Real-World Management of Patients with Pulmonary Arterial Hypertension: Insights from EXPOSURE.

INTRODUCTION: Further insights into real-world management and outcomes of patients with pulmonary arterial hypertension (PAH) are needed. This interim analysis of the ongoing, multicentre, prospective EXPOSURE (EUPAS19085) observational study describes characteristics, treatment patterns and outcomes of patients with PAH initiating a new PAH-specific therapy in Europe/Canada. METHODS AND RESULTS: All analyses were descriptive. In total, 1944 patients with follow-up information were included; the majority were female, with World Health Organization functional class II/III symptoms and with idiopathic PAH or connective tissue disease-associated PAH. Most incident patients (N = 1100; diagnosed for ≤ 6 months) initiated treatment as monotherapy (48%) or double therapy (43%). Of those initiating monotherapy, 38% (199/530) escalated to double therapy (median [Q1, Q3] time to escalation 3.4 [1.9, 6.6] months), and of those initiating double therapy, 17% (78/457) escalated to triple therapy (median [Q1, Q3] time to escalation 7.0 [3.4, 12.7] months) during the observation period (median [Q1, Q3]: 17.0 [7.5, 29.9] months). The majority of the 834 prevalent patients (diagnosed > 6 months) entered the study on initiation of combination therapy and most did not change treatment regimen during the observation period (median [Q1, Q3]: 19.6 [10.2, 32.2] months). One-year survival was 88% for incident patients and 90% for prevalent patients. CONCLUSIONS: Results from EXPOSURE suggest a shift towards combination therapy and the alignment of real-world treatment patterns with current guideline recommendations. While survival estimates are encouraging, the extent of monotherapy use at treatment initiation and follow-up highlight an opportunity for further improvements through optimisation of treatment strategies in line with current guidelines. A graphical abstract is also available with this article. TRIAL REGISTRATION NUMBER: EUPAS19085.

Pulmonary arterial hypertension (PAH) is a progressive disease. Clinical guidelines recommend that most patients start treatment with a combination of different PAH medications. While there is no cure for PAH, these medications help to control symptoms and slow disease worsening. To understand treatments currently used in clinical practice, we analysed data from EXPOSURE (EUPAS19085), an ongoing study collecting information from patients starting a new PAH medication in Europe and Canada. Most patients in the study were female, with World Health Organization functional class II/III symptoms, and idiopathic (unknown cause) PAH or PAH associated with connective tissue disorders. Among 1100 patients who were 'recently diagnosed' (diagnosed with PAH in the past 6 months), 88% were alive after 1 year. We found that 48% started treatment with one PAH medication, and 38% of those patients had a second medication prescribed within a median period of 3 months. Among the 457 'recently diagnosed' patients treated with two PAH medications when they entered the study, 17% had a third medication prescribed within a median period of 7 months. Among 834 patients with 'established PAH' (diagnosed more than 6 months ago), 90% were alive after 1 year. Most entered the study when they started a third medication and did not have further changes in treatment. Our findings show that patients with PAH are often treated with one medication in clinical practice as well as a combination of medications. While survival rates are encouraging, the extent to which one PAH medication is used suggests there is room for treatment improvement.

Four-Strata Risk Assessment in Patients with Pulmonary Arterial Hypertension Treated with Selexipag in Real-World Settings (EXPOSURE Study).

INTRODUCTION: Risk assessment can aid management of pulmonary arterial hypertension (PAH) and clinical decision-making. This analysis describes characteristics, treatment patterns and outcomes of patients with PAH, categorised by risk status at time of treatment escalation with selexipag in clinical settings. METHODS: Patients initiating selexipag in the ongoing multicentre, prospective EXPOSURE (EUPAS19085) study were grouped as low, intermediate-low, intermediate-high or high risk of 1-year mortality according to the ESC/ERS 4-strata method. RESULTS: As of November 2022, 77% (535/698) of patients initiating selexipag had data allowing for risk calculation; 14% (N = 76) were low, 31% (N = 168) intermediate-low, 34% (N = 182) intermediate-high and 20% (N = 109) high risk of 1-year mortality. Overall, patients were predominantly female (71%), with idiopathic/heritable PAH (56%) or PAH associated with connective tissue disease (CTD-PAH; 27%), median age of 60 years and prevalent (2 years) disease. From low to high risk, proportion of CTD-PAH and age increased (from 12%-40% and 46-68 years, respectively); time from diagnosis decreased and presence of cardiovascular risk factors increased. Most patients across risk groups (74-81%) initiated selexipag as part of triple oral combination therapy. Overall median (Q1, Q3) selexipag exposure duration was 10.1 (3.5, 24.1) months. Proportions of hospitalised patients increased with increasing risk group (16-42% from low to high, respectively); more hospitalisations were PAH-related for the high risk (71%) versus other risk groups (47-54%). Kaplan-Meier survival estimates were 98%, 98%, 93% and 80% at 1-year and 98%, 92%, 81% and 67% at 2-years, from low to high risk, respectively. CONCLUSIONS: In clinical settings, selexipag is initiated across all risk groups, predominantly as triple therapy. Only 45% of patients being at low/intermediate-low risk at selexipag initiation suggests an opportunity for more frequent patient monitoring and earlier treatment escalation, given that 4-strata risk assessment was prognostic for hospitalisations and survival in this contemporary PAH cohort. A graphical abstract is available with this article.

