Trial Rationale: Therapeutic interventions directed towards the damaged endothelium may improve outcome for patients with PCAS. Prostacyclin/Iloprost (PGI2) is an endogenous prostanoid which is formed and released by endothelial cells with anti-platelet, vasodilatory and cytoprotective properties36 and is expected to be beneficial by protecting and deactivating the endothelium and by restoring vascular integrity in patients suffering from endothelial breakdown.