This research emphasis would help identify novel pulmonary hypertension biomarkers of disease risk and progression that can be used for early detection or as outcome measures in prevention trials or treatment of PH, which is a disease currently still not curable with high mortality rate.

NHLBI Division of Lung Diseases just launched the multi-center PVDOMICS research program last September that will enroll ~1,500 patients in the next 5 years for deep phenotyping PH. PVDOMICS will provide a perfect foundation and platform for this proposed featured study about informative and clinically relevant biomarkers of PH, and make answering this proposed question more feasible in the next 5-10 years.
Although significant advances in the treatment of pulmonary hypertension have been made in the past two decades, currently pulmonary hypertension remains a devastating disease without many clinically relevant and specific biomarkers available. Novel new informative and clinically relevant pulmonary hypertension biomarkers would greatly help advance the subtype-specific early diagnosis and precision treatment of this disease that could potentially decrease the mortality of PH.

Hydroxyurea is a widely available disease-modifying therapy for sickle cell disease (SCD), but its effectiveness is currently limited by inadequate utilization, and less than optimal response. Research is needed to improve adherence to this evidence-based therapy and emphasis needs to be placed on determining whether therapy with hydroxyurea can prevent or even reverse organ dysfunction. In addition, research identifying new adjunct therapies to blood transfusion and hydroxyurea, as well as disease-specific therapies for co-morbidities such as kidney disease, hypertension, obstructive lung disease, and pulmonary hypertension will be valuable in the management and treatment of SCD.

i. In patients with pulmonary hypertension, the use of multiple tests to characterize the type and severity has long been recommended by global experts; one commonly used diagnostic algorithm recommends more than ten different tests to accurately define this complex, heterogeneous disease. Despite the algorithm used, to confirm a diagnosis of one specific type of PH, pulmonary arterial hypertension (PAH), one must always directly measure the pressures in the heart and pulmonary artery through a right heart catheterization (RHC). Complications for this procedure are rare, but not non-existent with potentially 1 in every 100 patients having a right heart catheterization experiencing a serious adverse event (Hoeper MM 2006). Patients would significantly benefit from a non-invasive method of quantifying their pulmonary artery pressures and/or disease progression, but to date this has not been possible with echocardiography due to measurement errors (Laver 2014), CT scan due in part to measurement inconsistencies (Alhamad 2011), and cardiac MRI due to lack of standardization and multicenter trials (Peacock 2013). Not only would wider utilization of a non-invasive method of measuring pulmonary artery pressures and disease progression potentially reduce the risk from RHC, depending on the modality it could lead to earlier diagnosis of this progressive disease and/or application in countries where RHC is less common.

Addressing a non-invasive method of measuring pulmonary artery pressures requires investment in both technology and multicenter clinical trials to validate these measures.

The evolution of the anticoagulation recommendation in pulmonary arterial hypertension (PAH) is a relatively logical one at face value. Early in the modern era of PAH management, a “thrombosis” in the small pulmonary arteries was identified and described; studies since then have demonstrated hypercoagulability in patients with severe disease. Together, these observations led to a theory that in-situ thrombosis contributed to the PAH disease progression and a belief that anticoagulation should be beneficial. The empirical evidence currently supporting this recommendation comes mostly from a retrospective cohort study of the European COMPERA PH registry and a systematic review of 7 retrospective cohort studies that are at least 10 years old—2 of which did not suggest a survival benefit—and in a time where only 4 of the widely used PAH-targeted therapies were approved by the FDA. Purely based on observational evidence with a number of potential biases, warfarin (Coumadin) is widely used in PAH management to this day. Warfarin in this patient population is not without its risks, as some subgroups of PAH patients are at increased risk of bleeding complications based on their disease process alone. Assessing the true benefit of this widely used background therapy could allow clinicians and patients to more accurately weigh the risks and burden of anticoagulation with a true understanding of the survival benefit.

