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Biomedical subjects

G Simonneau

Publications and source records attributed to G Simonneau.

At least 19 recordsLinked to original sources

Fractalkine-induced smooth muscle cell proliferation in pulmonary hypertension.

Pulmonary hypertension is characterised by a progressive increase in pulmonary arterial resistance due to endothelial and smooth muscle cell proliferation resulting in chronic obstruction of small pulmonary arteries. There is evidence that inflammatory mechanisms may contribute to the pathogenesis of human and experimental pulmonary hypertension. The aim of the study was to address the role of fractalkine (CX3CL1) in the inflammatory responses and pulmonary vascular remodelling of a monocrotaline-induced pulmonary hypertension model. The expression of CX3CL1 and its receptor CX3CR1 was studied in monocrotaline-induced pulmonary hypertension by means of immunohistochemistry and quantitative reverse-transcription PCR on laser-captured microdissected pulmonary arteries. It was demonstrated that CX3CL1 was expressed by inflammatory cells surrounding pulmonary arterial lesions and that smooth muscle cells from these vessels had increased CX3CR1 expression. It was then shown that cultured rat pulmonary artery smooth muscle cells expressed CX3CR1 and that CX3CL1 induced proliferation but not migration of these cells. In conclusion, the current authors proposed that fractalkine may act as a growth factor for pulmonary artery smooth muscle cells. Chemokines may thus play a role in pulmonary artery remodelling.

Analysis of Variance↗

Dendritic cell recruitment in lesions of human and experimental pulmonary hypertension.

In the present study, the hypothesis that dendritic cells (DCs), key players in immunity and tolerance, might be involved in the immunopathology of idiopathic pulmonary arterial hypertension (IPAH) was tested. The phenotype and localisation of DCs were characterised by immunohistochemistry and double-labelling immunofluorescence in lung samples from controls, human IPAH patients and an experimental pulmonary hypertension model (monocrotaline-exposed rats). As compared with controls, morphometric analysis demonstrated increased numbers of dendritic cell-specific intercellular adhesion molecule-grabbing nonintegrin (DC-SIGN)-positive cells in muscular pulmonary arteries in IPAH and OX-62-positive DCs in monocrotaline-induced pulmonary hypertension. In human samples, the mean+/-SEM number of DC-SIGN-positive cells.artery(-1) of 100-300 microm diameter was 1.4+/-0.4 in controls versus 26.4+/-2.7 in IPAH. In rats, the number of OX-62-positive cells.artery(-1) of 50-150 microm diameter was 0.5+/-0.2 in controls, and 0.7+/-0.5, 3.1+/-0.5 and 8.4+/-0.6 at day 7, 14 and 28 after monocrotaline exposure, respectively. Human complex lesions of muscular pulmonary arteries showed transmural DC infiltration. Phenotyping revealed an immature DC profile in human and experimental pulmonary hypertension. The results support the concept that immature dendritic cells accumulate in remodelled pulmonary vessels and hence could be involved in the immunopathology of pulmonary hypertension.

Animals↗

Long-term outcome in pulmonary arterial hypertension patients treated with subcutaneous treprostinil.

Pulmonary arterial hypertension (PAH) is fatal if untreated. Intravenous epoprostenol improves exercise capacity and haemodynamics in PAH, and increases survival in idiopathic PAH (IPAH). To evaluate the effects of subcutaneous (SC) treprostinil, a longer-acting prostacyclin analogue, followed by the addition of other PAH therapies if needed, 860 PAH patients treated with SC treprostinil for up to 4 yrs were followed. Survival is reported as Kaplan-Meier estimates. For 332 IPAH patients with baseline haemodynamics, observed survival is also compared with predicted survival using the National Institute of Health formula. Out of the 860 patients, 199 (23%) discontinued due to adverse events, 136 (16%) died, 117 (14%) discontinued due to deterioration, 29 (3%) withdrew consent and 11 (1%) underwent transplantation. In total, 97 patients (11%) switched from SC treprostinil to an alternative prostacyclin analogue; bosentan was added in 105 patients (12%) and sildenafil in 25 (3%). In conclusion, survival was 87-68% over 1-4 yrs for all 860 patients and 88-70% over 1-4 yrs with subcutaneous treprostinil monotherapy. For the idiopathic pulmonary arterial hypertension subset with baseline haemodynamics (n = 332), survival was 91-72% over 1-4 yrs. In contrast, predicted survival was 69-38% over 1-4 yrs. The safety profile for long-term subcutaneous treprostinil was consistent with previous short-term trials with no unexpected adverse events.

