Hospitalization is an important outcome in pulmonary arterial hypertension (PAH), shown previously to correlate with survival. Using the Registry to Evaluate Early and Long-term PAH Disease Management (REVEAL Registry), we sought to characterize first-time hospitalizations and their effect on subsequent hospitalization and survival in patients with newly diagnosed disease. Patients with newly diagnosed PAH (n = 862, World Health Organization group 1) were evaluated for first-time hospitalization. The hospitalizations were categorized as PAH related or PAH unrelated based on the case report form. Categories for PAH-related and PAH-unrelated hospitalization were defined before independent review. Patient demographics and disease characteristics are described as well as freedom from hospitalization and survival. Of 862 patients, 490 (56.8%) had one or more hospitalizations postenrollment: 257 (52.4%) PAH related, 214 (43.7%) PAH unrelated, and 19 (3.9%) of undetermined causes. The most common causes of PAH-related hospitalization were congestive heart failure and placement/removal of a central venous catheter. Patients with PAH-related hospitalizations were more likely to receive parenteral therapy, be in functional class III/IV, and have higher risk scores before hospitalization at enrollment. Following discharge, 25.4% ± 3.2% and 31.0% ± 4.0% of patients with PAH-related and PAH-unrelated first hospitalization, respectively, remained hospitalization-free for 3 years (P = .11). Survival estimates at 3 years postdischarge were 56.8% ± 3.5% and 67.8% ± 3.6% (P = .037) for patients with PAH-related and PAH-unrelated hospitalization, respectively. In the REVEAL Registry, PAH-related hospitalization was associated with relatively more rehospitalizations and worse survival at 3 years. ClinicalTrials.gov; No.: NCT00370214; URL: www.clinicaltrials.gov.

Registry data worldwide indicate an overall female predominance for pulmonary arterial hypertension (PAH) of 2–4 over men. Genetic predisposition accounts for only 1–5% of PAH cases, while autoimmune diseases and infections are closely linked to PAH. Idiopathic PAH may include patients with undiagnosed autoimmune diseases based on the relatively high presence of autoantibodies in this group. The two largest PAH registries to date report a sex ratio for autoimmune connective tissue disease-associated PAH of 9:1 female to male, highlighting the need for future studies to analyze subgroup data according to sex. Autoimmune diseases that have been associated with PAH include female-dominant systemic sclerosis, systemic lupus erythematosus, rheumatoid arthritis, Sjögren’s syndrome, and thyroiditis as well as male-dominant autoimmune diseases like myocarditis which has been linked to HIV-associated PAH. The sex-specific association of PAH to certain infections and autoimmune diseases suggests that sex hormones and inflammation may play an important role in driving the pathogenesis of disease. However, there is a paucity of data on sex differences in inflammation in PAH, and more research is needed to better understand the pathogenesis underlying PAH in men and women. This review uses data on sex differences in PAH and PAH-associated autoimmune diseases from registries to provide insight into the pathogenesis of disease.

Pulmonary arterial hypertension (PAH) has a high morbidity rate and is fatal if left untreated. Increasing evidence supports early intervention, possibly with initial combination therapy. PAH-specific pharmaceuticals, however, are expensive and may have serious adverse effects, particularly when used in combination. The currently dynamic health care economy reinforces the need for a review of early intervention from both outcomes and economic perspectives. We aimed to review the clinical and economic impact of PAH therapy, particularly examining drug cost, hospitalization burden, and health care economics impact, and the effect of early intervention on clinical outcomes. We searched PubMed, Scopus, Ovid, and MEDLINE databases from 2005 to 2017 for studies comparing drug cost, clinical outcomes, and hospitalization burden associated with therapy for PAH. Emerging data indicate that early therapy is effective, but drug therapy is expensive, particularly with combination therapy. Efficacy studies also generally show benefit of combination therapy for patients in World Health Organization functional class II, with a consistent decrease in hospitalization. Pharmacoeconomic studies are limited but indicate that increased pharmacy costs are at least partially offset by decreased health care utilization, particularly inpatient care. Modeling also shows a cost benefit with combination therapy at 2 years. Nonetheless, more rigorously collected health care economic data should be incorporated into future drug efficacy trials to provide a clearer understanding of the impact and the associated cost benefit of early PAH therapy. Increasing evidence in support of early intervention and combination therapy for PAH is associated with rising medication costs that are largely offset by reduced hospitalization, on the basis of the currently available literature. Nonetheless, the studies performed to date have methodologic limitations that highlight the need for prospective studies using more robust economic modeling.

The possibility that pulmonary hypertension (PH) may develop in patients with chronic obstructive pulmonary disease (COPD) is well established, but prevalence data vary. The current World Health Organization clinical classification includes COPD in diagnostic group III: PH associated with disorders of the respiratory system or hypoxemia. The National Institute of Health defines PH as a mean pulmonary artery pressure of greater than 25 mmHg. Approximately 10% of the patients seen over the last decade in the PH Clinic at Mayo Clinic in Jacksonville, Florida, have PH due to COPD. The pathophysiology is likely complex and involves hypoxic pulmonary vasoconstriction. Ultimately, chronic hypoxia results in vascular remodeling with narrowing of the vascular lumen. The right heart is forced to generate increased driving pressures to overcome the increased vascular resistance. As the disease progresses, cor pulmonale may develop. The mortality in this setting is increased with five-year survival of 20% to 36% and seems to correlate with worsening PH and age. Fortunately, the PH in most cases is mild and occurs primarily in those with severe hypoxemia. Only 1% to 4% of patients have PH seemingly out of proportion to the severity of the COPD. This disproportionate subgroup may represent an important phenotype that requires a different therapeutic approach. Although supplemental oxygen remains the primary treatment for all PH in association with chronic hypoxia, pulmonary arterial vasodilators may have a therapeutic role in this subgroup. Vasodilators may worsen gas exchange, however, and to date, have no proven benefit. Rigorous future study will be required to determine whether there is a role for using pulmonary arterial vasodilators in this setting.