Hemodynamics and epoprostenol use are associated with thrombocytopenia in pulmonary arterial hypertension

Platelet aggregates in lung capillaries in severely decompensated pulmonary hypertension

The mechanism of thrombocytopenia during acute pulmonary hypertension (PH) decompensation may be partly due to platelet aggregation in the lung. Platelet aggregates in explanted lung from 16 lung transplant patients during acute PH decompensation with and without thrombocytopenia were identified by immunohistochemistry. Scanning electron microscopy (SEM) was performed. 7 explant lung controls without PH and thrombocytopenia were also examined. Compared with controls, the median number of platelet aggregates was higher in patients with acute PH decompensation with thrombocytopenia (19.4 [IQR 3.4-38.3] vs 147.5 [IQR 26.5-203.2]). SEM showed capillaries filled with platelet aggregates. Our study suggests that platelets may aggregate in the lungs during acute PH decompensation.

The role of anticoagulation on the long-term survival of patients with pulmonary arterial hypertension: A meta-analysis of 15 cohort studies

INTRODUCTION

Anticoagulation was once recommended for patients with pulmonary arterial hypertension (PAH). However, its survival benefit still remained controversial. We performed a meta-analysis to evaluate the effect of anticoagulation on the long-term survival of PAH patients.

METHODS

The PubMed, EMBASE, Web of Science, and WanFang electronic database were searched for eligible studies. Pooled hazard ratios (HRs) with 95 % confidence intervals (CIs) were calculated for effect estimate regarding anticoagulation on the survival of PAH patients.

RESULTS

Fifteen cohort studies involving 4266 PAH patients were included. Approximately 45.8 % patients received anticoagulation. The mean follow-up period ranged from 2.1 to 14 years. Anticoagulation had a tendency to, however, did not significantly reduce mortality of PAH patients (HR: 0.86, 95 % CI: 0.73-1.02). In subgroup analysis, anticoagulation decreased the mortality risk as analyzed from retrospective studies (HR: 0.80, 95 % CI: 0.65-0.98), but not prospective studies (HR: 0.95, 95 % CI: 0.70-1.29). For both idiopathic PAH (IPAH) and connective tissue disease associated PAH (CTD-PAH), anticoagulation therapy did not significantly improve the long-term survival rate (HR: 0.83, 95 % CI: 0.65-1.07, and HR: 1.05, 95 % CI: 0.77-1.42, respectively), and this result remained unchanged when pooling data from either retrospective or prospective studies. Further analysis showed that anticoagulation had no advantage in reducing mortality in patients with systemic sclerosis associated PAH, systemic erythematosus lupus related PAH (free of antiphospholipid syndrome), or CTD-PAH of non-specified etiology.

CONCLUSION

Anticoagulation may not reduce the long-term mortality of PAH patients, including those with IPAH and CTD-PAH. In the management of PAH, anticoagulants should be prescribed with caution before comprehensive risk to benefit evaluation. Larger and more vigorously designed controlled trials are warranted.

Effect of epoprostenol-induced thrombocytopaenia on lung transplantation for pulmonary arterial hypertension

OBJECTIVES

Preoperative intravenous epoprostenol therapy can cause thrombocytopaenia, which may increase the risk of perioperative bleeding during lung transplantation. This study aimed to determine whether lung transplantation can be safely performed in patients with epoprostenol-induced thrombocytopaenia.

METHODS

From June 2008 to July 2022, we performed 37 lung transplants in patients with pulmonary arterial hypertension (PAH), including idiopathic PAH (n = 26), congenital heart disease-associated PAH (n = 7), pulmonary veno-occlusive disease (n = 3) and peripheral pulmonary artery stenosis (n = 1) at our institution. Of these, 26 patients received intravenous epoprostenol therapy (EPO group), whereas 11 patients were treated with no epoprostenol (no-EPO group). We retrospectively analysed the preoperative and postoperative platelet counts and post-transplant outcomes in each group.

RESULTS

Preoperative platelet counts were relatively lower in the EPO group than in the no-EPO group (median EPO: 127 000 vs no-EPO: 176 000/μl). However, blood loss during surgery was similar between the 2 groups (EPO: 2473 ml vs no-EPO: 2615 ml). The platelet counts significantly increased over 1 month after surgery, and both groups showed similar platelet counts (EPO: 298 000 vs no-EPO: 284 000/μl). In-hospital mortality (EPO: 3.9% vs no-EPO: 18.2%) and the 3-year survival rate (EPO: 91.4% vs no-EPO: 80.8%) were similar between the 2 groups.

CONCLUSIONS

Patients with PAH treated with intravenous epoprostenol showed relatively lower platelet counts, which improved after lung transplantation with good post-transplant outcomes.

Resolution of Severe Portopulmonary Hypertension With Inhaled Treprostinil and Liver Transplantation

Portopulmonary hypertension is a rare condition with a poor prognosis. Prompt management is essential for liver transplantation eligibility, a potentially curative option. This report presents a case of severe portopulmonary hypertension that resolved with a conservative therapeutic regimen of tadalafil, macitentan, and inhaled treprostinil, which ultimately enabled successful liver transplantation. There was no recurrence of pulmonary hypertension after transplantation, and the patient was weaned off most pulmonary arterial hypertension therapies. This case report is the first to provide evidence that inhaled treprostinil is a safe and effective alternative to continuous intravenous prostacyclins in portopulmonary hypertension.

