In hospital cardiac arrest (IHCA) is a major challenge imposed on almost all health care systems worldwide. Despite significant progress in cardiopulmonary resuscitation in the past few years, outcomes remain relatively poor with an approximate 49 % survival rate.

Epinephrine administration remains a cornerstone in the treatment of cardiac arrest. However, the preferred route of administration remains a matter of debate within the medical community .

Various routes of administration, including intravenous, intramuscular, intraosseous and endotracheal routes have been studied.

Initially, American guidelines for the treatment of cardiac arrest recommended injection of 0.5 mg of epinephrine directly into the right ventricle through the parasternal approach, aiming to achieve higher peak intracardiac concentrations and a more central effect, however the intravenous route remained preferable due to its feasibility and safety .

To our knowledge, intra-coronary epinephrine administration for intraprocedural cardiac arrest has not been evaluated or compared with other routes of administration.

Inclusion Criteria:

• Aged above 18 years old
• Diagnosed with non-ST elevation myocardial infarction (NSTEMI) or ST elevation myocardial infarction (STEMI)
• Received dual antiplatelet therapy (acetylsalicylic acid and ticagrelor), or triple therapy (oral anticoagulant, acetylsalicylic acid and clopidogrel)
• Event of cardiac arrest during percutaneous intervention

Exclusion Criteria:

• cardiac arrest documented prior to being transported to cardiac catheterization laboratory.
• Patients who suffered cardiac arrest for less than 60 seconds were excluded from the study.
• Received mechanical circulatory support such as intra-aortic balloon pump, temporary percutaneous ventricular assist devices, or extracorporeal membrane oxygenation (ECMO) during hospitalization.
• Presenting with any cardiac rhythm on admission other than sinus rhythm or atrial fibrillation/flutter
• Signs of infection or a history of hepatic, oncologic or allergy to contrast media and end stage renal failure
• Patients who underwent primary fibrinolysis.
• Furthermore, patients who received atropine, amiodarone, lidocaine, or any other antiarrhythmic prior to CPR
• who received targeted temperature management post CPR .

This is a prospective, cohort, dual center pilot study, conducted in the Hospital of the Lithuanian University of Health Sciences Kaunas Clinics and the Republican Hospital of Panevezys from 2018 to 2022. Both cardiac centers covers six out of ten administrative regions in the republic of Lithuania.