Use of selective serotonin reuptake inhibitors and outcomes in pulmonary arterial hypertension

Serotonin and Pulmonary Hypertension; Sex and Drugs and ROCK and Rho

Serotonin is often referred to as a "happy hormone" as it maintains good mood, well-being, and happiness. It is involved in communication between nerve cells and plays a role in sleeping and digestion. However, too much serotonin can have pathogenic effects and serotonin synthesis is elevated in pulmonary artery endothelial cells from patients with pulmonary arterial hypertension (PAH). PAH is characterized by elevated pulmonary pressures, right ventricular failure, inflammation, and pulmonary vascular remodeling; serotonin has been shown to be associated with these pathologies. The rate-limiting enzyme in the synthesis of serotonin in the periphery of the body is tryptophan hydroxylase 1 (TPH1). TPH1 expression and serotonin synthesis are elevated in pulmonary artery endothelial cells in patients with PAH. The serotonin synthesized in the pulmonary arterial endothelium can act on the adjacent pulmonary arterial smooth muscle cells (PASMCs), adventitial macrophages, and fibroblasts, in a paracrine fashion. In humans, serotonin enters PASMCs cells via the serotonin transporter (SERT) and it can cooperate with the 5-HT1B receptor on the plasma membrane; this activates both contractile and proliferative signaling pathways. The "serotonin hypothesis of pulmonary hypertension" arose when serotonin was associated with PAH induced by diet pills such as fenfluramine, aminorex, and chlorphentermine; these act as indirect serotonergic agonists causing the release of serotonin from platelets and cells through the SERT. Here the role of serotonin in PAH is reviewed. Targeting serotonin synthesis or signaling is a promising novel alternative approach which may lead to novel therapies for PAH. © 2022 American Physiological Society. Compr Physiol 12: 1-16, 2022.

Prevalence, Risk Factors and Intervention for Depression and Anxiety in Pulmonary Hypertension: A Systematic Review and Meta-analysis

Background

Current guidelines recommend psychological support for patients with pulmonary hypertension suffering from psychological adversity. However, little is known about the prevalence and risk factors of depression and anxiety in patients with pulmonary hypertension (PH).

Methods

Medline and Embase were searched from inception to 6 May 2021. Meta-analysis of proportions using the generalized linear mixed model was conducted to analyze the pooled prevalence rates of depression and anxiety in PH patients. Risk factors for depression and anxiety in PH patients were evaluated using meta regression.

Results

A total of 24 studies involving 2,161 PH patients were included. The pooled prevalence of depression in PH was 28.0% (95% CI: 20.5–36.8) and pooled prevalence of anxiety was 37.1% (95% CI: 28.7–46.4). There was a significantly higher prevalence of anxiety (p = 0.0013) amongst PH patients in Asia (61.1%) compared to Europe (40.3%) and North America (22.9%). In terms of risk factors, congenital heart disease-related pulmonary arterial hypertension (PAH-CHD) were significantly associated with both depression (OR: 1.68, 95% CI: 1.27–2.23, p = 0.024) and anxiety (OR: 1.63, 95% CI: 1.45–1.83, p = 0.002). On the other hand, chronic thromboembolic pulmonary hypertension (CTEPH, OR: 1.18, 95% CI: 1.10–1.26, p = 0.004) was significantly associated with depression, whereas worse pulmonary vascular resistance (β: 0.30, 95% CI: 0.09–0.52, p = 0.005) and cardiac index (β: −0.96, 95% CI: −1.58 to −0.35, p = 0.002) were significantly correlated with anxiety.

Conclusion

The prevalence of anxiety and depression in PH patients is alarmingly high, with an increased prevalence of anxiety in Asia compared to Europe or North America. Psychological support is warranted for patients with PH, particularly those with underlying congenital heart disease, CTEPH, and severe disease.

Systematic Review Registration

CRD42021251733.

