Oral Anticoagulation for Pulmonary Arterial Hypertension: Systematic Review and Meta-analysis

Platelet hyperresponsiveness and increased platelet-neutrophil aggregates in dogs with myxomatous mitral valve disease and pulmonary hypertension

BACKGROUND

Pulmonary hypertension (PH) in dogs with myxomatous mitral valve disease (MMVD) is caused by increased pulmonary venous pressure. Thrombosis, vascular remodeling, and vasoconstriction mediated by platelets could exacerbate PH.

HYPOTHESIS

Dogs with PH will exhibit a hypercoagulable state, characterized by increased platelet activation, platelet-leukocyte, and platelet-neutrophil aggregate formation.

ANIMALS

Eleven dogs (≥3.5 kg) diagnosed with MMVD and PH and 10 dogs with MMVD lacking PH.

METHODS

Prospective cohort ex vivo study. All dogs underwent echocardiographic examination, CBC, 3-view thoracic radiographs, and heartworm antigen testing. Severity of PH and MMVD were assessed by echocardiography. Viscoelastic monitoring of coagulation was assessed using thromboelastography (TEG). Platelet activation and platelet-leukocyte/platelet-neutrophil interactions were assessed using flow cytometry. Plasma serotonin concentrations were measured by ELISA.

RESULTS

Unstimulated platelets from dogs with MMVD and PH expressed more surface P-selectin than MMVD controls (P = .03). Platelets from dogs with MMVD and PH had persistent activation in response to agonists. The number of platelet-leukocyte aggregates was higher in dogs with MMVD and PH compared with MMVD controls (P = .01). Ex vivo stimulation of whole blood resulted in higher numbers of platelet-neutrophil aggregates in dogs with MMVD and PH (P = .01). Assessment of hypercoagulability based on TEG or plasma serotonin concentrations did not differ between groups.

CONCLUSION AND CLINICAL IMPORTANCE

Platelet hyperresponsiveness and increased platelet-neutrophil interaction occur in dogs with MMVD and PH, suggesting that platelets play a role of in the pathogenesis of PH. Clinical benefits of antiplatelet drugs in dogs with MMVD and PH require further investigation.

A peripheral system disease-Pulmonary hypertension

Pulmonary hypertension (PH) is a cardiovascular disorder characterized by substantial morbidity and mortality rates. It is a chronic condition characterized by intricate pathogenesis and uncontrollable factors. We summarized the pathological effects of estrogen, genetics, neuroinflammation, intestinal microbiota, metabolic reorganization, and histone modification on PH. PH is not only a pulmonary vascular disease, but also a systemic disease. The findings emphasize that the onset of PH is not exclusively confined to the pulmonary vasculature, consequently necessitating treatment approaches that extend beyond targeting pulmonary blood vessels. Hence, the research on the pathological mechanism of PH is not limited to target organs such as pulmonary vessels, but also focuses on exploring other fields (such as estrogen, genetics, neuroinflammation, intestinal microbiota, metabolic reorganization, and histone modification).

Pulmonary arterial hypertension associated with connective tissue diseases (CTD-PAH): Recent and advanced data

Pulmonary arterial hypertension (PAH), corresponding to group 1 of pulmonary hypertension classification, is a rare disease with a major prognostic impact on morbidity and mortality. PAH can be either primary in idiopathic and heritable forms or secondary to other conditions including connective tissue diseases (CTD-PAH). Within CTD-PAH, the leading cause of PAH is systemic sclerosis (SSc) in Western countries, whereas systemic lupus erythematosus (SLE) and mixed connective tissue disease (MCTD) are predominantly associated with PAH in Asia. Although many advances have been made during the last two decades regarding classification, definition early screening and risk stratification and therapeutic aspects with initial combination treatment, the specificities of CTD-PAH are not yet clear. In this manuscript, we review recent literature data regarding the updated definition and classification of PAH, pathogenesis, epidemiology, detection, prognosis and treatment of CTD-PAH.

