Inhaled treprostinil in pulmonary hypertension associated with COPD: PERFECT study results.

BACKGROUND: Pulmonary hypertension (PH) accompanying COPD (PH-COPD) is associated with worse outcomes than COPD alone. There are currently no approved therapies to treat PH-COPD. The PERFECT study (ClinicalTrials.gov: NCT03496623) evaluated the safety and efficacy of inhaled treprostinil (iTRE) in this patient population. METHODS: Patients with PH-COPD (mean pulmonary arterial pressure ≥30 mmHg and pulmonary vascular resistance ≥4 WU) were enrolled in a multicentre, randomised (1:1), double-blind, placebo-controlled, 12-week, crossover study. A contingent parallel design was also prespecified and implemented, based on a blinded interim analysis of missing data. Patients received treatment with iTRE up to 12 breaths (72 µg) 4 times daily or placebo. The primary efficacy end-point was change in peak 6-min walk distance (6MWD) at week 12. RESULTS: In total, 76 patients were randomised, 64 in the original crossover design and 12 in the contingent parallel design; 66 patients received iTRE and 58 received placebo. The study was terminated early at the recommendation of the data and safety monitoring committee based on the totality of evidence that iTRE increased the risk of serious adverse events and suggestive evidence of an increased risk of mortality. The change in 6MWD was numerically worse with iTRE exposure than with placebo exposure. CONCLUSIONS: The risk-benefit observations associated with iTRE in patients with PH-COPD did not support continuation of the PERFECT study. The results of this study do not support iTRE as a viable treatment option in patients with PH-COPD.

Efficacy of Inhaled Treprostinil on Multiple Disease Progression Events in Patients with Pulmonary Hypertension due to Parenchymal Lung Disease in the INCREASE Trial.

Rationale: The INCREASE study of inhaled treprostinil met its primary endpoint of change in 6-minute-walk distance at Week 16. In addition, there were significantly fewer clinical worsening events in patients receiving inhaled treprostinil. However, the incidence of multiple events in the same patient is unknown. Objectives: This post hoc analysis evaluated the effect of continued treatment with inhaled treprostinil on the frequency and impact of multiple disease progression events. Methods: Patients enrolled in INCREASE were analyzed for disease progression events, defined as at least 15% decline in 6-minute-walk distance, exacerbation of underlying lung disease, cardiopulmonary hospitalization, lung transplantation, at least 10% decline in forced vital capacity, or death during the duration of the 16-week study. Measurements and Main Results: In total, 147 disease progression events occurred in the inhaled treprostinil group (89/163 patients, 55%) compared with 215 events (109/163 patients, 67%) in the placebo group (P = 0.018). There was a lower incidence of each disease progression component in the inhaled treprostinil group: 6-minute-walk distance decline (45 vs. 64 events), lung disease exacerbation (48 vs. 72 events), FVC decline (19 vs. 33), cardiopulmonary hospitalization (23 vs. 33 events), and death (10 vs. 12). Fewer patients receiving inhaled treprostinil had multiple progression events compared with those receiving the placebo (35 vs. 58, 22% vs. 36%; P = 0.005). Conclusions: Patients who received inhaled treprostinil were significantly less likely to experience further disease progression events after an initial event compared with patients receiving placebo. These results support the continuation of inhaled treprostinil despite the occurrence of disease progression in clinical practice.

Prostacyclin in Intubated Patients with COVID-19 and Severe Endotheliopathy: A Multicenter, Randomized Clinical Trial.

