Astragaloside-IV promotes autophagy via the Akt/mTOR pathway to improve cellular lipid deposition.

The current study aimed to investigate the potential role of astragaloside IV (AS-IV) in improving cellular lipid deposition and its underlying mechanism. A fatty liver cell model was established by treating hepatoma cells with palmitic acid. AS-IV and SC79 were used for treatment. Oil Red O staining was applied to detect intracellular lipid deposition, and transmission electron microscopy was utilized to assess autophagosome formation. Immunofluorescence double staining was applied to determine microtubule-associated proteins 1A/1B light chain 3 (LC3) expression. Western blot analysis was performed to detect the expression of LC3, prostacyclin, Beclin-1, V-akt murine thymoma viral oncogene homolog (Akt), phosphorylated Akt, mTOR, and phosphorylated mTOR. Oil Red O staining revealed that AS-IV reduced intracellular lipid accumulation. Further, it increased autophagosome synthesis and the expression of autophagy proteins LC3 and Beclin-1 in the cells. It also reduced the phosphorylation levels of Akt and mTOR and the levels of prostacyclin. However, the effects of AS-IV decreased with SC79 treatment. In addition, LC3B + BODIPY493/503 fluorescence double staining showed that AS-IV reduced intracellular lipid deposition levels by enhancing autophagy. AS-IV can reduce lipid aggregation in fatty liver cells, which can be related to enhanced hepatocyte autophagy by inhibiting the Akt/mTOR signaling pathway.

Vascular ATGL-dependent lipolysis and the activation of cPLA2-PGI2 pathway protect against postprandial endothelial dysfunction.

Adipose triglyceride lipase (ATGL) is involved in lipolysis and displays a detrimental pathophysiological role in cardio-metabolic diseases. However, the organo-protective effects of ATGL-induced lipolysis were also suggested. The aim of this work was to characterize the function of lipid droplets (LDs) and ATGL-induced lipolysis in the regulation of endothelial function. ATGL-dependent LDs hydrolysis and cytosolic phospholipase A2 (cPLA2)-derived eicosanoids production were studied in the aorta, endothelial and smooth muscle cells exposed to exogenous oleic acid (OA) or arachidonic acid (AA). Functional effects of ATGL-dependent lipolysis and subsequent activation of cPLA2/PGI2 pathway were also studied in vivo in relation to postprandial endothelial dysfunction.The formation of LDs was invariably associated with elevated production of endogenous AA-derived prostacyclin (PGI2). In the presence of the inhibitor of ATGL or the inhibitor of cytosolic phospholipase A2, the production of eicosanoids was reduced, with a concomitant increase in the number of LDs. OA administration impaired endothelial barrier integrity in vitro that was further impaired if OA was given together with ATGL inhibitor. Importantly, in vivo, olive oil induced postprandial endothelial dysfunction that was significantly deteriorated by ATGL inhibition, cPLA2 inhibition or by prostacyclin (IP) receptor blockade.In summary, vascular LDs formation induced by exogenous AA or OA was associated with ATGL- and cPLA2-dependent PGI2 production from endogenous AA. The inhibition of ATGL resulted in an impairment of endothelial barrier function in vitro. The inhibition of ATGL-cPLA2-PGI2 dependent pathway resulted in the deterioration of endothelial function upon exposure to olive oil in vivo. In conclusion, vascular ATGL-cPLA2-PGI2 dependent pathway activated by lipid overload and linked to LDs formation in endothelium and smooth muscle cells has a vasoprotective role by counterbalancing detrimental effects of lipid overload on endothelial function.

Endothelium-mediated regulation of platelet activation: Involvement of multiple protein kinases.