Management of Pulmonary Arterial Hypertension

Pulmonary arterial hypertension (PAH) is a rare pulmonary vascular disease characterized by progressive pulmonary arterial remodeling, increased pulmonary vascular resistance, right ventricular dysfunction, and reduced survival. Effective therapies have been developed that target three pathobiologic pathways in PAH: nitric oxide, endothelin-1, and prostacyclin. Approved therapies for PAH include phosphodiesterase type-5 inhibitors, soluble guanylate cyclase stimulators, endothelin receptor antagonists, prostacyclin analogs, and prostacyclin receptor agonists. Management of PAH in the modern era incorporates multidimensional risk assessment to guide the use of these medications. For patients with PAH and without significant comorbidities, current guidelines recommend two oral medications (phosphodiesterase type-5 inhibitor and endothelin receptor antagonist) for low- and intermediate-risk patients, with triple therapy including a parenteral prostacyclin to be considered in those at high or intermediate-high risk. Combination therapy may be poorly tolerated and less effective in patients with PAH and cardiopulmonary comorbidities. Thus, a single-agent approach with individualized decisions to add-on other PAH therapies is recommended in older patients and those with significant comorbid conditions. Management of PAH is best performed in multidisciplinary teams located in experienced centers. Other core pillars of PAH management include supportive and adjunctive treatments including oxygen, diuretics, rehabilitation, and anticoagulation in certain patients. Patients with PAH who progress despite optimal treatment or who are refractory to best medical care should be referred for lung transplantation, if eligible. Despite considerable progress, PAH is often fatal and new therapies that reverse the disease and improve outcomes are desperately needed.

Current pharmacogenomic recommendations in chronic respiratory diseases: Is there a biomarker ready for clinical implementation?

INTRODUCTION

The study of genetic variants in response to different drugs has predominated in fields of medicine such as oncology and infectious diseases. In chronic respiratory diseases, the available pharmacogenomic information is scarce but not less relevant.

AREAS COVERED

We searched the pharmacogenomic recommendations for respiratory diseases in the Table of Pharmacogenomic Biomarkers in Drug Labeling (U.S. Food and Drug Administration), the Clinical Pharmacogenomics Implementation Consortium (CPIC), and PharmGKB. The main pharmacogenomics recommendation in this field is to assess CFTR variants for using ivacaftor and its combination. The drugs' labels for arformoterol, indacaterol, and umeclidinium indicate a lack of influence of genetic variants in the pharmacokinetics of these drugs. Further studies should evaluate the contribution of CYP2D6 and CYP2C19 variants for formoterol. In addition, there are reports of potential pharmacogenetic variants in the treatment with acetylcysteine (TOLLIP rs3750920) and captopril (ACE rs1799752). The genetic variations for warfarin also are presented in PharmGKB and CPIC for patients with pulmonary hypertension.

EXPERT OPINION

The pharmacogenomics recommendations for lung diseases are limited. The clinical implementation of pharmacogenomics in treating respiratory diseases will contribute to the quality of life of patients with chronic respiratory diseases.

Pulmonary Hypertension in Scleroderma- Evaluation and Management

Pulmonary Arterial Hypertension (PAH) is a clinical syndrome consisting of physiologic/hemodynamic criteria that are a consequence of several etiologies. Systemic Sclerosis (SSc), one of the most common causes of PAH, is an autoimmune disorder of the connective tissue leading to fibrosis that involves the skin, gastrointestinal tract, lungs, heart, kidney etc. SSc has an annual prevalence of one to five cases for every 1000 individuals and nearly 15 percent of all cases develop PAH. At its core, Pulmonary hypertension (PH) in SSc is an obliterative vasculopathy in small to medium-sized pulmonary arterioles. A host of other local and systemic mechanisms operate in concert to gradually alter the hemodynamics resulting in elevated pulmonary vascular resistance and thus right ventricular afterload. A diagnosis of PAH in SSc is virtually a death sentence, with studies reporting a mortality rate of 50 per cent in the 3 years of diagnosis. Therefore, developing and implementing a robust screening and diagnosis protocol is crucial in the fight against this pervasive disease. This review aims to summarize the current literature of PAH in SSc, with a special focus on the screening and diagnosis protocols, newer treatment options and prognostic indicators for the same.