Adolescent↗

A randomized study comparing the efficacy and safety of nadroparin 2850 IU (0.3 mL) vs. enoxaparin 4000 IU (40 mg) in the prevention of venous thromboembolism after colorectal surgery for cancer.

BACKGROUND: The optimal thromboprophylactic dosage regimen of low-molecular-weight heparins in high-risk general surgery remains debatable. OBJECTIVES: We performed a randomized, double-blind study to compare the efficacy and safety of nadroparin 2850 IU (0.3 mL) and enoxaparin 4000 IU (40 mg) in the prevention of venous thromboembolism (VTE) after colorectal surgery for cancer. PATIENTS AND METHODS: Patients undergoing resection of colorectal adenocarcinoma were randomized to receive once daily either 2850 IU nadroparin or 4000 IU enoxaparin s.c. for 9 +/- 2 days. The primary efficacy outcome was the composite of deep vein thrombosis (DVT) detected by bilateral venography or documented symptomatic DVT or pulmonary embolism up to day 12. The main safety outcome was major bleeding. A blinded independent committee adjudicated all outcomes. RESULTS: Out of 1288 patients analyzed, efficacy was evaluable in 950 (73.8%) patients. The VTE rate was 15.9% (74/464) in nadroparin-treated patients and 12.6% (61/486) in enoxaparin-treated patients, a relative risk of 1.27 (95% confidence interval; CI: 0.93-1.74) that did not met the criterion for non-inferiority of nadroparin. The rate of proximal DVT was comparable in the two groups (3.2% vs. 2.9%, respectively), but that of symptomatic VTE was lower in nadroparin-treated patients (0.2% vs. 1.4%). There was significantly (P = 0.012) less major bleeding in nadroparin- than in enoxaparin-treated patients (7.3% vs. 11.5%, respectively). CONCLUSION: Compared with those receiving enoxaparin 4000 IU, patients treated with nadroparin 2850 IU showed a higher incidence of asymptomatic distal DVT, but a lower incidence of symptomatic VTE. Nadroparin treatment was safer in terms of bleeding risk.

Adult↗

Antibodies to fibroblasts in idiopathic and scleroderma-associated pulmonary hypertension.

The aim of the present study was to investigate the presence of anti-fibroblast antibodies in patients with idiopathic or scleroderma-associated pulmonary arterial hypertension (PAH) and healthy controls. PAH was documented by right-heart catheterisation (mean pulmonary artery pressure at rest >25 mmHg). Serum immunoglobulin (Ig)G and IgM reactivities of patients with idiopathic PAH (n = 35), scleroderma-associated PAH (n = 10), diffuse (n = 10) or limited cutaneous (n = 10) scleroderma without PAH and age- and sex-matched healthy individuals (n = 65) were analysed by cell-based ELISA and immunoblotting on normal human fibroblasts. As assessed by ELISA, 14 out of 35 (40%) patients with idiopathic PAH and three out of 10 (30%) patients with scleroderma-associated PAH expressed anti-fibroblast IgG antibodies. IgG from all individuals bound to one major 40-kDa protein band. IgG from patients with idiopathic PAH bound to two 25- and 60-kDa bands with a higher intensity than IgG from other individuals. In conclusion, immunoglobulin G anti-fibroblast antibodies are present in the serum of patients with pulmonary arterial hypertension. Immunoglobulin G from patients with idiopathic pulmonary arterial hypertension or scleroderma-associated pulmonary arterial hypertension express distinct reactivity profiles with fibroblasts antigens, suggesting distinct target antigens.

Adult↗

The efficacy of bosentan in inoperable chronic thromboembolic pulmonary hypertension: a 1-year follow-up study.

