Safety and efficacy of inhaled treprostinil as add-on therapy to bosentan in pulmonary arterial hypertension.

OBJECTIVES: This study evaluated the safety and efficacy of inhaled treprostinil as add-on therapy to oral bosentan in patients with pulmonary arterial hypertension (PAH). BACKGROUND: The addition of a long-acting prostacyclin analogue via the inhaled route might be a safe and effective strategy to optimize therapy in PAH patients on bosentan. METHODS: Twelve patients with symptomatic PAH despite bosentan received either 30 microg of inhaled treprostinil 4 times daily (n = 6) or 45 microg 4 times daily (n = 6), via an ultrasonic nebulizer. Six-min walk distance (6MWD), functional class, and hemodynamics were assessed at baseline and 12 weeks. RESULTS: One patient was excluded from analysis due to the subsequent finding of pulmonary capillary hemangiomatosis. In the remaining 11 patients, inhaled treprostinil was safe and well tolerated. Inhaled treprostinil was associated with an increase in 6MWD at 12 weeks (baseline 339 +/- 86, 12 week, 1 h post-inhalation 406 +/- 121 m, 67-m change, p = 0.01). An improvement in 6MWD of 49 m from baseline was noted during the trough period, just before inhalation of treprostinil (p = 0.009). The 6MWD improvement of at least 10% was noted in 1 of 6 patients receiving 30 microg versus 5 of 6 receiving 45 microg. Over 12 weeks, significant decreases were noted in mean pulmonary arterial pressure (-10%) and in pulmonary vascular resistance (-26%). Functional class improved from III to II in 9 of 11 patients. CONCLUSIONS: This trial suggests that inhaled treprostinil is safe, well tolerated, and associated with significant improvements in exercise capacity, functional class, and pulmonary hemodynamics in symptomatic patients with PAH on bosentan.     

Transitioning from i.v. epoprostenol to subcutaneous treprostinil in pulmonary arterial hypertension

OBJECTIVE: Continuous i.v. epoprostenol (prostacyclin) therapy improves survival and quality of life in patients with pulmonary arterial hypertension (PAH). i.v. epoprostenol therapy may be limited by serious complications related to the need for an implanted central venous catheter, and its chemical instability and short half-life. Treprostinil is a longer-acting prostacyclin analog, chemically stable, and suitable for continuous subcutaneous administration. We report successful transitioning to subcutaneous treprostinil of patients who presented with life-threatening complications of i.v. epoprostenol delivery. DESIGN: Open, uncontrolled study. SETTING: ICUs and departments of cardiology at academic hospitals. PATIENTS: Eight patients with PAH treated with continuous i.v. epoprostenol. INTERVENTION: Transition to subcutaneous treprostinil following an empiric protocol. RESULTS: Transition to treprostinil was achieved successfully in 21 to 96 h, with no major adverse side effects, and no change in the improved clinical status achieved with i.v. epoprostenol. Doses of epoprostenol before transition ranged from 3.5 to 75 ng/kg/min (mean, 27 ng/kg/min). Doses of treprostinil at completion of the transition ranged from 3 to 65 ng/kg/min (mean, 22 ng/kg/min). Four to 11 months later, the patients remained clinically improved. In spite of mild-to-moderate infusion site pain, all patients reported an improved sense of comfort and well-being. CONCLUSION: Patients with PAH can be safely transitioned from treatment with i.v. epoprostenol to subcutaneous treprostinil.     

Efficacy of long-term subcutaneous treprostinil sodium therapy in pulmonary hypertension

