinil induction-transition for faster titration. Assertive side effect management may help patients reach higher and more efficacious doses of oral treprostinil.

Quantification of treprostinil concentration in rat and human using a novel validated and rapid liquid chromatography-tandem mass spectrometry method: Experimental and clinical applications in ischemia-reperfusion injury.

Treprostinil (Remodulin®) is a Food and Drug Administration (FDA) approved prostacyclin analog to treat pulmonary arterial hypertension. Recently, treprostinil has been investigated to reduce ischemia-reperfusion injury (IRI) during transplantation, which currently has no approved treatment. A validated analytical method is necessary to measure treprostinil concentrations in biological specimens. Here, a novel, sensitive, and specific method to measure treprostinil concentrations in rat serum, human serum, and human plasma has been developed using liquid chromatography with tandem mass spectrometry (LC-MS/MS). Biological samples were processed by protein precipitation before chromatography and 6-keto Prostaglandin F1α-d4 was used as an internal standard. A gradient method was established with a total run time of 4 min. The assay was linear over the range of 0.25-75.0 ng/ml with accuracy (92.97-107.87 %), intra-assay precision (1.16-3.34 %), and inter-assay precision (1.11-4.58 %) in all biological matrices, which are within FDA acceptance criteria. No significant variation in treprostinil or 6-keto Prostaglandin F1α-d4 concentrations were observed under the investigated storage conditions. This novel, sensitive, and specific LC/MS-MS method is cost-effective and suitable for measuring treprostinil concentrations in animal studies and human biological samples for clinical applications.

Stroke in Pregnancy and Preeclampsia: Effect of Low-Dose Aspirin Treatment on Collateral Flow Velocity and Cerebral Blood Flow Autoregulation During Ischemia in Rats.

BACKGROUND: Experimental preeclampsia (ePE) has been shown to have worsened outcome from stroke. We investigated the effect of low-dose aspirin, known to prevent preeclampsia, on stroke hemodynamics and outcome, and the association between the vasoconstrictor and vasodilator cyclooxygenase products thromboxane A2 and prostacyclin. METHODS AND RESULTS: Middle cerebral artery occlusion was performed for 3 hours with 1 hour of reperfusion in normal pregnant rats on day 20 of gestation and compared with ePE treated with vehicle or low-dose aspirin (1.5 mg/kg per day). Multisite laser Doppler was used to measure changes in cerebral blood flow to the core middle cerebral artery and collateral vascular territories. After 30 minutes occlusion, phenylephrine was infused to increase blood pressure and assess cerebral blood flow autoregulation. Infarct and edema were measured using 2,3,5-triphenyltetrazolium chloride staining. Plasma levels of thromboxane A2, prostacyclin, and inflammatory markers in plasma and cyclooxygenase levels in cerebral arteries were measured. ePE had increased infarction compared with normal pregnant rats (P<0.05) that was reduced by aspirin (P<0.001). ePE also had intact cerebral blood flow autoregulation and reduced collateral perfusion during induced hypertension that was also prevented by aspirin. Aspirin increased prostacyclin in ePE (P<0.05) without reducing thromboxane B2, metabolite of thromboxane A2, or 8-isoprostane-prostaglandin-2α, a marker of lipid peroxidation. There were no differences in cyclooxygenase levels in cerebral arteries between groups. CONCLUSIONS: Low-dose aspirin in ePE reduced infarction that was associated with increased vasodilator prostacyclin and improved collateral perfusion during induced hypertension. The beneficial effect of aspirin on the brain and cerebral circulation is likely multifactorial and worth further study.

Therapeutic Potential of Treprostinil Inhalation Powder for Patients with Pulmonary Arterial Hypertension: Evidence to Date.

Pulmonary arterial hypertension (PAH) is a complex and incurable disease for which pulmonary vasodilators remain the core therapy. Of the three primary pathways that vasodilators target, the prostacyclin pathway was the earliest to be used and currently has the largest number of modalities for drug delivery. Inhaled treprostinil has been introduced as a treatment option in PAH and, more recently, pulmonary hypertension (PH) due to interstitial lung disease (PH-ILD), and the earlier nebulized form has been joined by a dry powder form allowing for more convenient use. In this review, we discuss inhaled treprostinil, focusing on the dry powder inhalation (DPI) formulation, and explore its dosing, applications, and evidence to support patient tolerance and acceptance. Recent trials underpinning the evidence for use of inhaled treprostinil and the most recent developments concerning the drug are discussed. Finally, the review looks briefly into premarket formulations of inhaled treprostinil and relevant early studies suggesting efficacy in PAH treatment.

Prostacyclin synthase deficiency exacerbates systemic inflammatory responses in lipopolysaccharide-induced septic shock in mice.