Rationale: The mortality in patients infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) who require mechanical ventilation remains high, and endotheliopathy has been implicated. Objectives: To determine the effect of prostacyclin infusion in mechanically ventilated patients infected with SARS-CoV-2 with severe endotheliopathy. Methods: We conducted a multicenter, randomized clinical trial in adults infected with coronavirus disease (COVID-19) who required mechanical ventilation and had a plasma level of thrombomodulin >4 ng/ml; patients were randomized to 72-hour infusion of prostacyclin 1 ng/kg/min or placebo. Measurements and Main Results: The main outcome was the number of days alive and without mechanical ventilation within 28 days. Key secondary outcomes were 28-day mortality and serious adverse events within 7 days. Eighty patients were randomized (41 prostacyclin and 39 placebo). The median number of days alive without mechanical ventilation at 28 days was 16.0 days (SD, 12) versus 5.0 days (SD, 10) (difference of the medians, 10.96 days; 95% confidence interval [CI], -5 to 21; P = 0.07) in the prostacyclin and the placebo groups, respectively. The 28-day mortality was 21.9% versus 43.6% in the prostacyclin and the placebo groups, respectively (risk ratio, 0.50; 95% CI, 0.24 to 0.96; P = 0.06). The incidence of serious adverse events within 7 days was 2.4% versus 12.8% (risk ratio, 0.19; 95% CI, 0.001 to 1.11; P = 0.10) in the prostacyclin and the placebo groups, respectively. Conclusions: Prostacyclin was not associated with a significant reduction in the number of days alive and without mechanical ventilation within 28 days. The point estimates, however, favored the prostacyclin group in all analyses, including 28-day mortality, warranting further investigation in larger trials. Clinical trial registered with www.clinicaltrials.gov (NCT04420741); EudraCT Identifier: 2020-001296-33.

In-vitro and in-vivo comparisons of high versus low concentrations of inhaled epoprostenol to adult intubated patients.

BACKGROUND: Inhaled epoprostenol (iEPO) has been shown to reduce pulmonary artery pressure and improve oxygenation. iEPO is mainly delivered via a syringe pump with feed tubing connected to a vibrating mesh nebulizer with high or low formulation concentration delivery. METHODS: An in vitro study and a two-period retrospective case-control study were implemented. The in vitro study compared iEPO delivery via invasive ventilation at low concentrations of 7.5, and 15 mcg/mL and high concentration at 30 mcg/mL, to deliver the ordered dose of 30 and 50 ng/kg/min for three clinical scenarios with predicted body weight of 50, 70 and 90 kg. While in the clinical study, adult patients receiving iEPO via invasive ventilation to treat refractory hypoxemia, pulmonary hypertension, or right ventricular failure were included. 80 patients received low concentration iEPO at multiple concentrations (2.5, 7.5, and 15 mcg/mL, depending on the ordered dose) from 2015 to 2017, while 84 patients received high concentration iEPO at 30 mcg/mL from 2018 to 2019. RESULTS: In the in vitro study, there were no significant differences in aerosol deposition between high vs low concentrations of iEPO at a dose of 50 ng/kg/min. In the clinical study, age, gender, ethnicity, and indications for iEPO were similar between high and low concentration groups. After 30-120 min of iEPO administration, both delivery strategies significantly improved oxygenation in hypoxemic patients and reduced mean pulmonary arterial pressure (mPAP) for patients with pulmonary hypertension. However, no significant differences of the incremental changes were found between two delivery groups. Compared to low concentration, high concentration delivery group had better adherence to the iEPO weaning protocol (96% vs 71%, p < 0.001), fewer iEPO syringes utilized per patient (5 [3, 10] vs 12 [6, 22], p = 0.001), and shorter duration of invasive ventilation (6 [3, 12] vs 9 [5, 18] days, p = 0.028). Intensive care unit length of stay and mortality were similar between two groups. CONCLUSION: Compared to low concentration delivery of iEPO, high concentration iEPO via a vibrating mesh nebulizer maintained clinical benefits and increased clinician compliance with an iEPO weaning protocol, required less medication preparation time, and shortened duration of invasive ventilation.

Rapid Switch From Subcutaneous to Intravenous Treprostinil in Precapillary Pulmonary Hypertension by Pump Implantation.

ABSTRACT: Limited data are available on the transition from subcutaneous to intravenous prostacyclin in precapillary pulmonary hypertension. We performed a retrospective analysis of all patients who were switched from subcutaneous to intravenous treprostinil with an implantable infusion pump. We included 85 consecutive, clinically stable patients (mean age 66 years and range 16-85), who had been treated with subcutaneous treprostinil for mean 9 months (range 1-78) before pump implantation. An interdisciplinary expert panel defined standards for this procedure before the first implantation. As the first patient experienced a significant hypotensive episode indicating treprostinil overdose postoperatively, the time span to stop subcutaneous treprostinil was reduced to 60 minutes for all following patients. No events associated with the switch from subcutaneous to intravenous treprostinil were observed during postoperative hospital stay in 84 (98.8%) patients. Taking into account a likely depot effect of subcutaneous treprostinil patients can safely be switched to the intravenous route by the implantation of an infusion pump.