STUDY OBJECTIVES: The aim of this long-term multicenter analysis was to investigate whether subcutaneously infused treprostinil could provide sustained improvements of exercise capacity and survival benefits in patients with pulmonary arterial hypertension (PAH) and inoperable chronic thromboembolic pulmonary hypertension (CTEPH). Subcutaneous administration of the prostacyclin analog treprostinil is an effective treatment for PAH that, unlike epoprostenol, does not require the insertion of a permanent central venous catheter. DESIGN: Multicenter retrospective study. SETTING: Three European university hospitals. METHODS: Ninety-nine patients with PAH and 23 patients with CTEPH in New York Heart Association (NYHA) classes II-IV were followed up for a mean of 26.2 +/- 17.2 months (+/- SE) [range, 3 to 57 months]. Long-term efficacy was assessed by 6-min walking distance (SMWD), Borg dyspnea score, and NYHA class. Clinical events were monitored to assess survival and event-free survival. RESULTS: At 3 years, significant improvements from baseline were observed in mean SMWD (305 +/- 11 to 445 +/- 12 m, p = 0.0001), Borg dyspnea score (5.7 +/- 0.2 to 4.5 +/- 1, p = 0.0006), and NYHA class (3.20 +/- 0.04 to 2.1 +/- 0.1, p = 0.0001). These changes were observed under a mean dose of subcutaneously infused treprostinil at 40 +/- 2.6 ng/kg/min (range, 16 to 84 ng/kg/min). Subcutaneously infused treprostinil was well tolerated, and local pain at the subcutaneous site accounted for treatment interruption in only 5% of the cases. Survival was 88.6% and 70.6% at 1 year and 3 years, respectively. At the same time points, the event-free survival rates, defined as survival without hospitalization for clinical worsening, transition to IV epoprostenol, and need for combination therapy or atrial septostomy, were 83.2% and 69%, respectively. CONCLUSIONS: Long-term subcutaneous therapy with treprostinil appears to continuously improve exercise tolerance and symptoms in patients with PAH and inoperable CTEPH. Moreover, treatment may provide a significant survival benefit.     

Transition of stable pediatric patients with pulmonary arterial hypertension from intravenous epoprostenol to intravenous treprostinil

Intravenous epoprostenol was the first agent approved by the United States Food and Drug Administration for the management of pulmonary arterial hypertension (PAH). However, epoprostenol therapy carries the risks of a short half-life (<6 minutes) and side effects, including jaw pain, flushing, and headache. Recently, intravenous treprostinil has been studied, primarily in adults with PAH, and found to provide effective therapy. The effects of continuous intravenous treprostinil were retrospectively evaluated in 13 children with stable PAH who had been treated with epoprostenol for >1 year. Children were transitioned in the hospital over 24 hours using a rapid or slow strategy. The children were a mean age of 11 years (range 3 to 17) and were transitioned to treprostinil from August 2004 to August 2005. The baseline 6-minute walking distance was on average 516 +/- 115 m (n = 9) and did not change after transition. Patients were treated with treprostinil for 1.1 +/- 0.5 years. There were 2 deaths, and 2 patients transitioned to other therapy. Seven patients experienced > or =1 central-line infection. Despite a higher dose of treprostinil, the side effects were subjectively diminished. In conclusion, treprostinil provides an alternative therapy in children with PAH, with fewer side effects. However, evaluation regarding rates of infection requires further exploration.     

Transition from intravenous epoprostenol to intravenous treprostinil in pulmonary hypertension

RATIONALE: Intravenous epoprostenol improves exercise capacity and survival in patients with pulmonary arterial hypertension. The prostacyclin analog treprostinil is also efficacious by subcutaneous infusion, is easier to administer, and has a longer half-life. With the demonstration of bioequivalence between subcutaneous and intravenous treprostinil, intravenous treprostinil may have an overall better risk-benefit profile than intravenous epoprostenol. OBJECTIVE: To evaluate the safety and efficacy of transitioning patients with pulmonary arterial hypertension from intravenous epoprostenol to intravenous treprostinil. METHODS: Patients enrolled in a 12-wk prospective open label study were switched from intravenous epoprostenol to intravenous treprostinil over 24 to 48 h. The intravenous treprostinil dose was adjusted to minimize symptoms/side effects. RESULTS: Thirty-one patients (mean age, 43 yr; 22 women) were enrolled. Twenty-seven patients completed the protocol; 4 patients transitioned back to epoprostenol. Six-minute walk distance (n = 27; baseline, 438 +/- 16 m; Week 12, 439 +/- 16 m), Naughton-Balke treadmill test time (n = 26; baseline, 582 +/- 50 s; Week 12, 622 +/- 48 s), functional class, and Borg score were maintained with intravenous treprostinil at Week 12 versus intravenous epoprostenol before transition. At Week 12, mean pulmonary artery pressure increased 4 +/- 1 mm Hg (n = 27, p < 0.01), cardiac index decreased 0.4 +/- 0.1 L/min/m2 (n = 27, p = 0.01), and pulmonary vascular resistance increased 3 +/- 1 Wood units x m2 (n = 26, p < 0.01). No serious adverse events were attributed to treprostinil. CONCLUSIONS: These data suggest that transition from intravenous epoprostenol to intravenous treprostinil is safe and effective; whether the hemodynamic differences associated with intravenous treprostinil are clinically important requires longer follow-up.     

