The aim of the trial is to compare immediate angiography in survivors of out of hospital cardiac arrest (OHCA) without ST-segment elevation versus delayed/selective catheterization with respect to 30 day mortality.

The TOMAHAWK trial is supported by the Deutsches Zentrum für Herz-Kreislauf-Forschung (DZHK).

After inclusion and exclusion criteria have been checked patients will be randomized:

Group 1: Immediate angiography Patients randomized to group 1 will be transported to the catheterization laboratory as soon as possible after hospital admission for evaluation of coronary anatomy.

Group 2: Delayed/selective angiography Upon hospital admission, patients assigned to group 2 will first be transported to the ICU for further evaluation and stratification of OHCA etiology. Further triage will depend on the results of clinical examination and objective testing and will be left to the individual physician according to clinical judgment. Depending on clinical circumstances, further management may comprise medical therapy, laboratory testing, imaging such as echocardiography and/or computed tomography, hemodynamic or neurological monitoring, the initiation of therapeutic hypothermia or other measures of intensive care. If a high likelihood of an acute coronary trigger for OHCA persists (i.e. inconclusive results from clinical evaluation with ongoing suspicion of an acute coronary event, etc.), the treating physician may proceed to coronary angiography after a delay of 24h after the onset of cardiac arrest.

Vital status will be assessed at 30 days, 6 and 12 months after randomization by direct questioning if the patient is still hospitalized or structured telephone interview. Clinical events will be verified by original source data. At 6 and 12 months, quality of life will be assessed by the the Euroqol 5D questionnaire.

The TOMAHAWK trial is supported by the Deutsches Zentrum für Herz-Kreislauf-Forschung (DZHK).

Inclusion Criteria:

• Documented resuscitated OHCA of possible cardiac origin and return of spontaneous circulation
• Age ≥30 years
• Informed consent

Exclusion Criteria:

• ST-segment elevation or new left bundle branch block
• No return of spontaneous circulation upon hospital admission
• Severe hemodynamic or electrical instability requiring immediate coronary angiography/intervention (delay clinically not acceptable)
• Obvious extra-cardiac etiology such as traumatic brain injury, primary metabolic or electrolyte disorders, intoxication, overt hemorrhage, respiratory failure due to known lung disease, suffocation, drowning
• In-hospital cardiac arrest
• Known or likely pregnancy
• Participation in another intervention study