Transition from Intravenous Epoprostenol to Treprostinil Due to Intolerable Side Effects in Patients With Pulmonary Arterial Hypertension

Intravenous epoprostenol improves exercise capacity and survival in patients with pulmonary arterial hypertension (PAH); however, it has side effects. Reviewing the side effects associated with epoprostenol and treprostinil is essential for improving the long-term treatment strategies for PAH. This retrospective review included patients with PAH who transitioned from intravenous epoprostenol to intravenous treprostinil owing to intolerable side effects, including high cardiac output symptoms, ascites, and thrombocytopenia. Of the 85 patients who received epoprostenol at our hospital between 2013 and 2021, 16 (11 women), with a median age of 33 (range 26 to 40) years (including 12 with idiopathic PAH, 3 with hereditary PAH, and 1 with connective tissue disease pulmonary hypertension), had to switch from intravenous epoprostenol to treprostinil owing to the side effects. After transitioning, epoprostenol-associated intolerable side effects, such as high cardiac output symptoms, ascites, and thrombocytopenia, were ameliorated. In conclusion, for patients with PAH who have intolerable side effects from epoprostenol and have difficulty in continuing treatment, switching from epoprostenol to treprostinil may be an option. Switching treatment leads to better adherence and improved long-term prostacyclin therapy.

Platelet-leukocyte aggregate formation and inflammation in patients with pulmonary arterial hypertension and CTEPH

Pulmonary hypertension (PH) is defined by increased mean pulmonary artery pressure, and the clinical classification includes five etiologies, of which we investigated subgroup 1, pulmonary arterial hypertension (PAH) and subgroup 4, chronic thrombotic and/or embolic disease (CTEPH). Platelets participate in both innate and adaptive immune responses and could possibly contribute to the suggested systemic inflammation associated with PAH. In this study, we utilized flow cytometry to analyze platelet activation and platelet-monocyte (PMA) and granulocyte (PGA) aggregates in PAH and CTEPH patients and healthy control subjects. The plasma concentration of proinflammatory cytokines was measured by multiplex electrochemiluminescence. Our main finding is that circulating platelets are activated in the circulation and form aggregates with both monocytes and granulocytes in patients with idiopathic PAH (IPAH), associated PAH (APAH) and pulmonary hypertension due to CTEPH. There was a strong correlation between the platelet activation, assessed as P-selectin, and the number of aggregates formed. IL-6, IL-8, IL-10 and TNF-α were increased in all PH subgroups as compared to healthy controls, and PMAs were associated with circulating IL-6, IL-8 and IL-10, whereas PGAs were associated with IL-6. The increased concentrations of platelet-leukocyte aggregates found in PAH/CTEPH patients might thus contribute to the inflammatory state in PH.

Abnormal platelet aggregation in pediatric pulmonary hypertension

Endogenous prostacyclin stimulates pulmonary vasodilation and inhibits platelet aggregation. For the synthetic analog treprostinil, used in the treatment of pulmonary hypertension (PH), conflicting, anecdotal evidence exists regarding its effects on clinically relevant platelet function. This study investigated whether treprostinil therapy results in inhibition of platelet aggregation in pediatric PH patients. This is a single institution, prospective, cohort study. Pediatric patients ≤18 years of age on medical therapy for PH underwent platelet function testing by light transmission aggregometry with U-46619-a stable analog of endoperoxide prostaglandin H2, exhibiting properties similar to thromboxane A2 (TXA2). Results were compared for those on continuous treprostinil therapy (TRE) versus those on other, non-prostacyclin therapies (non-TRE). Thirty-five patients were enrolled: 18 in the TRE group and 17 in the non-TRE group. There was no difference in platelet aggregation abnormalities between the two groups: 44% (n = 8) in the TRE group and 41% (n = 7) in the non-TRE group were abnormal. Furthermore, subgroup analysis showed no difference based on treprostinil dosing. This study demonstrated similar, moderately high rates of abnormal platelet aggregation in pediatric PH patients on continuous treprostinil therapy compared to those on other, non-prostacyclin therapies. The high rate of abnormal platelet aggregation in the entire cohort, however, warrants follow-up study to identify a potential inherent risk in this population.

A narrative review on adverse effects of dasatinib with a focus on pharmacotherapy of dasatinib-induced pulmonary toxicities

Chronic myeloid leukemia (CML), a myeloproliferative disorder caused by the over activity of BCR-ABL1 (breakpoint cluster region-Abelson), has been successfully treated by Tyrosine kinase inhibitors (TKIs). While imatinib is known as the first-line treatment of CML, in some cases other TKIs including dasatinib, nilotinib, bosutinib, and ponatinib may be preferred. Dasatinib, a second-generation TKI, inhibits multiple family kinases including BCR-ABL, SRC family kinases, receptor kinases, and TEC family kinases. It is effective against most imatinib-resistant cases except T315I mutation. Despite the superiority of dasatinib in its hematologic and cytogenetic responses in CML compared to imatinib, its potentially harmful pulmonary complications including pleural effusion (PE) and pulmonary arterial hypertension (PAH) may limit its use. Appropriate management of these serious adverse reactions is critical in both improving the quality of life and the outcome of the patient. In this narrative review, we will scrutinize the pulmonary complications of dasatinib and focus on the management of these toxicities.