The endothelial regulation of platelet activity is incompletely understood. Here we describe novel approaches to find molecular pathways implicated on the platelet-endothelium interaction. Using high-shear whole-blood microfluidics, employing coagulant or non-coagulant conditions at physiological temperature, we observed that the presence of human umbilical vein endothelial cells (HUVEC) strongly suppressed platelet adhesion and activation, via the collagen receptor glycoprotein VI (GPVI) and the PAR receptors for thrombin. Real-time monitoring of the cytosolic Ca2+ rises in the platelets indicated no major improvement of inhibition by prostacyclin or nitric oxide. Similarly under stasis, exposure of isolated platelets to HUVEC reduced the Ca2+ responses by collagen-related peptide (CRP-XL, GPVI agonist) and thrombin (PAR agonist). We then analyzed the label-free phosphoproteome of platelets (three donors), exposed to HUVEC, CRP-XL, and/or thrombin. High-resolution mass spectrometry gave 5463 phosphopeptides, corresponding to 1472 proteins, with good correlation between biological and technical replicates (R > .86). Stringent filtering steps revealed 26 regulatory pathways (Reactome) and 143 regulated kinase substrates (PhosphoSitePlus), giving a set of protein phosphorylation sites that was differentially (44) or similarly (110) regulated by HUVEC or agonist exposure. The differential regulation was confirmed by stable-isotope analysis of platelets from two additional donors. Substrate analysis indicated major roles of poorly studied protein kinase classes (MAPK, CDK, DYRK, STK, PKC members). Collectively, these results reveal a resetting of the protein phosphorylation profile in platelets exposed to endothelium or to conventional agonists and to endothelium-promoted activity of a multi-kinase network, beyond classical prostacyclin and nitric oxide actors, that may contribute to platelet inhibition.

Ralinepag Phase II Open-Label Extension Study in Patients with Pulmonary Arterial Hypertension.

INTRODUCTION: Ralinepag is a potent, titratable, orally administered prostacyclin (IP) receptor agonist to treat pulmonary arterial hypertension. A phase II randomized, double-blind, parallel-group, placebo-controlled, 22-week study of immediate-release (IR) ralinepag safety and efficacy met its primary endpoint, significantly reducing pulmonary vascular resistance (PVR) compared with placebo. This phase II open-label extension (OLE) study assessed long-term safety and tolerability of ralinepag. METHODS: Participants were eligible for the OLE if they completed the parent study or experienced a clinical worsening event while receiving placebo. Those previously receiving IR ralinepag remained on their current dose, and participants formerly administered placebo were titrated to the highest tolerated dose. Participants were transitioned to an extended-release ralinepag formulation toward the end of the OLE. The primary objective evaluated long-term safety and tolerability; secondary endpoints included changes in 6-min walk distance (6MWD), World Health Organization/New York Heart Association functional class, clinical worsening, and hemodynamic measures. RESULTS: In total, 45/61 participants enrolled in the OLE study, 30 from the IR ralinepag group and 15 from the placebo group. The most common adverse events (AEs) were known prostacyclin-related effects (e.g., headache, 64.4%; diarrhea, 37.8%; jaw pain, 33.3%). There was a notable decline in AEs after reaching and maintaining a stable dose. At month 24 after entering the OLE, 6MWD significantly increased by a mean of 36.3 m (P = 0.004) from OLE baseline, and most participants remained stable in their functional class (84.8%). Post-baseline PVR in 1 or 2 years decreased by a median of 52.2 dyn.s/cm5 and mean pulmonary arterial pressure decreased by a median of 2.0 mmHg (P = 0.05). CONCLUSION: Ralinepag produced sustained, durable improvements in 6MWD along with durable reductions in PVR and a manageable AE profile. Most participants continuing treatment with ralinepag maintained functional measures throughout the OLE and those switching from placebo to ralinepag often experienced functional improvements.

Pulmonary arterial hypertension is a rare disease caused by elevated pressure in the blood vessels connecting the heart to the lungs. A previous phase 2 study found that ralinepag significanlty reduced pulmonary vascular resistance (the force or resistance that blood encounters as it flows through the blood vessels in the lungs) compared with placebo. This clinical study of 45 patients investigated whether ralinepag was safe and effective for long-term use to treat people with pulmonary arterial hypertension. All participants received ralinepag twice daily until a new once daily pill was available later in the study. The primary endpoints were long-term safety and tolerability, and secondary endpoints included exercise capacity, impact on daily life (functional class), clinical worsening, and hemodynamic measures (metrics to measure how well the heart is working). The study found that ralinepag had a manageable side effect profile, with a decrease in side effects for patients who continued taking ralinepag over time. Moreover, the study showed that ralinepag improved the ability to exercise, maintained functional measures, and helped to reduce pressure in the blood vessels connecting the heart to the lungs over a 24-month period for participants with pulmonary arterial hypertension.