Pulmonary Arterial Hypertension Secondary to Drugs and Toxins

Pulmonary arterial hypertension secondary to drugs and toxins is an important subgroup of group 1 pulmonary hypertension associated with significant morbidity and mortality. Many drugs and toxins have emerged as risk factors for pulmonary arterial hypertension, which include anorexigens, illicit agents, and several US Food and Drug Administration-approved therapeutic medications. Drugs and toxins are classified as possible or definite risk factors for pulmonary arterial hypertension. This article reviews agents that have been implicated in the development of pulmonary arterial hypertension, their pathologic mechanisms, and methods to prevent the next deadly outbreak of drug- and toxin-induced pulmonary arterial hypertension.

SSRIs: Applications in inflammatory lung disease and implications for COVID-19

Selective serotonin reuptake inhibitors (SSRIs) have anti-inflammatory properties that may have clinical utility in treating severe pulmonary manifestations of COVID-19. SSRIs exert anti-inflammatory effects at three mechanistic levels: (a) inhibition of proinflammatory transcription factor activity, including NF-κB and STAT3; (b) downregulation of lung tissue damage and proinflammatory cell recruitment via inhibition of cytokines, including IL-6, IL-8, TNF-α, and IL-1β; and (c) direct suppression inflammatory cells, including T cells, macrophages, and platelets. These pathways are implicated in the pathogenesis of COVID-19. In this review, we will compare the pathogenesis of lung inflammation in pulmonary diseases including COVID-19, ARDS, and chronic obstructive pulmonary disease (COPD), describe the anti-inflammatory properties of SSRIs, and discuss the applications of SSRIS in treating COVID-19-associated inflammatory lung disease.

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.

Roles of specific drug therapies for severe pulmonary arterial hypertension in palliative care: a case report

Pulmonary arterial hypertension (PAH) is an uncommon but potentially life-threatening illness. The elevated pulmonary arterial blood pressure will lead to right heart failure and even cardiopulmonary collapse if it is severe. Apart from general supportive measures, pulmonary hypertension-specific therapies (PHST) are available to slow down disease progression, but they are not curative. According to previous studies, many patients with severe PAH often had significant physical symptoms and psychological distress for both themselves and their families at the end of life. Moreover, they would have repeated admissions due to physical deterioration and decline in functioning associated with worsening in cardiac function. Some of these patients might suffer from unnecessary aggressive interventions and resuscitation because of lack of advance care planning discussion. As such, Palliative Care (PC) would be an important element as part of the overall management. Hereby, we reported a patient with severe PAH and schizoaffective disorder achieved good outcome from the use of combination PHST and PC input. Her physical and psychosocial needs could be addressed well by PC team. This case report showed the collaborative work between PC and parent teams. While parent team was able to manage the medical conditions related to PAH, however the physical and psychosocial needs should be addressed by PC team. More importantly, the PC team has essential roles of providing advance care planning discussions with the patient and help to reduce unnecessary interventions. Furthermore, PC would coordinate the community service to support her while staying at home. Roles of PHST will also be discussed in this case. Clinicians must take into account possible hemodynamic effects of any palliative intervention for PAH.

Hemodynamic effects of fluoxetine in pulmonary arterial hypertension: an open label pilot study

In order to evaluate the therapeutic potential of fluoxetine in pulmonary arterial hypertension, 13 patients with pulmonary arterial hypertension underwent catheterization before and after 12 (N = 5) or 24 (N = 8) weeks fluoxetine therapy. No change was seen in the primary endpoint of pulmonary vascular resistance, other hemodynamic values, or any secondary endpoints.

Increased pulmonary serotonin transporter in patients with chronic obstructive pulmonary disease who developed pulmonary hypertension

Purpose

Pulmonary hypertension (PH) is characterized by a progressive remodelling of the pulmonary vasculature resulting in right heart failure and eventually death. The serotonin transporter (SERT) may be involved in the pathogenesis of PH in patients with chronic-obstructive pulmonary disease (COPD). This study investigated for the first time the SERT in vivo availability in the lungs of patients with COPD and PH (COPD+PH).

