Data on the effect of initial combination therapy with ambrisentan and tadalafil on long-term outcomes in patients with pulmonary arterial hypertension are scarce.
In this event-driven, double-blind ...study, we randomly assigned, in a 2:1:1 ratio, participants with World Health Organization functional class II or III symptoms of pulmonary arterial hypertension who had not previously received treatment to receive initial combination therapy with 10 mg of ambrisentan plus 40 mg of tadalafil (combination-therapy group), 10 mg of ambrisentan plus placebo (ambrisentan-monotherapy group), or 40 mg of tadalafil plus placebo (tadalafil-monotherapy group), all administered once daily. The primary end point in a time-to-event analysis was the first event of clinical failure, which was defined as the first occurrence of a composite of death, hospitalization for worsening pulmonary arterial hypertension, disease progression, or unsatisfactory long-term clinical response.
The primary analysis included 500 participants; 253 were assigned to the combination-therapy group, 126 to the ambrisentan-monotherapy group, and 121 to the tadalafil-monotherapy group. A primary end-point event occurred in 18%, 34%, and 28% of the participants in these groups, respectively, and in 31% of the pooled-monotherapy group (the two monotherapy groups combined). The hazard ratio for the primary end point in the combination-therapy group versus the pooled-monotherapy group was 0.50 (95% confidence interval CI, 0.35 to 0.72; P<0.001). At week 24, the combination-therapy group had greater reductions from baseline in N-terminal pro-brain natriuretic peptide levels than did the pooled-monotherapy group (mean change, -67.2% vs. -50.4%; P<0.001), as well as a higher percentage of patients with a satisfactory clinical response (39% vs. 29%; odds ratio, 1.56 95% CI, 1.05 to 2.32; P=0.03) and a greater improvement in the 6-minute walk distance (median change from baseline, 48.98 m vs. 23.80 m; P<0.001). The adverse events that occurred more frequently in the combination-therapy group than in either monotherapy group included peripheral edema, headache, nasal congestion, and anemia.
Among participants with pulmonary arterial hypertension who had not received previous treatment, initial combination therapy with ambrisentan and tadalafil resulted in a significantly lower risk of clinical-failure events than the risk with ambrisentan or tadalafil monotherapy. (Funded by Gilead Sciences and GlaxoSmithKline; AMBITION ClinicalTrials.gov number, NCT01178073.).
Patients with severe pulmonary arterial hypertension (PAH) in New York Heart Association (NYHA) functional class (FC) III/IV have a poor prognosis, despite survival benefits being demonstrated with ...intravenous epoprostenol. In this pilot study, the efficacy and safety of a triple combination therapy regimen in patients with severe PAH was investigated. Data from newly diagnosed NYHA FC III/IV PAH patients (n=19) initiated on upfront triple combination therapy (intravenous epoprostenol, bosentan and sildenafil) were collected retrospectively from a prospective registry. Significant improvements in 6-min walk distance and haemodynamics were observed after 4 months' triple combination therapy in 18 patients (p<0.01); 17 patients had improved to NYHA FC I or II. One patient was not included in the month 4 assessment (due to an emergency lung transplant in month 3). At the final evaluation (mean ± sd 32 ± 19 months), all 18 patients had sustained clinical and haemodynamic improvement. Overall survival estimates for the triple combination cohort were 100% at 1, 2 and 3 years. Expected survival calculated from the French equation was 75% (95% CI 68-82%), 60% (95% CI 50-70%) and 49% (95% CI 38-60%) at 1, 2 and 3 years, respectively. This pilot study provides preliminary evidence of the long-term benefits of upfront triple combination therapy in patients with severe PAH.