The treatment of choice for chronic thromboembolic pulmonary hypertension (CTEPH) is pulmonary endarterectomy (PEA). However, many patients develop a severe progressive small vessel pulmonary arteriopathy that is inaccessible to surgical intervention and is associated with poor survival. The purpose of the present study was to evaluate the medium-term efficacy and safety of the dual endothelin receptor antagonist, bosentan, in inoperable CTEPH. Forty-seven patients with inoperable CTEPH (distal disease or persistent pulmonary hypertension following PEA) underwent evaluation after 1 yr of bosentan therapy. Outcomes included assessment of 6-min walk test (6MWT), haemodynamics and World Health Organization functional classification. Monitoring of serious adverse effects and changes in therapy was undertaken. Patients showed sustained improvements in 6MWT (49+/-8 m), functional classification, cardiac index (+0.2+/-0.07 L.min(-1).m(-2)) and total pulmonary resistance (-139+/-42 dyn.s.cm(-5)). Those patients with persisting pulmonary hypertension following PEA showed the greatest improvement. One-yr survival was 96%, and bosentan was well tolerated with only one patient developing deranged liver function. Although all patients with chronic thromboembolic pulmonary hypertension should be considered for pulmonary endarterectomy, bosentan provides an alternative medical therapy to improve function and delay the progression of this devastating disease in those in whom surgery is not suitable.

Adult↗

Bosentan for the treatment of pulmonary arterial hypertension associated with congenital heart defects.

BACKGROUND: Bosentan is an effective first-line therapy in New York Heart Association (NYHA) III patients with idiopathic pulmonary arterial hypertension (PAH). Pre-clinical data support the rationale for the potential benefit of bosentan in PAH associated with congenital heart disease (CHD). MATERIALS AND METHODS: We performed a retrospective analysis of patients with PAH-associated CHD who were treated with bosentan on top of conventional therapy. Bosentan was started at 62.5 mg bid for 4 weeks, then titrated to 125 mg bid. New York Heart Association (NYHA) functional class, 6-min walking distance (6MWD), Borg dyspnoea index, arterial oxygen saturation and cardiopulmonary haemodynamic data (cardiac output, pulmonary blood flow and systemic and pulmonary vascular resistances) were collected at baseline and at follow up. RESULTS: Twenty-seven patients (23 females, mean 35 +/- 15 years) with NYHA class III-IV PAH-associated CHD (not repaired in 23 cases) were treated with bosentan for a mean 18.3 +/- 9.9 months. Bosentan improved 6MWD from 298 +/- 92 m at baseline to 355 +/- 82 m at 3 months (P = 0.0002) and to 364 +/- 92 m (P = 0.0001) at the last follow up (mean 15.2 +/- 9.7 months). At the last follow up, 13 patients had improved (= 1 NYHA class) and 14 remained stable. A favourable effect was observed in pulmonary blood flow and pulmonary vascular resistance for the 11 available patients. No change in pulse oximetry or liver enzyme elevation was reported. CONCLUSIONS: Bosentan improves exercise capacity, functional class and haemodynamics in most patients with PAH-associated CHD, without serious side-effects, suggesting bosentan may be an important treatment option for these patients.

Adolescent↗

Heart rate responses during the 6-minute walk test in pulmonary arterial hypertension.

Patients with pulmonary arterial hypertension (PAH) exhibit a limited increase in stroke volume on exercise, and the heart rate (HR) increases may reflect the main mechanism that allows cardiac output to increase. The current prospective study documented the contribution of HR to the 6-min walking distance (6MWD) in idiopathic (IPAH) and nonidiopathic PAH. Eighty-three patients (46 IPAH and 37 nonidiopathic PAH) underwent haemodynamic evaluation and a 6MWD test. Chronotropic response (peak walking HR minus resting HR) and peripheral oxygen saturation were monitored. Fifty-seven patients were also assessed after 5+/-2 months of treatment (bosentan n = 38, epoprostenol n = 14, bosentan-epoprostenol n = 3, iloprost n = 2). Before treatment, the 6MWD was related to numerous demographic, haemodynamic and walking test characteristics. Stepwise regression analysis indicated that the only factors significantly associated with the 6MWD were stroke volume and chronotropic response in both IPAH and nonidiopathic PAH patients. Following treatment, changes in 6MWD were significantly related to changes in chronotropic response in both IPAH and nonidiopathic PAH. In conclusion, baseline stroke volume and chronotropic response were independently associated with the 6-min walking distance in pulmonary arterial hypertension. The lack of chronotropic response may reflect the loss in normal physiological reserve in more unwell patients.