Addressing this compelling question is indeed feasible through an NIH-sponsored randomized, double-blind, placebo-controlled trial of anticoagulation in patients with certain types of pulmonary arterial hypertension.

Pulmonary arterial hypertension is a heterogeneous condition generally characterized by high blood pressure in the lungs and increased pulmonary vascular resistance that leads to right heart failure if left untreated. Though some causes of PAH are seen in both adult and pediatric populations, some etiologies are seen exclusively in pediatric populations, including persistent pulmonary hypertension of the newborn, bronchopulmonary dysplasia, lung hypoplasia, and alveolar capillary dysplasia. Despite these differences in disease etiology, and known physiologic differences in pediatric populations, inhaled nitric oxide (iNO) in the acute setting is the only approved medication for PAH treatment in children. A number of issues have decreased pediatric PAH pharmaceutical research, including protection of the pediatric population as vulnerable subjects, principle of scientific necessity, balance of risk and potential benefit, parental consent/child assent, and feasibility of pediatric clinical trial design and implementation. Encouraging clinical trials of existing adult medications and potentially emerging, novel agents specifically for pediatrics—either through direct sponsorship or regulatory incentives—would not only lead to better outcomes for pediatric PAH patients, but potentially to a better and more comprehensive characterization of the developing pulmonary vascular system and right ventricle.

Several challenges exist for addressing this critical challenge. First, there are a number of differences between conducting clinical research in pediatric populations compared to adult populations. This not only includes the broad items referenced above, but items as noted by Rose and colleagues related to clinical trial design and analysis including (1) accepted age-matched normal ranges for laboratory values; (2) requirements for the validation of clinical endpoints for the assessment of efficacy and safety; and (3) standards for long-term safety monitoring and pharmacovigilance (Rose K, et al. NEJM 2005). Sponsorship of this type of clinical research is a second concern, which could either be mitigated by direct support from the National Institutes of Health of pediatric PAH clinical trials or in regulatory changes incentivizing pediatric clinical research in rare diseases.

Understanding of many components of the PAH disease state have evolved significantly in the past thirty years. When initially described by an NIH registry, in a time where pulmonary transplantation was the only treatment for PAH, the average life expectancy of PAH patients was estimated to be 2.8 years. Since then, 12 PAH-targeted therapies have been approved by the FDA; these therapies primarily act by dilating the pulmonary arteries in order to allow blood to flow easier through the pulmonary vascular system. Despite these advances and complex therapies, long-term afterload reduction is not achievable in most PAH patients. Patients continue to die from right ventricular failure, highlighting the important relationship of the pulmonary arterial system and right ventricle. Little is known about how and why the RV progresses from hypertrophy to full RV failure, the diagnostic signs indicating early RV failure, and how best to intervene to support the failing ventricle. Knowledge in this area is critical, however, as the RV is able to recover in many patients with severe PAH after lung transplantation. The relationship between the lung vasculature and cardiac function, and specifically a characterization of RV failure, was included as a research opportunity in the Strategic Plan for Lung Vascular Research in an NHLBI-ORDR Workshop Report (Erzurum S, et al. 2010).

The primary challenge of addressing this CQ on how right ventricular function can be improved in the setting of increased afterload is the comprehensive analysis and support that will need to be provided, spanning from basic to clinical science. To begin, strong support of biologic characterization of the right ventricle needs to be provided. The RV is distinctly different from the more comprehensively studied left ventricle (LV), and subsequently responds differently to changes in pressure, neurotransmitters, hormones, and pharmaceutical therapies to name only a few. However, when identified, these RV biologic distinctions can be further explored to develop a better understanding of RV failure and potential points of intervention.

In the past twenty years, 12 PAH targeted-therapies have been approved by the FDA. This increase in disease state awareness and in the treatment armamentarium have contributed to an increase in average survival from 2.8 years to an estimated 8-10 years. However, current treatments primarily address the vasoconstrictive component of the disease and do not address the now accepted theory of post-apoptotic overgrowth of hyperproliferative cells of the pulmonary vessels. A number of circulating stem and progenitor cells, derived from the bone marrow, have been identified that could have roles in repair of the pulmonary vascular system when interacting with the quickly, abnormally growing cells in the lung vessels. Work in this area has been named as a future research opportunity in the NHLBI-ORDR Strategic Plan for Lung Vascular Research (Erzurum S, et al. 2010).

