Phase 3 Trial of Sotatercept for Treatment of Pulmonary Arterial Hypertension.

BACKGROUND: Pulmonary arterial hypertension is a progressive disease involving proliferative remodeling of the pulmonary vessels. Despite therapeutic advances, the disease-associated morbidity and mortality remain high. Sotatercept is a fusion protein that traps activins and growth differentiation factors involved in pulmonary arterial hypertension. METHODS: We conducted a multicenter, double-blind, phase 3 trial in which adults with pulmonary arterial hypertension (World Health Organization [WHO] functional class II or III) who were receiving stable background therapy were randomly assigned in a 1:1 ratio to receive subcutaneous sotatercept (starting dose, 0.3 mg per kilogram of body weight; target dose, 0.7 mg per kilogram) or placebo every 3 weeks. The primary end point was the change from baseline at week 24 in the 6-minute walk distance. Nine secondary end points, tested hierarchically in the following order, were multicomponent improvement, change in pulmonary vascular resistance, change in N-terminal pro-B-type natriuretic peptide level, improvement in WHO functional class, time to death or clinical worsening, French risk score, and changes in the Pulmonary Arterial Hypertension-Symptoms and Impact (PAH-SYMPACT) Physical Impacts, Cardiopulmonary Symptoms, and Cognitive/Emotional Impacts domain scores; all were assessed at week 24 except time to death or clinical worsening, which was assessed when the last patient completed the week 24 visit. RESULTS: A total of 163 patients were assigned to receive sotatercept and 160 to receive placebo. The median change from baseline at week 24 in the 6-minute walk distance was 34.4 m (95% confidence interval [CI], 33.0 to 35.5) in the sotatercept group and 1.0 m (95% CI, -0.3 to 3.5) in the placebo group. The Hodges-Lehmann estimate of the difference between the sotatercept and placebo groups in the change from baseline at week 24 in the 6-minute walk distance was 40.8 m (95% CI, 27.5 to 54.1; P<0.001). The first eight secondary end points were significantly improved with sotatercept as compared with placebo, whereas the PAH-SYMPACT Cognitive/Emotional Impacts domain score was not. Adverse events that occurred more frequently with sotatercept than with placebo included epistaxis, dizziness, telangiectasia, increased hemoglobin levels, thrombocytopenia, and increased blood pressure. CONCLUSIONS: In patients with pulmonary arterial hypertension who were receiving stable background therapy, sotatercept resulted in a greater improvement in exercise capacity (as assessed by the 6-minute walk test) than placebo. (Funded by Acceleron Pharma, a subsidiary of MSD; STELLAR ClinicalTrials.gov number, NCT04576988.).

Sotatercept for the Treatment of Pulmonary Arterial Hypertension.

BACKGROUND: Pulmonary arterial hypertension is characterized by pulmonary vascular remodeling, cellular proliferation, and poor long-term outcomes. Dysfunctional bone morphogenetic protein pathway signaling is associated with both hereditary and idiopathic subtypes. Sotatercept, a novel fusion protein, binds activins and growth differentiation factors in the attempt to restore balance between growth-promoting and growth-inhibiting signaling pathways. METHODS: In this 24-week multicenter trial, we randomly assigned 106 adults who were receiving background therapy for pulmonary arterial hypertension to receive subcutaneous sotatercept at a dose of 0.3 mg per kilogram of body weight every 3 weeks or 0.7 mg per kilogram every 3 weeks or placebo. The primary end point was the change from baseline to week 24 in pulmonary vascular resistance. RESULTS: Baseline characteristics were similar among the three groups. The least-squares mean difference between the sotatercept 0.3-mg group and the placebo group in the change from baseline to week 24 in pulmonary vascular resistance was -145.8 dyn · sec · cm-5 (95% confidence interval [CI], -241.0 to -50.6; P = 0.003). The least-squares mean difference between the sotatercept 0.7-mg group and the placebo group was -239.5 dyn · sec · cm-5 (95% CI, -329.3 to -149.7; P<0.001). At 24 weeks, the least-squares mean difference between the sotatercept 0.3-mg group and the placebo group in the change from baseline in 6-minute walk distance was 29.4 m (95% CI, 3.8 to 55.0). The least-squares mean difference between the sotatercept 0.7-mg group and the placebo group was 21.4 m (95% CI, -2.8 to 45.7). Sotatercept was also associated with a decrease in N-terminal pro-B-type natriuretic peptide levels. Thrombocytopenia and an increased hemoglobin level were the most common hematologic adverse events. One patient in the sotatercept 0.7-mg group died from cardiac arrest. CONCLUSIONS: Treatment with sotatercept resulted in a reduction in pulmonary vascular resistance in patients receiving background therapy for pulmonary arterial hypertension. (Funded by Acceleron Pharma; PULSAR ClinicalTrials.gov number, NCT03496207.).