Methods

SERT availability was assessed using SERT-selective [¹¹C]DASB and positron emission tomography/computed tomography (PET/CT) with dynamic acquisition over 30 min in 4 groups of 5 participants each: COPD, COPD+PH, pulmonary arterial hypertension, and a healthy control (HC). Time activity curves were generated based on a volume of interest within the middle lobe. Tissue-to-blood concentration ratios after 25 to 30 min (TTBR_25–30) served as receptor parameter for group comparison and were corrected for lung tissue attenuation. Participants underwent comprehensive pulmonary workup. Statistical analysis included group comparisons and correlation analysis.

Results

[¹¹C]DASB uptake peak values did not differ among the cohorts after adjusting for lung tissue attenuation, suggesting equal radiotracer delivery. Both the COPD and COPD+PH cohort showed significantly lower TTBR_25–30 values after correction for lung attenuation than HC. Attenuation corrected TTBR_25–30 values were significantly higher in the COPD+PH cohort than those in the COPD cohort and higher in non-smokers than in smokers. They positively correlated with invasively measured severity of PH and inversely with airflow limitation and emphysema. Considering all COPD patients ± PH, they positively correlated with right heart strain (NT-proBNP).

Conclusion

By applying [¹¹C]DASB and PET/CT, semiquantitative measures of SERT availability are demonstrated in the lung vasculature of patients with COPD and/or PH. COPD patients who developed PH show increased pulmonary [¹¹C]DASB uptake compared to COPD patients without PH indicating an implication of pulmonary SERT in the development of PH in COPD patients.

Electronic supplementary material

The online version of this article (10.1007/s00259-020-05056-7) contains supplementary material, which is available to authorized users.

Pulmonary Arterial Hypertension: A Palliative Medicine Review of the Disease, Its Therapies, and Drug Interactions

Pulmonary arterial hypertension (PAH) is often a progressive and ultimately fatal disease. It is characterized by an elevated mean pulmonary arterial pressure because of disease of the small pulmonary arterioles. PAH leads to a constellation of symptoms, including dyspnea, fatigue, syncope, chest discomfort, and peripheral edema. Disease-targeted therapies for PAH produce symptomatic and functional improvement, but long-term survival remains uncommon without lung transplantation. Palliative care is appropriate to support patients with advanced PAH who typically have a high symptom burden. However, palliative care has historically focused on supporting patients with malignant disease, rather than progressive chronic disease such as PAH. Our aim is to provide palliative care clinicians with a background in the classification, pathophysiology, and modern treatment of PAH. This review describes disease-targeted therapies and their effects on symptoms, physical functioning, and health-related quality of life. We also review the unique physiology of PAH and its implication for palliative interventions. Pharmacological interactions with, and precautions related to commonly used palliative care medications, are discussed.

Current and future treatments of pulmonary arterial hypertension

Therapeutic options for pulmonary arterial hypertension (PAH) have increased over the last decades. The advent of pharmacological therapies targeting the prostacyclin, endothelin, and NO pathways has significantly improved outcomes. However, for the vast majority of patients, PAH remains a life-limiting illness with no prospect of cure. PAH is characterised by pulmonary vascular remodelling. Current research focusses on targeting the underlying pathways of aberrant proliferation, migration, and apoptosis. Despite success in preclinical models, using a plethora of novel approaches targeting cellular GPCRs, ion channels, metabolism, epigenetics, growth factor receptors, transcription factors, and inflammation, successful transfer to human disease with positive outcomes in clinical trials is limited. This review provides an overview of novel targets addressed by clinical trials and gives an outlook on novel preclinical perspectives in PAH. LINKED ARTICLES: This article is part of a themed issue on Risk factors, comorbidities, and comedications in cardioprotection. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v178.1/issuetoc.