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.

Coagulation Profiles of Pulmonary Arterial Hypertension Patients, Assessed by Non-Conventional Hemostatic Tests and Markers of Platelet Activation and Endothelial Dysfunction

Many pathophysiologic processes of pulmonary arterial hypertension (PAH), namely, excess vasoconstriction, vascular remodeling and in situ thrombosis, involve the coagulation cascade, and more specifically, platelets. The aim of this study was to globally assess coagulation processes in PAH, by using non-conventional hemostatic tests, along with markers of platelet activation and endothelial dysfunction. We studied 44 new PAH patients (22 with idiopathic PAH and 22 with connective tissue disease) and 25 healthy controls. The following tests were performed: platelet function analyzer-100 (PFA-100), light transmission aggregometry (LTA), rotational thromboelastometry (ROTEM), endogenous thrombin potential (ETP), serotonin, thromboxane A2 and p-selectin plasma levels, and von Willebrand antigen (VWF:Ag) and activity (VWF:Ac). Our results showed that PAH patients had diminished platelet aggregation, presence of disaggregation, defective initiation of the clotting process and clot propagation, and diminished thrombin formation capacity. Serotonin, thromboxane A2 and p-selectin levels were increased, and VWF:Ag and VWF:Ac decreased in the same population. The results of this study suggest that the platelets of PAH patients are activated and present functional abnormalities. The procoagulant activity, in general, appears to be impaired probably due to a sustained and prolonged activation of the procoagulant processes. Larger observational studies are warranted to confirm these laboratory findings.

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.

Is Anticoagulation Beneficial in Pulmonary Arterial Hypertension?

Background Data about anticoagulation in pulmonary arterial hypertension (PAH) patients are inconsistent. The objective of this study was to examine the impact of adjunctive oral anticoagulants in patients with PAH through meta-analysis, and to further assess whether response differs by PAH subtype. Methods and Results Cochrane CENTRAL, Medline, and Scopus databases were searched for randomized or nonrandomized studies that assessed the association between anticoagulation and outcomes in patients with PAH. Hazard ratios (HRs) for mortality were pooled using the random effects model. Subgroup analyses were performed for type of PAH and study design. Twelve nonrandomized studies, at moderate risk of bias, were included. These consisted of 2512 patients (1342 receiving anticoagulation and 1170 controls). Anticoagulation significantly reduced mortality in the overall PAH cohort (HR, 0.73 [0.57, 0.93]; P=0.001; I²=64%). On subgroup analysis, a significant mortality reduction was seen in idiopathic PAH patients (HR, 0.73 [0.56, 0.95]; P=0.02; I²=46%), whereas no significant difference was observed in connective tissue disease-related PAH (HR, 1.16 [0.58, 2.32]; P=0.67; I²=71%). Sensitivity analysis specific to scleroderma-associated PAH demonstrated a significant increase in mortality with anticoagulant use (HR, 1.58 [1.08, 2.31]; P=0.02; I²=9%). Conclusions This meta-analysis shows that use of anticoagulation may improve survival in idiopathic PAH patients, while increasing mortality when used in scleroderma-associated-PAH patients. Currently, no randomized clinical trials have been published, and until randomized data are available, anticoagulant use in PAH should be tailored to PAH subtype.

Mortality associated with cardiovascular drugs in patients with chronic obstructive pulmonary disease and right-sided heart failure - A danish nationwide registry-based study

BACKGROUND

The optimal medical treatment in patients with chronic obstructive pulmonary disease (COPD) and right-sided heart failure (RHF) is unknown. We aimed to estimate the risks of all-cause mortality associated with the current clinical use of various cardiovascular drugs in this patient-group.

