Risk assessment in pulmonary arterial hypertension: Insights from the GRIPHON study.

BACKGROUND: Approaches to risk assessment in pulmonary arterial hypertension (PAH) include the noninvasive French risk assessment approach (number of low-risk criteria based on the European Society of Cardiology and European Respiratory Society guidelines) and Registry to Evaluate Early and Long-term PAH Disease Management (REVEAL) 2.0 risk calculator. The prognostic and predictive value of these methods for morbidity/mortality was evaluated in the predominantly prevalent population of GRIPHON, the largest randomized controlled trial in PAH. METHODS: GRIPHON randomized 1,156 patients with PAH to selexipag or placebo. Post-hoc analyses were performed on the primary composite end-point of morbidity/mortality by the number of low-risk criteria (World Health Organization functional class I-II; 6-minute walk distance >440 m; N-terminal pro-brain natriuretic peptide <300 ng/liter) and REVEAL 2.0 risk category. Hazard ratios and 95% confidence intervals were calculated using Cox proportional hazard models. RESULTS: Both the number of low-risk criteria and the REVEAL 2.0 risk category were prognostic for morbidity/mortality at baseline and any time-point during the study. Patients with 3 low-risk criteria at baseline had a 94% reduced risk of morbidity/mortality compared to patients with 0 low-risk criteria and were all categorized as low-risk by REVEAL 2.0. The treatment effect of selexipag on morbidity/mortality was consistent irrespective of the number of low-risk criteria or the REVEAL 2.0 risk category at any time-point during the study. Selexipag-treated patients were more likely to increase their number of low-risk criteria from baseline to week 26 than placebo-treated patients (odds ratio 1.69, p = 0.0002); similar results were observed for REVEAL 2.0 risk score. CONCLUSIONS: These results support the association between risk profile and long-term outcome and suggest that selexipag treatment may improve risk profile.

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.

The study of risk in pulmonary arterial hypertension.

A growing body of published evidence exists on the risk factors for disease progression in pulmonary arterial hypertension (PAH). The Scientific Steering Committee for the Study of Risk in PAH was established to bring together leading clinical and statistical experts in PAH and risk modelling, for the purpose of advancing the understanding of the risk of development and progression of PAH. Herein, we discuss the impact of this information on three key areas: 1) clinical decision-making; 2) policy and reimbursement; and 3) future trials and research.

Interactions between rheumatologists and cardio-/pulmonologists in the assessment and use of outcome measures in pulmonary arterial hypertension related to systemic sclerosis.

OBJECTIVES: Pulmonary arterial hypertension in patients with systemic sclerosis is a disease involving multiple organ systems. We investigated the differences in perceptions of how to measure PAH-SSc among cardiologists, pulmonologists and rheumatologists. We also examined how a Delphi exercise can improve agreement among these subspecialties. METHODS: The outcome measures derived from the recent Delphi survey were used for a detailed analysis of the contribution of the various specialties contributing to it. We compared rheumatologists and cardiologist/pulmonologists with regards to preferences and ratings of various endpoints and the actual use of tools to measure these outcomes. We also examined the effects of the Delphi process among these groups. RESULTS: We could show that the different expert groups each tended to contribute differently to the development of the core set of measures and that interactions in the Delphi process resulted in convergence of rankings. Despite agreement on the high importance of the domains in the Delphi, the use of tools within those domains was sometimes divergent and dependent on specialty. CONCLUSIONS: Based on these results, use of differing tools in the diagnosis and treatment of PAH-SSc can be anticipated. Further, the convergence of results provides evidence, for the first time, for the ability of various approaches in these disciplines to reach harmonious endpoints of care for PAHSSc patients. A collaborative, interdisciplinary approach is advantageous for PAH-SSc patients.

Hemodynamic and functional assessment of patients with sickle cell disease and pulmonary hypertension.

RATIONALE: Although pulmonary hypertension (PH) is a common complication of sickle cell disease (SCD) associated with high mortality, there exist few data characterizing hemodynamics and cardiopulmonary function in this population. OBJECTIVES: To characterize hemodynamics and cardiopulmonary function in patients with SCD with and without PH. METHODS: Patients with SCD with PH (n = 26) were compared with control subjects with SCD but without PH (n = 17), matched for age, hemoglobin levels, and fetal hemoglobin levels. MEASUREMENTS AND MAIN RESULTS: Upon catheterization, 54% of the patients with PH had pulmonary arterial hypertension, and 46% had pulmonary venous hypertension. When compared with control subjects, patients with PH exhibited lower six-minute-walk distance (435 +/- 31 vs. 320 +/- 20 m, p = 0.002) and oxygen consumption (50 +/- 3% vs. 41 +/- 2% of predicted, p = 0.02), and also had mild restrictive lung disease and more perfusion abnormalities on radionuclide lung scans. The six-minute-walk distance in this population inversely correlated with tricuspid regurgitant jet velocity (r = -0.55, p < 0.001), and mean pulmonary artery pressure (r = -0.57, p < 0.001), and directly correlated with maximal oxygen consumption (r = 0.49, p = 0.004), even after adjustment for hemoglobin, supporting an independent contribution of increasing pulmonary artery pressures to loss of exercise capacity. CONCLUSIONS: Patients with SCD-associated PH have both pulmonary arterial and venous PH associated with severe limitations in exercise capacity, likely compounded by interstitial lung fibrosis and severe anemia. These data support the use of the six-minute-walk distance as an index of PH and cardiopulmonary function in patients with SCD.