Safe, effective therapy is needed for pediatric pulmonary arterial hypertension.
Children (n=235; weight ≥8 kg) were randomized to low-, medium-, or high-dose sildenafil or placebo orally 3 times ...daily for 16 weeks in the Sildenafil in Treatment-Naive Children, Aged 1-17 Years, With Pulmonary Arterial Hypertension (STARTS-1) study. The primary comparison was percent change from baseline in peak oxygen consumption (PV(O(2))) for the 3 sildenafil doses combined versus placebo. Exercise testing was performed in 115 children able to exercise reliably; the study was powered for this population. Secondary end points (assessed in all patients) included hemodynamics and functional class. The estimated mean±SE percent change in PV(O(2)) for the 3 doses combined versus placebo was 7.7±4.0% (95% confidence interval, -0.2% to 15.6%; P=0.056). PV(O(2)), functional class, and hemodynamics improved with medium and high doses versus placebo; low-dose sildenafil was ineffective. Most adverse events were mild to moderate in severity. STARTS-1 completers could enter the STARTS-2 extension study; patients who received sildenafil in STARTS-1 continued the same dose, whereas placebo-treated patients were randomized to low-, medium-, or high-dose sildenafil. In STARTS-2 (ongoing), increased mortality was observed with higher doses.
Sixteen-week sildenafil monotherapy is well tolerated in pediatric pulmonary arterial hypertension. Percent change in PV(O(2)) for the 3 sildenafil doses combined was only marginally significant; however, PV(O(2)), functional class, and hemodynamic improvements with medium and high doses suggest efficacy with these doses. Combined with STARTS-2 data, the overall profile favors the medium dose. Further investigation is warranted to determine optimal dosing based on age and weight.
http://www.clinicaltrials.gov. Unique identifier: NCT00159913.
Current therapies for pulmonary arterial hypertension have been adopted on the basis of short-term trials with exercise capacity as the primary end point. We assessed the efficacy of macitentan, a ...new dual endothelin-receptor antagonist, using a primary end point of morbidity and mortality in a long-term trial.
We randomly assigned patients with symptomatic pulmonary arterial hypertension to receive placebo once daily, macitentan at a once-daily dose of 3 mg, or macitentan at a once-daily dose of 10 mg. Stable use of oral or inhaled therapy for pulmonary arterial hypertension, other than endothelin-receptor antagonists, was allowed at study entry. The primary end point was the time from the initiation of treatment to the first occurrence of a composite end point of death, atrial septostomy, lung transplantation, initiation of treatment with intravenous or subcutaneous prostanoids, or worsening of pulmonary arterial hypertension.
A total of 250 patients were randomly assigned to placebo, 250 to the 3-mg macitentan dose, and 242 to the 10-mg macitentan dose. The primary end point occurred in 46.4%, 38.0%, and 31.4% of the patients in these groups, respectively. The hazard ratio for the 3-mg macitentan dose as compared with placebo was 0.70 (97.5% confidence interval CI, 0.52 to 0.96; P=0.01), and the hazard ratio for the 10-mg macitentan dose as compared with placebo was 0.55 (97.5% CI, 0.39 to 0.76; P<0.001). Worsening of pulmonary arterial hypertension was the most frequent primary end-point event. The effect of macitentan on this end point was observed regardless of whether the patient was receiving therapy for pulmonary arterial hypertension at baseline. Adverse events more frequently associated with macitentan than with placebo were headache, nasopharyngitis, and anemia.
Macitentan significantly reduced morbidity and mortality among patients with pulmonary arterial hypertension in this event-driven study. (Funded by Actelion Pharmaceuticals; SERAPHIN ClinicalTrials.gov number, NCT00660179.).
Patients with pulmonary arterial hypertension who achieve a six-minute walk distance of 380-440 m may have improved prognosis. Using the randomized controlled trial of macitentan in pulmonary ...arterial hypertension (SERAPHIN), the association between six-minute walk distance and long-term outcomes was explored.
Patients with six-minute walk distance data at Month 6 were dichotomized as above or below the median six-minute walk distance (400 m) and assessed for future risk of pulmonary arterial hypertension-related death or hospitalization and all-cause death. Additionally, six-minute walk distance values at baseline, Month 6 and the change from baseline to Month 6 were categorized by quartiles. All associations were analyzed by the Kaplan-Meier method using a log-rank test and Cox regression models.
