Use of Sildenafil in Pulmonary Arterial Hypertension: Findings from a U.S. Healthcare Claims Database

Background: Pulmonary arterial hypertension (PAH) is a disease characterized by dyspnea, fatigue, chest pain and syncope. As there is no known cure for PAH, the goal of treatment is to control symptoms and slow disease progression. Sildenafil, a phosphodiesterase-5 inhibitor, has been indicated to improve exercise capacity in PAH in both the United States and the European Union since 2005; since 2009, it also has been indicated in the United States to delay clinical worsening. Patterns of sildenafil use in PAH patients have not been reported. Objectives: To describe patterns of treatment with sildenafil among commercially insured patients in the United States with PAH. Methods: Using a large U.S. healthcare claims database, we identified all patients with evidence of PAH (International Classification of Disease, 9th Revision, Clinical Modification [ICD-9-CM] diagnosis codes 416.0, 416.8) and receipt of sildenafil between January 1, 2005 and September 30, 2008. The date of each patient’s earliest pharmacy claim for sildenafil was designated as his or her “index date”; patients with