Clinical efficacy and survival with first-line inhaled iloprost therapy in patients with idiopathic pulmonary arterial hypertension

Aims: To describe the long-term clinical efficacy of inhaled iloprost as first-line vasodilator mono-therapy in patients with idiopathic pulmonary arterial hypertension (IPAH). Methods and results: Seventy-six IPAH patients were prospectively identified and treated with inhaled iloprost. Clinical, haemodynamic, and exercise parameters were obtained at baseline, after 3 and 12 months of therapy and yearly thereafter. Four endpoints were prospectively defined as follows: (i) death, (ii) transplantation, (iii) switch to intravenous (i.v.) therapy, or (iv) addition of or switch to other active oral therapy. During follow-up (535 ± 61 days), 11 patients died, six were transplanted, 25 were switched to i.v. prostanoids, 16 received additional or other oral therapy, and 12 patients discontinued iloprost inhalation for other reasons. Event-free survival at 3, 12, 24, 36, 48, and 60 months was 81, 53, 29, 20, 17 and 13%, respectively. Among haemodynamic and exercise parameters, mixed venous oxygen saturation (P < 0.001), right atrial pressure (P < 0.001), and peak oxygen uptake (P = 0.002) were associated with event-free survival. Conclusion: In this study, only a minority of patients could be stabilized with inhaled iloprost monotherapy during a follow-up period of up to 5 years. In the presence of multiple treatment options, chronic iloprost inhalation as mono-therapy appears to have a limited role.