Patients with a six-minute walk distance >400 m vs. ≤400 m at Month 6 have a reduced risk of pulmonary arterial hypertension-related death or hospitalization (hazard ratio 0.48; 95% confidence interval 0.33-0.69). The risk was also lower for patients with higher quartiles of six-minute walk distance at baseline or Month 6 (baseline: hazard ratio Q4 (>430 m) vs. Q1 (≤300 m) 0.23; 95% confidence interval 0.15-0.36; Month 6: hazard ratio Q4 (>455 m) vs. Q1 (≤348 m) 0.33; 95% confidence interval 0.19-0.55). In contrast, six-minute walk distance changes at Month 6 were not associated with the risk of pulmonary arterial hypertension-related death or hospitalization (p = 0.477). These findings were consistent when adjusted for known confounders. Similar results were observed for the risk of all-cause death up to end of study.
Patients with pulmonary arterial hypertension walking >400 m had better long-term prognosis. Although changes in six-minute walk distance were not associated with long-term outcomes, assessing absolute six-minute walk distance values remains important in the clinical management of patients with pulmonary arterial hypertension.
Registry data suggest that disease progression in pulmonary arterial hypertension (PAH) is indicative of poor prognosis. However, the prognostic relevance of PAH-related morbidity has not been ...formally evaluated in randomized controlled trials.
The purpose of these analyses was to assess the impact of morbidity events on the risk of subsequent mortality using the landmark method and data from the SERAPHIN and GRIPHON studies.
For each study, the risk of all-cause death up to the end of the study was assessed from the landmark time point (months 3, 6, and 12) according to whether a patient had experienced a primary endpoint morbidity event before the landmark. Each analysis was conducted using data from all patients who were available for survival follow-up at the landmark.
In the SERAPHIN study, on the basis of the 3-month landmark time point, patients who experienced a morbidity event before month 3 had an increased risk of death compared with patients who did not (hazard ratio HR: 3.39; 95% confidence interval CI: 1.94 to 5.92). In the GRIPHON study, on the basis of the 3-month landmark time point, there was also an increased risk with a HR of 4.48; (95% CI: 2.98 to 6.73). Analyses based on 6-month and 12-month landmarks also showed increased risk in patients who experienced morbidity events, albeit with a reduced HR.
These results demonstrate the prognostic relevance of PAH-related morbidity as defined in the SERAPHIN and GRIPHON studies, highlighting the importance of preventing disease progression in patients with PAH and supporting the clinical relevance of SERAPHIN and GRIPHON morbidity events. (Study of Macitentan ACT-064992 on Morbidity and Mortality in Patients With Symptomatic Pulmonary Arterial Hypertension SERAPHIN; NCT00660179; Selexipag ACT-293987 in Pulmonary Arterial Hypertension GRIPHON; NCT01106014)
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The effect of macitentan on haemodynamic parameters and NT-proBNP levels was evaluated in pulmonary arterial hypertension (PAH) patients in the SERAPHIN study. Association between these parameters ...and disease progression, assessed by the primary endpoint (time to first morbidity/mortality event), was explored.
Of the 742 randomized patients, 187 with right heart catheterization at baseline and month 6 participated in a haemodynamic sub-study. Prespecified endpoints included change from baseline to month 6 in cardiac index (CI), right atrial pressure (RAP), mean pulmonary arterial pressure (mPAP), pulmonary vascular resistance (PVR), mixed-venous oxygen saturation, and NT-proBNP. Exploratory analyses examined associations between CI, RAP, and NT-proBNP and disease progression using the Kaplan-Meier method and Cox regression models. Macitentan improved CI, RAP, mPAP, PVR and NT-proBNP vs. placebo at month 6. Absolute levels of CI, RAP and NT-proBNP at baseline and month 6, but not their changes, were associated with morbidity/mortality events. Patients with CI > 2.5 L/min/m2, RAP < 8 mmHg, or NT-proBNP < 750 fmol/ml at month 6 had a lower risk of morbidity/mortality than those not meeting these thresholds (HR 0.49, 95% CL 0.28-0.86; HR 0.72, 95% CL 0.42-1.22; and HR 0.22, 95% CL 0.15-0.33, respectively).
For all treatment groups, baseline and month 6 values of CI, RAP, and NT-proBNP, but not their changes, were associated with morbidity/mortality events, confirming their relevance in predicting disease progression in patients with PAH. By improving those parameters, macitentan increased the likelihood of reaching threshold values associated with lower risk of morbidity/mortality.
