Clinical Practice of Pulmonary Arterial Hypertension (PAH) and Potential Barriers to Intensive Treatment Among PAH-Specialized and Non-PAH-Specialized Centers in Japan.

Pulmonary arterial hypertension (PAH) is a rare and progressive disease characterized by remodeling of the pulmonary vasculature, which leads to increased pulmonary artery pressure and ultimately right ventricular failure. Although Japanese guidelines recommend combination therapy, real-world data show inconsistencies in its implementation. We thus conducted a cross-sectional, web-based questionnaire survey to understand the recent real-world clinical practices in Japan and identify factors associated with treatment decisions, with a particular focus on the use of combination therapies. The findings indicated that oral PAH medications were widely available and commonly prescribed, whereas inhaled and parenteral infusion therapy were less accessible and used less frequently. Moreover, physicians working in PAH-specialized centers were significantly more likely to prescribe parenteral infusion therapies (adjusted odds ratio [aOR] = 2.6, 95% confidence interval [CI]: 1.5-4.3, p < 0.001) and adopt dual (aOR = 3.0, 95% CI: 1.4-6.5, p = 0.01) or triple combination regimens (aOR = 2.7, 95% CI: 1.5-2.7, p < 0.001). Physicians with experience treating high risk patients at PAH-specialized centers were also significantly more likely to prescribe parenteral infusion therapies (aOR = 3.5, 95% CI: 1.8-6.6, p < 0.001) and adopt dual (aOR = 5.9, 95% CI: 2.5-14.2, p < 0.001) or triple combination regimens (aOR = 3.4, 95% CI: 1.7-6.7, p < 0.001). This study revealed differences in clinical practice between PAH-specialized and non-specialized centers in real-world settings. Management of PAH at PAH-specialized centers was associated with increased treatment intensification, indicating the need for enhanced collaboration between PAH-specialized and non-specialized centers to ensure optimal care for patients with PAH.