Platelets, extracellular vesicles and coagulation in pulmonary arterial hypertension

Pulmonary arterial hypertension is a rare disease of the pulmonary vasculature, characterised pathologically by proliferation, remodelling and thrombosis in situ. Unfortunately, existing therapeutic interventions do not reverse these findings and the disease continues to result in significant morbidity and premature mortality. A number of haematological derangements have been described in pulmonary arterial hypertension which may provide insights into the pathobiology of the disease and opportunities to explore new therapeutic pathways. These include quantitative and qualitative platelet abnormalities, such as thrombocytopaenia, increased mean platelet volume and altered platelet bioenergetics. Furthermore, a hypercoagulable state and aberrant negative regulatory pathways can be observed, which could contribute to thrombosis in situ in distal pulmonary arteries and arterioles. Finally, there is increasing interest in the role of extracellular vesicle autocrine and paracrine signalling in pulmonary arterial hypertension, and their potential utility as biomarkers and novel therapeutic targets. This review focuses on the potential role of platelets, extracellular vesicles and coagulation pathways in the pathobiology of pulmonary arterial hypertension. We highlight important unanswered clinical questions and the implications of these observations for future research and pulmonary arterial hypertension-directed therapies.

Critical care outcomes in patients with pre-existing pulmonary hypertension: insights from the ASPIRE registry

Pulmonary hypertension (PH) is a life-shortening condition characterised by episodes of decompensation precipitated by factors such as disease progression, arrhythmias and sepsis. Surgery and pregnancy also place additional strain on the right ventricle. Data on critical care management in patients with pre-existing PH are scarce.

We conducted a retrospective observational study of a large cohort of patients admitted to the critical care unit of a national referral centre between 2000–2017 to establish acute mortality, evaluate predictors of in-hospital mortality and establish longer term outcomes in survivors to hospital discharge.

242 critical care admissions involving 206 patients were identified. Hospital survival was 59.3%, 94% and 92% for patients admitted for medical, surgical or obstetric reasons, respectively. Medical patients had more severe physiological and laboratory perturbations than patients admitted following surgical or obstetric interventions. Higher APACHE II (Acute Physiology and Chronic Health Evaluation) score, age and lactate, and lower oxygen saturation measure by pulse oximetry/inspiratory oxygen fraction (S_pO2/F_iO2) ratio, platelet count and sodium level were identified as independent predictors of hospital mortality. An exploratory risk score, OPALS (oxygen (S_pO2/F_iO2) ≤185; platelets ≤196×10⁹·L⁻¹; age ≥37.5 years; lactate ≥2.45 mmol·L⁻¹; sodium ≤130.5 mmol·L⁻¹), identified medical patients at increasing risk of hospital mortality. One (11%) out of nine patients who were invasively ventilated for medical decompensation and 50% of patients receiving renal replacement therapy left hospital alive. There was no significant difference in exercise capacity or functional class between follow-up and pre-admission in patients who survived to discharge.

These data have clinical utility in guiding critical care management of patients with known PH. The exploratory OPALS score requires validation.

Critical care survival is worse in PH patients admitted for medical rather than surgical/obstetric indications. Nevertheless, many show longer term survival and functional recovery. Markers of severity of acute illness at admission are prognostic.https://bit.ly/2YX9Fw9

Severe thrombocytopenia in patients with idiopathic pulmonary arterial hypertension provided several strategies for lung transplantation

While the prognosis of idiopathic pulmonary arterial hypertension has improved significantly due to newer medications, lung transplantation remains a critical therapeutic option for severe pulmonary arterial hypertension. Hence, it is essential for patients awaiting lung transplantation to avoid complications, including thrombocytopenia, which may affect their surgical outcomes. Herein we present the case of a 21-year-old woman diagnosed with idiopathic pulmonary arterial hypertension at the age of 15. She developed thrombocytopenia while awaiting lung transplantation. Her medication was switched from epoprostenol to treprostinil, suspecting possible drug-induced thrombocytopenia. Furthermore, she was administered thrombopoietin receptor agonists in view of the possibility of idiopathic thrombocytopenic purpura, along with maximum support for right heart failure. Subsequently, her platelet count increased to >70,000/µL, enabling her to successfully undergo bilateral lung transplantation. Post-bilateral lung transplantation, pulmonary arterial hypertension as well as thrombocytopenia appeared to have resolved. In this case, we suspected that thrombocytopenia could have resulted owing to a combination of pulmonary arterial hypertension, right heart failure, drug interactions, and idiopathic thrombocytopenic purpura. Thrombocytopenia is a very critical condition in patients with pulmonary arterial hypertension, especially those awaiting lung transplantation. Several approaches are known to improve intractable thrombocytopenia in patients with pulmonary arterial hypertension.

Biventricular diastolic dysfunction, thrombocytopenia, and red blood cell macrocytosis in experimental pulmonary arterial hypertension