In this study we explored the microRNAs responsible for the regulation of PAI‐1 during LPS‐stimulated inflammation in human aortic endothelial cells and subsequently studied the effect of a newly ...synthesized mitochondria‐targeted esculetin (Mito‐Esc) that was shown for its anti‐atherosclerotic potential, in modulating PAI‐1 levels and its targeted miRs during angiotensin‐II‐induced atherosclerosis in ApoE−/− mice. LPS‐stimulated PAI‐1 was accompanied with an upregulation of miR‐19b and down‐regulation of miR‐30c. These effects of LPS on PAI‐1 were reversed in the presence of both parent esculetin and Mito‐Esc. However, the effect of Mito‐Esc was more pronounced in the regulation of PAI‐1. In addition, LPS‐stimulated PAI‐1 expression was significantly decreased in cells treated with Anti‐miR‐19b, thereby suggesting that miR‐19b co‐expression plays a key role in PAI‐1 regulation. The results also show that incubation of cells with Stattic, an inhibitor of STAT‐3, inhibited LPS‐stimulated PAI‐1 expression. Interestingly, knockdown of SIRT3, a mitochondrial biogenetic marker, enhanced PAI‐1 levels via modulation of miR‐19b and ‐30c. Mito‐Esc treatment significantly inhibited Ang‐II‐induced PAI‐1, possibly via altering miR‐19b and 30c in ApoE−/− mice. The association between PAI‐1, miR‐19b and ‐30c were further confirmed in plasma and microparticles isolated from patients suffering from acute coronary syndrome of various degrees. Taken together, LPS‐induced PAI‐1 involves co‐expression of miR‐19b and down regulation of miR‐30c, and Mito‐Esc treatment by modulating miR‐19b and miR‐30c through SIRT3 activation, inhibits PAI‐1 levels that, in part, contribute to its anti‐atherosclerotic effects. Moreover, there exists a strong positive correlation between miR‐19b and PAI‐1 in patients suffering from ST‐elevated myocardial infarction.
LPS‐induced PAI‐1 involves co‐expression of miR‐19b and down regulation of miR‐30c. Mito‐Esc treatment by modulating miR‐19b and miR‐30c through SIRT3 activation, inhibits PAI‐1 levels. An association between PAI‐1, miR‐19b, and ‐30c was observed in plasma and microparticles isolated from patients suffering from acute coronary syndrome of various degrees.
•The influence of innovative multi strut with dual cavity on scramjet combustor is investigated.•Innovative strut aids in generating intense vorticity which helps in efficient mixing of fuel and ...oxidiser.•Combustion efficiency was higher with innovative strut in comparison with base strut.•Shear shock layer enhances the mixing rate by intensifying turbulence phenomena.•Total pressure loss in base strut is 10% lower than that of modified strut.
To analyze the influence of flow physics and operating parameters (i.e., injection pressure (2, 4, 6, and 8 bars), a simulation is performed on a scramjet combustor (modified) using the shear stress transport (SST) k- ω turbulence model and Reynolds Averaged Navier Stokes (RANS) equations. Wall pressures, the pattern of shock-wave, and static temperature of the combustor are three major parameters that have been analyzed in this study. An acceptable range of results indicates that the simulation approach adopted can be used for additional studies. According to the results of this study, the shock-wave position is destabilized when the hydrogen jet pressure is enhanced by varying the flame characteristics. Moreover, it was also observed that the shock wave travels upstream due to the pressure exerted by the main flow. A normal shock wave moves ahead of the strut as soon as the pressure in the hydrogen jet increases to 4 bar. According to this study, it is beneficial to have lower hydrogen jet pressures in supersonic flows for the geometry considered. The penetration depth of fuel in the axial direction increases, which deteriorates the combustion efficiency with an increase in the total pressure losses.
