The general aim of this study is to compare the efficacy and safety of tenecteplase to standard treatment during cardiopulmonary resuscitation in patients suffering from out-of-hospital cardiac arrest.

The trial is a prospective, international, multi-centre, randomised (1:1), double-blind, parallel group comparison conducted for investigating the efficacy and safety of tenecteplase and placebo in patients with cardiac arrest of presumed cardiac origin.

Approximately 1300 patients (two groups of 650 patients; tenecteplase or matching placebo) suffering from witnessed (by eye or ear) out-of-hospital cardiac arrest of presumed cardiac origin, who are treated with ALS-CPR will be randomised at approximately 40 study centres. Randomisation is done immediately after insertion of an IV line is established. Study drug application, as a single IV bolus over 5-10 seconds, should be done immediately after the first vasopressor application during the ALS-CPR procedure.

PCI facilities will be required at all participating sites, i.e. hospitals receiving patients.

Study Hypothesis:

The primary aim of the trial is to demonstrate superiority in the intent-to-treat analysis of tenecteplase over placebo with regard to primary endpoint as the incidence of 30-day survival (30daysurv).

Comparison(s):

Group A (experimental; fibrinolytic treatment) Tenecteplase, as a single IV bolus over 5-10 seconds, immediately after first vasopressor dosage during standardised ALS-CPR procedures according to the International CPR Guidelines.

Group B (reference) Placebo, as a single IV bolus over 5-10 seconds, immediately after first vasopressor dosage during standardised ALS-CPR procedures according to the International CPR Guidelines.

Patients, indicated for pre-hospital ALS-CPR procedures* must fulfil the following inclusion criteria:

• Age at least 18 years (known or estimated; no upper limit)
• Out-of-hospital cardiac arrest of presumed cardiac origin (including recurrent cardiac arrest(s) after initial ROSC)
• Witnessed (by eye and/or ear) cardiac arrest
• BLS-CPR started within 10 min of onset (known or estimated time) and may be performed for up to 10 min, followed by ALS-CPR - or ALS-CPR started within 10 min of onset (known or estimated time)

Subjects who meet any of the following criteria will be excluded from randomisation into the study:

• In-hospital cardiac arrest
• Cardiac arrest of presumed non-cardiac origin (e.g., drug overdose, carbon monoxide poisoning, drowning, hypothermia, exsanguination, electrocution, asphyxia, hypoxia, trauma, cerebrovascular accident)
• Obvious significant internal bleeding
• Known neurological impairment
• Known coagulation disorder
• Known pregnancy
• Known current participation in any other clinical study
• Known hypersensitivity to study medication
• Institutionalised subjects (e.g., prisoner)
• Any other condition that the investigator feels would place the patient at increased risk if the investigational therapy is initiated