The AWAKE trial is an investigator-initiated, multicenter, observational trial currently underway in 4 centers in Spain (Hospital Clínico San Carlos, Hospital Universitario La Paz, Hospital General Universitario de Ciudad Real, and Hospital Universitario Gregorio Marañón), and open to more participant hospitals. Only tertiary care hospitals with extensive expertise in the management of SCD and post-resuscitation care will participate in the trial. All of them are required to have on-site 24 hours a day, 7 days a week availability for percutaneous coronary intervention, and critical care units staffed by cardiologists and/or critical care specialists. This selective center recruitment is supported by recent data suggesting that direct admission to invasive heart centers is associated with lower mortality in patients with out-of-hospital cardiac arrest (OHCA).