Circumstances in a young German cohort with sudden cardiac death: Systematic insights and implications

Background: Data on circumstances of sudden cardiac death (SCD) in Germany are limited. The present study aimed to investigate systematically the current pre- and in-hospital circumstances of a SCD cohort at young age (65 years or younger) in Germany. In this analysis, we focused on young patients, as they have a different risk profile than older SCD patients, and as the younger age cohort is usually underrepresented in studies and thus the available data are very limited.

Methods: In the period from 2010 to 2021, we enrolled 232 consecutive patients with SCD at a university hospital in the Ruhr area, Germany. Clinical baseline characteristics and cardiopulmonary resuscitation (CPR) data were assessed. In 45 patients the aetiology of SCD could not be recognized, e.g. for the absence of coronary angiography or further diagnostical evaluation due to death. 187 patients underwent coronary angiography and were systematically analysed regarding the cause of death. These 187 patients were then divided into groups with coronary-related (n=139) and non-coronary-related aetiology (n=48).

Results: A total of 232 patients (median age: 56 years (ranging from 16 to 65 years); 82% males) were included. The median duration of hospitalization was nine days. 114 patients (49.1%) deceased during hospitalization.
The patients suffered SCD during non-stressful daily activities (34.5%), while working (12.9%), exercising (9.9%) or resting (7.8%). In 34.9% of cases the activity could not be recognized. Patients experienced SCD most often at home (34.5%), in public (26.3%), in hospital (17.7%), at work (12.9%), or in the emergency ambulance (5.2%). The location was unknown in 3.4% of cases. Bystander-witnessed cardiac arrest was reported in 83.6% of cases. However, lay resuscitation was performed in only 37.9% of cases, and within 10 minutes of SCD event in only 28.4%. Median total duration of CPR was 31-44 minutes. The first-monitored rhythm was most frequently ventricular fibrillation (67.2%), followed by asystole (18.1%), ventricular tachycardia (6.0%), pulseless electrical activity (4.3%) and bradycardia (1.7%). If an external defibrillator was used, an average of three shocks were delivered. Mechanical resuscitation assistance was used in 5.2% of cases.
In patients with coronary-associated SCD, ventricular fibrillation was more common, and ventricular tachycardia, asystole, and pulseless electrical activity were less common compared to patients with non-coronary-associated causes. Additionally, the average shock delivery was twice as high (3 shocks vs. 1.5 shocks). Interestingly, layperson-initiated CPR was more frequent in patients with non-coronary-associated causes (45.8% vs. 37.4%), despite comparable rates of bystander-witnessed cardiac arrest (87.5% vs. 85.6%). It is also noteworthy that the mean CPR duration, overall as well as prehospital and in-hospital, was shorter in patients with non-coronary-associated causes (11-20 minutes vs. 21-30 minutes).

Conclusion: Compared to other studies, we detected lower rates of SCD occurring at home and higher rates in public, at work or during sports. This may be related to the fact that only younger patients under the age of 65 were included in this SCD cohort. Furthermore, the lay resuscitation rate was significantly below the European and national average.