Prostacyclin Mitigates Renal Fibrosis by Activating Fibroblast Prostaglandin I 2 Receptor.

SIGNIFICANCE STATEMENT: Renal fibrosis is a common pathologic process of progressive CKD. We have provided strong evidence that PGI 2 is an important component in the kidney injury/repairing process by reducing fibrosis and protecting renal function from declining. In our study, administration of a PGI 2 analog or selective PTGIR agonist after the acute injury ameliorated renal fibrosis. Our findings provide new insights into the role of PGI 2 in kidney biology and suggest that targeting PGI 2 /PTGIR may be a potential therapeutic strategy for CKD. BACKGROUND: Prostanoids have been demonstrated to be important modulators to maintain tissue homeostasis in response to physiologic or pathophysiologic stress. Prostacyclin (PGI 2 ) is a member of prostanoids. While limited studies have shown that PGI 2 is involved in the tissue injury/repairing process, its role in renal fibrosis and CKD progression requires further investigation. METHODS: Prostacyclin synthase ( Ptgis )-deficient mice, prostaglandin I 2 receptor ( Ptgir )-deficient mice, and an oral PGI 2 analog and selective PTGIR agonist were used to examine the role of PGI 2 in renal fibrosis in mouse models. We also analyzed the single-cell RNA-Seq data to examine the PTGIR -expressing cells in the kidneys of patients with CKD. RESULTS: Increased PTGIS expression has been observed in fibrotic kidneys in both humans and mice. Deletion of the PTGIS gene aggravated renal fibrosis and decline of renal function in murine models. A PGI 2 analog or PTGIR agonist that was administered after the acute injury ameliorated renal fibrosis. PTGIR, the PGI 2 receptor, deficiency blunted the protective effect of the PGI 2 analog. Fibroblasts and myofibroblasts were the major cell types expressing PTGIR in the kidneys of patients with CKD. Deletion of PTGIR in collagen-producing fibroblastic cells aggravated renal fibrosis. The protective effect of PGI 2 was associated with the inhibition of fibroblast activation through PTGIR-mediated signaling. CONCLUSIONS: PGI 2 is an important component in the kidney injury/repairing process by preventing the overactivation of fibroblasts during the repairing process and protecting the kidney from fibrosis and decline of renal function. Our findings suggest that PGI 2 /PTGIR is a potential therapeutic target for CKD.

Prostacyclin in trauma patients with hemorrhagic shock: A randomized clinical trial.

BACKGROUND: A main cause of trauma morbidity and mortality is multiple-organ failure, and endotheliopathy has been implicated. Pilot studies indicate that low-dose prostacyclin improves endothelial functionality in critically ill patients, suggesting that this intervention may improve trauma patient outcome. METHODS: We conducted a multicenter, randomized, blinded, clinical investigator-initiated trial in 229 trauma patients with hemorrhagic shock who were randomized 1:1 to 72 hours infusion of the prostacyclin analog iloprost (1 ng/kg/min) or placebo. The primary outcome was the number of intensive care unit (ICU)-free days alive within 28 days of admission. Secondary outcomes included 28-day all-cause mortality and hospital length of stay. RESULTS: The mean number of ICU-free days alive within 28 days was 15.64 days in the iloprost group versus 13.99 days in the placebo group (adjusted mean difference, -1.63 days [95% confidence interval (CI), -4.64 to 1.38 days]; p = 0.28). The 28-day mortality was 18.8% in the iloprost group versus 19.6% in the placebo group (odds ratio, 1.01 [95% CI, 0.51-2.0]; p = 0.97). The mean hospital length of stay was 19.96 days in the iloprost group versus 27.32 days in the placebo group (adjusted mean difference, 7.84 days [95% CI, 1.66-14.02 days], p = 0.01). CONCLUSION: Iloprost did not result in a statistically significant increase in the number of ICU-free days alive within 28 days of admission, whereas it was safe and a statistically significant reduction in hospital length of stay was observed. Further research on prostacyclin in shocked trauma patients is warranted. LEVEL OF EVIDENCE: Therapeutic/Care Management; Level II.