Comparison of Fixed-Dose Inhaled Epoprostenol and Inhaled Nitric Oxide for Acute Respiratory Distress Syndrome in Critically Ill Adults.

PURPOSE: Several reports have demonstrated similar effects on oxygenation between inhaled epoprostenol (iEPO) compared to inhaled nitric oxide (iNO) for acute respiratory distress syndrome (ARDS). Previous studies directly comparing oxygenation and clinical outcomes between iEPO and iNO exclusively in an adult ARDS patient population utilized a weight-based dosing strategy. The purpose of this study was to compare the clinical and economic impact between iNO and fixed-dosed iEPO for ARDS in adult intensive care unit (ICU) patients. METHODS: This retrospective cohort study was conducted at a major academic medical center between January 1, 2014, and October 31, 2018. Patients ≥18 years of age with moderate-to-severe ARDS were included. The primary end point was to compare the mean change in partial arterial oxygen pressure to fraction of inspired oxygen (Pao 2: Fio 2) at 4 hours from baseline between iEPO and iNO. Other secondary aims were total acquisition drug costs, in-hospital mortality, ICU and hospital length of stay, and duration of mechanical ventilation. RESULTS: A total of 239 patients were included with 139 (58.2%) and 100 (41.8%) in the iEPO and iNO groups, respectively. The mean change in Pao 2: Fio 2 at 4 hours from baseline in the iEPO and iNO groups were 31.4 ± 54.6 and 32.4 ± 42.7 mm Hg, respectively (P = .88). The responder rate at 4 hours was similar between iEPO and iNO groups (64.7% and 66.0%, respectively, P = .84). Clinical outcomes including mortality, overall hospital and ICU length of stay, and mechanical ventilation duration were similar between iEPO and iNO groups. Estimated annual cost-savings realized with iEPO was USD1 074 433. CONCLUSION: Fixed-dose iEPO was comparable to iNO in patients with moderate-to-severe ARDS for oxygenation and ventilation parameters as well as clinical outcomes. Significant cost-savings were realized with iEPO use.

Periprocedural safety and outcome after pump implantation for intravenous treprostinil administration in patients with pulmonary arterial hypertension.

METHODS: In this retrospective observational study, we analyzed all patients with pulmonary arterial hypertension undergoing LenusPro® pump implantation between November 2013 and October 2019 at our center. Periprocedural safety was assessed by describing all complications that occurred within 28 days after surgery; complications that occurred later were described to assess long-term safety. Clinical outcomes were measured by comparison of clinical parameters and echocardiographic measurements of right ventricular function from baseline to 6-months-follow-up. RESULTS: Fifty-four patients underwent LenusPro® pump implantation for intravenous treprostinil treatment during the investigation period. Periprocedural complications occurred in 5 patients; the only anesthesia-related complication (right heart failure with recovery after prolonged intensive care and death in the further course) occurred in the only patient who underwent general anesthesia. All other patients underwent local anesthesia with or without short-acting (analgo-) sedation. Eighteen long-term complications occurred in 15 patients, most notably pump pocket or catheter related problems. Transplant-free survival rates at 1, 2, and 3 years were 77 %, 56 %, and 48 %, respectively. CONCLUSIONS: Subcutaneous pump implantation under local anesthesia and conscious analgosedation while avoiding intubation and mechanical ventilation is feasible in patients with advanced PAH. Controlled studies are needed to determine the safest anesthetic approach for this procedure. BACKGROUND/OBJECTIVES: Intravenous treprostinil treatment via a fully implantable pump is a treatment option for patients with advanced pulmonary arterial hypertension. However, there is no consensus on the preferred anesthetic approach for the implantation procedure. Primary objective was to assess periprocedural safety with particular attention to feasibility of local anesthesia and conscious analgosedation instead of general anesthesia. Long-term safety and clinical outcomes were secondary endpoints.

Use of Treprostinil in Pediatric Pulmonary Hypertension: Case Reports and Review of the Literature.