METHODS

We followed all patients with registered COPD and RHF (defined as a diagnosis of pulmonary hypertension plus use of loop-diuretics) for the risk of all-cause mortality (Jan 1, 1995 to Dec 31, 2015) using the Danish nationwide administrative registries. The association between mortality and claimed prescriptions for cardiovascular drugs was assessed by multivariable Cox regression models.

RESULTS

5991 patients (mean age 74 ± standard deviation 10 years, 51% women) were included. Of these, 1440 (24%) used beta-blockers, 2149 (36%) renin-angiotensin system inhibitors [RASi], 1340 (22%) oral anticoagulants, 1376 (23%) calcium channel blockers, 1194 (20%) statins, 1824 (30%) spironolactone, and 2099 (35%) low-dose aspirin. During an average follow-up of 2.2 years (±standard deviation 2.8, min-max 0-19.6 years), 5071 (85%) died, corresponding to a mortality rate of 38 per 100 person-years (95% confidence interval 37-39). Compared to no use, beta-blockers were associated with adjusted hazards ratio 0.90 (95% confidence interval 0.84-0.98), RASi 0.92 (0.86-0.98), calcium channel blockers 0.86 (0.80-0.92), spironolactone 1.17 (1.10-1.24), statins 0.85 (0.78-0.92), oral anticoagulants 0.87 (0.79-0.95), and aspirin 0.99 (0.93-1.05). Propensity-score matched analyses and inverse-probability-weighted models yielded similar results.

CONCLUSION

Several cardiovascular drugs may be associated with lowered mortality in COPD and RHF. Given the grave prognosis, randomized clinical trials are warranted to test this hypothesis.

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.

Evolving cardiovascular uses of direct-acting oral anticoagulants: a paradigm shift on the horizon?

Direct-acting oral anticoagulants (DOACs), by virtue of pharmacological properties perceived as innovative, are changing the therapeutic scenario of patients requiring short- and long-term anticoagulation. The evidence gathered so far (from pre-approval pivotal trials to real-world post-marketing observational data) consistently confirms that DOACs are overall comparable to vitamin-K antagonists (VKAs) in terms of safety, efficacy, effectiveness and unequivocally documents a clinically relevant reduced risk of intracranial bleeding in the settings of non-valvular atrial fibrillation (AF) and venous thromboembolism. The following issues are attracting considerable clinical interest: (a) identifying specific subpopulations of patients with AF most likely to benefit from one of these agents (the so-called tailored therapy), and (b) expanding therapeutic indications in emerging diseases characterized by arterial and venous thromboembolic risk. In these scenarios, the risk-benefit profile of DOACs, as compared to VKAs or heparins, is still incompletely characterized. In cardiology, the challenging task of selecting a suitable or even the most appropriate DOAC for patients with AF and a particular phenotype prompted experts to provide suggestions based on careful review of subgroups of patients from pivotal RCTs. However, in the past few months, variegated multicenter trials have been published (RE-CIRCUIT, PIONEER-AF-PCI, GEMINI-ACS-1), with potential influence on clinical practice. Therefore, this review aims to update the latest evidence on the evolving therapeutic uses of DOACs in the cardiovascular area, addressing potential impact for clinicians.

The role of platelets in autoimmunity, vasculopathy, and fibrosis: Implications for systemic sclerosis

INTRODUCTION

Systemic sclerosis (SSc) is an autoimmune disease characterized by vasculopathy, autoimmunity, and widespread dermal and visceral fibrosis. This article summarizes the current knowledge about the potential contribution of platelets in the disease process and the rationale of targeting platelets as an adjunct treatment for SSc.

METHODS

We performed an electronic search (Medline) using the keywords platelets, systemic sclerosis, autoimmunity, fibrosis, Raynaud, and pulmonary arterial hypertension.