Selexipag for the Treatment of Pediatric Pulmonary Hypertension: A Systematic Review.

PURPOSE: To systematically evaluate the safety, dosing regimen, and efficacy of selexipag for pediatric patients with pulmonary hypertension (PH). METHODS: A literature search of the electronic databases of PubMed, Embase, Web of Science, Cochrane Library, and Google Scholar was performed from inception through February 28, 2023. Two reviewers independently searched and evaluated the quality of the studies and pooled data when appropriate. Full-text articles of studies of children diagnosed with PH and treated with selexipag were eligible. Pediatric patients with PH were classified into 2 groups: the add-on therapy group, in which selexipag was used as a third therapy in addition to the baseline treatment, and the transition therapy group, in which patients were switched from parenteral prostacyclin analogs to selexipag. FINDINGS: Fourteen studies involving 58 pediatric patients with PH were included. All studies were either case reports or case series. Overall, 30 and 28 patients were in the add-on and transition therapy groups, respectively. In both groups, selexipag was initially administered as 50-200 µg twice daily and titrated to a tolerated dosage of 200-1,600 µg twice daily. Prostacyclin analogs were simultaneously weaned for patients in the transition group. In the add-on therapy group, 16 patients (80.0%) were at low risk of the World Health Organization functional class (WHO FC I/II), 12 (76.9%) were at low risk of the 6-minute walk distance (6MWD; >350 m), and 21 (95.5%) were at low risk of the pulmonary vascular resistance index (PVRi; <20 WU/m2). Furthermore, N-terminal pro-brain natriuretic peptide and mean pulmonary arterial pressure were significantly improved. More than 70% of patients experienced common tolerable side effects, such as headache, nausea, and diarrhea. In the transition therapy group, 5 patients (55.6%) were at low risk according to WHO FC I/II, 6 (66.7%) were at low risk according to 6MWD, and 14 (87.5) were at low risk according to PVRi; however, selexipag had no significant effect on their hemodynamic parameters. Additionally, more than 80% of patients experienced no side effects. IMPLICATIONS: Selexipag as add-on therapy or for transition from prostacyclin analogs may have a favorable safety profile and potential efficacy for pediatric patients with PH. Further high-quality evidence of the efficacy and safety of selexipag for the treatment of pediatric PH is warranted.

Widening the Prostacyclin Paradigm: Tissue Fibroblasts Are a Critical Site of Production and Antithrombotic Protection.

BACKGROUND: Prostacyclin is a fundamental signaling pathway traditionally associated with the cardiovascular system and protection against thrombosis but which also has regulatory functions in fibrosis, proliferation, and immunity. Prevailing dogma states that prostacyclin is principally derived from vascular endothelium, although it is known that other cells can also synthesize it. However, the role of nonendothelial sources in prostacyclin production has not been systematically evaluated resulting in an underappreciation of their importance relative to better characterized endothelial sources. METHODS: To address this, we have used novel endothelial cell-specific and fibroblast-specific COX (cyclo-oxygenase) and prostacyclin synthase knockout mice and cells freshly isolated from mouse and human lung tissue. We have assessed prostacyclin release by immunoassay and thrombosis in vivo using an FeCl3-induced carotid artery injury model. RESULTS: We found that in arteries, endothelial cells are the main source of prostacyclin but that in the lung, and other tissues, prostacyclin production occurs largely independently of endothelial and vascular smooth muscle cells. Instead, in mouse and human lung, prostacyclin production was strongly associated with fibroblasts. By comparison, microvascular endothelial cells from the lung showed weak prostacyclin synthetic capacity compared with those isolated from large arteries. Prostacyclin derived from fibroblasts and other nonendothelial sources was seen to contribute to antithrombotic protection. CONCLUSIONS: These observations define a new paradigm in prostacyclin biology in which fibroblast/nonendothelial-derived prostacyclin works in parallel with endothelium-derived prostanoids to control thrombotic risk and potentially a broad range of other biology. Although generation of prostacyclin by fibroblasts has been shown previously, the scale and systemic activity was unappreciated. As such, this represents a basic change in our understanding and may provide new insight into how diseases of the lung result in cardiovascular risk.