Analysis of Variance↗

Occult alveolar haemorrhage in pulmonary veno-occlusive disease.

Pulmonary veno-occlusive disease (PVOD) is a rare cause of pulmonary arterial hypertension that affects predominantly post-capillary pulmonary vessels. A major concern with PVOD is the poor response to available therapies and the risk of pulmonary oedema with continuous intravenous epoprostenol. The present authors hypothesised that alveolar haemorrhage may be a characteristic feature of pulmonary veno-occlusive disease, as compared with other forms of pulmonary arterial hypertension that predominantly involve pre-capillary pulmonary arteries. This paper reports a series of 19 patients with either PVOD (n = 8) or idiopathic pulmonary arterial hypertension (IPAH; n = 11) who underwent bronchoalveolar lavage. Cytological analyses were performed and differential counts were made on Perls-stained preparations. The Golde score was used to assess alveolar haemorrhage. As compared with IPAH, PVOD was characterised by a higher percentage of haemosiderin-laden macrophages (40+/-37 versus 3+/-6%), resulting in elevated Golde scores (81+/-88 versus 4+/-10). It was concluded that occult alveolar haemorrhage is a common feature of pulmonary veno-occlusive disease. Detecting occult alveolar haemorrhage may be of interest in the diagnostic approach of pulmonary veno-occlusive disease.

Adult↗

[Diagnosis and classification of pulmonary arterial hypertension].

The clinical classification of types of pulmonary hypertension has made it possible to better standardize the approach to the diagnosis and treatment of patients, to perform clinical studies among homogeneous patients, and to discover common laboratory abnormalities that may serve as markers or help elucidate mechanisms of disease. Pulmonary arterial hypertension groups together different diseases that affect the small-caliber pulmonary arteries and lead to a progressive increase in pulmonary arterial resistance and right heart failure. A specific diagnosis of pulmonary arterial hypertension is generally based on a detailed and methodical clinical evaluation. Pulmonary biopsy is rarely indicated. Work-up in a center specialized in the management of this disease is frequently appropriate when the cause of the hypertension is not clear or when a specific treatment is envisaged.

Diagnostic Imaging↗

[Treatment of pulmonary arterial hypertension].

Pulmonary arterial hypertension (PAH) is characterized by vasoconstriction, in situ thrombosis, and vascular remodeling of small pulmonary arteries. It induces a fixed pulmonary arterial obstruction, persistent elevation of pulmonary arterial resistance, and eventually right heart failure. Conventional therapy is based on simple measures (exercise limitation) and nonspecific treatments (warfarin, diuretics, and oxygen). Pure vasodilators, such as calcium channel blockers, are effective only in a minority of patients who have an acute response to vasodilator testing. Intravenous prostacyclin (epoprostenol) and endothelin receptor blockers have vasodilator and antiproliferative properties. Epoprostenol therapy has significantly improved PAH prognosis and remains the first-line treatment for patients with the most severe disease. Bosentan is an interesting first-line treatment for NYHA functional class III patients. Availability of novel specific drugs (endothelin receptor type A antagonists, prostacyclin analogues, type 5 phosphodiesterase inhibitors) is opening new perspectives in PAH treatment. The long-term benefit of these drugs remains to be evaluated and their respective place in treatment of these patients is still uncertain. The evolution of therapy from vasodilators to antiproliferative agents reflects the advancement in our understanding of the mechanisms mediating pulmonary arterial hypertension.

Algorithms↗

[Treatment for pulmonary arterial hypertension under the new French hospital financing system. Recommendations of the Pulmonary Vascular Diseases Working Group of the French Society of Pulmonary Medicine].

Activity-based financing (that is, casemix-based hospital payments, known as T2A) is intended to harmonize and improve the fairness of remuneration of public and private hospitals. T2A will ultimately rely mainly on a flat rate per admission, set according to the diagnosis-related group (DRG). Although payment for drugs is usually included in the DRG price, some expensive drugs will be reimbursed on an additional cost basis after implementation of a "best practices" agreement. Four drugs used for treatment of pulmonary arterial hypertension are eligible for this additional reimbursement: 3 prostacyclin derivatives (intravenous epoprostenol, inhaled iloprost, and subcutaneous treprostinil), and oral bosentan, an endothelin receptor antagonist. The Pulmonary Vascular Diseases working group of the French Society of Pulmonary Medicine has developed guidelines for the best practices in use of these drugs.