OBJECTIVES: Sepsis is a systemic inflammatory disorder characterized by life-threateningorgan dysfunction resulting from a dysregulated host response to infection. Prostacyclin (PGI2) is a bioactive lipid produced by PGI synthase (PGIS) and is known to play important roles in inflammatory reactions as well as cardiovascular regulation. However, little is known about the roles of PGIS and PGI2 in systemic inflammatory responses such as septic shock. METHODOLOGY: Systemic inflammation was induced by intraperitoneal injection of 5 mg/kg lipopolysaccharide (LPS) in wild type (WT) or PGIS knockout (KO) mice. Selexipag, a selective PGI2 receptor (IP) agonist, was administered 2 h before LPS injection and again given every 12 h for 3 days. RESULTS: Intraperitoneal injection of LPS induced diarrhea, shivering and hypothermia. These symptoms were more severe in PGIS KO mice than in WT micqe. The expression of Tnf and Il6 genes was notably increased in PGIS KO mice. In contrast, over 95% of WT mice survived 72 h after the administration of LPS, whereas all of the PGIS KO mice had succumbed by that time. The mortality rate of LPS-administrated PGIS KO mice was improved by selexipag administration. CONCLUSION: Our study suggests that PGIS-derived PGI2 negatively regulates LPS-induced symptoms via the IP receptor. PGIS-derived PGI2-IP signaling axis may be a new drug target for systemic inflammation in septic shock.

Selexipag Dosing Strategies for Pediatric Patients with Pulmonary Arterial Hypertension.

This retrospective chart review of patients less than 18 years old with pulmonary arterial hypertension (PAH) receiving selexipag was conducted to describe selexipag dosing practices, impact on concomitant PAH therapies, and the safety and efficacy of selexipag. Twenty-seven patients aged 1-17 years started a median dose of oral selexipag 100 µg twice daily. Therapy was increased by a median of 100 µg twice daily every 6 days to a maximally tolerated median dose of 800 µg twice daily. All 24 patients on another prostacyclin derivative were able to discontinue therapy at their maximum tolerated selexipag dose; other concomitant PAH therapies did not change. Changes in echocardiogram data and 6-MWT results were variable. No patients discontinued selexipag; four patients received decreased doses due to flushing (n = 1), drug interactions (n = 2), or increased frequency of nose bleeds (n = 1).

Effectiveness of a Prostacyclin IP Receptor Agonist in Patients With Pulmonary Arterial Hypertension in the Real-world Andalusian Setting: The RAMPHA Study.

PURPOSE: The pillar for therapeutic decisions in the evolution of pulmonary arterial hypertension (PAH) is the patients' prognostic stratification. METHODS: A retrospective cohort study was conducted in a Spanish real-world setting to assess the clinical improvement of PAH patients treated with selexipag measured as changes in the risk profile. Secondary objectives were to describe their baseline characteristics, initial risk status, and variables used to assess patient survival and adverse events. FINDINGS: Total 42 patients (mean age 52.36 [SD: 15.09] years) were included. All had received initial endothelin receptor antagonist treatment and 95.2% dual therapy with phosphodiesterase-5 inhibitor or riociguat. At 6 to 12 months from baseline, patients risk stratification tripled the percentage of patients with low risk, and a trend towards improved risk stratification (P = 0.122). World Health Organization functional class changed, with more patients in milder classes (P = 0.003), and symptom progression slowed down (P < 0.0001). At 3-years, survival was 85.7% and the estimated median survival time was 2.73 years (SD: 1.351; 95% CI: 2.51-2.95). IMPLICATIONS: Selexipag did not achieve a significant improvement in risk profile, although it did show an excellent survival rate, effectively improved functional class, and delayed symptom progression in real life. Selexipag was well tolerated and showed a favorable safety profile, supporting a clinical benefit for PAH patients.

A nomogram model for the occurrence of bladder spasm after TURP in patients with prostate enlargement based on serum prostacyclin and 5-hydroxytryptamine and clinical characteristics.