Treprostinil-based therapy in the treatment of moderate-to-severe pulmonary arterial hypertension: long-term efficacy and combination with bosentan

BACKGROUND: Treprostinil, a long-acting prostacyclin analog, diminished the symptoms of pulmonary arterial hypertension (PAH) in controlled 12-week clinical efficacy studies. This retrospective, single-center, open-label study was designed to assess the efficacy of long-term, subcutaneously administered, treprostinil-based therapy alone or in combination with bosentan for the treatment of moderate-to-severe PAH. METHODS: Thirty-eight patients with pulmonary hypertension treated with subcutaneous treprostinil were followed up for a mean (+/-SD) duration of 984+/-468 days (range, 165 to 1,847 days). Oral bosentan was added to the treprostinil regimen if patients remained in New York Heart Association (NYHA) functional class III or II with intolerable prostacyclin side effects that limited therapy. Hemodynamic studies, Borg dyspnea score evaluations, 6-min walk (6MW) tests, and NYHA functional class determinations were performed at approximately 6-month intervals. RESULTS: Mean pulmonary artery pressure decreased from 59.7 to 50.5 mm Hg (p<0.001). Significant and sustained improvement in 6MW distance (p=0.022) and Borg dyspnea score (p=0.023) were observed. At the final observation, the mean dose of treprostinil was 37.8 ng/kg/min (range, 7.5 to 115 ng/kg/min). At baseline, 5% of patients were in NYHA functional class 2 or lower vs 58% at the last follow-up. Bosentan was added to the regimens of 19 patients. In those patients, significant additional improvement occurred in the pulmonary arterial pressure (p<0.001), 6MW distance (p=0.001), and Borg dyspnea scale (p=0.020) compared to baseline. CONCLUSIONS: Long-term treatment with subcutaneous treprostinil-based therapy improved functional parameters and hemodynamics in patients with moderate-to-severe PAH. In patients requiring combination therapy, the addition of oral bosentan to treprostinil-based therapy was safe, well-tolerated, and associated with further clinical improvements.     

Pulmonary hypertension and right ventricular failure. Part XIV. Differentiated therapy of primary (idiopathic) and associated forms of pulmonary arterial hypertension

In a series of articles the authors discuss literature data concerning epidemiology of pulmonary arterial hypertension (PAH), its modern classification, peculiarities of its pathogenesis and treatment in various diseases and conditions. The last 14-th communication contains consideration of issues of differentiated administration of modern pulmonary vasodilators to patients with PAH taking into account etiology and severity of the disease, availability of evidence based efficacy and safety data, method of application, and contraindications. In patients with PAH of II and III functional class (FC) endothelin receptor blocker bosentan is believed to be the drug of first choice. Bosentan can be administered orally. In patients with significant liver involvement phosphodiesterase inhibitor type 5 sildenafil should be used instead of bosentan for long term treatment of PAH. Sildenafil also can be taken orally. If bosentan is not sufficiently effective it can be combined with sildenafil; inhalations of prostanoid iloprost can be added to this combination when necessary. Is this tiple combination is not effective iloprost inhalations can be replaced by subcutaneous treprostinil or continuous intravenous infusion of epoprostenol. In patients with IV FC PAH therapy is started with subcutaneous administration of treprostinil or infusion of epoprostenol, while bosentan or/and sildenafil is added when necessary.     