The evolving landscape of pulmonary arterial hypertension clinical trials.

Although it is a rare disease, the number of available therapeutic options for treating pulmonary arterial hypertension has increased since the late 1990s, with multiple drugs developed that are shown to be effective in phase 3 randomised controlled trials. Despite considerable advancements in pulmonary arterial hypertension treatment, prognosis remains poor. Existing therapies target pulmonary endothelial dysfunction with vasodilation and anti-proliferative effects. Novel therapies that target proliferative vascular remodelling and affect important outcomes are urgently needed. There is need for additional innovations in clinical trial design so that all emerging candidate therapies can be rigorously studied. Pulmonary arterial hypertension trial design has shifted from short-term submaximal exercise capacity as a primary endpoint, to larger clinical event-driven trial outcomes. Event-driven pulmonary arterial hypertension trials could face feasibility and efficiency issues in the future because increasing sample sizes and longer follow-up durations are needed, which would be problematic in such a rare disease. Enrichment strategies, innovative and alternative trial designs, and novel trial endpoints are potential solutions that could improve the efficiency of future pulmonary arterial hypertension trials while maintaining robustness and clinically meaningful evidence.

Sotatercept for the treatment of pulmonary arterial hypertension: PULSAR open-label extension.

BACKGROUND: In participants with pulmonary arterial hypertension, 24 weeks of sotatercept resulted in a significantly greater reduction from baseline in pulmonary vascular resistance than placebo. This report characterises the longer-term safety and efficacy of sotatercept in the PULSAR open-label extension. We report cumulative safety, and efficacy at months 18-24, for all participants treated with sotatercept. METHODS: PULSAR was a phase 2, randomised, double-blind, placebo-controlled study followed by an open-label extension, which evaluated sotatercept on top of background pulmonary arterial hypertension therapy in adults. Participants originally randomised to placebo were re-randomised 1:1 to sotatercept 0.3 or 0.7 mg·kg-1 (placebo-crossed group); those initially randomised to sotatercept continued the same sotatercept dose (continued-sotatercept group). Safety was evaluated in all participants who received ≥1 dose of sotatercept. The primary efficacy endpoint was change from baseline to months 18-24 in pulmonary vascular resistance. Secondary endpoints included 6-min walk distance and functional class. Two prespecified analyses, placebo-crossed and delayed-start, evaluated efficacy irrespective of dose. RESULTS: Of 106 participants enrolled in the PULSAR study, 97 continued into the extension period. Serious treatment-emergent adverse events were reported in 32 (30.8%) participants; 10 (9.6%) reported treatment-emergent adverse events leading to study discontinuation. Three (2.9%) participants died, none considered related to study drug. The placebo-crossed group demonstrated significant improvement across primary and secondary endpoints and clinical efficacy was maintained in the continued-sotatercept group. CONCLUSION: These results support the longer-term safety and durability of clinical benefit of sotatercept for pulmonary arterial hypertension.

Effects of sotatercept on haemodynamics and right heart function: analysis of the STELLAR trial.