Prostaglandin and prostaglandin receptors: present and future promising therapeutic targets for pulmonary arterial hypertension.

BACKGROUND: Pulmonary arterial hypertension (PAH), Group 1 pulmonary hypertension (PH), is a type of pulmonary vascular disease characterized by abnormal contraction and remodeling of the pulmonary arterioles, manifested by pulmonary vascular resistance (PVR) and increased pulmonary arterial pressure, eventually leading to right heart failure or even death. The mechanisms involved in this process include inflammation, vascular matrix remodeling, endothelial cell apoptosis and proliferation, vasoconstriction, vascular smooth muscle cell proliferation and hypertrophy. In this study, we review the mechanisms of action of prostaglandins and their receptors in PAH. MAIN BODY: PAH-targeted therapies, such as endothelin receptor antagonists, phosphodiesterase type 5 inhibitors, activators of soluble guanylate cyclase, prostacyclin, and prostacyclin analogs, improve PVR, mean pulmonary arterial pressure, and the six-minute walk distance, cardiac output and exercise capacity and are licensed for patients with PAH; however, they have not been shown to reduce mortality. Current treatments for PAH primarily focus on inhibiting excessive pulmonary vasoconstriction, however, vascular remodeling is recalcitrant to currently available therapies. Lung transplantation remains the definitive treatment for patients with PAH. Therefore, it is imperative to identify novel targets for improving pulmonary vascular remodeling in PAH. Studies have confirmed that prostaglandins and their receptors play important roles in the occurrence and development of PAH through vasoconstriction, vascular smooth muscle cell proliferation and migration, inflammation, and extracellular matrix remodeling. CONCLUSION: Prostacyclin and related drugs have been used in the clinical treatment of PAH. Other prostaglandins also have the potential to treat PAH. This review provides ideas for the treatment of PAH and the discovery of new drug targets.

[Targeted therapy for pulmonary arterial hypertension in patients without comorbidities]. / Gezielte medikamentöse Therapie der pulmonalarteriellen Hypertonie bei Patient*innen ohne Komorbiditäten.

The 2022 guidelines on pulmonary hypertension from the European Society of Cardiology (ESC) and the European Respiratory Society (ERS) provide therapeutic strategies that account for the variability in the clinical presentation of newly diagnosed patients. We summarize treatment recommendations for pulmonary arterial hypertension (PAH) in patients without significant comorbidities, particularly for idiopathic, hereditary, drug/toxin-induced, or connective tissue disease-associated PAH. In this group of patients, multidimensional assessments for short-term mortality risk guide initial treatment decisions and treatment decisions during follow-up. Upfront dual combination therapy (phosphodiesterase type-5 inhibitor and endothelin receptor antagonist) is recommended for low- and intermediate-risk patients, and triple therapy including a parenteral prostacyclin should be considered in high- or intermediate-high-risk patients. If a low or intermediate-low-risk profile cannot be achieved during therapy, sequential add-on therapy escalation with parenteral prostacyclin or a prostacyclin receptor agonist should be considered, and switching from a phosphodiesterase type-5 inhibitor to a guanylate cyclase stimulator may also be considered.

Hospitalization-related costs associated with oral agents targeting the prostacyclin pathway for pulmonary arterial hypertension.