Experiences with treprostinil in the treatment of pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) is a chronic condition of elevated pulmonary arterial pressures with associated increases in pulmonary vascular resistance leading to right ventricular failure, which was almost uniformly fatal prior to the introduction of pulmonary hypertension specific therapy. Systemic prostacyclin analogs are the first PAH-specific therapies to be made available and are typically recommended as first-line therapy for subjects with severe disease. Treprostinil is a newer prostacyclin analog similar to epoprostenol in its mechanism of action and relative efficacy with the advantage of a longer half life in human serum and room temperature stability. It is unique in that it is available in multiple formulations for alternative routes of delivery, including subcutaneous, intravenous and inhalational routes. Additionally, oral treprostinil is currently under investigation. Both subcutaneous and intravenous forms of treprostinil have demonstrated efficacy in short-term clinical trials and are currently approved for use in subjects with PAH and New York Heart Association functional class (NYHA FC) II-IV symptoms in the USA and for subjects with NYHA FC III and IV in Europe. Inhaled treprostinil has also demonstrated efficacy in short-term clinical trials primarily as add-on therapy and is currently approved for use in subjects with PAH and NYHA FC III-IV symptoms in the USA and Europe. The different formulations of treprostinil have significantly increased the treatment options and opportunities for treatment of patients with PAH.     

Treatment of pulmonary arterial hypertension: a preliminary decision analysis

STUDY OBJECTIVE: New therapies for pulmonary arterial hypertension (PAH) improve functional status, quality of life (QOL), and survival. Clinicians must chose between very different therapies without the availability of comparison studies. We constructed a "virtual" clinical trial to help inform these treatment choices. DESIGN: We compare key outcomes related to survival, costs, and QOL using a Markov-type decision model to estimate the expected outcomes and costs for PAH patients treated for 1 year with bosentan and treprostinil compared to patients treated with epoprostenol, as well as patients treated with bosentan compared to those treated with treprostinil. The allowed transitions in the model were between World Health Organization functional class I to IV and death. Transition probabilities were based on observed transitions for bosentan. Treatment effect was estimated using 6-min walk data for treprostinil and epoprostenol. Utilities were calculated from estimated EuroQol health states. Cost was estimated from average wholesale price and Medicare reimbursement data. The effects of changing values of input variables on the key outcomes were calculated. RESULTS: Treatment with bosentan compared to treatment with either epoprostenol or treprostinil was less costly and resulted in a greater gain in quality-adjusted life years (QALYs). Conversely, treprostinil was significantly more expensive than epoprostenol, without an appreciable gain in QALYs. These findings were not substantially affected by the reasonable adjustments of transition probabilities, utility values, or tachyphylaxis to epoprostenol. CONCLUSION: Treatment with bosentan is more cost-effective than treatment with either treprostinil or epoprostenol. In addition, a net improvement in quality-adjusted survival may be expected.     

Pulmonary arterial hypertension: New management options

The past decade has realized remarkable advances in the treatment of pulmonary arterial hypertension (PAH), a progressive and potentially fatal disease. A small proportion of patients will have a dramatic hemodynamic response to acute vasodilator testing performed at the time of right heart catheterization and may be candidates for calcium channel blocker therapy. The vast majority of patients with PAH will not benefit from calcium channel blockers and should be treated with one of the three US Food and Drug Administration-approved therapies for PAH; bosentan, treprostinil, or epoprostenol. Because of the ease of administration relative to other therapies, the majority of patients with functional class III symptoms should be treated with the oral nonselective endothelin antagonist bosentan. Randomized controlled trials with treprostinil have demonstrated improvements in exercise endurance and hemodynamics. Patients who are critically ill, with functional class IV symptoms, should be started on epoprostenol because it is the most rapidly effective therapy. Intravenous epoprostenol improves exercise endurance, quality of life, hemodynamics, and survival in PAH. Investigational therapies on the horizon include phosphodiesterase inhibitors, prostacyclin analogues with alternative delivery routes (eg, inhaled, oral), and selective endothelin A receptor antagonists. The future of PAH therapy will likely include combinations of these therapies based on the multiple mechanisms of action.     

