Risk of Cardiovascular Disease in Family Members of Young Sudden Cardiac Death Victims

Study Questions:

Do relatives of those who die at a young age from sudden cardiac death have an increased risk for cardiovascular disease (CVD)?


Data for all victims of sudden cardiac death, residing in Denmark (2000-2006) and between the ages of 1 and 35 years, were identified using the Danish National Patient Register. This register includes information from all Danish hospitals starting in 1978, using Classification of Disease (ICD) codes. First- and second-degree relatives were then identified using the Danish Civil Registration System, which assigns a unique identification number to each resident and allows for identification of relatives. Data from the general population (using similar techniques) were used as a comparator group. The primary outcome of interest was cardiovascular events identified in relatives through the Danish National Patient Register.


A total of 470 young sudden death victims and 3,073 first- and second-degree relatives were included in this analysis. Risk for CVD events was highest in the first year after sudden cardiac death in a relative. Compared to the general population comparator group, those related to sudden death victims had more CVD events over 11 years of follow-up (292 vs. 219, standardized incidence ratio [SIR], 1.33; 95% confidence interval [CI], 1.19-1.50). Risks varied significantly with age; the SIR for those <35 years was 3.53 (95% CI, 2.65-4.69), compared with SIRs of 1.59 (95% CI, 1.35-1.89) and 0.91 (95% CI, 0.75-1.10) for those ages 35-60 years or >60 years, respectively (Phomogeneity < 0.0001). For first-degree relatives <35 years, SIRs for ischemic heart disease, cardiomyopathy, and ventricular arrhythmia were 5.99 (95% CI, 1.95-0.13.98), 17.91 (95% CI, 4.88-45.87), and 19.15 (95% CI, 7.70-39.45), respectively.


The investigators concluded that risk for CVD events increases significantly when a young relative dies from sudden cardiac death. Younger first-degree relatives appear to be at the greatest risk for events.


These data suggest that relatives, in particular younger first-degree relatives of those who have experienced sudden cardiac death (prior to the age of 35), have an increased risk for CVD themselves. Such information provides an opportunity for counseling and risk factor modification. However, given that this study was conducted in one population, an examination of this hypothesis in other populations will be of benefit.

Clinical Topics: Arrhythmias and Clinical EP, Heart Failure and Cardiomyopathies, SCD/Ventricular Arrhythmias

Keywords: Incidence, Myocardial Ischemia, Follow-Up Studies, Cardiomyopathies, Denmark, Cardiovascular Diseases, Risk Factors, Death, Sudden, Cardiac

< Back to Listings