Antihypertensive Agents↗

[Surgical treatment of chronic thromboembolic pulmonary hypertension].

Chronic thromboembolic pulmonary hypertension is a condition that has long remained in the shadows, a kind of orphan disease, because of the lack of any curative treatment. The renewal of interest by pulmonary specialists, cardiologists and thoracic surgeon is due to the development over the past 20 years of major new treatments: lung transplantation, continuous prostacyclin infusion, and pulmonary endarterectomy, in chronological order. Most patients with postembolic pulmonary arterial hypertension (PEPAH) in a sufficiently proximal location can benefit from curative surgical treatment by bilateral endarterectomy of the pulmonary arteries. This complex surgery, performed under deep hypothermic circulatory arrest, clears out the pulmonary vascular bed down through its subsegmental branches and results in a frank reduction in pulmonary vascular resistance and normalization of cardiopulmonary function. It is a curative procedure with a perioperative mortality rate less than 7% and a definitive result, unlike pulmonary and cardiopulmonary transplantation, which have a postoperative mortality rate of 20% and a 5-year survival rate of 50%. It is difficult to recognize the postembolic nature of pulmonary hypertension because there is no known history of venous thrombosis or embolic phenomena in more than 50% of cases. Diagnosis is based on the presence of mismatched segmental defects in the radioisotopic ventilation-perfusion scanning. To be accessible to endarterectomy, lesions must involve the main, lobar, or segmental arteries. When conducted by experienced operators according to specific protocols, pulmonary (frontal and lateral views of each lung) and multislice CT angiography optimize assessment of the lesion site. When the pulmonary vascular resistance evaluated by catheterization is correlated with the anatomical obstruction visible on the images, pulmonary endarterectomy has a mortality rate below 4% and offers the patient a substantial chance to regain normal cardiorespiratory function. In cases of pulmonary arterial hypertension due to older embolisms, major arteriolitis occurs in the nonobstructed areas and aggravates the pulmonary hypertension, which may become suprasystemic. The endarterectomy mortality rate is then higher, and in specific cases justifies preoperative medical treatment. Pulmonary or cardiopulmonary transplantation is indicated in this disease only when the lesions are too distal and thus inaccessible to endarterectomy.

Cardiac Catheterization↗

Pulmonary hypertension associated with sarcoidosis: mechanisms, haemodynamics and prognosis.

BACKGROUND: Pulmonary hypertension (PH) is a rare complication of sarcoidosis, although it is not uncommon in advanced disease. METHODS: A retrospective series of 22 sarcoidosis patients (16 men) of mean (SD) age 46 (13) years with PH was divided into two groups depending on the absence (stage 0: n = 2, stage II: n = 4, stage III: n = 1) or presence (n = 15) of radiographic pulmonary fibrosis at the time of PH diagnosis. RESULTS: In both groups PH was moderate to severe and there was no response to acute vasodilator challenge. In non-fibrotic cases no other cause of PH was found, suggesting a specific sarcoidosis vasculopathy, although no histological specimens were available. In cases with fibrosis there was no correlation between haemodynamics and lung volumes or arterial oxygen tensions, suggesting other mechanisms for PH in addition to pulmonary destruction and hypoxaemia. These included extrinsic arterial compression by lymphadenopathies in three cases and histologically proven pulmonary veno-occlusive disease in the five patients who underwent lung transplantation. Ten patients received high doses of oral prednisone for PH (stage 0: n = 1, stage II: n = 4 and stage IV: n = 5); three patients without pulmonary fibrosis experienced a sustained haemodynamic response. Survival of the overall population was poor (59% at 5 years). Mortality was associated with NYHA functional class IV but not with haemodynamic parameters or with lung function. CONCLUSION: Two very different phenotypes of sarcoidosis combined with PH are observed depending on the presence or absence of pulmonary fibrosis. PH is a severe complication of sarcoidosis.

Adrenal Cortex Hormones↗

Splenectomy and chronic thromboembolic pulmonary hypertension.