AIMS: Pulmonary arterial hypertension (PAH) is a rare, progressive, and ultimately fatal form of the broader condition pulmonary hypertension. ESC/ERS guidelines recommend therapy targeting the prostacyclin pathway for patients not achieving low-risk mortality status. Currently, only oral selexipag (OS) and oral treprostinil (OT) have this mechanism of action and are available in the United States (US). A recent database analysis has shown significantly lower hospitalization risk for patients treated with OS versus OT. Nevertheless, differences in hospitalization and treatment costs among PAH patients taking oral prostacyclin pathway agents (PPAs) in the US healthcare system remain unclear. This study aims to estimate the difference in costs for patients who achieve a stable maintenance dose from a US payer perspective. MATERIALS AND METHODS: We developed a cost calculator including direct medical costs from the US third-party payer perspective to estimate PAH-related hospitalizations and costs associated with oral PPA use over 2 years, in a hypothetical US payer plan with 1 million members. The treatment-eligible population was estimated from real-world epidemiological data. Treatment-specific hospitalizations were estimated from a study using the Optum Clinformatics administrative claims database. Influence of each model parameter was tested in one-way sensitivity analyses (OWSA), while scenario analysis tested the impact of key assumptions. RESULTS: For 78 PAH patients included in the model, the base case scenario estimated total costs of $46,736,768 with 98 PAH-related admissions for OS, and total costs of $60,113,620 and 161 PAH-related admissions over 2 years for OT. Using OS was associated with 22.3% cost reduction and 39.1% hospitalizations averted; the number of patients needed treated with selexipag to avoid one hospital admission was 1.23. OWSA indicated medication cost was the most sensitive parameter, followed by population parameters. LIMITATIONS AND CONCLUSIONS: OS use over 2 years would result in lower total, drug, and hospitalization-related costs compared with OT, thus providing financial savings for payers.

Real life use of prostacyclin analog (iloprost), a multi-centric survey data from the Scleroderma study group Emilia Romagna (Sclero-RER) and review of the literature.

BACKGROUND AND AIM: Iloprost is recommend worldwide for the treatment of RP and the healing of DUs. The aim of this study is to report the regimens of Iloprost administered in different rheumatological centers within the same regional Health System Methods: A questionnaire exploring different items related to the use of Iloprost was developed and reviewed by three expert rheumatologists. The questionnaire was distributed as an online survey to all local SSc referral centers in Emilia-Romagna (Italy). Data are reported as percentage or median with interquartile range (IQR), as appropriate. An updated review of world literature on this topic was also carried out. RESULTS: All the invited centers completed the survey. There were both local (8) and university hospitals (4). The majority (58%) had a rheumatologist as head physician. All centers used Iloprost: a single monthly administration was the most common treatment (75%). The cycle lasted 1 [IQR 1-2] days with a 0.5-2.0 ng/Kg/min dose according to the drug tolerance of the patients. There were overall 68 spots (beds, reclining armchair, or simple armchair); 2.0 [1.5-4.0] patients were able to receive Iloprost at the same time. University Hospitals had more physicians at their disposal than local hospitals but less paramedic personnel (respectively: 1.8 vs 1.2 physicians, 1.5 vs 2.1 nurses). CONCLUSIONS: These observations were in line with the majority of previous studies reporting different regimens, comparing similar (but not identical) dose and schedule administration, however, despite differences being at times substantial, no standard infusion method is yet available.

Diverse effects of prostacyclin on angiogenesis-related processes in the porcine endometrium.

Angiogenesis is important for endometrial remodeling in mature females. The endometrium synthesizes high amounts of prostacyclin (PGI2) but the role of PGI2 in angiogenesis-related events in this tissue was not fully described. In the present study, porcine endometrial endothelial (pEETH) cells and/or a swine umbilical vein endothelial cell line (G1410 cells) were used to determine the regulation of PGI2 synthesis and PGI2 receptor (PTGIR) expression by cytokines and to evaluate the effect of PGI2 on pro-angiogenic gene expression, intracellular signaling activation, cell proliferation and migration, cell cycle distribution, and capillary-like structure formation. We found that IL1ß, IFNγ, and/or TNFα increased PGI2 secretion and PTGIR expression in pEETH cells. Iloprost (a PGI2 analogue) acting through PTGIR enhanced the transcript abundance of KDR, FGFR2, and ANGPT2 and increased proliferation of pEETH cells. This latter was mediated by PI3K and mTOR activation. In support, transfection of G1410 cells with siRNA targeting PGI2 synthase decreased pro-angiogenic gene expression and cell proliferation. Furthermore, iloprost accelerated the gap closure and promoted cell cycle progression. Intriguingly, the formation of capillary-like structures was inhibited but not completely blocked by iloprost. These findings point to a complex pleiotropic role of PGI2 in angiogenesis-related events in the porcine uterus.