Anxiety and depression in patients with pulmonary arterial hypertension and chronic thromboembolic pulmonary hypertension: Results from a Chinese survey

Limited studies have focused on mental symptoms (anxiety and depression) and their impact on quality of life (QoL) in patients with pulmonary hypertension (PH). The objective of the present study was to assess the prevalence of anxiety and depression and their association with QoL in patients with pulmonary arterial hypertension (PAH) and chronic thromboembolic PH (CTEPH) in a Chinese population. Patients diagnosed with PH by right heart catheterization between March 2015 and February 2016 were recruited. QoL [short form 36 Health Survey Questionnaire (SF-36)] and depression (Patient Health Questionnaire depression scale-9) and anxiety (Generalized Anxiety Disorder-7) were assessed at baseline. Patients were followed up every 3 months. A total of 36 patients with PAH and 62 patients with CTEPH were enrolled. According to the results of the clinical examination and the questionnaires for depression and anxiety, patients were divided into two groups: Group 1, with depression and/or anxiety (n=65, 66.3%) and group 2, without depression or anxiety (n=33, 33.7%). At baseline, the two groups did not differ in their hemodynamics. Patients with depression and/or anxiety (group 1) had a significantly lower score in all subscales of SF-36 (P<0.05). The impairment of QoL significantly correlated with the severity of depression (P<0.001) and anxiety (P<0.05). During the follow-up period, end-point events (death or admission due to deterioration) occurred in 17 patients (17.3%); 8 patients (8.1%) were lost to follow-up. The end-point event-free survival rate in group 2 was significantly higher than that in group 1. Multivariate logistic regression analysis suggested that the financial situation and right ventricular enlargement were influencing factors of depression and/or anxiety. In conclusion, in patients with PH from a Chinese population, anxiety and depression were frequently encountered and significantly correlated with QoL. The significant relevant factors influencing anxiety/depression were the financial situation and right ventricular enlargement and patients with depression had a worse prognosis than those without.

The burden of comorbidities in pulmonary arterial hypertension

Patients with comorbidities are often excluded from clinical trials, limiting the evidence base for pulmonary arterial hypertension (PAH)-specific therapies. This review aims to discuss the effect of comorbidities on the diagnosis and management of PAH. The comorbidities discussed in this review (systemic hypertension, obesity, sleep apnoea, clinical depression, obstructive airway disease, thyroid disease, diabetes, and ischaemic cardiovascular event) were chosen based on their prevalence in patients with idiopathic PAH in the REVEAL registry (Registry to EValuate Early and Long-term PAH disease management). Comorbidities can mask the symptoms of PAH, leading to delays in diagnosis and also difficulty evaluating disease progression and treatment effects. Due to the multifactorial pathophysiology of pulmonary hypertension (PH), the presence of comorbidities can lead to difficulties in distinguishing between Group 1 PH (PAH) and the other group classifications of PH. Many comorbidities contribute to the progression of PAH through increased pulmonary artery pressures and cardiac output, therefore treatment of the comorbidity may also reduce the severity of PAH. Similarly, the development of one comorbidity can be a risk factor for the development of other comorbidities. The management of comorbidities requires consideration of drug interactions, polypharmacy, adherence and evidence-based strategies. A multidisciplinary team should be involved in the management of patients with PAH and comorbidities, with appropriate referral to supportive services when necessary. The treatment goals and expectations of patients must be managed in the context of comorbidities.

Anxiety and depression in patients with pulmonary hypertension: impact and management challenges

Background

Anxiety and depression are frequent disorders in patients with pulmonary arterial hypertension (PAH), but despite this only less than one-fourth of them is treated. Our aim was to review the studies regarding the prevalence and the impact of anxiety and depression and to propose management challenges.

Methods

A literature review regarding 1) anxiety and depression studies in PAH patients and caregivers, 2) psychological interventions, 3) slow breathing approach, and 4) pharmacological approach was performed, based on evidence of effectiveness through a search of the most well-known databases (Cochrane Library, Medline, PsychINFO [2004–2018]).