Summary Background Treatments for pulmonary arterial hypertension have been mainly studied in patients with advanced disease (WHO functional class FC III and IV). This study was designed to assess ...the effect of the dual endothelin receptor antagonist bosentan in patients with WHO FC II pulmonary arterial hypertension. Methods Patients with WHO FC II pulmonary arterial hypertension aged 12 years or over with 6-min walk distance of less than 80% of the normal predicted value or less than 500 m associated with a Borg dyspnoea index of 2 or greater were enrolled in this double-blind, placebo-controlled, multicentre trial. 185 patients were randomly assigned to receive bosentan (n=93) or placebo (n=92) for the 6-month double-blind treatment period via a centralised integrated voice recognition system. Primary endpoints were pulmonary vascular resistance at month 6 expressed as percentage of baseline and change from baseline to month 6 in 6-min walk distance. Analyses of the primary endpoints were done with all randomised patients who had a valid baseline assessment and an assessment or an imputed value for month 6. This trial was registered with ClinicalTrials.gov , number NCT00091715. Findings Analyses were done with 168 patients (80 in the bosentan group, 88 in the placebo group) for pulmonary vascular resistance and with 177 (86 and 91) for 6-min walking distance. At month 6, geometric mean pulmonary vascular resistance was 83·2% (95% CI 73·8–93·7) of the baseline value in the bosentan group and 107·5% (97·6–118·4) of the baseline value in the placebo group (treatment effect −22·6%, 95% CI −33·5 to −10·0; p<0·0001). Mean 6-min walk distance increased from baseline in the bosentan group (11·2 m, 95% CI −4·6 to 27·0) and decreased in the placebo group (−7·9 m, −24·3 to 8·5), with a mean treatment effect of 19·1 m (95% CI 3·6–41·8; p=0·0758). 12 (13%) patients in the bosentan group and eight (9%) in the placebo group reported serious adverse events, the most common of which were syncope in the bosentan group and right ventricular failure in the placebo group. Interpretation Bosentan treatment could be beneficial for patients with WHO FC II pulmonary arterial hypertension. Funding Actelion Pharmaceuticals Ltd.
Treatment options for pulmonary arterial hypertension target the prostacyclin, endothelin, or nitric oxide pathways. Tadalafil, a phosphodiesterase type-5 inhibitor, increases cGMP, the final ...mediator in the nitric oxide pathway.
In this 16-week, double-blind, placebo-controlled study, 405 patients with pulmonary arterial hypertension (idiopathic or associated), either treatment-naive or on background therapy with the endothelin receptor antagonist bosentan, were randomized to placebo or tadalafil 2.5, 10, 20, or 40 mg orally once daily. The primary end point was the change from baseline to week 16 in the distance walked in 6 minutes. Changes in World Health Organization functional class, clinical worsening, and health-related quality of life were also assessed. Patients completing the 16-week study could enter a long-term extension study. Tadalafil increased the distance walked in 6 minutes in a dose-dependent manner; only the 40-mg dose met the prespecified level of statistical significance (P<0.01). Overall, the mean placebo-corrected treatment effect was 33 m (95% confidence interval, 15 to 50 m). In the bosentan-naive group, the treatment effect was 44 m (95% confidence interval, 20 to 69 m) compared with 23 m (95% confidence interval, -2 to 48 m) in patients on background bosentan therapy. Tadalafil 40 mg improved the time to clinical worsening (P=0.041), incidence of clinical worsening (68% relative risk reduction; P=0.038), and health-related quality of life. The changes in World Health Organization functional class were not statistically significant. The most common treatment-related adverse events reported with tadalafil were headache, myalgia, and flushing.
In patients with pulmonary arterial hypertension, tadalafil 40 mg was well tolerated and improved exercise capacity and quality of life measures and reduced clinical worsening.