Pulmonary arterial hypertension (PAH) is a disease that gets worse over time. To make decisions about treatment, we need to know the stage of the disease. We can do this by measuring the patient's risk of death during the next few years. Selexipag is a medication for PAH. This analysis included patients living in Europe and Canada who started treatment with selexipag for their PAH disease. Our findings suggest that the monitoring of patients' health and the timing of starting selexipag can be improved. This analysis includes 698 patients taking part in the EXPOSURE study (EUPAS19085), which looks at the real-life treatment of patients with PAH. Overall, 71% of patients were female, the median age was 60 years, most had been diagnosed with PAH for around 2 years and were already taking two other medications for their PAH disease. At the beginning of selexipag treatment, 14% of patients were classified as low risk, 31% as intermediate-low risk, 34% as intermediate-high risk and 20% as high risk of mortality within the next year. More high-risk patients were hospitalised compared with the lower risk groups. After 1 year of treatment, more patients in the low (98%) and intermediate-low groups (98%) were alive than those in the intermediate-high (93%) and high risk groups (80%). The same was true after 2 years of treatment with selexipag (98%, 92%, 81% and 67%, respectively). This study confirms that assessing patients' risk levels can indicate how well they will do over time and shows that earlier treatment with selexipag should be considered to potentially prevent worsening of the disease.

Selexipag in patients with pulmonary arterial hypertension associated with connective tissue disease (PAH-CTD): Real-world experience from EXPOSURE.

Selexipag is indicated for the treatment of pulmonary arterial hypertension (PAH), including PAH associated with connective tissue disease (CTD), and further insights into the management of selexipag-treated PAH-CTD patients in clinical settings are needed. These analyses of the ongoing, multicenter, prospective EXPOSURE (EUPAS19085) study describe characteristics, treatment patterns, tolerability, and outcomes of PAH-CTD patients initiating selexipag in Europe/Canada. All analyses were descriptive, with idiopathic PAH patients who typically display better prognosis included for context. Six hundred ninety-eight selexipag-treated patients had follow-up information; 178 (26%) had PAH-CTD. The median age was 68 years, patients were predominantly female (88%), and with WHO functional class III symptoms (63%); the median time since diagnosis was 1.7 years. There were 5% patients at low, 25% intermediate-low, 40% intermediate-high, and 30% high risk of 1-year mortality, according to the ESC/ERS 4-strata risk score. Most (80%) initiated selexipag as a triple oral therapy, and most of these (62%) remained on triple therapy 6 months post-baseline. Over a median (Q1-Q3) selexipag exposure period of 8.6 (2.5-17.2) months, 79 (44%) patients discontinued selexipag; 36 (20%) due to tolerability/adverse events. Sixty (34%) patients were hospitalized at least once; 120 hospitalizations occurred, with 49 (48%) deemed PAH-related. Survival at 1 year was 85%, and at 2 years was 71%; 29 (16%) patients died. These results describe the use of combination therapy with selexipag for patients with PAH-CTD. These findings suggest an opportunity to optimize the benefits of selexipag among patients with PAH-CTD by moving from escalating after years in response to clinical deterioration to escalating sooner to prevent clinical deterioration.

Lateral mobility of nicotinic acetylcholine receptors on neurons is determined by receptor composition, local domain, and cell type.