BACKGROUND: In the phase 3 STELLAR trial, sotatercept, an investigational first-in-class activin signalling inhibitor, demonstrated beneficial effects on 6-min walk distance and additional efficacy endpoints in pre-treated participants with pulmonary arterial hypertension (PAH). METHODS: This post hoc analysis evaluated data from right heart catheterisation (RHC) and echocardiography (ECHO) obtained from the STELLAR trial. Changes from baseline in RHC and ECHO parameters were assessed at 24 weeks. An analysis of covariance (ANCOVA) model was used to estimate differences in least squares means with treatment and randomisation stratification (mono/double versus triple therapy; World Health Organization functional class II versus III) as fixed factors, and baseline value as covariate. RESULTS: Relative to placebo, treatment with sotatercept led to significant (all p<0.0001 except where noted) improvements from baseline in mean pulmonary artery (PA) pressure (-13.9 mmHg), pulmonary vascular resistance (-254.8 dyn·s·cm-5), mean right atrial pressure (-2.7 mmHg), mixed venous oxygen saturation (3.84%), PA elastance (-0.42 mmHg·mL-1·beat-1), PA compliance (0.58 mL·mmHg-1), cardiac efficiency (0.48 mL·beat-1·mmHg-1), right ventricular (RV) work (-0.85 g·m) and RV power (-32.70 mmHg·L·min-1). ECHO showed improvements in tricuspid annular plane systolic excursion (TAPSE) to systolic pulmonary artery pressure ratio (0.12 mm·mmHg-1), end-systolic and end-diastolic RV areas (-4.39 cm2 and -5.31 cm2, respectively), tricuspid regurgitation and RV fractional area change (2.04% p<0.050). No significant between-group changes from baseline were seen for TAPSE, heart rate, cardiac output, stroke volume or their indices. CONCLUSION: In pre-treated patients with PAH, sotatercept demonstrated substantial improvements in PA pressures, PA compliance, PA-RV coupling and right heart function.

Aggressive Afterload Lowering to Improve the Right Ventricle: A New Target for Medical Therapy in Pulmonary Arterial Hypertension?

Despite numerous therapeutic advances in pulmonary arterial hypertension, patients continue to suffer high morbidity and mortality, particularly considering a median age of 50 years. This article explores whether early, robust reduction of right ventricular afterload would facilitate substantial improvement in right ventricular function and thus whether afterload reduction should be a treatment goal for pulmonary arterial hypertension. The earliest clinical studies of prostanoid treatment in pulmonary arterial hypertension demonstrated an important link between lowering mean pulmonary arterial pressure (or pulmonary vascular resistance) and improved survival. Subsequent studies of oral monotherapy or sequential combination therapy demonstrated smaller reductions in mean pulmonary arterial pressure and pulmonary vascular resistance. More recently, retrospective reports of initial aggressive prostanoid treatment or initial combination oral and parenteral therapy have shown marked afterload reduction along with significant improvements in right ventricular function. Some data suggest that reaching threshold levels for pressure or resistance (components of right ventricular afterload) may be key to interrupting the self-perpetuating injury of pulmonary vascular disease in pulmonary arterial hypertension and could translate into improved long-term clinical outcomes. Based on these clues, the authors postulate that improved clinical outcomes might be achieved by targeting significant afterload reduction with initial oral combination therapy and early parenteral prostanoids.

Two polymorphic gene loci associated with treprostinil dose in pulmonary arterial hypertension.

OBJECTIVE: Prostacyclin infusion for pulmonary arterial hypertension (PAH) is an effective therapy with varied dosing requirements and clinical response. The major aim of this study was to determine new biologically-based predictors of prostacyclin treatment response heterogeneity. METHODS: Ninety-eight patients with hemodynamically defined PAH at two academic medical centers volunteered for registry studies. A stable dose of treprostinil was the quantitative phenotype for the genome-wide association study (GWAS). Candidate genes with the largest effect sizes and strongest statistical associations were further characterized with in silico and in-vitro assays to confirm mechanistic hypotheses. The clinical significance of these candidate predictors was assessed for mechanistically consistent physiologic effects in an independent cohort of patients. RESULTS: GWAS identified three loci for association with P < 10-6. All three loci had clinically significant effect sizes. Specific single-nucleotide polymorphisms (SNPs) at two of the loci: rs11078738 in phosphoribosylformylglycinamidine synthase and rs10023113 in CAMK2D encoded sequence changes with clear predicted consequences. Production of the primary mediator of prostacyclin-induced vasodilation, cyclic AMP, was reduced in human cell lines by the missense variant rs11078738 (p.L621P). Located in the promoter of CAMK2D, the allele of rs10023113 associated with a higher treprostinil dose has higher ventricular transcription of CAMK2δ. At initial diagnostic catheterization in a separate cohort of patients, the same allele of rs10023113 was associated with elevated right mean atrial and ventricular diastolic pressures. CONCLUSIONS: The quantitative phenotype of stable treprostinil dose identified two gene loci associated with pharmacodynamic response and right ventricular function in PAH worth further investigation.