Pulmonary arterial hypertension is a fatal disease, where death is associated with right heart failure and reduced cardiorespiratory reserve. The Sugen 5416, hypoxia and normoxia Fischer rat model mimics human pulmonary arterial hypertension, although the cause(s) of death remains incompletely understood. Here, we hypothesized that these animals develop biventricular diastolic dysfunction that contributes to tissue hypoperfusion coincident with severe pulmonary arterial hypertension. We performed comprehensive echocardiographic and hematologic assessments. Serial echocardiogram at 3-5 weeks was performed followed by blood sampling via aortic or cardiac puncture. Echocardiogram revealed pulmonary arterial hypertension in pulmonary artery Doppler waves, including notched wave envelopes, and decreased pulmonary artery acceleration time/pulmonary artery ejection time ratio and right ventricular outflow tract velocity time integral. Impaired right ventricular systolic function, assessed by decreased tricuspid annular plane systolic excursion and tricuspid tissue Doppler systolic positive wave velocity, was observed in pulmonary arterial hypertension. Tricuspid and mitral pulsed wave and tissue Doppler findings suggested biventricular diastolic dysfunction, with dynamic changes in early and late diastolic filling waves, their fusion patterns, and a decrease in e' velocity. Heart rate and ejection fraction did not change, but cardiac output, stroke volume, and end-diastolic volume were decreased, and inferior vena cava respiratory variation was decreased. Blood electrolyte values were suggestive of intravascular volume expansion early in the disease followed by volume contraction and tissue hypoperfusion in the latter stages of disease. Complete blood count showed thrombocytopenia and non-anemic macrocytosis with reticulocytosis and an increase in red blood cell distribution width. Thus, pulmonary, cardiac, and hematological findings in Fischer animals with pulmonary arterial hypertension are characteristic of humans and provide an insightful experimental platform to resolve mechanisms of disease progression.

Thrombocytopenia During Prostacyclin Analogue Therapies of Pulmonary Arterial Hypertension-Possible Pathomechanisms and Implications

Pulmonary arterial hypertension is a quite rare, but problematic disease in everyday cardiologists' practice. Prostanoids are the most important group of drugs used in this disease. One of the biggest problems encountered during treatment with analogs of prostacyclin is thrombocytopenia. Based on hematological guidelines we suggest common therapeutic schemes depending on the number of platelets or the severity of bleeding conducting the therapy.

Thrombocytopenia independently predicts death in idiopathic PAH

BACKGROUND

Pulmonary arterial hypertension (PAH) is a progressive vascular disorder with a high mortality. Clinical experience and small case series suggest thrombocytopenia may be frequent in this population and associated with a poor prognosis. We sought to estimate the prevalence of thrombocytopenia in patients with PAH and characterize its association with disease characteristics and patient outcome.

METHODS

Single center cohort study of 714 incident adult patients with Group 1 PH who were evaluated for baseline platelet count at the time of diagnosis. Pts were stratified into three groups: normal platelet count (>150 × 10⁹/L), Grade 1 thrombocytopenia (75-149 × 10⁹/L) and Grade 2-4 thrombocytopenia (<75 × 10⁹/L).

RESULTS

The median platelet count was 209 × 10⁹/L (IQR 163, 264). There were 572 (80%) pts without thrombocytopenia, 107 (15%) with Grade 1 and 35 (5%) with Grade 2-4 thrombocytopenia. The median pt age was 55 years (IQR 44-65) with no difference between platelet groups (p = 0.85). Men were more likely to have thrombocytopenia (62, 34%) than women (80, 15%, p < 0.0001). Thrombocytopenia was frequent with portopulmonary PAH (84%) as opposed to idiopathic PAH (iPAH; 14%) or connective tissue disease associated PAH (12%). Platelet counts were not associated with functional class symptoms, the degree of right ventricular enlargement or dysfunction or tricuspid regurgitation by echocardiography. Invasive hemodynamics of right atrial pressure, mean pulmonary artery pressure and pulmonary vascular resistance were also similar between platelet groups. Thrombocytopenia was associated with higher mortality in iPAH patients (age- and sex-adjusted 5 year mortality [HR 1.95 (1.20, 3.08) p = 0.008] but not in other etiology groups. In a multivariate model of iPAH patients (adjusted for age, sex, DLCO, PVR, creatinine and 6MW distance) thrombocytopenia was most predictive of 5-year mortality [HR 1.68 (1.32, 2.12), p < 0.0001].

CONCLUSION

Thrombocytopenia in the context of iPAH portends a poor prognosis and is a simple independent factor to consider in judging severity of disease.

Idiopathic pulmonary arterial hypertension - a unrecognized cause of high-shear high-flow haemostatic defects (otherwise referred to as acquired von Willebrand syndrome) in children

Acquired von Willebrand syndrome (AVWS) is reported in high-flow high-shear congenital cardiac disorders. We hypothesized that the narrowed pulmonary vasculature in idiopathic pulmonary arterial hypertension (IPAH) may induce AVWS. We conducted a cross-sectional evaluation of children with IPAH. Patients with bleeding symptoms and/or laboratory abnormalities (thrombocytopenia, anomalies in coagulation screening tests) were tested in-depth for haemostatic defects. Fourteen children were followed with IPAH of which 8 were eligible. Four children exhibited abnormal bleeding scores (International Society on Thrombosis and Haemostasis Bleeding Assessment Tool: 3-5). All 8 patients showed very prolonged platelet function analyser (PFA)-100 closure times. Six children demonstrated either mild thrombocytopenia or low-normal von Willebrand factor (VWF) antigen (VWF:Ag) or VWF activity [mean (range), in iu/dl: VWF:Ag: 70 (61-91); VWF activity: 57 (34-70)]. Average VWF collagen binding capacity (VWF:CB) was 64 iu/dl (range: 53-123 iu/dl), with low-normal VWF activity/VWF:Ag or VWF:CB/VWF:Ag ratios occurring in five patients. All children had normal multimers distribution patterns. One patient underwent a lung transplantation, with normalization of haemostatic abnormalities post-surgery. Overall, 8 out of 14 children with IPAH had mild to moderate bleeding symptoms and/or laboratory abnormalities in keeping with AVWS. Normalization of the haemostatic defects following lung transplantation and lack of family history of bleeding attests to the acquired nature of their defects.