RESULTS

The link that connects vasculopathy, autoimmunity, and fibrosis in SSc remains obscure. Experimental data suggest that platelets are not solely cell fragments regulating hemostasis but they have a pleiotropic role in several biologic processes including immune regulation, vasculopathy, fibrosis, and all key features of SSc. Platelets interplay with the impaired endothelium, can interact with immune cells, and they are storages of bioactive molecules involved in tissue injury and remodeling. The potential role of platelets in the pathogenesis of SSc is further supported by experimental data in animal models of SSc. Platelet-derived serotonin represents a novel target in SSc and serotonin blockade is currently being tested in clinical trials.

CONCLUSION

Platelets may be actively involved in the pathogenesis of SSc by activating immune responses and facilitating the fibrotic process. However, definite conclusions cannot be drawn until more data from both basic and clinical research are available.

Anticoagulation in Pulmonary Arterial Hypertension

Pulmonary arterial hypertension (PAH) is characterized by molecular and pathologic alteration to the pulmonary circulation, resulting in increased pulmonary vascular resistance, right ventricular failure, and eventual death. Pharmacologic treatment of PAH consists of use of a multitude of pulmonary vasodilators, sometimes in combination. PAH has been associated with increased thrombosis and disrupted coagulation and fibrinolysis, making anticoagulation an attractive and frequently employed therapeutic modality. Observational studies have provided some insight into the therapeutic potential of anticoagulation in idiopathic PAH, but there is a distinct lack of well-controlled prospective trials. Due to the conflicting evidence, there is a large amount of heterogeneity in the application of therapeutic anticoagulation in PAH and further well-controlled prospective trials are needed to clarify its role in treating PAH.

Multicentre randomised placebo-controlled trial of oral anticoagulation with apixaban in systemic sclerosis-related pulmonary arterial hypertension: the SPHInX study protocol

INTRODUCTION

Systemic sclerosis (SSc) is a severe and costly multiorgan autoimmune connective tissue disease characterised by vasculopathy and fibrosis. One of the major causes of SSc-related death is pulmonary arterial hypertension (PAH), which develops in 12-15% of patients with SSc and accounts for 30-40% of deaths. In situ thrombosis in the small calibre peripheral pulmonary vessels resulting from endothelial dysfunction and an imbalance of anticoagulant and prothrombotic mediators has been implicated in the complex pathophysiology of SSc-related PAH (SSc-PAH), with international clinical guidelines recommending the use of anticoagulants for some types of PAH, such as idiopathic PAH. However, anticoagulation has not become part of standard clinical care for patients with SSc-PAH as only observational evidence exists to support its use. Therefore, we present the rationale and methodology of a phase III randomised controlled trial (RCT) to evaluate the efficacy, safety and cost-effectiveness of anticoagulation in SSc-PAH.

METHODS AND ANALYSIS

This Australian multicentre RCT will compare 2.5 mg apixaban with placebo, in parallel treatment groups randomised in a 1:1 ratio, both administered twice daily for 3 years as adjunct therapy to stable oral PAH therapy. The composite primary outcome measure will be the time to death or clinical worsening of PAH. Secondary outcomes will include functional capacity, health-related quality of life measures and adverse events. A cost-effectiveness analysis of anticoagulation versus placebo will also be undertaken.

ETHICS AND DISSEMINATION

Ethical approval for this RCT has been granted by the Human Research Ethics Committees of all participating centres. An independent data safety monitoring board will review safety and tolerability data for the duration of the trial. The findings of this RCT are to be published in open access journals.

TRIAL REGISTRATION NUMBER

ACTRN12614000418673, Pre-results.

Where do we go from here? Reappraising the data on anticoagulation in pulmonary arterial hypertension

The use of anticoagulation as part of the treatment regimen in pulmonary arterial hypertension (PAH) remains a topic of debate. A recently published analysis of anticoagulation use in the Registry to Evaluate Early and Long-Term PAH Disease Management (REVEAL) study offers conflicting conclusions regarding the benefit of this therapeutic strategy. There remains no robust randomized trial in PAH weighing the risks versus benefits of including anticoagulation in treatment regimens, leaving clinicians to surmise value in individual patients. Reexamination of available data may help to provide guidance on this controversial topic in the absence of future dedicated investigations.