Results

The prevalence of mental disorders in PAH patients lies between 7.5% and 53% for depression and 19% and 51% for anxiety and panic disorders. The latest guidelines of the European Society of Cardiology recommend a psychological support with a class of recommendation I and a level of evidence c. The analysis of psychological intervention shows that at present there is no evidence of specific psychological interventions in these patients. However, treatment approaches based on other chronic illnesses are suggested, especially based on relaxation training, slow breathing, and cognitive behavioral therapy. Finally, data concerning the use of antidepressant drugs are conflicting.

Conclusion

Firstly, our data demonstrate a common underestimation of mental disorders by health professionals and secondly, the need of implementing appropriate methods of screening for mental disorders in PAH patients. However, the paucity of large observational studies in this area requires the attention of researchers. The evidence about optimal approaches for managing anxiety and depression in PAH also remains unclear and largely speculative. The challenge is the introduction of routine psychological intervention, as suggested by the European Society of Cardiology and already applied in other chronic disease.

Systematic review and meta-analysis of interventions tested in animal models of pulmonary hypertension

A systematic review and meta-analysis was performed to test candidate therapeutic approaches in pulmonary hypertension (PH). The efficacy of 522 interventions with >200 unregistered drugs was tested on 7254 animals. We propose a modified formula to assess meta-data that concerns the contribution of PH animal model to the denoted efficacy of tested agents. The measure of efficacy expressed as a response ratio for right ventricle systolic pressure was 0.48 (95% CI, 0.46-0.50; P < 0.00001), mean pulmonary artery pressure was 0.54 (0.52-0.56; P < 0.00001), right ventricle hypertrophy was 0.49 (0.48-0.51; P < 0.00001) and pulmonary artery wall thickness was 0.58 (0.56-0.61; P < 0.00001). Only 41 out of 522 interventions were ineffective. The most potent agents to improve both haemodynamic and hypertrophic parameters were ATP-sensitive potassium channel openers with iptakalim, Rho/ROCK inhibitors with fasudil, RAAS regulators with adenosine and ACE2 activators, and anti-inflammatories with n-3 polyunsaturated fatty acids and NF-кB inhibitors.

Drug-associated pulmonary arterial hypertension

INTRODUCTION

While pulmonary arterial hypertension remains an uncommon diagnosis, various therapeutic agents are recognized as important associations. These agents are typically categorized into "definite", "likely", "possible", or "unlikely" to cause pulmonary arterial hypertension, based on the strength of evidence.

OBJECTIVE

This review will focus on those therapeutic agents where there is sufficient literature to adequately comment on the role of the agent in the pathogenesis of pulmonary arterial hypertension.

METHODS

A systematic search was conducted using PubMed covering the period September 1970- 2017. The search term utilized was "drug induced pulmonary hypertension". This resulted in the identification of 853 peer-reviewed articles including case reports. Each paper was then reviewed by the authors for its relevance. The majority of these papers (599) were excluded as they related to systemic hypertension, chronic obstructive pulmonary disease, human immunodeficiency virus, pulmonary fibrosis, alternate differential diagnosis, treatment, basic science, adverse effects of treatment, and pulmonary hypertension secondary to pulmonary embolism. Agents affecting serotonin metabolism (and related anorexigens): Anorexigens, such as aminorex, fenfluramine, benfluorex, phenylpropanolamine, and dexfenfluramine were the first class of medications recognized to cause pulmonary arterial hypertension. Although most of these medications have now been withdrawn worldwide, they remain important not only from a historical perspective, but because their impact on serotonin metabolism remains relevant. Selective serotonin reuptake inhibitors, tryptophan, and lithium, which affect serotonin metabolism, have also been implicated in the development of pulmonary arterial hypertension. Interferon and related medications: Interferon alfa and sofosbuvir have been linked to the development of pulmonary arterial hypertension in patients with other risk factors, such as human immunodeficiency virus co-infection. Antiviral therapies: Sofosbuvir has been associated with two cases of pulmonary artery hypertension in patients with multiple risk factors for its development. Its role in pathogenesis remains unclear. Small molecule tyrosine kinase inhibitors: Small molecule tyrosine kinase inhibitors represent a relatively new class of medications. Of these dasatinib has the strongest evidence in drug-induced pulmonary arterial hypertension, considered a recognized cause. Nilotinib, ponatinib, carfilzomib, and ruxolitinib are newer agents, which paradoxically have been linked to both cause and treatment for pulmonary arterial hypertension. Monoclonal antibodies and immune regulating medications: Several case reports have linked some monoclonal antibodies and immune modulating therapies to pulmonary arterial hypertension. There are no large series documenting an increased prevalence of pulmonary arterial hypertension complicating these agents; nonetheless, trastuzumab emtansine, rituximab, bevacizumab, cyclosporine, and leflunomide have all been implicated in case reports. Opioids and substances of abuse: Buprenorphine and cocaine have been identified as potential causes of pulmonary arterial hypertension. The mechanism by which this occurs is unclear. Tramadol has been demonstrated to cause severe, transient, and reversible pulmonary hypertension. Chemotherapeutic agents: Alkylating and alkylating-like agents, such as bleomycin, cyclophosphamide, and mitomycin have increased the risk of pulmonary veno-occlusive disease, which may be clinically indistinct from pulmonary arterial hypertension. Thalidomide and paclitaxel have also been implicated as potential causes. Miscellaneous medications: Protamine appears to be able to cause acute, reversible pulmonary hypertension when bound to heparin. Amiodarone is also capable of causing pulmonary hypertension by way of recognized side effects.