BACKGROUND: Add-on therapy with prostacyclin in pediatric refractory pulmonary hypertension (PH) poses a challenge, especially when considering continuous intravenous administration in younger children. A search for alternate routes of drug delivery has led to the clinical investigation of stable and long-acting prostacyclin analogues, such as subcutaneous treprostinil. We reported 2 pediatric cases of PH treated with subcutaneous treprostinil and reviewed the literature on treprostinil use in children. METHOD: The literature review used 3 electronic databases and a combination of terms (treprostinil, pediatric, PH, prostanoid, etc). We also searched for pediatric clinical trials on treprostinil registered on international clinical trial registries. RESULTS: The reported cases highlighted the multifactorial nature of PH in pediatrics: a female child with a giant omphalocele, and intracardiac and extracardiac shunts; and a male premature child with a congenital diaphragmatic hernia and long-term PH. The literature review identified 19 studies reporting treprostinil use in 421 children with various types of PH (groups 1 and 3). Subcutaneous treprostinil was the most administered formulation, at a mean dose of 40 ng/kg/min. Overall, 12 clinical trials on treprostinil for children with PH were registered on the clinical trial registries. Most authors concluded that subcutaneous treprostinil was effective, well tolerated, and represented an alternative to intravenous epoprostenol. CONCLUSIONS: Subcutaneous treprostinil may be a useful adjunct in the therapeutic algorithm for children with severe PH, refractory to oral drugs, and after a complete check-up for all PH etiologies.

Pharmacokinetics of Oral Treprostinil in Children With Pulmonary Arterial Hypertension.

As part of a clinical trial, this study examined the pharmacokinetics (PK) of oral treprostinil (TRE) in children with pulmonary arterial hypertension. The trial consisted of the following 3 cohorts: transition from parenteral (cohort 1) or inhaled (cohort 2) TRE, or de novo addition (cohort 3). Oral TRE was dosed 3 times daily. PK samples were obtained before an oral TRE dose, and at 2, 4, 6, and 8 hours thereafter. The PK parameters were calculated using noncompartmental analysis. Thirty-two children (n = 10 in cohorts 1 and 2, n = 12 in cohort 3) were enrolled; the median age was 12 years (range 7-17 years), and the median weight was 42.2 kg (range 19.3-78 kg). The median oral TRE dose for all subjects was 3.8 mg (5.9, 3.5, and 4.0 mg for cohorts 1, 2, and 3, respectively). The TRE concentration versus time profile demonstrated a peak concentration at a median of 3.8 hours with wide variability. In cohort 1, oral dosing led to higher peak (5.9 ng/mL) and lower trough (1 ng/mL) concentrations than parenteral (peak 5.4 ng/mL and trough 4.2 ng/mL), but a lower mean concentration (3.61 vs. 4.46 ng/mL), likely due to variable metabolism and noncomparable dosing. Both the area under the curve and average concentration were linearly correlated with oral TRE dose and dose normalized to body weight, but not with weight or age alone. In pediatric patients, an increased oral TRE dose or dose frequency may be required to minimize PK variability and achieve greater correlation with parenteral dosing.

Marked Reduction of Pulmonary Artery Pressure After Registration for Lung Transplantation Is Associated With Long-Term Survival in Patients With Pulmonary Arterial Hypertension　- Cohort Study.

BACKGROUND: The waiting period for lung transplantation (LT) is approximately 3 years in Japan. The prognosis of patients with pulmonary arterial hypertension (PAH) awaiting LT is poor without LT. Patients at the present center often survive in the long term after registration for LT. The aim of this study was to elucidate why some patients survive in the long term by investigating changes in pulmonary artery pressure (PAP) after registration, and medication used.Methods and Results:This study involved 57 patients with PAH who were enrolled in a registry for LT at Okayama University Hospital. We divided patients into 3 groups according to outcome: LT (n=27); death without LT (n=21); and survival without LT (n=9). The median interval from PAH diagnosis to epoprostenol treatment was shorter in the survival group (58 days) than in the LT group (378 days) and death group (545 days). Eight patients in the survival group, 13 in the LT group, and 13 in the death group underwent right heart catheterization after registration. Percent change in mean PAP after registration was significantly greater in the survival group (-32%) than in the LT group (-13%) and death group (1%; P<0.01). CONCLUSIONS: Even after LT registration, patients who received epoprostenol infusion soon after diagnosis of PAH often had marked reduction in PAP and long-term survival without LT.

Effectiveness, Safety, and Economic Comparison of Inhaled Epoprostenol Brands, Flolan and Veletri, in Acute Respiratory Distress Syndrome.

