Out-of-hospital cardiac arrest - insights from the german cardiac arrest registry (G-CAR)

In Europe, more than 300,000 people per year suffer from out-of-hospital cardiac arrest (OHCA). Despite advances in emergency and intensive care medicine, survival rates with good neurological outcome remain low. Due to the acuity and heterogeneity of OHCA, no or only insufficient evidence from randomised trials is available. Therefore, systematic collection of data on the management and outcome of OHCA patients in a real-world setting is warranted.

In 2021, the German Cardiac Arrest Registry (G-CAR) was established as a national, prospective, multicentre registry. Currently (as of 10/2024), over 1,600 adult OHCA patients from 20 national cardiac arrest centres are included. As OHCA often occurs for cardiac causes, G-CAR focusses on cardiovascular and interventional aspects such as revascularisation therapies and the use of mechanical circulatory support devices. The registry includes a prospective 12-month follow-up assessing mortality, neurological outcomes and various patient-reported psychosocial outcomes.

Median age of the patients was 66 (interquartile range 56;75) years, 74.0% were male. Mostly, OHCA occurred in private homes (54.0%), followed by public spaces in around one-third of cases (32.1%). 75.2% of the OHCA events were witnessed; lay resuscitation was performed in 49.0%. Cardiopulmonary resuscitation (CPR) was dispatcher-assisted in 10.7%; automatic external defibrillators were used in 4.8%, and a first-responder App in only 0.9% of cases. The initial rhythm was shockable in 42.7%. Notably, 34.7% of the patients had ongoing CPR at hospital admission. Extracorporeal cardiopulmonary resuscitation (eCPR) was performed in 9.8% of the patients. Main presumed underlying causes of CPR were acute coronary syndromes and/or cardiogenic shock in 45.8% followed by primary arrhythmias (10.8%) and hypoxia (9.8%). In 26.9%, ST-segment elevations were observed after return of spontaneous circulation, mostly (61.5%) with an anterior location. In total, 54.7% of the patients underwent coronary angiography (CAG). In 82.4%, CAG was performed immediately, in 13.5% within 24 hours, and in 4.2% in an elective setting. Out of all patients undergoing CAG, 62.6% received percutaneous coronary intervention (PCI). In three quarters of patients (75.5%) culprit-only PCI was performed, while 24.5% received immediate multivessel PCI. In-hospital mortality was 75.0%, with anoxic brain damage being the main presumed cause of death (36.8%) followed by circulatory failure in 34.9%.

G-CAR is a multicentre German registry for adult OHCA patients including long-term follow-up. The primary aim is a better understanding of the determinants of acute and long-term outcomes with the perspective of optimized treatment.