Impact on survival of warfarin in patients with pulmonary arterial hypertension receiving subcutaneous treprostinil

INTRODUCTION

Anticoagulation is a common treatment modality in patients with pulmonary arterial hypertension (PAH). Further studies are needed to appropriately assess the risk/benefit ratio of anticoagulation, particularly in PAH patients receiving PAH-specific therapies.

AIMS

We use observational long-term data on PAH patients treated with subcutaneous (SQ) treprostinil from a large open-label study. Patients were followed for up to 4 years. The use of warfarin and bleeding events were recorded.

RESULTS

At total of 860 patients (age [mean±SD] 46±15 years, 76% female, 83% Caucasian, 49% idiopathic PAH, and 76% New York Heart Association [NYHA] functional class III) were included. All patients received SQ treprostinil (15% also other pulmonary hypertension [PH]-therapies) and 590 (69%) received warfarin during the study. The proportions of women, African American, and idiopathic pulmonary hypertension (IPAH) patients were higher in the group receiving warfarin. A higher proportion of patients with congenital heart disease and portopulmonary hypertension did not receive warfarin. There were no differences in unadjusted long-term survival between PAH patients receiving warfarin or not (log-rank test, P value=.69), even when only considering idiopathic PAH (P=.32). In addition, no difference was found in adjusted long-term survival both in PAH (P=.84) and idiopathic PAH patients (P=.44) based on the use of warfarin. Furthermore, no survival difference based on the use of warfarin were noted between propensity score-matched PAH patients (P=.37).

CONCLUSIONS

Long-term anticoagulation with warfarin was not associated with any significant effect on survival in PAH or idiopathic PAH patients treated with SQ treprostinil.

Successful Pulmonary Artery Embolization for the Management of Hemoptysis in a Patient with Eisenmenger Syndrome Caused by Patent Ductus Arteriosus

The patient was a 19-year-old woman who was diagnosed with patent ductus arteriosus complicating Eisenmenger syndrome at a previous medical institution. She was referred to our hospital and arranged for lung transplantation. She developed hemoptysis after the introduction of i.v. epoprostenol, which was administered as a bridging treatment while the patient awaited lung transplantation. She continued to suffer from recurrent hemoptysis, even after switching from i.v. epoprostenol to i.v. treprostinil. Angiography of the systemic and pulmonary arteries revealed the vessel responsible for the recurrent hemoptysis and pulmonary artery embolization was successfully performed. It is essential to identify the culprit vessel and physicians must not hesitate in performing embolization when patients develop lethal hemoptysis.

High Frequency of Acute Adverse Cardiovascular Events After Lung Transplantation in Patients With Pulmonary Arterial Hypertension Receiving Preoperative Long-Term Intravenous Prostacyclin

Adverse cardiovascular events after lung transplantation (LT) increase the mortality in patients with pulmonary arterial hypertension (PAH). Long-term intravenous prostacyclin is the usual treatment in severe patients with PAH, but it may increase the risk of hemorrhage due to its antiplatelet aggregation effect or thrombocytopenia. We investigated the impact of length of intravenous prostacyclin therapy on acute adverse cardiovascular events including hemorrhagic complication after LT. We retrospectively compared the incidence of adverse events (death, intrathoracic hematoma and bleeding, cardiac congestion or shock, cerebral infarction and pulmonary embolism) within 30 days after LT between no/short-term (median 0.6 years, n = 13) and long-term (median 3.7 years, n = 15) intravenous prostacyclin groups. There were no differences in the dose of intravenous prostacyclin and pulmonary artery pressure between the two groups. Among 22 adverse events (0.8 ± 1.1 events/patient), 4 events occurred in the no/short-term intravenous prostacyclin group and 18 occurred in the long-term intravenous prostacyclin group. The event rate per patient in the long-term intravenous prostacyclin group (1.2 ± 1.3 events/patient) was significantly higher than that in the no/short-term intravenous prostacyclin group (0.3 ± 0.5 events/patient) (P < 0.05). Intrathoracic hematoma and bleeding was the most frequent adverse event (9 events, 41%). Preoperative long-term intravenous prostacyclin therapy increases acute adverse cardiovascular events after LT in patients with PAH.

New pharmacotherapy options for pulmonary arterial hypertension

INTRODUCTION

Epoprostenol was the first targeted therapy available for the treatment of pulmonary arterial hypertension (PAH). Since then great advances in our knowledge of the disease have been made and the spectrum of therapeutic options for PAH has expanded. After an overview of current available treatments, this article describes the new pharmacotherapy options and their place in the management of PAH.

AREAS COVERED

This paper is based on a literature search and the review of studies published on PAH pharmacotherapy using the MEDLINE database.

EXPERT OPINION

The last decade has been particularly important in PAH management with the emergence of six new molecules, the development of novel routes of administration and improvement of pharmacokinetics. Moreover, pediatric formulations have been developed. However, further research is required to inform clinicians regarding optimal choices of combination therapies (progressive add-on therapy or upfront combination therapy, selection of associated molecules regarding the patient's profile...), to continue to improve the quality of life of patients with new drugs and to reach the ultimate goal of curing the disease.