Pulmonary arterial hypertension (PAH) is a progressive, fatal disease. We studied 674 consecutive adult patients who were prospectively enrolled in the French PAH registry (121 incident and 553 ...prevalent cases). Two survival analyses were performed. First, the cohort of 674 patients was followed for 3 yrs after study entry and survival rates described. Then, we focused on the subset with incident idiopathic, familial and anorexigen-associated PAH (n = 56) combined with prevalent patients who were diagnosed <3 yrs prior to study entry (n = 134). In the cohort of 674 patients, 1-, 2-, and 3-yr survival rates were 87% (95% CI 84-90), 76% (95% CI 73-80), and 67% (95% CI 63-71), respectively. In prevalent idiopathic, familial and anorexigen-associated PAH, 1-, 2-, and 3-yr survival rates were higher than in incident patients (p = 0.037). In the combined cohort of patients with idiopathic, familial and anorexigen-associated PAH, multivariable analysis showed that survival could be estimated by means of a novel risk-prediction equation using patient sex, 6-min walk distance, and cardiac output at diagnosis. This study highlights survivor bias in prevalent cohorts of PAH patients. Survival of idiopathic, familial and anorexigen-associated PAH can be characterised by means of a novel risk-prediction equation using patients' characteristics at diagnosis.
Pulmonary arterial hypertension (PAH) is a progressive disease characterised by remodelling of small pulmonary arteries leading to an increased pulmonary vascular resistance, right ventricular ...failure and death. Available treatments try to re-establish the equilibrium on three signalling pathways: the prostacyclin, the endothelin (ET)-1 and the nitric oxide. Prostanoids, such as epoprostenol or treprostinil have a vasodilator, antiproliferative and immunomodulatory effect and, despite the administration inconveniences, represent established therapies for severe cases of PAH. Recently oral prostacyclin receptor agonists have shown encouraging results. Many clinical studies targeting the vasoconstrictor ET-1 pathway with receptor antagonists like bosentan and ambrisentan have shown strong results, even more optimism coming from macitentan, the newest drug. Sildenafil and tadalafil, two phosphodiesterase type-5 inhibitors, have shown improved exercise capacity by increasing the nitric oxide level. Riociguat, acting on the same nitric oxide pathway, as a guanylatecyclase activator, has shown promising results in clinical trials and will be available soon. Long-awaited results for tyrosin-kinase inhibitor, imatinib, as an antiproliferative therapy in PAH have been disappointing, due to severe adverse events. In conclusion, although it remains a disease with severe prognosis, the past 20 years have represented a huge progress in terms of treatments for PAH with interesting opportunities for the future.
Sildenafil inhibits phosphodiesterase type 5, an enzyme that metabolizes cyclic guanosine monophosphate, thereby enhancing the cyclic guanosine monophosphate-mediated relaxation and growth inhibition ...of vascular smooth-muscle cells, including those in the lung.
In this double-blind, placebo-controlled study, we randomly assigned 278 patients with symptomatic pulmonary arterial hypertension (either idiopathic or associated with connective-tissue disease or with repaired congenital systemic-to-pulmonary shunts) to placebo or sildenafil (20, 40, or 80 mg) orally three times daily for 12 weeks. The primary end point was the change from baseline to week 12 in the distance walked in six minutes. The change in mean pulmonary-artery pressure and World Health Organization (WHO) functional class and the incidence of clinical worsening were also assessed, but the study was not powered to assess mortality. Patients completing the 12-week randomized study could enter a long-term extension study.
The distance walked in six minutes increased from baseline in all sildenafil groups; the mean placebo-corrected treatment effects were 45 m (+13.0 percent), 46 m (+13.3 percent), and 50 m (+14.7 percent) for 20, 40, and 80 mg of sildenafil, respectively (P<0.001 for all comparisons). All sildenafil doses reduced the mean pulmonary-artery pressure (P=0.04, P=0.01, and P<0.001, respectively), improved the WHO functional class (P=0.003, P<0.001, and P<0.001, respectively), and were associated with side effects such as flushing, dyspepsia, and diarrhea. The incidence of clinical worsening did not differ significantly between the patients treated with sildenafil and those treated with placebo. Among the 222 patients completing one year of treatment with sildenafil monotherapy, the improvement from baseline at one year in the distance walked in six minutes was 51 m.
Sildenafil improves exercise capacity, WHO functional class, and hemodynamics in patients with symptomatic pulmonary arterial hypertension.