Pulmonary Vasodilator Therapy in Pediatric Patients on Ventricular Assist Device Support: A Single-Center Experience and Proposal for Use.

Pediatric precapillary pulmonary hypertension can develop in response to systemic atrial hypertension. Systemic atrial decompression following ventricular assist device (VAD) implantation may not sufficiently lower pulmonary vascular resistance (PVR) to consider heart transplant candidacy. Prostacyclins have been used in adult VAD patients with success, but pediatric data on safety and efficacy in this population are limited. We sought to describe our center's experience to show its safety and to present our current protocol for perioperative use. We reviewed our use of prostacyclin therapy in pediatric patients on VAD support with high PVR from 2016 to 2021. Of the 17 patients who met inclusion, 12 survived to transplant and 1 is alive with VAD in situ . All patients survived posttransplant. With continuous intravenous (IV) epoprostenol or treprostinil therapy, there were no bleeding complications or worsening of end-organ function. A significant reduction was observed in vasoactive inotropic scores by 49% in the first 24 hours post-prostacyclin initiation. The proportion of patients surviving to transplant in this high-risk cohort is favorable. In conclusion, prostacyclins may be safe to use in patients with elevated PVR as part of their VAD and transplant course and may provide a transplant option in those otherwise not candidates.

Management of Pulmonary Arterial Hypertension.

Pulmonary arterial hypertension (PAH) is a rare pulmonary vascular disease characterized by progressive pulmonary arterial remodeling, increased pulmonary vascular resistance, right ventricular dysfunction, and reduced survival. Effective therapies have been developed that target three pathobiologic pathways in PAH: nitric oxide, endothelin-1, and prostacyclin. Approved therapies for PAH include phosphodiesterase type-5 inhibitors, soluble guanylate cyclase stimulators, endothelin receptor antagonists, prostacyclin analogs, and prostacyclin receptor agonists. Management of PAH in the modern era incorporates multidimensional risk assessment to guide the use of these medications. For patients with PAH and without significant comorbidities, current guidelines recommend two oral medications (phosphodiesterase type-5 inhibitor and endothelin receptor antagonist) for low- and intermediate-risk patients, with triple therapy including a parenteral prostacyclin to be considered in those at high or intermediate-high risk. Combination therapy may be poorly tolerated and less effective in patients with PAH and cardiopulmonary comorbidities. Thus, a single-agent approach with individualized decisions to add-on other PAH therapies is recommended in older patients and those with significant comorbid conditions. Management of PAH is best performed in multidisciplinary teams located in experienced centers. Other core pillars of PAH management include supportive and adjunctive treatments including oxygen, diuretics, rehabilitation, and anticoagulation in certain patients. Patients with PAH who progress despite optimal treatment or who are refractory to best medical care should be referred for lung transplantation, if eligible. Despite considerable progress, PAH is often fatal and new therapies that reverse the disease and improve outcomes are desperately needed.

The perioperative use of inhaled prostacyclins in cardiac surgery: a systematic review and meta-analysis.