CONCLUSIONS

Pulmonary arterial hypertension remains a rare diagnosis, with drug-induced causes even more uncommon, accounting for only 10.5% of cases in large registry series. Despite several agents being implicated in the development of PAH, the supportive evidence is typically limited, based on case series and observational data. Furthermore, even in the drugs with relatively strong associations, factors that predispose an individual to PAH have yet to be elucidated.

The serotonin hypothesis in pulmonary hypertension revisited: targets for novel therapies (2017 Grover Conference Series)

Increased synthesis of serotonin and/or activity of serotonin in pulmonary arteries has been implicated in the pathobiology of pulmonary arterial hypertension (PAH). The incidence of PAH associated with diet pills such as aminorex, fenfluramine, and chlorphentermine initially led to the “serotonin hypothesis of pulmonary hypertension.” Over the last couple of decades there has been an accumulation of convincing evidence that targeting serotonin synthesis or signaling is a novel and promising approach to the development of novel therapies for PAH. Pulmonary endothelial serotonin synthesis via tryptophan hydroxlase 1 (TPH1) is increased in patients with PAH and serotonin can act in a paracrine fashion on underlying pulmonary arterial smooth muscle cells (PASMCs), In humans, serotonin can enter PASMCs via the serotonin transporter (SERT) or activate the 5-HT1B receptor; 5-HT1B activation and SERT activity cooperate to induce PASMC contraction and proliferation via activation of downstream proliferative and contractile signaling pathways. Here we will review the current status of the serotonin hypothesis and discuss potential and novel therapeutic targets.

Update on pulmonary arterial hypertension research: proceedings from a meeting of experts

BACKGROUND

While pulmonary arterial hypertension (PAH) remains a progressive, symptomatic condition characterized by increased pulmonary vascular resistance, ultimately leading to right heart failure, great strides have been made in its understanding and treatment over the past two decades.

REVIEW

Continued research in pre-clinical, clinical, and health economic areas of research, in addition to registry analyses and technology advances, is critical for understanding the pathophysiology of the disease and devising the best ways to monitor and manage patients. On December 3, 2016, the latest pre-clinical, clinical, health economic outcome, and registry data on PAH was presented in a symposium sponsored by Actelion. This paper reviews the published research and insight into upcoming research that was presented at this interactive meeting.