Bosentan improves exercise tolerance and Tei index in patients with pulmonary hypertension and prostanoid therapy

STUDY OBJECTIVE: Pulmonary arterial hypertension (PAH) is a progressive disease with a bad prognosis. Prostanoids are well established in the medical treatment of this disease. Treatment of patients with progressive disease despite prostanoids remains a therapeutic challenge. In this study, we examined the effect of adding bosentan, an endothelin antagonist, to existing prostanoid therapy on exercise capacity (6-min walking distance [6MWD]) and right ventricular (RV) function (Tei index) in patients with progressive pulmonary hypertension. DESIGN: Prospective, nonrandomized, open-label study. SETTING: University hospital. PATIENTS: Sixteen patients with pulmonary hypertension (PAH, n = 10; pulmonary hypertension due to other cause, n = 6) with progressive disease receiving either beraprost (n = 3), inhaled iloprost (n = 10), or iloprost IV (n = 3). INTERVENTIONS: Combination therapy with bosentan (final dosage, 125 mg bid) was initiated following an interval of 3-months minimum of unchanged prostanoid therapy. MEASUREMENTS AND RESULTS: Tei index, 6MWD, and New York Heart Association (NYHA) functional class were assessed prior to the initiation of combination therapy (baseline), at 6 months after initiation of combination therapy, and every 3 months thereafter. Two patients were followed up for 6 months only; all remaining patients reached a mean follow-up period (+/- SD) of 13.5 +/- 5.0 months (range, 9 to 22 months). 6MWD increased by 42.5 +/- 66 m at 6 months and 44.6 +/- 66 m at the last follow-up (both time points vs baseline, p < 0.001), and Tei index improved by -0.13 +/- 0.08 at 6 months and - 0.13 +/- 0.11 at the last follow-up (both time points vs baseline, p < 0.001). All patients reported subjective improvements. Nine of 16 patients exhibited improvement in NYHA functional class at 6 months. No side effects occurred that required dose adjustment or discontinuation of the study medication. CONCLUSION: Bosentan administered to patients with progressive pulmonary hypertension receiving prostanoids resulted in an increased exercise capacity and an improved RV function. Bosentan therefore appears to be well suited for combination therapy with prostanoids in selected patients pending results of ongoing randomized trials.     

Addition of sildenafil to bosentan monotherapy in pulmonary arterial hypertension.

Combination therapy has been recommended for the treatment of pulmonary arterial hypertension (PAH). However, there is scant information on combination therapy after failure of monotherapy, particularly in patients with scleroderma-associated PAH (PAH-SSD). From a group of 82 consecutive patients with PAH who received initial bosentan monotherapy, a total of 13 idiopathic PAH (IPAH) and 12 PAH-SSD patients requiring additional therapy with sildenafil were studied. Sildenafil was added for clinical deterioration based upon symptoms, New York Heart Association (NYHA) classification or 6-min walk distance (6MWD). Clinical data and haemodynamics were collected at baseline. Assessments were made at 1-3-month intervals. At baseline, there were no differences in demographics, NYHA classification, haemodynamics or 6MWD between the two groups. After initiation of bosentan, both groups experienced clinical improvement but ultimately deteriorated (median time to monotherapy failure 792 versus 458 days for IPAH and PAH-SSD patients, respectively). After addition of sildenafil, more IPAH patients tended to improve in NYHA class (five out of 13 versus two out of 12) and walked further (mean difference in 6MWD 47+/-77 m versus -7+/-40 m) compared with PAH-SSD patients. In conclusion, addition of sildenafil after bosentan monotherapy failure improved New York Heart Association class and 6-min walk distance in idiopathic pulmonary arterial hypertension patients but failed to improve either parameter in scleroderma-associated pulmonary arterial hypertension patients. Additional studies are needed to assess the tolerability and efficacy of this combination in patients with scleroderma-associated pulmonary arterial hypertension.     