Background: No previous studies exist examining 2 inhaled epoprostenol formulations in an acute respiratory distress syndrome (ARDS) patient population. Objective: The study aim was to evaluate a formulary conversion from inhaled Flolan to Veletri to determine the impact on effectiveness, safety, and cost in patients with ARDS. Methods: This was a single-center, retrospective, matched cohort observational study at a tertiary care academic medical center. Patients included were mechanically ventilated, adult patients with ARDS receiving inhaled Flolan or Veletri for ≥1 hour in the intensive care unit. Results: A total of 132 patients were included in the matched cohort. There was no difference detected in change in partial pressure of arterial O2/fraction of inspired O2 (PaO2/FiO2) ratio after 1 hour of therapy between the inhaled Flolan and Veletri groups (27.2 ± 46.2 vs 30 ± 68 mm Hg, P = 0.78). Significant differences in secondary outcomes included incidence of hypotension (83% vs 95.5%, P = 0.04) and thrombocytopenia (9.1% vs 29.5%, P < 0.01) in the inhaled Flolan and Veletri groups, respectively, with no difference in cost per duration of therapy (P = 0.29). Conclusions and Relevance: There was no difference in the change in PaO2/FiO2 ratio after 1 hour of therapy between inhaled Flolan and Veletri in an ARDS patient population. The formulary conversion from inhaled Flolan to Veletri was likely justified.

A Bayesian Network Meta-analysis of Add-on Drug Therapies Specific for Pulmonary Arterial Hypertension.

Background: Recently published meta-analyses did not discriminate between drug agents used for initial and sequential combination therapy. Objective: To assess the comparative efficacy of drugs specific for the treatment of pulmonary arterial hypertension (PAH) as add-on therapies based on 6-minute walk distance (6MWD), all-cause mortality, and discontinuation due to adverse events (AEs). Methods: EMBASE, PubMed, Cochrane Library, and ClinicalTrials.gov were searched until December 9, 2018, for the randomized, placebo-controlled clinical trials (RCTs) conducted on primarily adult patients diagnosed with PAH. Data extracted from applicable RCTs were as follows: for 6MWD mean change from baseline, the total number of patients, and the number of patients with events, per treatment. Network meta-analysis (NMA) was conducted in a Bayesian framework. Results: A total of 16 RCTs were eligible for analysis, with 4112 patients. Add-on therapy with tadalafil or inhaled treprostinil performed better than endothelin receptor antagonists alone [27 m; 95% credible interval (CrI): (11, 43); and 19 m; 95% CrI: (10, 27); respectively]. Add-on therapy with macitentan or bosentan performed better than phosphodiesterase type 5 inhibitors alone [26 m; 95% CrI: (6.4, 45); and 22 m; 95% CrI: (5.1, 38); respectively]. Differences in all-cause mortality and discontinuation due to AEs were nonsignificant. Conclusion and Relevance: Our NMA evaluated efficacy and safety of add-on therapies in patients with PAH. None of the previous meta-analyses evaluated RCTs focusing solely on patients pretreated with another PAH-specific drug therapy. Our results support guideline recommendations on combination therapy in PAH patients and add the quantitative perspective on which sequential therapy demonstrated the greatest effect size.

Inpatient Initiation of Oral Treprostinil in an Academic Medical System.

PURPOSE: Clinicians may transition patients on parenteral or inhaled prostacyclins to oral treprostinil for ease of use or to avoid adverse effects related to parenteral therapy. However, few data are available to guide these transitions in inpatients. The purpose of this analysis is to describe the inpatient initiation of oral treprostinil at an academic medical system. METHODS: This is a retrospective cohort analysis of patients newly initiated on oral treprostinil at Cleveland Clinic Heath System from 2015 to 2017. Demographic information regarding pulmonary arterial hypertension (PAH) history and previous PAH therapies were recorded. Outcomes evaluated included doses of oral treprostinil utilized, adverse effects related to therapy, and measures of clinical and functional status before and after the initiation of oral treprostinil. RESULTS: Overall, 29 patients were prescribed oral treprostinil, of which 15 patients were included in the analysis. Common reasons for initiation of oral treprostinil included disease progression (6, 40%) and patient desire (4, 25%). The median duration of transition/initiation of oral treprostinil was 4 days (range, 3-11 days). Median daily dose of oral treprostinil on day 1 of initiation was 2 mg (0.25-4 mg). By day 7, median daily dose was 15 mg (0.75-27.75 mg). Common adverse effects related to therapy were gastrointestinal (7, 47%) and headache (4, 27%). No patients required discontinuation of oral treprostinil due to adverse effects within 90 days of initiation. CONCLUSION: Inpatient initiation/transition to oral treprostinil was relatively well tolerated. Future studies should evaluate clinical outcomes surrounding the transitioning to oral treprostinil.

