The Investigator therefore propose a prospective, observational study in which the investigator will incorporate a minimally invasive and minimal risk measurement of blood biomarkers at time of ROSC. This would be done by drawing blood at ROSC (0-59mins), and additional blood draws at hours 6, 12, 18, 24, 48, 72, and on day 4, 5, and 6. The Investigator will then determine whether biomarker levels correlates with survival to hospital admission, survival to hospital discharge, and functional neurologic outcome at discharge and at 6 months. The Investigator intend to sample patients that present to the emergency department with non-CA chest pain in our study as well, which will allow us to draw stable inferences.