Comparison of coronary-related and non-coronary-related aetiologies in a cohort of young patients aged 18 to 65 years suffering from sudden cardiac death

Previous publications show significant differences between countries concerning epidemiology and outcome of patients suffering from sudden cardiac death (SCD).

Data on epidemiology, aetiology and outcome in Germany is sparse. This study includes young patients aged between 18 and 65 years suffering from SCD. Our aim was to compare different aetiologies focusing on coronary-related causes vs. non-coronary-related causes.

We conducted a monocentric study focusing on individuals between 18 and 65 years of age at admission to hospital suffering from SCD. 

Eventually, we curated a dataset comprising 232 patients. Within this collective, 171 patients suffered from out-of-hospital SCD, whereas 53 patients have been resuscitated within the hospital. We systematically conducted a comprehensive retrospective review, assessment, and analysis of data from the archives and available within the hospital information system.

Patients have been categorized into three distinct groups based on the diagnosed aetiologies. Group 1 representing cases with an underlying coronary cause, that includes coronary artery disease, vasospasm and acute coronary vessel dissection. Group 2 comprises patients with non-coronary aetiologies such as cardiomyopathies, channelopathies, myocarditis and cases categorized as idiopathic. Patients which deceased before further diagnostics could be carried out have been assigned to group 3. Eventually, a number of 139 patients has been assigned to group 1 and 48 patients to group 2. 
In line with previous findings, we observed a male overbalance in both groups (88.5% in group 1 and 66.7% in group 2). While in 83.6% of cases a bystander witnessed the cardiac arrest, only in 37.9% of cases initial layman CPR has been performed.

The initial monitored heart rhythm has primarily been ventricular fibrillation in all groups (75.5% in group 1 and 68.8% in group 2) with a smaller number of patients presenting with asystole (12.9% in group 1 and 16.7% in group 2) and a minority accounting for pulseless electrical activity (PEA) (1.4% in group 1 and 4.2% in group 2) or different kinds of bradycardic heart rhythms (1.4% in group 1 and 2.1% in group 2).

As it is to expect, in a multivariate analysis the duration of CPR has a significant impact on patient outcome with a considerable excess intrahospital mortality concerning those resuscitated over 60 minutes (OR 9.059, p<0.001). Hypothermia treatment has not shown a significant effect on intrahospital mortality in the multivariate analysis (OR 0.608, p=0.286).

Cardiovascular risk factors are of higher significance in group 1 (i.e. 41.7% vs. 8.3% active smoker status, 23% vs. 12.5% Diabetes mellitus or 54.7% vs. 43.8% arterial hypertension). There have not been any instances of previous myocardial infarction in the non-coronary related group compared to an incidence of 18.7% in group 1. Interestingly, in two patient cases which have before been categorized as idiopathic, evidence of a channelopathy could be identified after thorough second-look ECG investigation.

The data represented in our cohort illustrates the importance of further research and the collection of data in larger cohorts to get a better understanding of the highly diverse patient collective presenting with sudden cardiac death. It also emphazises the importance of thorough and standardized diagnostic procedures, especially in those patients diagnosed with idiopathic ventricular tachyarrythmia.