Midterm postoperative prognosis of patients with severe left heart valvular disease combined with moderate or severe pulmonary hypertension treated with treprostinil.

BACKGROUND: To investigate the midterm postoperative prognosis of patients with severe left heart valvular disease combined with moderate or severe pulmonary hypertension (PAH) using subcutaneous injection of treprostinil. METHODS: A retrospective study was conducted on 61 patients with severe left heart valvular disease combined with moderate or severe PAH who had undergone mechanical mitral and/or aortic valve replacement from April 2018 to October 2018. The patients were divided into the treprostinil group and the conventional treatment group according to whether they received treprostinil. The patients were assessed by SwanGanz catheterization, echocardiography, the 6-min walk test (6-MWT), the Borg dyspnoea score and the SF-36 questionnaire. RESULTS: Compared with the preoperative data, the mPAP measured by SwanGanz catheterization, the results of the 6-MWT and the Borg score were significantly improved in both groups during the 1 year follow-up (P < 0.05). Regarding the comparison between the groups, the results in group T were significantly better than those in group C, including the results of the 6-MWT and the general health, vitality and mental health of SF-36 during the 1 year follow-up (P < 0.05). CONCLUSIONS: Continuous subcutaneous infusion of treprostinil was not capable of decreasing pulmonary pressures in patients with severe left heart valvular disease combined with moderate or severe PAH during 1 year follow-up, although which some of our data suggest that might improve the symptoms and quality of life of these patients.

Interventions for frostbite injuries.

BACKGROUND: Frostbite is a thermal injury caused when tissue is exposed to sub-zero temperatures (in degrees Celsius) long enough for ice crystals to form in the affected tissue. Depending on the degree of tissue damage, thrombosis, ischaemia, necrosis (tissue death), gangrene and ultimately amputation may occur. Several interventions for frostbite injuries have been proposed, such as hyperbaric oxygen therapy, sympathectomy (nerve block), thrombolytic (blood-thinning) therapy and vasodilating agents such as iloprost, reserpine, pentoxifylline and buflomedil, but the benefits and harms of these interventions are unclear. OBJECTIVES: To assess the benefits and harms of the different management options for frostbite injuries. SEARCH METHODS: On 25 February 2020, we searched the Cochrane Central Register of Controlled Trials (CENTRAL) in the Cochrane Library, Ovid MEDLINE(R), Ovid MEDLINE(R) In-Process & Other Non-Indexed Citations, Ovid MEDLINE(R) Daily and Ovid OLDMEDLINE(R), Embase (OvidSP), ISI Web of Science: Science Citation Index Expanded (SCI-EXPANDED), Conference Proceedings Citation Index-Science (CPCI-S), as well as trials registers. Shortly before publication, we searched Clinicaltrials.gov, the World Health Organization (WHO) International Clinical Trials Registry Platform, OpenGrey and GreyLit (9 November 2020) again. We investigated references from relevant articles, and corresponded with a trial author. SELECTION CRITERIA: We included randomised controlled trials (RCTs) that compared any medical intervention, e.g. pharmacological therapy, topical treatments or rewarming techniques, for frostbite injuries to another treatment, placebo or no treatment. DATA COLLECTION AND ANALYSIS: Two authors independently extracted data. We used Review Manager 5 for statistical analysis of dichotomous data with risk ratio (RR) with 95% confidence intervals (CIs). We used the Cochrane 'Risk of bias' tool to assess bias in the included trial. We assessed incidence of amputations, rates of serious and non-serious adverse events, acute pain, chronic pain, ability to perform activities of daily living, quality of life, withdrawal rate from medical therapy due to adverse events, occupational effects and mortality. We used GRADE to assess the quality of the evidence. MAIN RESULTS: We included one, open-label randomised trial involving 47 participants with severe frostbite injuries. We judged this trial to be at high risk of bias for performance bias, and uncertain risk for attrition bias; all other risk of bias domains we judged as low. All participants underwent rapid rewarming, received 250 mg of aspirin and 400 mg intravascular (IV) buflomedil (since withdrawn from practice), and were then randomised to one of three treatment groups for the following eight days. Group 1 received additional IV buflomedil 400 mg for one hour per day. Group 2 received the prostacyclin, iloprost, 0.5 ng to 2 ng/kg/min IV for six hours per day. Group 3 received IV iloprost 2 ng/kg/min for six hours per day plus fibrinolysis with 100 mg recombinant tissue plasminogen activator (rtPA) for the first day only. The results suggest that iloprost and iloprost plus rtPA may reduce the rate of amputations in people with severe frostbite compared to buflomedil alone, RR 0.05 (95% CI 0.00 to 0.78; P = 0.03; very low-quality evidence) and RR 0.31 (95% CI 0.10 to 0.94; P = 0.04; very low-quality evidence), respectively. Iloprost may be as effective as iloprost plus rtPA at reducing the amputation rate, RR 0.14 (95% CI 0.01 to 2.56; P = 0.19; very low-quality evidence). There were no reported deaths or withdrawals due to adverse events in any of the groups; we assessed evidence for both outcomes as being of very low quality. Adverse events (including flushing, nausea, palpitations and vomiting) were common, but not reported separately by comparator arm (very low-quality evidence). The included study did not measure the outcomes of acute pain, chronic pain, ability to perform activities of daily living, quality of life or occupational effects. AUTHORS' CONCLUSIONS: There is a paucity of evidence regarding interventions for frostbite injuries. Very low-quality evidence from a single small trial indicates that iloprost, and iloprost plus rtPA, in combination with buflomedil may reduce the need for amputation in people with severe frostbite compared to buflomedil alone. However, buflomedil has been withdrawn from use. High quality randomised trials are needed to establish firm evidence for the treatment of frostbite injuries.

