The aim of the project is to establish the value of circulating microparticles as a new biomarker for neurological prognosis of patients recovered from sudden cardiac death who remain comatose.

This is a pilot study. Analytical, observational, longitudinal, retrospective and prospective, non-randomized. Patients recovered from sudden cardiac death of ischemic cause and remain comatose will be included in the protocol if they fit the pre-specified inclusion criteria. Biological samples will be collected (at admission, at 24 and 72 hours) and stored in the Biobank of Hospital de la Santa Creu i Sant Pau for further analysis. In addition demographic, clinical and analytical variables will be collected. At the end of the recruitment period, we will analyse the concentrations of circulating microparticles according to ICCC-IIBSantPau methodology in the samples obtained. The primary outcome variable will be the neurological status at Coronary Care Unit discharge and at 6 months. The objective of the study will evaluate the relationship between the neurological status and the blood concentrations of circulating microparticles.

Inclusion Criteria:

• Over 18 years old.
• Patients recovered from a sudden cardiac death (in-hospital and out-of-hospital) with return of spontaneous circulation (ROSC) (defined as systolic blood pressure > 60 mmHg or palpable pulse for > 5 minutes) who remain unconsciousness (defined as a score on the Glasgow Coma Scale <8 ) for > 5-10 minutes after ROSC.
• Treated with hypothermia as recommended by the European guidelines for resuscitation ( 2010)..

Exclusion Criteria:

• Non-cardiac sudden death.
• Active oncologic pathology .
• Traumatic or spontaneous intra-cranial haemorrhage.
• Inability to obtain required blood samples or refusal of the informed consent necessary for it.

We will include patients who have suffered a sudden cardiac death of ischemic cause admitted to the Coronary Care Unit of the Hospital de la Santa Creu i Sant Pau in Barcelona from the date of commencement of the study. The sample will be retrospectively completed with patients of the same features admitted to the unit since January 2012 and who have biological samples stored in the Biobank of Hospital de la Santa Creu i Sant Pau.