Safety and efficacy of IV treprostinil for pulmonary arterial hypertension: a prospective, multicenter, open-label, 12-week trial

BACKGROUND: Pulmonary arterial hypertension (PAH) is a life-threatening disease for which both continuous IV epoprostenol and continuous subcutaneous treprostinil have proven effective. With continuous IV treprostinil having potential advantages over both of the above therapies, we investigated the safety and efficacy of this regimen in patients with PAH. METHODS: We conducted a 12-week, prospective, open-label, uncontrolled, multicenter study of continuous IV treprostinil in 16 patients with PAH that was idiopathic (n = 8), related to connective tissue disease (n = 6), or related to congenital heart disease (n = 2). The primary end point was change from baseline to week 12 in exercise capacity assessed by the 6-min walk (6MW) test. RESULTS: Continuous IV treprostinil increased 6MW distance (mean +/- SE) by 82 m from baseline (319 +/- 22 m) to week 12 (400 +/- 26 m) [n = 14; p = 0.001]. There were also significant improvements in the secondary end points of Naughton-Balke treadmill time (p = 0.007), Borg dyspnea score (p = 0.008), and hemodynamics (mean pulmonary artery pressure, p = 0.03; cardiac index, p = 0.002; pulmonary vascular resistance, p = 0.001) at week 12 compared with baseline. Side effects were mild and consistent with those reported with prostacyclin treatment. One death, unrelated to study drug, occurred during the 12-week study in a patient who received 3 days of treprostinil and died 2 weeks later. CONCLUSIONS: Long-term IV infusion of treprostinil is safe and appears to be effective for the treatment of patients with PAH.     

Prostanoids for pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) is a severe condition that markedly reduces exercise capacity and survival in the affected patient population. PAH includes primary pulmonary hypertension (PPH) and pulmonary hypertension associated with collagen vascular diseases, congenital systemic-to-pulmonary shunts, portal hypertension and HIV infection. All these conditions share virtually identical obstructive pathologic changes of the pulmonary microcirculation and probably similar pathobiologic processes. The pathophysiology is characterized by a progressive increase in pulmonary vascular resistance, leading to right ventricular failure and death. Prostacyclin is an endogenous substance that is produced by vascular endothelial cells and induces vasodilatation, inhibition of platelet activity, and antiproliferative effects. A dysregulation of prostacyclin metabolic pathways has been shown in patients with PAH and this represents the rationale for the exogenous therapeutic administration of this substance. The clinical use of prostacyclin in patients with PAH has been made possible by the synthesis of stable analogs that possess different pharmacokinetic properties but share similar pharmacodynamic effects. Experience in humans has been initially collected with epoprostenol, which is a synthetic salt of prostacyclin. Epoprostenol has a short half-life in the circulation and requires continuous administration by the intravenous route by means of infusion pumps and permanent tunnelized catheters. In addition, epoprostenol is unstable at room temperature, and the complex delivery system required is associated with several adverse effects and potentially serious complications. For these reasons, alternatives to intravenous epoprostenol have been sought and this has led to the development of analogs that can be administered subcutaneously (treprostinil), orally (beraprost sodium) or by inhalation (iloprost). Three unblinded clinical trials and several uncontrolled trials have shown that treatment with epoprostenol improved symptoms and exercise capacity in New York Heart Association (NYHA) class III and IV PAH patients and also survival in patients with PPH. Subcutaneous treprostinil improved symptoms, exercise, hemodynamics and clinical events in the largest clinical trial ever performed in PAH, but local infusion site reactions limited efficacy in a proportion of patients. Oral beraprost sodium improved exercise capacity only in patients with PPH and is the only prostacyclin analog that has also been tested in NYHA class II patients. Inhaled iloprost has improved symptoms, exercise capacity and clinical events in patients with PAH and inoperable chronic thromboembolic pulmonary hypertension. The favorable effects of prostanoids observed in all studies coupled with different profiles of adverse events and tolerability for each prostacyclin analog allow the unique opportunity to select the most appropriate compound for the individual patient with PAH.     