Systemic Consequences of Pulmonary Hypertension and Right-Sided Heart Failure.

Pulmonary hypertension (PH) is a feature of a variety of diseases and continues to harbor high morbidity and mortality. The main consequence of PH is right-sided heart failure which causes a complex clinical syndrome affecting multiple organ systems including left heart, brain, kidneys, liver, gastrointestinal tract, skeletal muscle, as well as the endocrine, immune, and autonomic systems. Interorgan crosstalk and interdependent mechanisms include hemodynamic consequences such as reduced organ perfusion and congestion as well as maladaptive neurohormonal activation, oxidative stress, hormonal imbalance, and abnormal immune cell signaling. These mechanisms, which may occur in acute, chronic, or acute-on-chronic settings, are common and precipitate adverse functional and structural changes in multiple organs which contribute to increased morbidity and mortality. While the systemic character of PH and right-sided heart failure is often neglected or underestimated, such consequences place additional burden on patients and may represent treatable traits in addition to targeted therapy of PH and underlying causes. Here, we highlight the current state-of-the-art understanding of the systemic consequences of PH and right-sided heart failure on multiple organ systems, focusing on self-perpetuating pathophysiological mechanisms, aspects of increased susceptibility of organ damage, and their reciprocal impact on the course of the disease.

Risk stratification in pulmonary arterial hypertension using Bayesian analysis.

BACKGROUND: Current risk stratification tools in pulmonary arterial hypertension (PAH) are limited in their discriminatory abilities, partly due to the assumption that prognostic clinical variables have an independent and linear relationship to clinical outcomes. We sought to demonstrate the utility of Bayesian network-based machine learning in enhancing the predictive ability of an existing state-of-the-art risk stratification tool, REVEAL 2.0. METHODS: We derived a tree-augmented naïve Bayes model (titled PHORA) to predict 1-year survival in PAH patients included in the REVEAL registry, using the same variables and cut-points found in REVEAL 2.0. PHORA models were validated internally (within the REVEAL registry) and externally (in the COMPERA and PHSANZ registries). Patients were classified as low-, intermediate- and high-risk (<5%, 5-20% and >10% 12-month mortality, respectively) based on the 2015 European Society of Cardiology/European Respiratory Society guidelines. RESULTS: PHORA had an area under the curve (AUC) of 0.80 for predicting 1-year survival, which was an improvement over REVEAL 2.0 (AUC 0.76). When validated in the COMPERA and PHSANZ registries, PHORA demonstrated an AUC of 0.74 and 0.80, respectively. 1-year survival rates predicted by PHORA were greater for patients with lower risk scores and poorer for those with higher risk scores (p<0.001), with excellent separation between low-, intermediate- and high-risk groups in all three registries. CONCLUSION: Our Bayesian network-derived risk prediction model, PHORA, demonstrated an improvement in discrimination over existing models. This is reflective of the ability of Bayesian network-based models to account for the interrelationships between clinical variables on outcome, and tolerance to missing data elements when calculating predictions.

Clinical trial design and new therapies for pulmonary arterial hypertension.

Until 20 years ago the treatment of pulmonary arterial hypertension (PAH) was based on case reports and small series, and was largely ineffectual. As a deeper understanding of the pathogenesis and pathophysiology of PAH evolved over the subsequent two decades, coupled with epidemiological studies defining the clinical and demographic characteristics of the condition, a renewed interest in treatment development emerged through collaborations between international experts, industry and regulatory agencies. These efforts led to the performance of robust, high-quality clinical trials of novel therapies that targeted putative pathogenic pathways, leading to the approval of more than 10 novel therapies that have beneficially impacted both the quality and duration of life. However, our understanding of PAH remains incomplete and there is no cure. Accordingly, efforts are now focused on identifying novel pathogenic pathways that may be targeted, and applying more rigorous clinical trial designs to better define the efficacy of these new potential treatments and their role in the management scheme. This article, prepared by a Task Force comprised of expert clinicians, trialists and regulators, summarises the current state of the art, and provides insight into the opportunities and challenges for identifying and assessing the efficacy and safety of new treatments for this challenging condition.