The lateral mobility of surface receptors can define the signaling properties of a synapse and rapidly change synaptic function. Here we use single-particle tracking with Quantum Dots to follow nicotinic acetylcholine receptors (nAChRs) on the surface of chick ciliary ganglion neurons in culture. We find that both heteropentameric alpha3-containing receptors (alpha3*-nAChRs) and homopentameric alpha7-containing receptors (alpha7-nAChRs) access synaptic domains by lateral diffusion. They have comparable mobilities and display Brownian motion in extrasynaptic space but are constrained and move more slowly in synaptic space. The two receptor types differ in the nature of their synaptic restraints. Disruption of lipid rafts, PDZ-containing scaffolds, and actin filaments each increase the mobility of alpha7-nAChRs in synaptic space while collapse of microtubules has no effect. The opposite is seen for alpha3*-nAChRs where synaptic mobility is increased only by microtubule collapse and not the other manipulations. Other differences are found for regulation of alpha3*-nAChR and alpha7-nAChR mobilities in extrasynaptic space. Most striking are effects on the immobile populations of alpha7-nAChRs and alpha3*-nAChRs. Disruption of either lipid rafts or PDZ scaffolds renders half of the immobile alpha3*-nAChRs mobile without changing the proportion of immobile alpha7-nAChRs. Similar results were obtained with chick sympathetic ganglion neurons, though regulation of receptor mobility differed in at least one respect from that seen with ciliary ganglion neurons. Control of nAChR lateral mobility, therefore, is determined by mechanisms that are domain specific, receptor subtype dependent, and cell-type constrained. The outcome is a system that could tailor nicotinic signaling capabilities to specific needs of individual locations.

Endogenous signaling through alpha7-containing nicotinic receptors promotes maturation and integration of adult-born neurons in the hippocampus.

Neurogenesis in the dentate gyrus occurs throughout adult mammalian life and is essential for proper hippocampal function. Early in their development, adult-born neurons express homomeric alpha7-containing nicotinic acetylcholine receptors (alpha7-nAChRs) and receive direct cholinergic innervation. We show here that functional alpha7-nAChRs are necessary for normal survival, maturation, and integration of adult-born neurons in the dentate gyrus. Stereotaxic retroviral injection into the dentate gyrus of wild-type and alpha7-knock-out (alpha7KO) male and female mice was used to label and birthdate adult-born neurons for morphological and electrophysiological measures; BrdU (5-bromo-2-deoxyuridine) injections were used to quantify cell survival. In alpha7KO mice, we find that adult-born neurons develop with truncated, less complex dendritic arbors and display GABAergic postsynaptic currents with immature kinetics. The neurons also have a prolonged period of GABAergic depolarization characteristic of an immature state. In this condition, they receive fewer spontaneous synaptic currents and are more prone to die during the critical period when adult-born neurons are normally integrated into behaviorally relevant networks. Even those adult-born neurons that survive the critical period retain long-term dendritic abnormalities in alpha7KO mice. Interestingly, local infection with retroviral constructs to knockdown alpha7-mRNA mimics the alpha7KO phenotype, demonstrating that the relevant alpha7-nAChR signaling is cell autonomous. The results indicate a profound role for alpha7-nAChRs in adult neurogenesis and predict that alpha7-nAChR loss will cause progressive impairment in hippocampal circuitry and function over time as fewer neurons are added to the dentate gyrus and those that are added integrate less well.

Behavioral Inhibition in Childhood: European Portuguese Adaptation of an Observational Measure (Lab-TAB).

The assessment of behaviorally inhibited children is typically based on parent or teacher reports, but this approach has received criticisms, mainly for being prone to bias. Several researchers proposed the additional use of observational methods because they provide a direct and more objective description of the child's functioning in different contexts. The lack of a laboratory assessment of temperament for Portuguese children justifies the adaptation of some episodes of the Laboratory Temperament Assessment Battery (Lab-TAB) as an observational measure for behavioral inhibition. Method: In our study, we included 124 children aged between 3 and 9 years and their parents. The evaluation of child behavioral inhibition was made by parent report (Behavioral Inhibition Questionnaire) and through Lab-TAB episodes. Parental variables with potential influence on parents' reports were also collected using the Social Interaction and Performance Anxiety and Avoidance Scale (SIPAAS) and the Parental Overprotection Measure (POM). Results and Discussion: The psychometric analyses provided evidence that Lab-TAB is a reliable instrument and can be incorporated in a multi-method approach to assess behavioral inhibition in studies involving Portuguese-speaking children. Moderate convergence between observational and parent report measures of behavioral inhibition was obtained. Mothers' characteristics, as well as child age, seem to significantly affect differences between measures, being potential sources of bias in the assessment of child temperament.

Postsynaptic action of brain-derived neurotrophic factor attenuates alpha7 nicotinic acetylcholine receptor-mediated responses in hippocampal interneurons.