Effects of long-term bosentan in children with pulmonary arterial hypertension

OBJECTIVES: This study investigated the long-term outcome of children with pulmonary arterial hypertension (PAH) treated with bosentan therapy, with or without concomitant prostanoid therapy. BACKGROUND: Bosentan, an oral endothelin ET(A)/ET(B) receptor antagonist, improves hemodynamics and exercise capacity in adults with PAH; however, limited data are available on its long-term effects in children. METHODS: In this retrospective study, 86 children with PAH (idiopathic, associated with congenital heart or connective tissue disease) started bosentan with or without concomitant intravenous epoprostenol or subcutaneous treprostinil therapy. Hemodynamics, World Health Organization (WHO) functional class, and safety data were collected. RESULTS: At the cutoff date, 68 patients (79%) were still treated with bosentan, 13 (15%) were discontinued, and 5 (6%) had died. Median exposure to bosentan was 14 months. In 90% of the patients (n = 78), WHO functional class improved (46%) or was unchanged (44%) with bosentan treatment. Mean pulmonary artery pressure and pulmonary vascular resistance decreased (64 +/- 3 mm Hg to 57 +/- 3 mm Hg, p = 0.005 and 20 +/- 2 U x m2 to 15 +/- 2 U x m2, p = 0.01, respectively; n = 49). Kaplan-Meier survival estimates at one and two years were 98% and 91%, respectively. The risk for worsening PAH was lower in patients in WHO functional class I/II at bosentan initiation than in patients in WHO class III/IV at bosentan initiation. CONCLUSIONS: These data suggest that bosentan, an oral endothelin ET(A)/ET(B) receptor antagonist, with or without concomitant prostanoid therapy, is safe and efficacious for the treatment of PAH in children.     

Transition from epoprostenol and treprostinil to the oral endothelin receptor antagonist bosentan in patients with pulmonary hypertension

STUDY OBJECTIVES: Prior to the availability of the oral endothelin antagonist bosentan, most patients with pulmonary arterial hypertension (PAH) were treated with continuously infused prostacyclins. Many patients receiving prostacyclins would have received bosentan if it had been available at the time of their diagnosis. Noninvasive criteria (symptoms, World Health Organization [WHO] functional class, 6-min walk test [6MWT] distances, and echocardiograms) are used to govern up-titration of prostacyclins and to assess response to bosentan. The purposes of this study were to see if some patients might be able to transition safely from prostacyclin to bosentan, and whether noninvasive criteria could be used to monitor this transition. METHODS: From January 2002 to July 2003, 23 stable patients with PAH attempted a transition from prostacyclin to bosentan over an 8-week period. 6MWT results, WHO class, and echocardiograms were recorded prior to transition and 1 month after successful transition. The transition was stopped and prostacyclin was resumed or up-titrated if any symptoms of PAH worsened. RESULTS: Of 23 candidates (19 female and 4 male; age range, 17 to 73 years), 15 patients were transitioned to bosentan. Of these patients, four patients experienced worsening symptoms (range, 7 weeks to 12 months after cessation of prostacyclin) and resumed treatment with prostacyclin. Of the remaining 11 patients, 2 patients had liver function abnormalities 3 months and 10 months after transition to bosentan, respectively; 9 patients remained on bosentan 3 to 16 months after prostacyclin cessation. Patients failing transition and resuming prostacyclin returned to their pretransition functional baseline. CONCLUSION: Nine of 23 carefully selected, stable patients with PAH receiving long-term prostacyclin were successfully transitioned to oral bosentan using noninvasive monitoring. No long-term adverse events were associated with failed transition attempts. Further studies need to be carried out to determine which patients are more likely to undergo the transition successfully.     