Catheter interventional treatment of congenital portosystemic venous shunts in childhood

OBJECTIVES

The study aimed on the catheter interventional treatment of congenital portosystemic venous shunt (CPSVS) in childhood and the impact on vascular growth of hypoplastic portal veins. Clinical course and follow up of partial or complete closure of CPSVS are described.

BACKGROUND

CPSVS is a very rare vascular malformation of the portal venous drainage resulting in potentially life threatening abdominal, pulmonary, cerebral, and cardiac complications. The anatomic type, clinical course, and diagnosis must be determined for optimal management.

METHODS

Single centre case series.

RESULTS

Eight (6 female) children with extrahepatic (n = 5) and intrahepatic (n = 3) CPSVS were diagnosed invasively by catheterization, including test balloon occlusion of the shunt and simultaneous retrograde angiography, and treated by catheter interventions (n = 5) with partial (n = 2) and complete (n = 3) occlusion of CPSVS at a median age of 3.9 years (range 0.7-21). Congenital heart disease (CHD) was the most frequent associated organ manifestation (n = 5) followed by mild to severe pulmonary arterial hypertension (n = 4), hepatopulmonary syndrome (n = 2), and portosystemic encephalopathy (n = 1). CHD was simple (n = 3) or complex type (n = 2). Three patients were untreated so far, because they were in excellent clinical condition at an age <1 year, refused treatment, or planned for later treatment.

CONCLUSIONS

Accurate invasive diagnosis of CPSVS with test balloon occlusion of the shunt is mandatory to depict the anatomic situation. Catheter interventional treatment of CPSVS offers a feasible and safe approach with complete or partial closure of the vascular malformation inducing potentially significant vascular growth of a former hypoplastic portal venous system. © 2015 Wiley Periodicals, Inc.

Anticoagulation in patients with pulmonary arterial hypertension: An update on current knowledge

Pulmonary hypertension is a severe clinical condition characterized by molecular and anatomic changes in pulmonary circulation. It is associated with increased pulmonary vascular resistance, which leads to right-sided heart failure if left untreated and, ultimately, death. Treatment of patients with pulmonary arterial hypertension (PAH) involves a complex strategy that takes into consideration disease severity, general and supportive measures, and combination drug regimens. Abnormalities of blood coagulation factors, anti-thrombotic factors, and the fibrinolytic system may contribute to a prothrombotic state in patients with idiopathic PAH. These physiologic changes, in concert with the presence of non-specific risk factors for venous thromboembolism such as heart failure and immobility, are thought to be the basis for oral anticoagulation in PAH. Several observational studies provide helpful information in favor of anticoagulation use in idiopathic PAH but not in other pulmonary hypertension etiologies. Guideline recommendations are based on the lack of prospective comparative trials in this regard. For that reason, large differences exist in the use of anticoagulants in different countries and centers. More studies should be carried out to clarify the risks and the potential benefits of anticoagulant use in a heterogeneous population of patients who are already at considerable life risk.

An Update on Pulmonary Arterial Hypertension

Pulmonary arterial hypertension (PAH) is a progressive disease that ultimately leads to right heart failure and death. PAH is defined as a mean pulmonary arterial pressure ≥ 25 mm Hg with a pulmonary capillary wedge pressure ≤ 15 mm Hg at rest. The diagnosis of PAH is one of exclusion; diagnostics include an extensive history, serology, chest radiograph, pulmonary function tests, ventilation/perfusion scan, transthoracic echocardiogram, and right heart catheterization. Treatment and care of patients with PAH can be complex. Therefore, the nurse practitioner is an integral member of the healthcare team caring for PAH patients, helping to ensure seamless care and support.