Aims To assess the acute vasodilator response and long-term response to calcium-channel blockers (CCB) in pulmonary arterial hypertension (PAH) with associated conditions. Methods and results The ...response to acute vasodilator testing >20% decrease in mean pulmonary artery pressure (mPAP) and total pulmonary resistance was assessed in 663 consecutive PAH patients with connective tissue disease (CTD; n = 168), portal hypertension (PoPH; n = 153), anorexigen use (n = 127), human immunodeficiency virus infection (HIV; n = 124), congenital heart disease (CHD; n = 50), and pulmonary veno-occlusive disease or capillary haemangiomatosis (PVOD/PCH; n = 41). An acute vasodilator response was observed in 13.4% of PAH-anorexigen patients, 12.2% of PVOD/PCH, 10.1% of CTD, 1.6% of HIV, 1.3% of PoPH, and was absent in CHD. A long-term response to CCB (marked haemodynamic improvement at 3–4 months and New York Heart Association functional class I or II after 1 year) was reported in 9.4% of PAH-anorexigen patients but was rare in HIV, PoPH, CTD (1.6, 0.7, and 0.6%, respectively) and absent in PVOD/PCH. All patients with a long-term CCB response were alive after 5 years; two deaths not related to PAH occurred after this time. Recent criteria for acute response based on the fall in mPAP to <40 mmHg are more specific to detect long-term responders to CCB. Conclusion A long-term CCB response was reported in patients with PAH associated with anorexigen use, but was rare in patients with PoPH or HIV and absent in PVOD/PCH, CHD, and the vast majority of CTD. The prognosis of long-term responders was favourable and related to the underlying cause of PAH.
This study aims to describe the haemodynamic and survival characteristics of patients with pulmonary hypertension in the recently individualised syndrome of combined pulmonary fibrosis and emphysema. ...A retrospective multicentre study was conducted in 40 patients (38 males; age 68+/-9 yrs; 39 smokers) with combined pulmonary fibrosis and emphysema, and pulmonary hypertension at right heart catheterisation. Dyspnoea was functional class II in 15%, III in 55% and IV in 30%. 6-min walk distance was 244+/-126 m. Forced vital capacity was 86+/-18%, forced expiratory volume in 1 s 78+/-19%, and carbon monoxide diffusion transfer coefficient 28+/-16% of predicted. Room air arterial oxygen tension was 7.5+/-1.6 kPa (56+/-12 mmHg). Mean pulmonary artery pressure was 40+/-9 mmHg, cardiac index 2.5+/-0.7 L x min(-1) x m(-2) and pulmonary vascular resistance 521+/-205 dyn x s x cm(-5). 1-yr survival was 60%. Higher pulmonary vascular resistance, higher heart rate, lower cardiac index and lower carbon monoxide diffusion transfer were associated with shorter survival. Patients with combined pulmonary fibrosis and emphysema syndrome and pulmonary hypertension confirmed by right heart catheterisation have a dismal prognosis despite moderately altered lung volumes and flows and moderately severe haemodynamic parameters.
Acute right ventricular failure in the setting of pulmonary arterial hypertension (PAH) often requires hospitalisation in intensive care units (ICU) to manage the subsequent low cardiac output and ...its consequences. There are very few data on these acute events. We recorded demographic, clinical and biological data and therapy in consecutive patients suffering from acute right heart failure requiring catecholamine treatment in the ICU of the French referral centre for pulmonary hypertension. These variables were analysed according to the survival status in ICU. 46 patients were included, the mean age was 50.3 yrs. ICU mortality was 41%. We found no difference in terms of demographics, clinical data, last haemodynamic measurements at admission. Systemic arterial pressure was significantly lower in the subgroup of patients whose clinical course was fatal. Plasma brain natriuretic peptide (BNP), C-reactive protein (CRP), serum sodium and creatinine at admission correlated with survival. Demonstration of an infection during the ICU stay was associated with a worse prognosis. These preliminary results underline the importance of some simple clinical and biological parameters in the prognostic evaluation of acute heart failure in the setting of PAH. Whether these parameters can guide therapy needs to be further investigated.
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