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

Prevalence of potential drug‐drug interactions with disease specific treatments in patients with pulmonary arterial hypertension or chronic thromboembolic pulmonary hypertension – a registry study

Polypharmacy increases the risk of drug–drug interactions that may disturb treatment effects. The aim of this study was to investigate the frequency of codispensing of potentially interacting or contraindicated drugs related to PH‐specific treatment in the Swedish pulmonary arterial hypertension (PAH) and chronic thromboembolic pulmonary hypertension (CTEPH) population. All prescribed drugs, on an individual level, dispensed 2016–2017 at pharmacies to patients with PAH or CTEPH were obtained from The National Board of Health and Welfare's pharmaceutical registry. Potential drug–drug interactions were investigated using the Drug Interaction tool in the IBM Micromedex® database. There were 4785 different dispensed drugs from 572 patients (mean age 61 ± 16 years, 61% female, mean number of drugs per patient 8.4 ± 4.2) resulting in 1842 different drug combinations involving a PH‐specific treatment. Of these drug combinations, 67 (3.5%) had a potential drug–drug interaction considered clinically relevant and it affected 232 patients (41%). The PH‐specific drugs with the highest number of potential drug–drug interactions was bosentan (n = 23, affected patients = 171) while the most commonly codispensed, potentially interacting drug combination was sildenafil/furosemide (119 patients affected). Other common codispensed and potentially interacting drugs were anticoagulants (n = 11, affected patients = 100) and antibiotic treatment (n = 12, affected patients = 26). In conclusion, codispensing of PH‐specific therapy and potentially interacting drugs was common, but codispensing of potentially contraindicated drugs was rare.

Perioperative approach to precapillary pulmonary hypertension in non-cardiac non-obstetric surgery

Pulmonary hypertension (PH) confers a significant challenge in perioperative care. It is associated with substantial morbidity and mortality. A considerable amount of information about management of patients with PH has emerged over the past decade. However, there is still a paucity of information to guide perioperative evaluation and management of these patients. Yet, a satisfactory outcome is feasible by focusing on elaborate disease-adapted anaesthetic management of this complex disease with a multidisciplinary approach. The cornerstone of the peri-anaesthetic management of patients with PH is preservation of right ventricular (RV) function with attention on maintaining RV preload, contractility and limiting increase in RV afterload at each stage of the patient's perioperative care. Pre-anaesthetic evaluation, choice of anaesthetic agents, proper fluid management, appropriate ventilation, correction of hypoxia, hypercarbia, acid-base balance and pain control are paramount in this regard. Essentially, the perioperative management of PH patients is intricate and multifaceted. Unfortunately, a comprehensive evidence-based guideline is lacking to navigate us through this complex process. We conducted a literature review on patients with PH with a focus on the perioperative evaluation and suggest management algorithms for these patients during non-cardiac, non-obstetric surgery.

Pulmonary arterial hypertension patients display normal kinetics of clot formation using thrombelastography

Pulmonary arterial hypertension is characterized by endothelial dysfunction and microthrombi formation. The role of anticoagulation remains controversial, with studies demonstrating inconsistent effects on pulmonary arterial hypertension mortality. Clinical anticoagulation practices are currently heterogeneous, reflecting physician preference. This study uses thrombelastography and hematology markers to evaluate whether clot formation and fibrinolysis are abnormal in pulmonary arterial hypertension patients. Venous blood was collected from healthy volunteers (n = 20) and patients with pulmonary arterial hypertension (n = 20) on stable medical therapy for thrombelastography analysis. Individual thrombelastography parameters and a calculated coagulation index were used for comparison. In addition, hematologic markers, including fibrinogen, factor VIII activity, von Willebrand factor activity, von Willebrand factor antigen, and alpha2-antiplasmin, were measured in pulmonary arterial hypertension patients and compared to healthy volunteers. Between group differences were analyzed using t tests and linear mixed models, accounting for repeated measures when applicable. Although the degree of fibrinolysis (LY30) was significantly lower in pulmonary arterial hypertension patients compared to healthy volunteers (0.3% ± 0.6 versus 1.3% ± 1.1, p = 0.04), all values were within the normal reference range (0–8%). All other thrombelastography parameters were not significantly different between pulmonary arterial hypertension patients and healthy volunteers (p ≥ 0.15 for all). Similarly, alpha2-antiplasmin activity levels were higher in pulmonary arterial hypertension patients compared to healthy volunteers (103.7% ± 13.6 versus 82.6% ± 9.5, p < 0.0001), but all individual values were within the normal range (75–132%). There were no other significant differences in hematologic markers between pulmonary arterial hypertension patients and healthy volunteers (p ≥ 0.07 for all). Sub-group analysis comparing thrombelastography results in patients treated with or without prostacyclin pathway targeted therapies were also non-significant. In conclusion, treated pulmonary arterial hypertension patients do not demonstrate abnormal clotting kinetics or fibrinolysis by thrombelastography.