Utility of B-type natriuretic peptides in the assessment of patients with systemic sclerosis-associated pulmonary hypertension in the PHAROS registry.

OBJECTIVES: To assess the utility of B-type natriuretic peptide (BNP) and N-terminal pro-BNP (NT-proBNP) in detecting and monitoring pulmonary hypertension (PH) in systemic sclerosis (SSc). METHODS: PHAROS is a multicenter prospective cohort of SSc patients at high risk for developing pulmonary arterial hypertension (SSc-AR-PAH) or with a definitive diagnosis of SSc-PH. We evaluated 1) the sensitivity and specificity of BNP≥64 and NT-proBNP≥210 pg/mL for the detection of SSc-PAH and/ or SSc-PH in the SSc-AR-PAH population; 2) baseline and longitudinal BNP and NT-proBNP levels as predictors of progression to SSc-PAH and/or SSc-PH; 3) baseline BNP≥180, NT-proBNP≥553 pg/mL, and longitudinal changes in BNP and NT-proBNP as predictors of mortality in SSc-PH diagnosed patients. RESULTS: 172 SSc-PH and 157 SSc-AR- PAH patients had natriuretic peptide levels available. Median BNP and NT-proBNP were significantly higher in the SSc-PH versus SSc-AR-PAH group. The sensitivity and specificity for SSc-PAH detection using baseline BNP≥64 pg/mL was 71% and 59%; and for NT-proBNP≥210 pg/mL, 73% and 78%. NT-proBNP showed stronger correlations with haemodynamic indicators of right ventricular dysfunction than BNP. Baseline creatinine, RVSP > 40 mmHg, and FVC%:DLco% ratio ≥1.8 were associated with progression from SSc-AR-PAH to SSc-PH but no association with individual or combined baseline BNP and NT-proBNP levels was observed. Baseline and follow-up BNP or NT-proBNP levels were not predictive of death, however, a composite BNP/NT-proBNP group predicted mortality (HR 3.81 (2.08-6.99), p<.0001). CONCLUSIONS: NT-proBNP may be more useful than BNP in the detection and monitoring of PAH in SSc patients, but additional studies are necessary.

Cardiac MRI right ventricle / left ventricle (RV/LV) volume ratio improves detection of RV enlargement.

PURPOSE: To determine the normal range of the ratio of right ventricular (RV) end-diastolic volume to left ventricular (LV) end-diastolic volume by magnetic resonance imaging (MRI) and examine whether combining this volume ratio with RVEDV indexed to body surface area (RVEDVi) increased the detection of RV dilation in patients with pulmonary arterial hypertension (PAH). MATERIALS AND METHODS: MRI-derived ventricular function and volumes were measured in a control group (n = 152) and in patients with PAH (n = 46). Images were acquired with a 1.5T Siemens or a 1.5T Philips scanner using a steady-state free procession sequence. Proposed criteria for the detection of RV enlargement, including RVEDVi alone, RV/LV volume ratio alone, and combining both criteria, were evaluated in both groups. RESULTS: The range (mean ± 2 standard deviations) for the volume ratio in the normal population was found to be 0.906-1.266; there was no difference between genders (P = 0.70). Combining this ratio with RVEDVi detected RV enlargement in 21.7% (P < 0.001) PAH patients (volume ratio ≥1.27) who were not identified by the RVEDVi alone (>104 mL/m(2) for females and >113 mL/m(2) for males). CONCLUSION: Combining RV/LV volume ratio with indexed RVEDV increased detection of RV enlargement in a PAH population. This result may have potential impact in RV size assessment. J. Magn. Reson. Imaging 2016;43:1379-1385.

Endothelin-1 Pathway Polymorphisms and Outcomes in Pulmonary Arterial Hypertension.