Hemodynamic effects of ambrisentan-tadalafil combination therapy on progressive portopulmonary hypertension

Intravenous epoprostenol is recommended for World Health Organization functional class (WHO-FC) IV patients with pulmonary arterial hypertension (PAH) in the latest guidelines. However, in portopulmonary hypertension (PoPH) patients, advanced liver dysfunction and/or thrombocytopenia often makes the use of intravenous epoprostenol challenging. Here we report the cases of two WHO-FC IV PoPH patients who were successfully treated with a combination of two oral vasodilators used to treat PAH: ambrisentan and tadalafil. Oral vasodilator therapy using a combination of ambrisentan and tadalafil may be a safe and effective therapeutic option for WHO-FC IV PoPH patients and should be considered for selected patients with severe and rapidly progressing PoPH.

Thrombocytopenia is an independent predictor of mortality in pulmonary hypertension

BACKGROUND

Established prognostic factors for pulmonary hypertension (PH) include brain natriuretic peptide, troponins and hemodynamic measures such as central venous pressure and cardiac output. The prognostic role of thrombocytopenia, however, has yet to be determined in patients with PH. The aim of this study was to evaluate effect of thrombocytopenia on mortality in patients with PH.

METHODS

521 patients with severe PH, defined by a pulmonary artery systolic pressure >60 mm Hg on transthoracic echocardiography and a platelet count measured within one month after diagnosis were enrolled from three hospitals of Montefiore Medical Center. The cohort was divided into two groups: mild thrombocytopenia to a normal platelet count (platelet count 100,000-450,000 per uL); and moderate to severe thrombocytopenia (platelet count <100,000 per uL). Inpatient and social security death records were used to determine 1-year all-cause mortality.

RESULTS

Mean age was 70.3 ± 15.6 with 40% of patients being male. Overall mortality at 1 year was 30.7%, with increased mortality in PH patients with mild thrombocytopenia compared to those with moderate to severe thrombocytopenia (46.5% vs. 27.0%, p < 0.001). In multivariate analysis, moderate to severe thrombocytopenia remained an independent predictor of mortality (HR 1.798, 95% CI 1.240-2.607, p = 0.002).

CONCLUSIONS

Moderate to severe thrombocytopenia is an independent predictor of higher mortality in patients with severe PH. These findings may support the use of thrombocytopenia as a useful prognostic indicator in patients with severe PH.

Effects of prostacyclin on the early inflammatory response in patients with traumatic brain injury-a randomised clinical study

OBJECTIVE AND DESIGN

A prospective, randomised, double-blinded, clinical trial was performed at a level 1 trauma centre to determine if a prostacyclin analogue, epoprostenol (Flolan®), could attenuate systemic inflammatory response in patients with severe traumatic brain injury (TBI).

SUBJECTS

46 patients with severe TBI, randomised to epoprostenol (n = 23) or placebo (n = 23).

TREATMENT

Epoprostenol, 0.5 ng · kg(-1) · min(-1), or placebo (saline) was given intravenously for 72 hours and then tapered off over the next 24 hours.

METHODS

Interleukin-6 (IL-6), interleukin-8 (IL-8), soluble intracellular adhesion molecule-1 (sICAM-1), C-reactive protein (CRP), and asymmetric dimethylarginine (ADMA) levels were measured over five days. Measurements were made at 24 h intervals ≤24 h after TBI to 97-120 h after TBI.

RESULTS

A significantly lower CRP level was detected in the epoprostenol group compared to the placebo group within 73-96 h (p = 0.04) and within 97-120 h (p = 0.008) after trauma. IL-6 within 73-96 h after TBI was significantly lower in the epoprostenol group compared to the placebo group (p = 0.04). ADMA was significantly increased within 49-72 h and remained elevated, but there was no effect of epoprostenol on ADMA levels. No significant differences between the epoprostenol and placebo groups were detected for IL-8 or sICAM-1.

CONCLUSIONS

Administration of the prostacyclin analogue epoprostenol significantly decreased CRP and, to some extent, IL-6 levels in patients with severe TBI compared to placebo. These findings indicate an interesting option for treatment of TBI and warrants future larger studies.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier, NCT01363583.

Clinical implications of haemoptysis in patients with pulmonary arterial hypertension

INTRODUCTION

Pulmonary arterial hypertension (PAH) is a disabling disease that may result in haemoptysis. Patients with congenital heart disease associated PAH (CHD-APAH) may have a survival advantage when compared with patients with other types of PAH presenting with haemoptysis. The effects of aetiology and subsequent management choice of haemoptysis in PAH patients is not well-defined.

METHODS

We conducted outcome analysis in CHD-APAH vs. all other subtypes of PAH patients presenting with haemoptysis to The Methodist Hospital. Twenty-one patients were identified, 13 patients in the CHD-APAH group and eight patients in the non-CHD group. We evaluated outcomes related to treatment (bronchial artery embolisation (BAE) vs. conservative management), hospital length of stay, mortality rates and survival in this cohort.

RESULTS

The CHD-APAH and non-CHD groups had similar baseline demographic, haemodynamic and laboratory values except BMI was higher in the non-CHD group and haematocrit was higher in the CHD-APAH group. Twenty-eight-day mortality (0% vs. 31%) and 1-year mortality (0% vs. 54%) was lower in the CHD-APAH patients as compared with non-CHD group. A statistically significant difference was found in the survival rate in favour of CHD-APAH group for the total follow-up period (p = 0.02). Although not statistically significant, patients treated with BAE had shorter length of stay (4.0 days ± 4.0 vs. 13.7 days ± 22.5; p = 0.26). There was recurrent haemoptysis in 43% of patients treated with BAE.