Ambulatory Transition from Parenteral Prostanoid to Inhaled Treprostinil in Patients with Pulmonary Arterial Hypertension.

PURPOSE: The intravenous or subcutaneous delivery of prostanoid drugs for moderate to severe pulmonary arterial hypertension has been fraught with complications and patient dissatisfaction. Combination therapy including inhaled treprostinil is an attractive alternative in clinically stable patients. Uncertainties exist about the patient characteristics and the optimal setting (inpatient versus office/home) for transition. METHODS: Sixteen stable patients with pulmonary arterial hypertension and favorable risk profile were transitioned from parenteral prostanoid to combination therapy including inhaled treprostinil in the home setting. Nine patients were using intravenous treprostinil, two patients were using subcutaneous treprostinil, and five patients were using intravenous epoprostenol at a median dose of 80 (interquartile range, IQR 72-90), 76.5 (68 and 85), and 28 (IQR 26-30) ng/kg/min respectively. Patients were followed up for a median of 732.5 days after transition (IQR 506.5-1294 days). RESULTS: Patients tolerated the transition to inhaled treprostinil well without significant change in functional class (81.25% FC I/II before transition vs. 87.5% after), 6-min walk distance [349 m (IQR 226-461 m) to 364 m (IQR 238-565 m), p = 0.09] or NT-proBNP [149 pg/ml (IQR 71.5-383 pg/ml) to 186.5 pg/ml (IQR 83.5-444 pg/ml), p = 0.38]. Hemodynamic data, where available, showed significant improvements in mean pulmonary artery pressure and pulmonary vascular resistance from 36 mmHg (IQR 27-46.5 mmHg) and 5.2 Wood Units (WU) (IQR 3.1-5.6 WU) to 28.5 mmHg (IQR 22-35.5 mmHg) and 3.2 WU (IQR 2.4-4.2 WU) (p-values 0.022 and 0.003). More patients were on triple therapy after transition, and side effects reported were less severe. CONCLUSION: For select patients, transition from a parenteral prostanoid-based therapy to a combination regimen including inhaled treprostinil in the home setting appears safe and well tolerated.

The Effect of Perioperative Administration of Treprostinil in Infants with Non-restrictive Ventricular Septal Defect and Severe Pulmonary Arterial Hypertension.

This study investigated the efficacy and safety of intravenous treprostinil during the perioperative period in infants with non-restrictive ventricular septal defect (VSD) and severe pulmonary arterial hypertension (PAH) undergoing surgical VSD repair. This was a retrospective study. There were 79 infants with non-restrictive VSD and severe PAH receiving surgical treatment from January to December 2019 in our cardiac center. The patients were divided into the treprostinil group and control group according to whether intravenous treprostinil was used during the perioperative period. There were no significant differences in the preoperative characteristics, including age, sex, weight, ventricular size, or preoperative pulmonary artery pressure, between the two groups. Although the pulmonary artery pressure in both groups was significantly lower postoperatively than preoperatively, the postoperative pulmonary artery systolic pressure was significantly lower in group T than in group C. The postoperative mechanical ventilation time, ICU stay, and hospital stay in group T were shorter than those in group C. Treprostinil can be used effectively and safely to reduce the perioperative pulmonary artery pressure in infants with non-restrictive VSD and severe PAH undergoing surgical VSD repair.