Efficacy of bosentan in a small cohort of adult patients with pulmonary arterial hypertension related to congenital heart disease

OBJECTIVES: This study was designed to assess the tolerability and efficacy of the oral endothelin receptor antagonist bosentan in adult patients with pulmonary arterial hypertension (PAH) related to congenital heart disease (CHD). BACKGROUND: Severe PAH in the setting of CHD is a debilitating syndrome for which there are limited treatment options. This is the first long-term study experience in adults reporting on the tolerability and efficacy of therapy with bosentan for this patient population. METHODS: A 12-month single-center experience with 19 women and 5 men with PAH associated with CHD (79% in New York Heart Association [NYHA] class III) was analyzed. Hemodynamic responses, exercise capacity, and Borg dyspnea index were assessed prior to the administration of bosentan, and again at 3, 6, and 12 months after the study began. Clinical assessments were performed monthly for up to 12 months. The change from baseline was tested using the Wilcoxon pairs test. RESULTS: There was significant improvement in hemodynamics from baseline to 12 months (mean [+/- SD] systolic pulmonary arterial pressure, 99 +/- 30 to 87 +/- 28 mm Hg [p 相似文献   

Transition from IV epoprostenol to subcutaneous treprostinil in pulmonary arterial hypertension: a controlled trial

BACKGROUND: We determined the relative efficacy of subcutaneous (SC) treprostinil in stable World Health Organization class II and III patients transitioned from IV epoprostenol. METHODS: This was an 8-week, multicenter, randomized study in which patients were transitioned from IV epoprostenol to SC treprostinil or placebo over a period of up to 14 days and monitored carefully during and after the transition period for signs of deterioration. Patients with clinical deterioration were returned promptly to epoprostenol. Placebo or SC treprostinil doses were titrated in response to symptoms. Time to adjudicated clinical deterioration was compared between treatment groups, and exercise capacity, symptoms of disease, and safety were assessed throughout the study. RESULTS: Twenty-two patients were enrolled and completed the study. Seven of 8 patients (88%) [corrected] withdrawn to placebo had clinical deterioration, while only 1 of 14 patients (7%) [corrected] withdrawn to SC treprostinil had clinical deterioration (p = 0.00023 based on a treatment comparison of time to deterioration). Analyses of exercise capacity and symptoms strongly supported the efficacy of SC treprostinil in epoprostenol-treated patients. Adverse events consisted of painful infusion site reactions and anticipated prostacyclin side effects. CONCLUSIONS: SC treprostinil is effective in pulmonary arterial hypertension and prevents clinical deterioration and maintains functional status in patients transitioned from epoprostenol.     

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.     

Randomized study of adding inhaled iloprost to existing bosentan in pulmonary arterial hypertension

RATIONALE: Small, open-label studies suggest that combinations of existing therapies may be effective for pulmonary arterial hypertension (PAH). OBJECTIVE: To evaluate the safety and efficacy of adding inhaled iloprost, a prostacyclin analog, to the endothelin receptor antagonist bosentan in patients with PAH. METHODS: In a randomized, multicenter, double-blind trial, inhaled iloprost (5 mug) or placebo was added to stable monotherapy with bosentan for 12 wk. Efficacy endpoints included change from baseline in 6-min-walk distance (6-MWD), modified New York Heart Association (NYHA) functional class, hemodynamic parameters, and time to clinical worsening. MEASUREMENTS AND MAIN RESULTS: A total of 67 patients with PAH (55% idiopathic PAH, 45% associated PAH, 94% NYHA class III, and mean baseline 6-MWD of 335 m) were randomized. At Week 12, patients receiving iloprost had a mean increase in 6-MWD of 30 m (p = 0.001); placebo patients had a mean 6-MWD increase of 4 m (p = 0.69), with a placebo-adjusted difference of +26 m (p = 0.051). NYHA status improved by one class in 34% of iloprost versus 6% of placebo patients (p = 0.002). Iloprost delayed the time to clinical worsening (p = 0.0219). Improvements were noted in postinhalation placebo-adjusted change in mean pulmonary artery pressure (-8 mm Hg; p < 0.001) and pulmonary vascular resistance (-254 dyn x s x cm(-5); p < 0.001). Combination therapy was well tolerated. CONCLUSIONS: Within the limitations of a relatively small sample size, results of this study demonstrate that the addition of inhaled iloprost in patients with PAH with reduced exercise capacity on bosentan monotherapy is safe and efficacious.