DALLAS, April 20 -- Researchers have shown, for the first time, that sudden cardiac death in men runs in families, according to a study in today's Circulation: Journal of the American Heart Association.
Researchers have long known that a person's genetic blueprint contributes to his or her heart attack risk, but this is the first study to identify a genetic risk for sudden cardiac death, which occurs in about 250,000 individuals each year in the United States.
The study's lead author, Xavier Jouven, M.D., says, "Physicians generally ask patients whether they have a family history of heart attacks. It would now be useful to ask patients about a possible parental history of sudden death." Jouven is a cardiologist at Service de Cardiologie, Hôpital Boucicaut, and epidemiologist at Unite INSERM 258 d'Epidemiologie Cardiovasculaire, Hopital Broussais, Paris.
In this study, The Paris Prospective Study I, sudden death is defined as natural death that occurs within an hour after onset of symptoms. The patient may or may not have had previously diagnosed heart disease.
The risk of sudden death among men whose mother or father had experienced sudden death was almost double that of males whose parents did not suffer sudden death. For men whose mother and father both died of sudden death, the sudden death risk was nine times higher than for those whose parents did not die of sudden death.
Familial history of sudden death may help identify those at high risk for this condition and motivate physicians to advise their patients about how to reduce the risk of heart disease, strokes and sudden death, Jouven says.
Prevention measures would include reducing risk factors such as excessive weight gain, high blood pressure, elevated blood levels of cholesterol, sedentary lifestyle and smoking.
"While we don't know if a parental history of sudden death is also an independent risk factor for women, it would be prudent for women who have a family history of sudden death also to consider preventive health measures," Jouven says.
In the study, researchers followed 7,079 middle-aged men employed by the City of Paris for an average of 23 years. During this period, 2,083 men died -- 118 due to sudden death and 192 due to fatal heart attacks, which were sudden. According to the researchers, a history of sudden death characterized 22 (18.6 percent) of the men who died of sudden death. Of the men who suffered a fatal heart attack -- not a sudden death -- 19 (9.9 percent) had a history of parental sudden death. Of the 6,769 individuals who did not die from either a heart attack or sudden death, only 718 (10.6 percent) had a history of parental sudden death.
Researchers found that a parental history of sudden death was an independent risk factor for predicting sudden death.
Too often, sudden death is the first -- and the last -- sign of heart disease. Of the approximately 250,000 men and women who suffer a sudden cardiac death each year in the United States, only about half were aware of their heart disease. Therefore, being able to identify people at high risk for sudden death is essential to timely intervention with effective preventive measures, says Jouven.
"Until this study, there was no known risk factor for identifying people at increased risk of sudden death other than the known risk factors for coronary heart disease, such as advancing age, obesity, diabetes, tobacco use, and elevations of blood pressure, resting heart rate, and blood cholesterol," Jouven says.
The other co-authors of this study include Michel Desnos, M.D.; Claude Guerot, M.D.; and Pierre Ducimetière, Ph.D.
Media advisory: Dr. Jouven can be reached at 33-15-378-8039; his fax number is 33-15-378-8017. (Please do not publish these numbers.)