Basic and translational research support is needed—including high-throughput approaches such as phage display and large-scale proteomic analysis—to better understand the relationship between circulating bone marrow-derived cells, lung-resident stem and progenitor cells, and endothelial cells of the pulmonary arterial system.

Since 2006, 12 medical therapies for PAH have been approved by the FDA, which have increased survival of this rare disease from around 2.8 years to approximately 9 years; these therapies primarily act by dilating the pulmonary arteries in order to reduce pulmonary vascular resistance to blood flow. However, patients continue to die from right ventricular failure, highlighting the important relationship of the pulmonary arterial system and right ventricle (RV). Despite patients ultimately dying from RV failure, little is known about the effect of the currently available PAH-targeted therapies on RV functional support. Prostacyclins, PDE5i, and sGC agonists are thought to enhance RV contractility—though the long-term effects remain unknown—while ERAs are thought to reduce it. The direct RV effect of some potential therapies targeting the pseudo-malignancy theory of PAH is a concern, as these therapies seek to reduce the hypertrophy and angiogenesis that may actually be supporting the adapting RV. Further, therapies targeting the ventricle directly have historically been centered on the LV—for example β-adrenergic receptor blockers and RAS inhibition—and either remain controversial or without data in the RV. There remains no identified RV-specific therapy to either provide support through increase contractility or molecularly prevent the progression from RV hypertrophy to ultimate failure.

The primary challenge of addressing this CC on the lack of RV-targeted therapies for the treatment of PAH is the comprehensive analysis and support that will need to be provided, spanning from basic to clinical science. To begin, strong support of biologic characterization of the right ventricle needs to be provided. The RV is distinctly different from the more comprehensively studied left ventricle, and subsequently responds differently to autocrine, paracrine, neuroendocrine, pressure, and pharmaceutical changes to name only a few. However, when identified, these RV biologic distinctions can be translated and tested clinically to more comprehensively and appropriately treat the RV-arterial uncoupling ultimately leading to right heart failure: through both reduction in afterload and an increase in contractility.

Pulmonary fibrosis has a mortality rate greater than that of most malignancies. Although medical therapy is finally available for some of these patients, this therapy, at best, results in a reduction in the rate of lung function decline and a reduced rate of mortality. Preventing the development of pulmonary fibrosis could result in substantial reductions in the morbidity and mortality experienced by those at risk.

Identifying patients with early stages of pulmonary fibrosis is not only feasible but is likely to be an expected result of the increase in chest CTs obtained through lung cancer screening. Increased consensus in the community about what defines early stages of pulmonary fibrosis will be needed for this field to truly move forward. It remains possible that medical and other targeted intervention trials could be initiated in patients felt to have early stages of pulmonary fibrosis.

Elucidation of molecular and cellular pathways driving and sustaining exacerbations in chronic lung diseases. Specifically, (1) discover what perturbs antecedent conditions precipitating mal(adaptive) compensatory mechanisms leading to pulmonary exacerbation including impact of heterogeneous resilience and concomitant chronic diseases and (2) clarify response heterogeneity of longitudinal molecular and cellular signature during treatment and recovery.

Longitudinal pulmonary exacerbation research nested with clinical care can be initiated within 1-2 years. As part of clinical care leveraging digital education/data (electronic health/medical records and attendant meaningful use requirements), an N-of-one research design could become self-sustaining within health care systems.
Pulmonary exacerbations exhibit multiple pathogenic pathways various concurrent pathophysiological pathways, and diverse clinical manifestations. Prevention and treatment of pulmonary exacerbations is hampered by this complex biology that is dynamic and appears to vary during the course of exacerbations. Progress toward precision medicine for exacerbations may require organization of a new taxonomy for disease, which reflects a set of clinically meaningful and exploitable similarities and differences between disease traits (exacerbation polypathomics).