Anticoagulation in Pulmonary Arterial Hypertension: Do We Know the Answer?

The shear stress and hypoxia in the pulmonary artery in patients with pulmonary arterial hypertension(PAH) causes endothelial dysfunction, smooth muscle proliferation and activation of thrombotic pathways leading to in situ thrombosis. Targeting the thrombotic pathways is a proposed mechanism to slow disease progression and improve survival. Over the years, the survival in patients with PAH has improved due to multiple factors with the increased use of anticoagulation as one of them. Both European Respiratory Society/European Society of Cardiology and American College of Cardiology/American Heart Association guidelines make grade II recommendations for using anticoagulation in PAH. The guidelines are based on weak observational studies with high risk of bias which have only studied warfarin as the choice of anticoagulation. In this article, we review the pathophysiology, rationale and the current literature investigating the role of anticoagulation in PAH.

Can anticoagulants improve the survival rate for patients with idiopathic pulmonary arterial hypertension? A systematic review and meta-analysis

BACKGROUND

Anticoagulant therapy is believed to be an important component of treatment for idiopathic pulmonary arterial hypertension (IPAH). Recent data suggest that therapy that does not include anticoagulants results in no significant difference in patient survival. We sought to evaluate the effect of anticoagulants on survival in patients with IPAH.

METHODS

A systematic review and a random-effects meta-analysis to estimate hazard ratio (HR) and 95% confidence intervals (CI) were performed. PubMed/MEDLINE, Web of Knowledge and other databases were searched for eligible literature. Review articles and references were also screened.

RESULTS

8 studies with a total of 1812 patients with IPAH were included in this analysis. No randomized controlled trials (RCT) were identified. All the 8 studies had a mean complete follow-up ranging from 3 to 14 years. In this analysis, use of anticoagulants did not significantly decrease mortality risk (P = 0.07, HR = 0.77, 95% CI [0.58, 1.02]). Sensitivity analysis showed similar results (P = 0.12, HR = 0.80, 95% CI [0.60, 1.06]). Subgroup analysis showed that anticoagulants performed no significant advantages with the use of PAH-specific therapies (P = 0.82, HR = 0.95, 95% CI [0.63, 1.44]).

CONCLUSIONS

No randomized evidence to support the use of anticoagulants in IPAH. No significant benefit for patients' survival was found in our analysis. The potential biases of included observational studies made it hard to achieve a meaningful conclusion. The necessity of anticoagulants for IPAH patients remains to be evaluated.

Management of Pulmonary Arterial Hypertension in Patients with Systemic Sclerosis

Systemic sclerosis (SSc) is a rare and complex immune-mediated connective tissue disease characterized by multi-organ fibrosis and dysfunction. Systemic sclerosis-associated pulmonary arterial hypertension (SSc-PAH) is a leading cause of death in this population. Pulmonary arterial hypertension (PAH) can coexist with other forms of pulmonary hypertension in SSc, including pulmonary hypertension related to left heart disease, interstitial lung disease, chronic thromboembolism and pulmonary venous occlusive disease, which further complicates diagnosis and management. Available pulmonary arterial hypertension therapies target the nitric oxide, endothelin and prostacyclin pathways. These therapies have been studied in SSc-PAH in addition to idiopathic PAH, often with different treatment responses. In this article, we discuss the management as well as the treatment options for patients with SSc-PAH.

A case report of pulmonary arterial hypertension in pregnancy and complications of anticoagulation therapy

RATIONALE

Treprostinil, a potent vasodilator, is the treatment of choice for severe pulmonary arterial hypertension (PAH) during pregnancy. Its inhibition of platelet aggregation increases the risk of hemorrhage. In addition, anticoagulation therapy is widely used in pregnancy with PAH due to the hypercoagulable state. However, very little is known about the complications of anticoagulants' use in pregnancy with PAH.

PATIENT CONCERNS

A 27-year-old pregnant woman was admitted to the hospital at 32weeks with progressive dyspnea.

DIAGNOSES

The pregnant was diagnosed with ventricular septal defect 12 years prior to presentation. Combining clinical manifestation with results of right heart catheterization (RHC) and echocardiography, it was consistent with severe World Health Organization (WHO) group I PAH.

INTERVENTIONS

Supportive treatment included supplemental oxygen, intravenous treprostinil, sildenafil and prophylactic anticoagulation.

OUTCOMES

Gastrointestinal bleeding is occurred in our patient when dalteparin were used in conjunction with treprostinil. Her care was further complicated refractory to usual conservative measures before delivery.

LESSONS

This case report illustrates the complexities that arise when prostacyclin therapies are combined with necessary anticoagulation in patients with PAH during pregnancy. More intention should play to the complications of anticoagulant in pregnancy with PAH during treprostinil therapy.