Stimulants and Pulmonary Arterial Hypertension: An Update

The connection between stimulants and pulmonary arterial hypertension (PAH) was first made apparent in the 1960s during an outbreak associated with anorexigen (amphetamine-like appetite suppressants) use. Since then, a total of 16 drugs and toxins have been linked to PAH (ie, drug and toxin-associated PAH [DT-APAH]), including illicit stimulants like methamphetamine. Recently, basic science research and novel genomic studies have started to shed light on possible pathologic and genetic mechanisms implicated in disease development, namely loss of function variants in genes involved in drug detoxification. This review will discuss the history and current state of knowledge regarding stimulants and their association with PAH. It will also discuss clinical management of patients with DT-APAH. Lastly, it will highlight the importance of ongoing research efforts to identify susceptibility factors implicated in DT-APAH and the need for increased pharmacovigilance and awareness to identify new drugs that may be risk factors for PAH. Ultimately, this may be our best strategy to improve clinical outcomes and prevent deadly future outbreaks of DT-APAH.

Psychiatric Aspects of Lung Disease in Critical Care

Respiratory conditions are some of the most common indications for admission to critical care units. Psychiatric disorders and symptoms are highly comorbid with lung disease. They can occur as a risk factor to lung disease, as a co-occurring condition, as a consequence of a pulmonary condition, or as a treatment side effect either from medications or assistive devices. Patients can experience a myriad of mood, anxiety, and cognitive disorder symptoms and conditions in critical care units. Intensivists and psychiatrists must be aware of the interplay between pulmonary and psychiatric symptoms as well as medication effects and interactions.

Future perspectives in pulmonary arterial hypertension

While there have been advances in the field of pulmonary arterial hypertension (PAH), disease management remains suboptimal for many patients. The development of novel treatments and strategies can provide opportunities to target other mechanisms that play a role in the complex pathobiology of PAH outside of the three main pathophysiological pathways. In this review, we highlight some of the potential PAH therapies or techniques that are being, or have been, investigated in phase II clinical trials. This review also discusses potential points for consideration in the development of novel therapies that target putative disease mediators or modifiers.

Novel therapies and well-designed trials are important for improving the management of PAH patientshttp://ow.ly/YHPY304XdvH

DNA Damage and Pulmonary Hypertension

Pulmonary hypertension (PH) is defined by a mean pulmonary arterial pressure over 25 mmHg at rest and is diagnosed by right heart catheterization. Among the different groups of PH, pulmonary arterial hypertension (PAH) is characterized by a progressive obstruction of distal pulmonary arteries, related to endothelial cell dysfunction and vascular cell proliferation, which leads to an increased pulmonary vascular resistance, right ventricular hypertrophy, and right heart failure. Although the primary trigger of PAH remains unknown, oxidative stress and inflammation have been shown to play a key role in the development and progression of vascular remodeling. These factors are known to increase DNA damage that might favor the emergence of the proliferative and apoptosis-resistant phenotype observed in PAH vascular cells. High levels of DNA damage were reported to occur in PAH lungs and remodeled arteries as well as in animal models of PH. Moreover, recent studies have demonstrated that impaired DNA-response mechanisms may lead to an increased mutagen sensitivity in PAH patients. Finally, PAH was linked with decreased breast cancer 1 protein (BRCA1) and DNA topoisomerase 2-binding protein 1 (TopBP1) expression, both involved in maintaining genome integrity. This review aims to provide an overview of recent evidence of DNA damage and DNA repair deficiency and their implication in PAH pathogenesis.

Depression in pulmonary arterial hypertension: An undertreated comorbidity

Pulmonary arterial hypertension (PAH) is a debilitating condition leading to progressive decline in functional capacity. As a result, PAH can lead to psychological impairment that can impact the overall disease status. The medical community has developed several screening questionnaires in order to assess depression in their patients allowing physicians to be at the forefront of recognizing clinical depression. There is a suggestion that depression symptomatology is more prevalent in the PAH population. The aim of this article is to review the current thought process about diagnosis and management of depression in PAH patients.

