Relatives of young sudden cardiac death victims appear to have a greater risk of cardiovascular disease than the general population, a Danish study showed.
During up to 11 years of follow-up, there were 292 incident cases of cardiovascular disease in a cohort of relatives, higher than the 219 expected in the background population (standardized incidence ratio 1.33, 95% CI 1.19 to 1.50), according to Mattis Flyvholm Ranthe, MD, of the Statens Serum Institute in Copenhagen, and colleagues.
The risks were particularly high in relatives younger than 35, the researchers reported online in the European Heart Journal.
The findings support a large hereditary component of sudden cardiac death, Ranthe and colleagues argued.
"Since the cardiovascular conditions on which we focused are treatable, early identification of at-risk persons is potentially a life-saving action," they wrote. "Our findings are the first of their kind and support the initiation of cascade screening in families experiencing a sudden cardiac death, with customization of screening based on the underlying condition suspected to have caused the [death] and family member ages."
Previous studies have shown that genetic mutations are related to cardiac conditions that can cause sudden cardiac death, including primary arrhythmia syndromes, cardiomyopathies, familial hypercholesterolemia, and premature ischemic heart disease. Other studies have suggested that relatives of sudden cardiac death victims have an elevated cardiovascular risk.
To explore the issue, the researchers performed a prospective, population-based cohort study using Danish national registries. They identified 470 individuals ages 1 to 35 years who suffered a sudden cardiac death from 2000 to 2006, and 3,073 relatives.
Compared with the general population, the relatives had a greater risk of developing cardiovascular disease during follow-up, although the risk varied by age.
First-degree relatives -- parents, children, siblings -- had a greater risk of cardiovascular disease compared with second-degree relatives, such as half-siblings, grandparents, grandchildren, aunts, uncles, nieces, and nephews.
Risks were particularly high for first-degree relatives younger than 35.
There was also a suggestion that the risks among the relatives were greater when the initial sudden cardiac death was verified by autopsy.
"A positive autopsy (especially with signs of cardiomyopathy or ischemic heart disease) might lead to increased medical awareness among relatives and more intense screening for cardiovascular disease," the authors wrote.
They acknowledged some limitations of the study, including the lack of information on certain behavioral risk factors for cardiovascular disease, including body mass index, smoking, and alcohol use, and the lack of detailed information on the underlying causes of the ventricular arrhythmia.
SOURCE: MedPage Today