Nicotinic mechanisms acting on the hippocampus influence attention, learning, and memory and constitute a significant therapeutic target for many neurodegenerative, neurological, and psychiatric disorders. Here, we report that brain-derived neurotrophic factor (BDNF) (1-100 ng/ml), a member of the neurotrophin gene family, rapidly decreases alpha7 nicotinic acetylcholine receptor responses in interneurons of the hippocampal CA1 stratum radiatum. Such effect is dependent on the activation of the TrkB receptor and involves the actin cytoskeleton; noteworthy, it is compromised when the extracellular levels of the endogenous neuromodulator adenosine are reduced with adenosine deaminase (1 U/ml) or when adenosine A(2A) receptors are blocked with SCH 58261 (2-(2-furanyl)-7-(2-phenylethyl)-7H-pyrazolo[4,3-e][1,2,4]triazolo[1,5-c]pyrimidin-5-amine) (100 nm). The intracellular application of U73122 (1-[6[[(17beta)-3-methoxyestra-1,3,5(10)-trien-17-yl]amino]hexyl]-1H-pyrrole-2,5-dione) (5 mum), a broad-spectrum inhibitor of phospholipase C, or GF 109203X (bisindolylmaleimide I) (2 mum), a general inhibitor of protein kinase C isoforms, blocks BDNF-induced inhibition of alpha7 nicotinic acetylcholine receptor function. Moreover, in conditions of simultaneous intracellular dialysis of the fast Ca(2+) chelator BAPTA (10 mm) and removal of extracellular Ca(2+) ions, the inhibitory action of BDNF is further prevented. The present findings disclose a novel target for rapid actions of BDNF that might play important roles on synaptic transmission and plasticity in the brain.

Postsynaptic scaffolds for nicotinic receptors on neurons.

Complex postsynaptic scaffolds determine the structure and signaling capabilities of glutamatergic synapses. Recent studies indicate that some of the same scaffold components contribute to the formation and function of nicotinic synapses on neurons. PDZ-containing proteins comprising the PSD-95 family co-localize with nicotinic acetylcholine receptors (nAChRs) and mediate downstream signaling in the neurons. The PDZ-proteins also promote functional nicotinic innervation of the neurons, as does the scaffold protein APC and transmembrane proteins such as neuroligin and the EphB2 receptor. In addition, specific chaperones have been shown to facilitate nAChR assembly and transport to the cell surface. This review summarizes recent results in these areas and raises questions for the future about the mechanism and synaptic role of nAChR trafficking.

MicroRNA-101 Regulates Multiple Developmental Programs to Constrain Excitation in Adult Neural Networks.

A critical feature of neural networks is that they balance excitation and inhibition to prevent pathological dysfunction. How this is achieved is largely unknown, although deficits in the balance contribute to many neurological disorders. We show here that a microRNA (miR-101) is a key orchestrator of this essential feature, shaping the developing network to constrain excitation in the adult. Transient early blockade of miR-101 induces long-lasting hyper-excitability and persistent memory deficits. Using target site blockers in vivo, we identify multiple developmental programs regulated in parallel by miR-101 to achieve balanced networks. Repression of one target, NKCC1, initiates the switch in γ-aminobutyric acid (GABA) signaling, limits early spontaneous activity, and constrains dendritic growth. Kif1a and Ank2 are targeted to prevent excessive synapse formation. Simultaneous de-repression of these three targets completely phenocopies major dysfunctions produced by miR-101 blockade. Our results provide new mechanistic insight into brain development and suggest novel candidates for therapeutic intervention.

Nicotinic control of adult-born neuron fate.

The hippocampus is one of only two regions in the adult brain where neurons are generated in significant numbers throughout the lifetime of the animal. Numerous studies have demonstrated that these adult-born neurons are essential for optimal cognitive function with unimpaired memory formation and retrieval. The extent to which adult-born neurons survive through an early "critical period" and become integrated into functional networks has been shown to depend on the richness of stimulation they receive during these formative stages. The dentate gyrus in the hippocampus - home of the adult-born neurons - receives extensive cholinergic innervation, and newly generated neurons in the adult hippocampus express substantial numbers of both major types of neuronal nicotinic acetylcholine receptors. Early studies indicated that nicotinic signaling may be important for the development of adult-born neurons: repeated exposure to nicotine impaired their long-term survival. Recent studies with mutant mice lacking either one of the two major nicotinic receptor subtypes demonstrate that receptor loss results in fewer adult-born neurons surviving the critical period and becoming integrated into neural networks. The key nicotinic receptor mediating the largest effects is one that has a high relative permeability to calcium. In view of this feature, it may not be surprising that excessive exposure to nicotine can have detrimental effects on survival and maturation of adult-born neurons in the dentate; these same receptors appear to be key. The results pose serious challenges for therapeutic strategies targeting an individual class of nicotinic receptors for global treatment in the recipient.