PURPOSE: Perioperative pulmonary hypertension (PH) is an independent risk factor for morbidity and mortality in cardiac surgery. While inhaled prostacyclins (iPGI2s) are an established treatment of chronic PH, data on the efficacy of iPGI2s in perioperative PH are scarce. METHODS: We searched PubMed, Embase, the Web of Science, CENTRAL, and the grey literature from inception until April 2021. We included randomized controlled trials investigating the use of iPGI2s in adult and pediatric patients undergoing cardiac surgery with an increased risk of perioperative right ventricle failure. We assessed the efficacy and safety of iPGI2s compared with placebo and other inhaled or intravenous vasodilators with random-effect meta-analyses. The primary outcome was mean pulmonary artery pressure (MPAP). Secondary outcomes included other hemodynamic parameters and mortality. RESULTS: Thirteen studies were included, comprising 734 patients. Inhaled prostacyclins significantly decreased MPAP compared with placebo (standardized effect size, 0.46; 95% confidence interval [CI], 0.11 to 0.87; P = 0.01) and to intravenous vasodilators (1.26; 95% CI, 0.03 to 2.49; P = 0.045). Inhaled prostacyclins significantly improved the cardiac index compared with intravenous vasodilators (1.53; 95% CI, 0.50 to 2.57; P = 0.004). In contrast, mean arterial pressure was significantly lower in patients treated with iPGI2s vs placebo (-0.39; 95% CI, -0.62 to 0.16; P = 0.001), but higher than in patients treated with intravenous vasodilators (0.81; 95% CI, 0.29 to 1.33; P = 0.002). With respect to hemodynamics, iPGI2s had similar effects as other inhaled vasodilators. Mortality was not affected by iPGI2s. CONCLUSION: The results of this systematic review and meta-analysis show that iPGI2s improved pulmonary hemodynamics with similar efficacy as other inhaled vasodilators, but caused a significant small decrease in arterial pressure when compared with placebo, indicating spill-over into the systemic circulation. These effects did not affect clinical outcomes. STUDY REGISTRATION DATE: PROSPERO (CRD42021237991); registered 26 May 2021.

RéSUMé: OBJECTIF: L'hypertension pulmonaire (HTAP) périopératoire est un facteur de risque indépendant de morbidité et de mortalité en chirurgie cardiaque. Bien que l'inhalation de prostacyclines (iPGI2) constitue un traitement établi de l'HTAP chronique, les données sur l'efficacité de ce traitement en cas d'HTAP périopératoire sont rares. MéTHODE: Nous avons effectué des recherches dans les bases de données PubMed, Embase, Web of Science, CENTRAL et dans la littérature grise depuis leur création jusqu'en avril 2021. Nous avons inclus des études randomisées contrôlées portant sur l'utilisation de l'iPGI2 chez la patientèle adulte et pédiatrique bénéficiant d'une chirurgie cardiaque avec un risque accru d'insuffisance ventriculaire droite périopératoire. Nous avons évalué l'efficacité et l'innocuité des iPGI2 par rapport à un placebo et à d'autres vasodilatateurs inhalés ou intraveineux avec des méta-analyses à effets aléatoires. Le critère d'évaluation principal était la pression artérielle pulmonaire moyenne (PAPm). Les critères d'évaluation secondaires incluaient d'autres paramètres hémodynamiques et la mortalité. RéSULTATS: Treize études portant sur 734 patient·es ont été incluses. Les prostacyclines inhalées ont diminué de manière significative la PAPm par rapport au placebo (taille d'effet standardisée, 0,46; intervalle de confiance [IC] à 95 %, 0,11 à 0,87; P = 0,01) et aux vasodilatateurs intraveineux (1,26; IC 95 %, 0,03 à 2,49; P = 0,045). Les prostacyclines inhalées ont significativement amélioré l'index cardiaque par rapport aux vasodilatateurs intraveineux (1,53; IC 95 %, 0,50 à 2,57; P = 0,004). En revanche, la pression artérielle moyenne était significativement plus faible chez les patient·es traité·es par iPGI2 vs placebo (−0,39; IC 95 %, −0,62 à 0,16; P = 0,001), mais plus élevée que chez les personnes traitées par vasodilatateurs intraveineux (0,81; IC 95 %, 0,29 à 1,33; P = 0,002). En ce qui concerne l'hémodynamie, les iPGI2 ont eu des effets similaires à ceux des autres vasodilatateurs inhalés. La mortalité n'a pas été affectée par les iPGI2. CONCLUSION: Les résultats de cette revue systématique et méta-analyse montrent que les iPGI2 ont amélioré l'hémodynamie pulmonaire avec une efficacité similaire à celle des autres vasodilatateurs inhalés, mais ont entraîné une diminution légère mais significative de la pression artérielle par rapport au placebo, indiquant un débordement dans la circulation systémique. Ces effets n'ont pas affecté les résultats cliniques. ENREGISTREMENT DE L'éTUDE: PROSPERO (CRD42021237991); enregistrée le 26 mai 2021.