Sudden cardiac death (SCD) remains a major public health issue with a low survival rate. The most common cause of SCD is acute coronary artery occlusion. Several registry based studies suggest that coronary angiography (CA) performed at admission followed if necessary by coronary angioplasty improves in-hospital and long term survival. Recent guidelines recommend performing an immediate CA in all survivors of SCD with no obvious non cardiac cause of arrest. However there is a lack of randomized data on this topic.

Several retrospective studies have shown that if the post-resuscitation electrocardiogram (ECG) shows ST segment elevation, the probability of finding an acute coronary artery lesion during the CA is high (70-80%). In contrast, if no ST segment elevation is present the probability is low (15-20%).

Performing an immediate CA in all survivors of SCD can be challenging. It requires admitting these patients to centers with an intensive care unit and facilities allowing 24/24 7/7 CA. It may increase the delay of performing other therapeutic modalities such as CT brain or thorax scan to determine the cause of SCD. Performing the CA 48 to 96 hours after admission would facilitate the management of these difficult patients. However if the cause of the arrest is a coronary artery occlusion and there is a delay in reperfusion, the rate of post-arrest shock and the mortality may increase. Therefore a randomized study comparing immediate versus delayed (between 48 to 96 hours) CA in survivors of SCD with no obvious non-cardiac cause of arrest is warranted.

The design consists in a multicenter national randomized open parallel group trial.

All eligible patients with SCD will be included and randomized by the Emergency Medical Service (EMS) to one of the 2 following arms: immediate CA vs delayed CA. Patients randomized in the immediate CA group will be admitted directly to the catheterization laboratory. Patients randomized in the delayed CA will be admitted to the intensive care unit and a CA will be planned 48 to 96 hours after admission. Investigators can perform the CA in the delayed group < 48 hours if the following events appear:

• ST segment elevation or new left bundle branch block on the ECG
• Shock unresponsive to inotropes
• "Electrical storm" (repeated Ventricular Tachycardia (VT)/Ventricular Fibrillation (VF))
• Segmental hypokinesia or akinesia on an echocardiogram

Echocardiography and assessment of neurological status are done at discharge form the Intensive Care Unit, at hospital discharge and during the follow-up visits (90 and 180 days).

Inclusion Criteria:

• Out-of-hospital SCD with return of spontaneous circulation
• Age ≥ 18 years of age
• No obvious non-cardiac cause of arrest
• Admitted to a center with an intensive care unit and a 24 hours a day, 7 days a week interventional cardiology department
• Affiliation to the French Social Security Health Care plan

Exclusion Criteria:

• Age < 18 years of age
• In-hospital SCD
• No return of spontaneous circulation
• Presence of ST segment elevation
• Suspected non-cardiac aetiology (trauma, respiratory, neurological, etc.)
• Presence of co-morbidities with life expectancy of less than a year
• Pregnancy
• Adults subject to a legal protection measure (guardianship or tutelage measure)
• Participation in another interventional trial