In SERAPHIN, a long-term, randomised, controlled trial (NCT00660179) in pulmonary arterial hypertension (PAH), macitentan significantly reduced the risk of morbidity/mortality and PAH-related ...death/hospitalisation. We evaluated disease progression and the effect of macitentan in treatment-naïve incident and prevalent cohorts.Patients allocated to placebo, or macitentan 3 mg or 10 mg were classified by time from diagnosis to enrolment as incident (≤6 months; n=110) or prevalent (>6 months; n=157). The risk of morbidity/mortality and PAH-related death/hospitalisation was determined using Cox regression.The risk of morbidity/mortality (Kaplan-Meier estimates at month 12: 54.4% versus 26.7%; p=0.006) and PAH-related death/hospitalisation (Kaplan-Meier estimates at month 12: 47.3% versus 19.9%; p=0.006) were significantly higher for incident versus prevalent patients receiving placebo, respectively. There was no significant difference in the risk of all-cause death between incident and prevalent cohorts (p=0.587). Macitentan 10 mg significantly reduced the risk of morbidity/mortality and PAH-related death/hospitalisation versus placebo in incident and prevalent cohorts.Incident patients had a higher risk for PAH progression compared with prevalent patients but not a higher risk of death. Macitentan delayed disease progression in both incident and prevalent PAH patients.
In a randomized, double-blind, crossover design, we compared the efficacy of sildenafil with placebo in patients with primary pulmonary hypertension (PPH). The primary end point was the change in ...exercise time on treadmill using the Naughton protocol. Secondary end points were change in cardiac index and pulmonary artery systolic pressure as assessed by Doppler echocardiography and quality of life (QOL) as assessed by a questionnaire.
Primary pulmonary hypertension is a disorder with limited treatment options. Uncontrolled studies had shown sildenafil to be beneficial in the treatment of PPH.
After initial clinical evaluation, including Doppler echocardiography and treadmill exercise test, patients were randomized to placebo or sildenafil with dosages ranging from 25 to 100 mg thrice daily on the basis of body weight. The evaluation was repeated after six weeks. Then patients were crossed over to alternate therapy. Final evaluation was performed after another six weeks of treatment.
Twenty-two patients completed the study. Exercise time increased by 44% from 475 +/- 168 s at the end of placebo phase to 686 +/- 224 s at the end of sildenafil phase (p < 0.0001). With sildenafil, cardiac index improved from 2.80 +/- 0.9 l/m2 to 3.45 +/- 1.1 l/m(2) (p < 0.0001), whereas pulmonary artery systolic pressure decreased insignificantly from 105.23 +/- 17.82 mm Hg to 98.50 +/- 24.38 mm Hg. There was significant improvement in the dyspnea and fatigue components of the QOL questionnaire. During the placebo phase, one patient died and another had syncope. There were no serious side effects with sildenafil.
Sildenafil significantly improves exercise tolerance, cardiac index, and QOL in patients with PPH.
Introduction
In SERAPHIN, a long-term, event-driven, double-blind randomised controlled trial in pulmonary arterial hypertension (PAH), macitentan 10 mg significantly reduced the risk of ...morbidity/mortality compared with placebo. Its open-label extension study (SERAPHIN OL) further assessed long-term safety and tolerability of macitentan 10 mg in PAH patients.
Methods
Patients in SERAPHIN who completed the double-blind treatment period or experienced a morbidity event during the study could enter SERAPHIN OL. Patients received macitentan 10 mg once daily, and safety and survival were assessed until end of treatment (+ 28 days). Two overlapping sets were analysed for safety: (1) all patients in SERAPHIN OL (OL safety set); (2) patients randomised to macitentan 10 mg in SERAPHIN (long-term safety/survival set). Survival was evaluated as an exploratory endpoint in the latter set.
Results
Of 742 patients randomised in SERAPHIN, 550 (74.1%) entered SERAPHIN OL (OL safety set); 242 patients were randomised to macitentan 10 mg in SERAPHIN (long-term safety/survival set). Median (min, max) exposure to macitentan 10 mg was 40.1 (0.1, 130.5) months (2074.7 patient-years; OL safety set) and 54.7 (0.1, 141.3) months (1151.0 patient-years; long-term safety/survival set). Safety in both analysis sets was comparable to the known safety profile of macitentan. Kaplan-Meier survival estimates (95% CI) at 1, 5, 7 and 9 years were 95.0% (91.3, 97.1), 73.3% (66.6, 78.9), 62.6% (54.6, 69.6) and 52.7% (43.6, 61.0), respectively (long-term safety/survival set; median follow-up: 5.9 years).
Conclusions
This analysis provides the longest follow-up for safety and survival published to date for any PAH therapy. The safety profile of macitentan 10 mg over this extensive treatment period was in line with that observed in SERAPHIN. As the majority of patients were receiving other PAH therapy at macitentan initiation, our study provides additional insight into the long-term safety of macitentan, including as part of combination therapy.
Trial Registration
ClinicalTrials.gov Identifiers: NCT00660179 and NCT00667823.
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