RATIONALE: Pulmonary arterial hypertension (PAH) is a progressive fatal disease. Variable response and tolerability to PAH therapeutics suggests that genetic differences may influence outcomes. The endothelin pathway is central to pulmonary vascular function, and several polymorphisms and/or mutations in the genes coding for endothelin (ET)-1 and its receptors correlate with the clinical manifestations of other diseases. OBJECTIVES: To examine the interaction of ET-1 pathway polymorphisms and treatment responses of patients with PAH treated with ET receptor antagonists (ERAs). METHODS: A total of 1,198 patients with PAH were prospectively enrolled from 45 U.S. and Canadian pulmonary hypertension centers or retrospectively from global sites participating in the STRIDE (Sitaxsentan To Relieve Impaired Exercise) trials. Comprehensive objective measures including a 6-minute-walk test, Borg dyspnea score, functional class, and laboratory studies were completed at baseline, before the initiation of ERAs, and repeated serially. Single-nucleotide polymorphisms from ET-1 pathway candidate genes were selected from a completed genome-wide association study performed on the study cohort. MEASUREMENTS AND MAIN RESULTS: Patient efficacy outcomes were analyzed for a relationship between ET-1 pathway polymorphisms and clinical efficacy using predefined, composite positive and negative outcome measures in 715 European descent samples. A single-nucleotide polymorphism (rs11157866) in the G-protein alpha and gamma subunits gene was significantly associated, accounting for multiple testing, with a combined improvement in functional class and 6-minute-walk distance at 12 and 18 months and marginally significant at 24 months. CONCLUSIONS: ET-1 pathway associated polymorphisms may influence the clinical efficacy of ERA therapy for PAH. Further prospective studies are needed.

Echocardiographic Diagnosis of Acute Pulmonary Embolism in Patients with McConnell's Sign.

BACKGROUND: "McConnell's sign" (McCS), described as hypo- or akinesis of the right ventricular (RV) free wall with preservation of the apex, is associated with acute pulmonary embolism (aPE). However, the sensitivity of McCS for the detection of aPE is limited. We sought to evaluate in patients with McCS, whether echocardiographic parameters of global and regional RV function could differentiate between patients with and without aPE. METHODS: We reviewed echocardiograms of 81 patients with McCS, who underwent CT or V/Q studies for suspected PE, and 40 normal controls (NL). Echocardiograms were analyzed to measure pulmonary artery systolic pressure (PASP), tricuspid regurgitation (TR) by vena contracta width, conventional indices of RV function, and speckle tracking-derived longitudinal free wall strain. ROC analysis was performed to evaluate the diagnostic accuracy of these parameters for diagnosis of aPE. RESULTS: Fifty-five of eighty-one (68%) had PE (McCS + PE), while 26 of 81 (32%) did not (McCS - PE). Compared to NL, global and segmental RV strain were lower in patients with McCS, contrary to the notion of normal apical function. In McCS + PE, compared to McCS - PE: (1) PASP, fractional area change and TR were significantly lower; (2) strain magnitude was significantly lower globally and in basal and apical segments. Individual parameters had similar diagnostic accuracy by ROC analysis, which further improved by combining parameters. In McCS - PE, 69% of patients had pulmonary hypertension (PH). CONCLUSIONS: McCS and aPE are not synonymous. RV free wall strain may aid in differential diagnosis of patients with McCS evaluated for aPE. Specifically, McCS should prompt an inquiry for evidence of PH, which would indicate that aPE is less likely.

Management of pulmonary hypertension and right heart failure in the intensive care unit.

Management of acute right ventricular failure, both with and without coexisting pulmonary hypertension, is a common challenge encountered in the intensive care setting. Both right ventricular dysfunction and pulmonary hypertension portend a poor prognosis, regardless of the underlying cause and are associated with significant morbidity and mortality. The right ventricle is embryologically distinct from the left ventricle and has unique morphologic and functional properties. Management of right ventricular failure and pulmonary hypertension in the intensive care setting requires tailored hemodynamic management, pharmacotherapy, and often mechanical circulatory support. Unfortunately, our understanding of the management of right ventricular failure lags behind that of the left ventricle. In this review, we will explore the underlying pathophysiology of the failing right ventricle and pulmonary vasculature in patients with and without pulmonary hypertension and discuss management strategies based on evidence-based studies as well as our current understanding of the underlying physiology.

Right ventricular strain in pulmonary arterial hypertension: a 2D echocardiography and cardiac magnetic resonance study.