OBJECTIVE: With the development of analytical methods, mathematical models based on humoral biomarkers have become more widely used in the medical field. This study aims to investigate the risk factors associated with the occurrence of bladder spasm after transurethral resection of the prostate (TURP) in patients with prostate enlargement, and then construct a nomogram model. MATERIALS AND METHODS: Two hundred and forty-two patients with prostate enlargement who underwent TURP were included. Patients were divided into Spasm group (n=65) and non-spasm group (n=177) according to whether they had bladder spasm after surgery. Serum prostacyclin (PGI2) and 5-hydroxytryptamine (5-HT) levels were measured by enzyme-linked immunoassay. Univariate and multivariate logistic regression were used to analyze the risk factors. RESULTS: Postoperative serum PGI2 and 5-HT levels were higher in patients in the Spasm group compared with the Non-spasm group (P<0.05). Preoperative anxiety, drainage tube obstruction, and elevated postoperative levels of PGI2 and 5-HT were independent risk factors for bladder spasm after TURP (P<0.05). The C-index of the model was 0.978 (0.959-0.997), with a χ2 = 4.438 (p = 0.816) for Hosmer-Lemeshow goodness-of-fit test. The ROC curve to assess the discrimination of the nomogram model showed an AUC of 0.978 (0.959-0.997). CONCLUSION: Preoperative anxiety, drainage tube obstruction, and elevated postoperative serum PGI2 and 5-HT levels are independent risk factors for bladder spasm after TURP. The nomogram model based on the aforementioned independent risk factors had good discrimination and predictive abilities, which may provide a high guidance value for predicting the occurrence of bladder spasm in clinical practice.

Maternal nano-titanium dioxide inhalation exposure alters placental cyclooxygenase and oxidant balance in a sexually dimorphic manner.

The placenta plays a critical role in nutrient-waste exchange between the maternal and fetal circulation, and thus impacts fetal growth and development. We have previously shown that nano-titanium dioxide (nano-TiO2) inhalation exposure during gestation decreased fetal female pup and placenta mass [1], which persists in the following generation [2]. In utero exposed females, once mated, their offspring's placentas had increased capacity for H2O2 production. Generation of oxidants such as hydrogen peroxide (H2O2), have been shown to impact cyclooxygenase activity, specifically metabolites such as prostacyclin (PGI2) or thromboxane (TXA2). Therefore, we hypothesized that maternal nano-TiO2 inhalation exposure during gestation results in alterations in placental production of prostacyclin and thromboxane mediated by enhanced H2O2 production in a sexually dimorphic manner. Pregnant Sprague-Dawley rats were exposed to nano-TiO2 aerosols or filtered air (sham--control) from gestational day (GD) 10-19. Dams were euthanized on GD 20, and fetal serum and placental tissue were collected based on fetal sex. Fetal placental zones (junctional zone (JZ) and labyrinth zone (LZ)) were assessed for xanthine oxidoreductase (XOR) activity, H2O2, and catalase activity, as well as 6-keto-PGF1α and TXB2 levels. Nano-TiO2 exposed fetal female LZ demonstrated significantly greater XOR activity compared to exposed males. Exposed fetal female LZ also demonstrated significantly diminished catalase activity compared to sham-control females. Exposed fetal female LZ had significantly increased abundance of 6-keto-PGF1α compared to sham-control females and increased TXB2 compared to exposed males. In the aggregate these data indicate that maternal nano-TiO2 inhalation exposure has a greater impact on redox homeostasis and PGI2/TXA2 balance in the fetal female LZ. Future studies need to address if treatment with an XO inhibitor during gestation can prevent diminished fetal female growth during maternal nano-TiO2 inhalation exposure.

Tributyltin-induced oxidative stress causes developmental damage in the cardiovascular system of zebrafish (Danio rerio).

Tributyltin (TBT) can be used as an antifouling agent with anticorrosive, antiseptic and antifungal properties and is widely used in wood preservation and ship painting. However, it has recently been found that TBT can be harmful to aquatic organisms. In this study, to gain insight into the effects of TBT with respect to the development of the cardiovascular system in zebrafish embryos, zebrafish embryos were exposed to different concentrations of TBT solutions (0.2 µg/L, 1 µg/L, and 2 µg/L) at 2 h post-fertilization (hpf) TBT exposure resulted in decreased hatchability and heart rate, deformed features such as pericardial edema, yolk sac edema, and spinal curvature in zebrafish embryos, and impaired heart development. Expression of cardiac development-related genes (vmhc, myh6, nkx2.5, tbx5a, gata4, tbx2b, nppa) is dysregulated. Transgenic zebrafish Tg (fli1: EGFP) were used to explore the effects of TBT exposure on vascular development. It was found that TBT exposure could lead to impaired development of intersegmental vessels (ISVs), common cardinal vein (CCV), subintestinal vessels (SIVs) and cerebrovascular. The expression of vascular endothelial growth factor (VEGF) signaling pathway-related genes (flt1, flt4, kdr, vegfa) was downregulated. Biochemical indices showed that ROS and MDA levels were significantly elevated and that SOD and CAT activities were significantly reduced. The expression of key genes for prostacyclin synthesis (pla2, ptgs2a, ptgs2b, ptgis, ptgs1) is abnormal. Therefore, it is possible that oxidative stress induced by TBT exposure leads to the blockage of arachidonic acid (AA) production in zebrafish embryos, which affects prostacyclin synthesis and consequently the normal development of the heart and blood vessels in zebrafish embryos.