Long-term experience with implantable treprostinil pumps in pulmonary arterial hypertension.

OBJECTIVES: To compare clinical parameters and quality of life in patients with pulmonary arterial hypertension (PAH) at the time of diagnosis, at the time of LenusPro pump implantation and during intravenous treptostinil treatment. METHODS: Seven patients with severe PAH treated with intravenous treptostinil via implantable LenusPro pumps were evaluated, including NYHA classification, six­minute walking test, BNP and quality of life assessment using the EQ-5D-5L questionnaire before and after pump implantation. RESULTS: No significant changes were observed in NYHA class and six­minute walking distance test. There was however a significant improvement in the quality of life and a decrease in BNP levels. The mean EQ-5D-5L index assessed during subcutaneous treptostinil treatment was significantly worse when compared to that assessed during its intravenous application (0.39 ± 0.24 vs 0.78 ± 0.28, p ˂ 0.05); the same is true about the pain/discomfort dimension. Complications occurred, namely one nonfatal pneumothorax, one nonfatal hemothorax, and one event of nonfatal treptostinil intoxication after refilling. CONCLUSIONS: In patients who do not tolerate subcutaneous treptostinil treatment, the use of the LenusPro implantable pump results in a significant improvement in quality of life with an acceptable safety profile (Tab. 2, Fig. 2, Ref. 19).

Advances in targeted therapy for chronic thromboembolic pulmonary hypertension.

Chronic thromboembolic pulmonary hypertension (CTEPH) is characterized by unresolved thrombi in the pulmonary arteries and microvasculopathy in nonoccluded areas. If left untreated, progressive pulmonary hypertension will induce right heart failure and, finally, death. Currently, pulmonary endarterectomy (PEA) remains the only method that has the potential to cure CTEPH. Unfortunately, up to 40% of patients are ineligible for this procedure for various reasons. In recent years, refined balloon pulmonary angioplasty (BPA) has become an alternative option for inoperable CTEPH patients, and it may be another curative treatment in the future, particularly in combination with prior PEA. Nevertheless, 23% of patients still suffer from persistent PH after BPA. Given that CTEPH shares many similarities with idiopathic pulmonary arterial hypertension (PAH), targeted drugs developed for PAH are also attractive options for CTEPH, especially for inoperable or persistent/recurrent CTEPH patients. To date, riociguat, macitentan, and subcutaneous treprostinil are the only drugs proven by randomized control trials to be capable of improving the exercise capacity (6-min walking distance) of CTEPH patients. In this review, we summarize the achievements and unresolved problems of PAH-targeted therapy for CTEPH over the last decade.

Subcutaneous and Intravenous Treprostinil Pharmacokinetics in Children With Pulmonary Vascular Disease.

This study evaluated the pharmacokinetics of intravenous (IV) and subcutaneous (SC) treprostinil in pediatric patients with pulmonary vascular disease, and compared them with existing adult data from a similar cohort. Blood samples were collected from pediatric patients receiving steady-state IV or SC treprostinil and were assessed for plasma treprostinil concentration using liquid chromatography and tandem mass spectrometry. Forty participants, 15 receiving IV and 25 receiving SC treprostinil, were included in the analysis. Age ranged from 0.1 to 15.6 years. The median dose of treprostinil was 45.5 ng·kg·min with a range of 8-146 ng·kg·min. There was a linear relationship between treprostinil dose and plasma concentration with an R of 0.57. On average, there were higher blood concentrations per given dose of IV treprostinil compared with those per given dose of SC, but the difference was not significant. Compared with adult data, the slope of the pediatric data was similar, but the y-intercept was significantly lower. Additionally, the concentration per dose ratio was significantly higher in adults compared with children. Pediatric patients have significantly lower average blood concentrations of treprostinil per given dose compared with adults, and higher, but not significantly so, blood concentrations when treprostinil is administered IV as compared with SC administration.