CONCLUSION

Haemoptysis in PAH patients is a serious event with a high mortality rate. CHD-APAH seems to confer a survival advantage, independent of therapy utilised. Termination of haemoptysis with BAE is rapid with relatively few complications except for frequent re-bleeding episodes. Further studies are needed to determine the risk factors that may predispose PAH patients to excessive mortality from haemoptysis and to identify an optimal therapeutic modality.

Subdural hematomas in pulmonary arterial hypertension patients treated with prostacyclin analogs [corrected]

Prostacyclin analogs therapy has been associated with development of thrombocytopenia. Little is known whether this treatment increases the risk of intracranial hemorrhage in pulmonary artery hypertension (PAH) patients. We queried the Cleveland Clinic billing database to identify cases of nontraumatic sudural hematoma (SDH) in patients with PAH. We identified those individuals who were receiving prostacyclin analogs therapy at the time of the neurological event and assessed whether these patients were also taking antiplatelet or anticoagulation therapies. We identified three cases of nontraumatic SDH in 856-patient-year of prostacylin analog treatment. All patients were women, had low normal platelet counts or thrombocytopenia, and were concomitantly receiving anticoagulation therapy in the appropriate therapeutic anticoagulation range. All three patients were managed conservatively and had no neurologic sequelae. Nontraumatic acute subdural hematoma is a rare event in patients with PAH treated with prostacyclin analogs. All affected patients were concomitantly receiving anticoagulation therapy.

Pulmonary arterial hypertension in pregnant women

Pulmonary arterial hypertension (PAH) is characterized by pulmonary vascular remodeling that limits the ability of the pulmonary vascular bed to withstand the physiological changes of pregnancy. Historically, pregnancy in PAH carries a high risk to the parturient. Normal pulmonary vasculature can withstand the hemodynamic and physiological changes associated with pregnancy without the development of respiratory symptomatology. However, in the presence of pulmonary vascular remodeling the capacity to handle these changes is compromised. During pregnancy, increase in cardiac output from the increased intravascular volume can lead to right heart failure. Therefore, all patients with PAH of childbearing potential should receive preconception counseling and be advised to use two methods of contraception. Patients with PAH should be advised against continuing pregnancy if they do become pregnant. According to the literature, deterioration in pregnancy mainly occurs in the second trimester and early in the third trimester; immediately postpartum is the most critical time for patients with PAH. In this review, we will discuss the recent advances in the management of parturient patients with PAH.

Portopulmonary hypertension: an update

Portopulmonary hypertension (POPH) is a serious complication of cirrhosis that is associated with mortality beyond that predicted by the Model for End-Stage Liver Disease (MELD) score. Increased pulmonary vascular resistance (PVR) may be initiated by pulmonary vasoconstriction, altered levels of circulating mediators, or shear stress, and can eventually lead to the classic vascular remodeling (plexiform lesion) that characterizes POPH. Portal hypertension is a prerequisite for the diagnosis of POPH, although the severity of pulmonary hypertension is unrelated to the severity of portal hypertension or the nature or severity of liver disease. POPH precludes liver transplantation (LT) unless the mean pulmonary artery pressure (MPAP) can be reduced to a safe level. The concept of an acceptable pressure has changed: we now consider both MPAP and PVR in the diagnosis, and we include the transpulmonary pressure gradient so that we can factor in fluid overload and left ventricular failure. Pulmonary vasodilator therapy includes oral, inhaled, and parenteral agents, and one or more of these agents may significantly lower pulmonary artery pressures to the point that LT becomes possible. The United Network for Organ Sharing recommends MELD exception points for patients with medically controlled POPH, but this varies by region. Patients who undergo LT need specialized intraoperative and postoperative management, which includes the availability of intraoperative transesophageal echocardiography for assessing right ventricular function, and rapidly acting vasodilators (eg, inhaled nitric oxide and/or epoprostenol). Published case series suggest excellent outcomes after LT for patients who respond to medical therapy.

Randomized clinical trial of aspirin and simvastatin for pulmonary arterial hypertension: ASA-STAT

BACKGROUND

Pulmonary arterial hypertension (PAH) is a progressive disease that causes exercise limitation, heart failure, and death. We aimed to determine the safety and efficacy of aspirin and simvastatin in PAH.

METHODS AND RESULTS

We performed a randomized, double-blind, placebo-controlled 2×2 factorial clinical trial of aspirin and simvastatin in patients with PAH receiving background therapy at 4 centers. A total of 92 patients with PAH were to be randomized to aspirin 81 mg or matching placebo and simvastatin 40 mg or matching placebo. The primary outcome was 6-minute walk distance at 6 months. Sixty-five subjects had been randomized when the trial was terminated by the Data Safety and Monitoring Board after an interim analysis showed futility in reaching the primary end point for simvastatin. After adjustment for baseline 6-minute walk distance, there was no significant difference in the 6-minute walk distance at 6 months between aspirin (n=32) and placebo (n=33; placebo-corrected difference −0.5 m, 95% confidence interval −28.4 to 27.4 m; P=0.97) or between simvastatin (n=32) and placebo (n=33; placebo-corrected difference −27.6 m, 95% confidence interval −59.6 to 4.3 m; P=0.09). There tended to be more major bleeding episodes with aspirin than with placebo (4 events versus 1 event, respectively; P=0.17).