Establishment of a study section on Pulmonary Vascular Biology and Translational Research will provide adequate funding to stimulate innovative research on this rapidly expanding field and promote translational research and thereby promote human health by providing potential novel therapeutic strategies for the devastating diseases such as pulmonary hypertension and acute lung injury.

In the aggregate, diseases characterized by fibrosis have been estimated to account for up to 45% of developed world deaths. Fibrotic diseases addressed by the NHLBI include heart failure with preserved ejection fraction (HFpEF), idiopathic pulmonary fibrosis (IPF), and myelofibrosis (MF), among many others. Each fibrotic disease represents an area of great unmet clinical need, as patients suffer and die with no or limited effective disease-modifying therapies. The impact of developing effective therapies for each of these diseases individually would be great; the impact of developing therapies effective for the entire class of fibrotic diseases across organs would truly be enormous. The clinical burden of HFpEF is staggering – more than 650,000 new patients are diagnosed with heart failure in the US each year, half with diastolic dysfunction. Although not as prevalent, IPF and MF are particularly lethal. IPF has a median survival of approximately three years. MF is arguably the most aggressive of the myeloproliferative disorders and is associated with significantly shortened survival. Although agents such as spironolactone have been unable to treat fibrosis in HFpEF as yet, two anti-fibrotic drugs, pirfenidone and nintedanib, have now been shown to slow progression of IPF, and the oral JAK1/2 inhibitor ruxolitinib has been shown to improve MF survival. These early successes underscore the great impact that developing effective anti-fibrotic therapies will have.

This challenge could be addressed by funding research efforts to identify and therapeutically target fundamental pathogenetic mechanisms shared by fibrotic diseases across organs. Although fibrotic diseases present clinically with organ-specific manifestations, there has been a growing appreciation of that these diseases share many aspects of their pathogenesis. Fibrosis In many of these diseases results from recurrent or non-resolving epithelial or endothelial injury, followed by over-exuberant or aberrant mesenchymal cell responses. Across all organs, these processes result in the pathologic accumulation of fibroblasts and extracellular matrix, with distortion of organ architecture and loss of organ function. Core pathways leading to epithelial and endothelial cell injury and senescence, to fibroblast accumulation and persistence, and to altered matrix biochemical and biomechanical properties, are now being identified. Therapeutics developed to target these core pathways could have broad clinical applicability. Funding initiatives aimed at better the characterization of core fibrotic pathways already identified, the identification of new core fibrotic pathways, and the development of therapies to target core fibrotic pathways, could allow the NHLBI to simultaneously and cost-effectively address the great unmet needs of the large patients with any of the many devastating fibrotic diseases that affect the heart, lungs and bone marrow.

Modest sized efficacy trials demonstrate substantial health benefits, that wane as Pulmonary rehabilitation is discontinued. We need to test the health and resource implications of "chronic" (e.g., 12 or 24 mos) pulmonary rehabilitation. Such information will benefit health systems seeking to implement care models for high-risk, costly, patients - patients with COPD are of increasing interest to health systems. Such a comparative effectiveness trial should also involve behavioral interventions to promote self-management and involve caregivers.

Pulmonary rehabilitation is the most effective therapy for COPD, leading to reduced shortness of breath and improved exercise capacity. It is under-utilized because of the relative paucity of studies evaluating its efficacy on mortality, hospitalization and hospital readmission.

Feasibility is very high. In the NIH National Emphysema Treatment Trial, a standardized pulmonary rehabilitation program was developed and implemented at multiple sites, many of which did not have existing pulmonary rehabilitation programs. The effective of this pulmonary rehabilitation program was documented (Chest 2005; 128:3799). Challenges include maintenance of the benefits of pulmonary rehabilitation using modern approaches to increase adherence.