Safety and Efficacy of Low-dose Prostacyclin Administration and Blood Pressure Target in Addition to Standard Therapy, as Compared to Standard Therapy Alone, in Post-cardiac-arrest-syndrome Patients - a Randomized, Controlled, Double-blinded Investigator-initiated Trial.

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.

Trial Population: Participants in the trial must be adult patients (≥18 years of age) with out-of-hospital cardiac arrest (OHCA) of presumed cardiac cause admitted to the Dept. of Cardiology, 2143, Rigshospitalet, Copenhagen.

Trial Design: Randomized, placebo controlled, double-blind investigator-initiated trial in 40 OHCA patients. 48 hours of active study drug (Iloprost, 1 ng/kg/min) versus placebo (saline) infusion.

Patients in both randomization groups will be treated in accordance with state-of-the art therapy including targeted temperature management. Interventions are considered emergency procedures and study drug infusion should be commenced as soon as possible after sustained return of spontaneous circulation (ROSC), screening and randomization.

Patients will only be enrolled after informed consent, but as the treatment has to be initiated earliest possible after the out of hospital cardiac arrest diagnosis i.e., at a time-point where patients are temporarily incompetent, scientific guardians will co-sign the informed consent form before inclusion. Next-of-kin and the patients' general practitioner will co-sign as soon as possible and the patient will provide informed consent whenever possible.