BACKGROUND: An increased prevalence of splenectomy has been reported in patients with idiopathic pulmonary arterial hypertension. Examination of small pulmonary arteries from these subjects has revealed multiple thrombotic lesions, suggesting that thrombosis may contribute to this condition. Based on these findings, we hypothesised that splenectomy could be a risk factor for chronic thromboembolic pulmonary hypertension (CTEPH), a condition defined by the absence of thrombus resolution after acute pulmonary embolism that causes sustained obstruction of the pulmonary arteries and subsequent pulmonary hypertension. METHODS: The medical history, clinical characteristics, thrombotic risk factors and haemodynamics of 257 patients referred for CTEPH between 1989 and 1999 were reviewed. In a case-control study the prevalence of splenectomy in patients with CTEPH was compared with that of patients evaluated during the same period for idiopathic pulmonary hypertension (n=276) or for lung transplantation in other chronic pulmonary conditions (n=180). RESULTS: In patients with CTEPH, 8.6% (95% CI 5.2 to 12.0) had a history of splenectomy compared with 2.5% (95% CI 0.7 to 4.4) and 0.56% (95% CI 0 to 1.6) in cases of idiopathic pulmonary arterial hypertension and other chronic pulmonary conditions, respectively (p<0.01). CONCLUSION: Splenectomy may be a risk factor for chronic thromboembolic pulmonary hypertension.

Case-Control Studies↗

Survival in patients with class III idiopathic pulmonary arterial hypertension treated with first line oral bosentan compared with an historical cohort of patients started on intravenous epoprostenol.

BACKGROUND: The oral dual endothelin receptor antagonist bosentan improves exercise capacity and delays clinical worsening in patients with pulmonary arterial hypertension, but its use could delay starting intravenous epoprostenol, a life saving treatment. METHODS: Survival in patients with functional class III idiopathic pulmonary arterial hypertension (PAH) treated with bosentan in clinical trials was compared with historical data from similar patients treated with epoprostenol in the clinic. Statistical methods were used to adjust for possible underlying differences between the two groups. RESULTS: Baseline factors for the 139 patients treated with bosentan and the 346 treated with epoprostenol suggested that the epoprostenol cohort had more severe disease-that is, a lower cardiac index (2.01 v 2.39 l/min/m2) and higher pressures and resistance. Kaplan-Meier survival estimates after 1 and 2 years were 97% and 91%, respectively, in the bosentan cohort and 91% and 84% in the epoprostenol cohort. Cox regression analyses adjusting for differences in baseline factors showed a greater probability of death in the epoprostenol cohort (hazard ratio 2.2 (95% confidence interval 1.2 to 4.0) in the model adjusted for haemodynamics). Alternative regression analyses and analyses to adjust for different data collection dates gave consistently similar results. When matched cohorts of 83 patients each were selected, survival estimates were similar. In the bosentan cohort 87% and 75% of patients followed for 1 and 2 years, respectively, remained on monotherapy. CONCLUSIONS: No evidence was found to suggest that initial treatment with oral bosentan, followed by or with the addition of other treatment if needed, adversely affected the long term outcome compared with initial intravenous epoprostenol in patients with class III idiopathic PAH.

Administration, Oral↗

[Pulmonary arterial hypertension].

INTRODUCTION: Pulmonary arterial hypertension (PAH) is a rare condition characterised by progressively elevated pulmonary arterial resistance leading to right heart failure. STATE OF THE ART: A recent classification distinguishes idiopathic PAH, familial PAH and PAH secondary to other conditions (connective tissue disease, congenital heart disease, portal hypertension, human immunodeficiency virus infection or appetite suppressant exposure). Echocardiography is the initial investigation of choice for non-invasive detection of PAH but measurement of pulmonary pressures and cardiac output during right-heart catheterization are necessary to confirm the diagnosis of PAH. Conventional treatment includes non-specific drugs (warfarin, diuretics, oxygen). Intravenous epoprostenol is the first-line treatment for the most severely affected patients. In less severe cases, the first-line treatment may include bosentan or a prostacyclin analogue. PERSPECTIVES AND CONCLUSIONS: Recent advances in the management of PAH have markedly improved prognosis. The avai-lability of novel specific drugs including type 5 phosphodiesterase inhibitors offers novel therapeutic perspectives but their exact role in the treatment of PAH is still uncertain. The evolution of therapy from vasodilators to antiproliferative agents reflects the advancement in our understanding of the mechanisms mediating pulmonary arterial hypertension.

Antihypertensive Agents↗