BACKGROUND: Right ventricular (RV) strain is a potentially useful prognostic marker in patients with pulmonary arterial hypertension (PAH). However, published reports regarding the accuracy of two-dimensional echocardiography (2DE)-derived RV strain against an independent reference in this patient population are limited. The aims of this study were: (1) to study the relationship between 2DE RV longitudinal strain and cardiovascular magnetic resonance (CMR)-derived RV ejection fraction (RVEF) in patients with PAH; (2) to compare 2DE-derived and CMR-derived RV longitudinal strain in these patients; and (3) to determine the reproducibility of these measurements. METHODS: Thirty patients with PAH underwent 2DE and CMR imaging within a 2-hour time period. 2DE RV longitudinal strain was measured from a focused RV apical four-chamber view using speckle tracking software. CMR RV longitudinal strain was measured from short-axis slices acquired using fast-strain-encoded sequence. Global peak systolic RV longitudinal strain was calculated for both 2DE and CMR. RESULTS: RV longitudinal strain using 2DE software correlated well with CMR-derived RVEF (R = 0.69, P = 0.0006). There was moderate agreement when comparing 2DE to CMR RV longitudinal strain (R = 0.74, P = 0.0002; bias -1%, limits of agreement -9 to 7%). Inter-observer variability and intra-observer variability for RV longitudinal strain were lower for 2DE than CMR. CONCLUSIONS: RV longitudinal strain by 2DE provides a good alternative for CMR-derived RVEF in patients with PAH. The moderate agreement in strain measurements between 2DE and CMR suggests that further software improvements are needed before these measurements can be used interchangeably in clinical practice.

New pharmacotherapies for pulmonary hypertension: where do they fit in?

Pulmonary arterial hypertension (PAH) is a rare, progressively worsening disease characterized by dysfunction among endothelial and smooth muscle cells within the pulmonary vasculature with a resultant increase in pulmonary vascular resistance, right ventricular maladaptation and failure, and ultimately early death. The three major therapeutic classes of medications available to treat PAH act as either prostacyclin analogs or endothelin receptor antagonists (ERAs) or by increasing local nitric oxide (NO) levels by means of phosphodiesterase type 5 inhibitors. Several recent trials have investigated the use of oral prostanoid therapy, next-generation ERAs, and soluble guanylate cyclase stimulators (to increase NO levels) as well as novel formulations of pre-existing therapies. The goal of this manuscript is to briefly review established therapies and then discuss recent developments and practical considerations in each of the major drug classes.

Epidemiology of pulmonary hypertension and right ventricular failure in left heart failure.

Pulmonary hypertension (PH) leading to right ventricular failure (RVF) is a common complication of left heart failure irrespective of the left ventricular ejection fraction. PH due to left heart disease is the most common cause of PH. The prevalence of PH and RVF in left heart failure varies depending on the patient population studied, the method used to diagnose PH, and the hemodynamic criteria used to define PH. Elevated left-sided filling pressure and functional mitral regurgitation are the two major determinants of PH in left heart failure. PH is associated with markers of disease severity, advanced symptoms, and worse long-term outcomes including heart failure hospitalization and mortality in left heart failure. RVF has independent, incremental prognostic value over PH for adverse outcomes in left heart failure. PH and RVF may be potential therapeutic targets in patients with left heart failure.

[New trial designs and potential therapies for pulmonary artery hypertension]. / Pulmoner arter hipertansiyonunda yeni çalisma tasarimlari ve potansiyel tedaviler.

A greater understanding of the epidemiology, pathogenesis, and pathophysiology of pulmonary artery hypertension (PAH) has led to significant advances, but the disease remains fatal. Treatment options are neither universally available nor always effective, underscoring the need for development of novel therapies and therapeutic strategies. Clinical trials to date have provided evidence of efficacy, but were limited in evaluating the scope and duration of treatment effects. Numerous potential targets in varied stages of drug development exist, in addition to novel uses of familiar therapies. The pursuit of gene and cell-based therapy continues, and device use to help acute deterioration and chronic management is emerging. This rapid surge of drug development has led to multicenter pivotal clinical trials and has resulted in novel ethical and global clinical trial I concerns. This paper will provide an overview of the opportunities and challenges that await the development of novel treatments for PAH. (J Am Coil Cardiol 2013;62:D82-91) ©2013 by the American College of Cardiology Foundation.