Tolerability and clinical efficacy of inhaled treprostinil in patients with group 1 pulmonary arterial hypertension

Background: Treprostinil is a prostacyclin analogue that directly vasodilates pulmonary and systemic arterial vascular beds. The United States Food and Drug Administration approved inhaled treprostinil in July 2009 for the treatment of group 1 pulmonary arterial hypertension. Inhaled treprostinil avoids issues with continuous infusion prostanoids. This study describes a single institutional experience with inhaled treprostinil. Methods: This was a retrospective review of group 1 pulmonary arterial hypertension patients receiving inhaled treprostinil from July 2009 through September 2015. Patient demographics, vital signs, prognostic indicators, pulmonary arterial hypertension assessments, treprostinil dosing, pulmonary arterial hypertension medications, and physician assessment were collected. Prognostic indicators and the physician assessment were used to assess treatment response. A modified Registry to Evaluate Early and Long-term Pulmonary Arterial Hypertension Disease Management (REVEAL) risk score was calculated prior to and after initiation of inhaled treprostinil. Results: The mean time on inhaled treprostinil for the 16 patients was 21 +/- 17 months. A total of 31% discontinued treatment. The New York Heart Association Functional Class, right ventricular size, and right ventricular function improved after inhaled treprostinil. Directional improvement in B-type natriuretic peptide, 6-minute walk distance, right arterial pressure and mean pulmonary artery pressure were also observed. The mean modified REVEAL risk score [RRS] was 7 +/- 3 at baseline. The RRS decreased in 7 of the 11 patients that improved and remained stable in 2 patients. Conclusion: The majority of patients in this consecutive series receiving inhaled treprostinil tolerated treatment. Most patients remained on therapy for over 12 months. Clinical assessments of disease severity all changed directionally toward improvement and the overall risk assessment was improved or stable in 56% by the RRS.