Pulmonary Hypertension: Intensification and Personalization of Combination Rx (PHoenix): A phase IV randomized trial for the evaluation of dose-response and clinical efficacy of riociguat and selexipag using implanted technologies.

Approved therapies for the treatment of patients with pulmonary arterial hypertension (PAH) mediate pulmonary vascular vasodilatation by targeting distinct biological pathways. International guidelines recommend that patients with an inadequate response to dual therapy with a phosphodiesterase type-5 inhibitor (PDE5i) and endothelin receptor antagonist (ERA), are recommended to either intensify oral therapy by adding a selective prostacyclin receptor (IP) agonist (selexipag), or switching from PDE5i to a soluble guanylate-cyclase stimulator (sGCS; riociguat). The clinical equipoise between these therapeutic choices provides the opportunity for evaluation of individualized therapeutic effects. Traditionally, invasive/hospital-based investigations are required to comprehensively assess disease severity and demonstrate treatment benefits. Regulatory-approved, minimally invasive monitors enable equivalent measurements to be obtained while patients are at home. In this 2 × 2 randomized crossover trial, patients with PAH established on guideline-recommended dual therapy and implanted with CardioMEMS™ (a wireless pulmonary artery sensor) and ConfirmRx™ (an insertable cardiac rhythm monitor), will receive ERA + sGCS, or PDEi + ERA + IP agonist. The study will evaluate clinical efficacy via established clinical investigations and remote monitoring technologies, with remote data relayed through regulatory-approved online clinical portals. The primary aim will be the change in right ventricular systolic volume measured by magnetic resonance imaging (MRI) from baseline to maximal tolerated dose with each therapy. Using data from MRI and other outcomes, including hemodynamics, physical activity, physiological measurements, quality of life, and side effect reporting, we will determine whether remote technology facilitates early evaluation of clinical efficacy, and investigate intra-patient efficacy of the two treatment approaches.

Targeted Therapies for Neonatal Pulmonary Hypertension: Beyond Nitric Oxide.

Pulmonary hypertension in the neonatal population can be acute or chronic and carries significant risk for morbidity and mortality. It can be idiopathic but more often is associated with comorbid pulmonary and heart disease. There are several pharmacotherapeutics aimed at pulmonary vasodilation. This review highlights the most common agents as well as those on the horizon for the treatment of pulmonary hypertension in the neonate.

Case report: Extracorporeal life support as a successful bridge to recovery in an incident case of pulmonary arterial hypertension.

Pulmonary arterial hypertension (PAH) is characterized by a progressive increase in pulmonary vascular resistance (PVR) due to vascular remodeling of the small pulmonary arteries. In advanced RV failure or severe hypoxemia, extra corporeal life support (ECLS) is now to be considered, with the objective to bridge patients back to their baseline clinical state while waiting or right after lung transplantation, or bridge to pharmacological optimization of PAH (i.e., bridge to recovery). We describe herein a case of a 30-year-old woman (gravida 6, para 6) with an incident case of heritable PAH revealed by refractory hypoxemia. Despite the use of mechanical ventilation and fluid optimization, the patient remained profoundly hypoxemic. ECLS was then initiated to avoid tissue hypoxia. The mechanical option chosen was peripheral femoro-femoral venoarterial extracorporeal membrane oxygen (VA-ECMO), percutaneously implanted. Due to the absence of evidence of chronic respiratory disease or chronic thromboembolic pulmonary hypertension, this severe pre-capillary pulmonary hypertension was attributed to PAH. Therefore, epoprostenol infusion and an association of oral treatments (bosentan and tadalafil) were administered. A dramatic improvement was observed, allowing decannulation 7 days after the initiation of pharmacological treatment. After 29 days, the patient was discharged from the hospital with epoprostenol, bosentan, and tadalafil. The assessment has been completed by positive research on mutations (c.741C > G, p.Tyr247) corresponding to a loss of function of the bone morphogenetic protein receptor 2 (BMPR2) gene. The final diagnosis was heritable PAH. The use of ECLS has been well demonstrated in patients with PAH complicated by acute RV failure or refractory hypoxemia in the "bridge-to-transplantation" strategy. Only a few reports have described the use of ECLS as a "bridge-to-recovery" with PAH drugs in untreated or undertreated PAH patients, but none has described such a rapid improvement with resolution of refractory hypoxemia. More studies are needed to assess the benefits and limitations of the "bridge-to-recovery" strategy and to identify the patients most likely to benefit from it.