People with relatives who die of sudden heart problems at risk of heart diseases
Relatives of young people who die suddenly from heart problems have a higher risk of heart diseases, a study shows. The authors suggest testing relatives for heart problems, but we need more evidence to be sure this would be worthwhile.
BMJ Group News
What do we know already?
Sudden cardiac death occurs when people die unexpectedly due to heart-related problems. This doesn’t happen that often. But when it does, particularly in younger people who seemed healthy, it can be shocking and extremely difficult for family and friends to deal with.
It’s not always possible to tell what causes a sudden cardiac death. Studies have looked at the results of tests done after people die to try to find out the cause of their death. These studies have found that as many as half of people who die suddenly because of changes in the heart’s rhythm have genes that increase their risk of heart diseases.
If it’s true that a sudden cardiac death can be linked to a person’s genes, this also suggests these genes could be inherited and shared by members of their family. If so, could relatives of people who die from sudden cardiac death also be at risk?
This new study has tried to answer this. Researchers looked at death registries and national health records to identify all the people aged 35 years and younger who died of sudden cardiac death in Denmark between 2000 and 2006. They found 470 people in total. The researchers then traced the relatives of these people, looking at whether they were more likely to have heart diseases than would be expected in the general population.
What does the new study say?
There were 3,073 relatives of people who died of sudden cardiac death, and 292 of these relatives had heart diseases. This is more than the 219 people who would be expected to have heart diseases in a group of people this size in the general population.
Relatives of people who died from sudden cardiac death were also two to three times more likely to have certain kinds of heart problems that affect the muscles in the heart ( cardiomyopathy) or the way the chambers in the heart beat (ventricular arrhythmias) than people in the general population. But they were no more likely to have a more common type of heart disease, ischaemic heart disease.
The risk of heart problems was higher in younger people. People aged 35 years or younger were three times as likely as people in the general population to have heart diseases.
Immediate family members of people who had died of sudden cardiac death (first-degree relatives) were more likely to have heart diseases than more distant relatives, such as aunts and uncles (second-degree relatives).
How reliable is the research?
This is a well-conducted study that made extensive use of death registries and national health records, which should mean the information gathered was reliable.
However, the researchers didn’t have any information on other factors that affect people’s risk of heart diseases, such as their weight or whether they smoked. So we can’t be sure the increased risk in people with sudden cardiac death was due to this relationship or other lifestyle or medical factors.