CONCLUSIONS

Neither aspirin nor simvastatin had a significant effect on the 6-minute walk distance, although patients randomized to simvastatin tended to have a lower 6-minute walk distance at 6 months. These results do not support the routine treatment of patients with PAH with these medications.

Prostacyclins in pulmonary arterial hypertension: the need for earlier therapy

Pulmonary arterial hypertension (PAH) is a rare but serious condition, which if untreated, is associated with a 2-3-year median survival time. A number of treatment options are available for PAH, leading to improvements in exercise capacity, symptoms, and hemodynamics. However, the disease remains incurable and most patients will ultimately progress to right heart failure and death. Three classes of drugs are currently available to improve PAH outcomes, although this review will focus solely on a class of potent vasodilators known as prostacyclins. Currently, four prostacyclin analogs are licensed for the treatment of PAH: epoprostenol, treprostinil, and iloprost in the USA and some European countries, and beraprost in Japan and Korea. Prostacyclins have become the treatment of choice in patients with severe PAH, but there is also evidence to suggest that their earlier use may also benefit patients with mild-to-moderate disease. This review discusses the advantages of prostacyclins in terms of their usefulness in patients whose condition has deteriorated following monotherapy with other agents, and their integral role in combination therapy. The latter appears to offer the potential for pulmonary vasculature remodeling and could be regarded as an emerging paradigm to treat and prevent the progression of PAH.

Rationale and design of a phase II clinical trial of aspirin and simvastatin for the treatment of pulmonary arterial hypertension: ASA-STAT

BACKGROUND

Pulmonary arterial hypertension (PAH) is a progressive disease which causes exercise limitation, heart failure, and death. Aspirin and simvastatin are highly effective and safe therapies for other cardiovascular diseases characterized by platelet activation and endothelial dysfunction, but have not been formally studied in PAH.

METHODS

ASA-STAT is a phase II, randomized, double-blind, placebo-controlled 2 × 2 factorial clinical trial of aspirin and simvastatin in patients with PAH. A total of 92 subjects were to be randomized to aspirin or aspirin placebo and simvastatin or simvastatin placebo. The primary outcome is the distance walked in 6 min at 6 months after randomization. Secondary measures include brachial artery flow-mediated dilation, circulating biomarkers of platelet and endothelial function, functional class, quality-of-life, and time to clinical end points. The incidence of adverse events will be compared between treatment groups. SCREENING AND ENROLLMENT: We screened a total of 712 individuals with PAH. Sixty-five subjects were enrolled when the trial was terminated for futility in reaching the primary end point for simvastatin.

CONCLUSIONS

This study aims to determine whether aspirin or simvastatin have beneficial biologic or clinical effects in patients with PAH. The safety and side effects of these commonly prescribed cardiovascular drugs will also be assessed.

Hemoptysis requiring bronchial artery embolization in pulmonary arterial hypertension

OBJECTIVES

Hemoptysis is an uncommon complication in patients with pulmonary arterial hypertension (PAH). Although the mechanism of hemoptysis is unknown, treatment with bronchial artery embolization (BAE) is proposed to be a safe and reliable method of treatment. We report our experience in treating PAH patients presenting with acute hemoptysis that required multiple BAEs.

METHODS

Three female and one male PAH patients, ages 45 + or - 9 years (mean + or - standard deviation [SD]) presented with acute hemoptysis. Right ventricular systolic pressure and cardiac index at the time of the first episode of hemoptysis were 85 + or - 17 mm Hg and 2.7 + or - 0.7 L/min/m, respectively. Two of the four patients had recurrent episodes of hemoptysis, requiring multiple BAEs. All four were on intravenous prostacyclin analogue. None were receiving warfarin or endothelin receptor antagonists at the time of the episode. During each episode of hemoptysis, international normalized ratio (INR) was 1.09 + or - 0.11 units, and platelet count was 124,000 + or - 47,000 per microliter.

RESULTS

Each episode of hemoptysis was acutely terminated with BAE. In the majority of cases, patients had multiple aberrant bronchial arteries embolized, and an average of 2.3 arteries was embolized per session (1-4 embolized arteries). Each BAE was performed utilizing polyvinyl alcohol particles, ranging from 250-500 microns. There were no reported complications of the 14 BAE procedures performed.

CONCLUSION

Although the incidence of hemoptysis is unknown and likely underreported, we report our experience in which recurrent hemoptysis was treated with multiple BAE procedures. This report emphasizes the efficacy and safety of BAE in terminating episodes of recurrent hemoptysis in patients with severe PAH.

Epoprostenol-associated pneumonitis: diagnostic use of a T-cell proliferation assay

We describe a case of severe drug-induced interstitial pneumonitis in a woman with idiopathic pulmonary arterial hypertension receiving epoprostenol confirmed by a drug T-cell proliferation assay. Proliferation assays were completed in our patient and in a healthy control. Isolated T cells were incubated with CD3-depleted peripheral blood mononuclear cells and then stimulated to proliferate with (3)H-thymidine in the presence of epoprostenol, other prostanoid analogs, and controls. A significant (p < 0.001) T-cell proliferation response occurred in our patient in the presence of epoprostenol alone. There was a trend towards an increased T-cell response to treprostinil but this was statistically insignificant. There was no significant T-cell response to the diluent alone, normal saline, iloprost, or alprostadil. There was no significant proliferation to any drug in the healthy control. Hence, a drug T-cell proliferation assay confirmed that epoprostenol can rarely incite a profound inflammatory response in the pulmonary interstitium.