Novel Targets of Drug Treatment for Pulmonary Hypertension

Biomedical advances over the last decade have identified the central role of proliferative pulmonary arterial smooth muscle cells (PASMCs) in the development of pulmonary hypertension (PH). Furthermore, promoters of proliferation and apoptosis resistance in PASMCs and endothelial cells, such as aberrant signal pathways involving growth factors, G protein-coupled receptors, kinases, and microRNAs, have also been described. As a result of these discoveries, PH is currently divided into subgroups based on the underlying pathology, which allows focused and targeted treatment of the condition. The defining features of PH, which subsequently lead to vascular wall remodeling, are dysregulated proliferation of PASMCs, local inflammation, and apoptosis-resistant endothelial cells. Efforts to assess the relative contributions of these factors have generated several promising targets. This review discusses recent novel targets of therapies for PH that have been developed as a result of these advances, which are now in pre-clinical and clinical trials (e.g., imatinib [phase III]; nilotinib, AT-877ER, rituximab, tacrolimus, paroxetine, sertraline, fluoxetine, bardoxolone methyl [phase II]; and sorafenib, FK506, aviptadil, endothelial progenitor cells (EPCs) [phase I]). While substantial progress has been made in recent years in targeting key molecular pathways, PH still remains without a cure, and these novel therapies provide an important conceptual framework of categorizing patients on the basis of molecular phenotype(s) for effective treatment of the disease.

The use of antidepressants and the risk of idiopathic pulmonary arterial hypertension

BACKGROUND

Serotonin has been implicated in the development of idiopathic pulmonary arterial hypertension (IPAH). Drugs modulating serotonin pathways, including antidepressants, have been associated with the incidence of IPAH, with conflicting reports as to the direction of the effect. We aimed to determine whether antidepressant exposure is associated with the incidence of IPAH.

METHODS

A nested case-control study was conducted using the United Kingdom Clinical Practice Research Datalink and the Hospital Episodes Statistics repository between January 1, 1988 and September 30, 2011. Incident cases of IPAH were identified and matched to all controls in the case's risk set on age, sex, general practice, and date of registration with the practice. Rate ratios (RRs) and 95% confidence intervals (CIs) were estimated for the use of antidepressants on the risk of IPAH, with an 18-month lag period before the diagnosis.

RESULTS

One hundred ninety-five IPAH cases were identified (incidence 3.84/million per year). Use of any antidepressant was associated with a 67% increased risk of IPAH (RR, 1.67; 95% CI, 1.17-2.37). The rate of IPAH was similar across antidepressant classes, whether with selective serotonin reuptake inhibitors (SSRIs) (RR, 1.67; 95% CI, 1.09-2.57) or non-SSRI antidepressants (RR, 1.66; 95% CI, 1.07-2.59). In sensitivity and exploratory analyses, no change in risk was observed with different lag times, serotonin transporter affinities, or durations of exposure.

CONCLUSIONS

The use of antidepressants was associated with a significantly increased risk of IPAH. However, the consistency of this risk across all antidepressants and absence of a dose-response relationship suggests a noncausal association.

Depression in pulmonary arterial hypertension and interstitial lung diseases

Advanced lung diseases such as pulmonary arterial hypertension (PAH) and interstitial lung diseases (ILD) are chronic diseases that cause significantly high morbidity and mortality. As a result, patients can undergo some psychological changes leading to a poor quality of life and depression. Diagnosis of depression is often obscured because fatigue and apathy, two common symptoms of depression, frequently overlap with PAH and ILD. Healthcare providers are sometimes reluctant to ask or mistakenly believe that these symptoms are part of the ongoing disease process, rather than a serious condition like depression. Screening tools are available for physicians to be well positioned in recognizing clinical depression in PAH and ILD. A MedLine/PubMED search was performed identifying all relevant articles with “PAH”, “ILD”, “screening tools” and/or “Depression” in the title. The aim of this review is to provide a brief description of some of the instruments used to screen patients and classes of psychotropic medications accessible to physicians. While pulmonary rehabilitation programs can have a positive impact on patients, physicians should also utilize cognitive behavioral therapy (CBT) as part of regular care.