Continuous intravenous iloprost to revert treatment failure of first-line inhaled iloprost therapy in patients with idiopathic pulmonary arterial hypertension

Aims: To describe the clinical and haemodynamic effects during the first 6 months of continuous intravenous iloprost treatment in patients with idiopathic pulmonary arterial hypertension (IPAH) and relevant disease progression despite continued mono therapy with aerosolized iloprost. Methods and results: Twenty-four IPAH patients with clinical decompensation to NYHA class IV despite therapy with aerosolized iloprost and optimized conservative treatment were assessed clinically, haemodynamically and by cardiopulmonary exercise testing for at least 6 months. Upon switching from inhaled to intravenous iloprost all patients improved clinically (NYHA III) while pulmonary vascular resistance (PVR) and right atrial pressure decreased from 2386 +/- 243 to 1381 +/- 124 dyne center dot s center dot cm(-5) and 12 +/- 1 to 8.5 +/- 1 mmHg, respectively (both p < 0.05). Despite this acute improvement haemodynamic (PVR increased from 1462 +/- 223 to 1978 +/- 327 dyne center dot s center dot cm(-5)) and clinical (4 deaths, 4 transplantations) deterioration occurred with continued intravenous treatment during the following 6 months. Conclusions: In the group of patients described in this report the clinical and haemodynamic deterioration occurring while on mono therapy with inhaled iloprost could be stopped by switching to continuous application of intravenous iloprost. However, with continued intravenous therapy only a subgroup of patients could clinically be stabilized and transplanted successfully.