Researchers in Israel, Michigan and Washington state say there's a 50 percent risk of sudden cardiac arrest if a close family relative suffered a similar attack.
And Belgian scientists say the risk is high for individuals with a "type D" personality -- who continually have a negative outlook, including insecurity and social inhibition. If they have already had a heart attack their risk is three times that of people with different personality types.
Both reports appeared in the medical journal Circulation. In the family connection study, researchers say their findings are "in agreement with many studies which have clearly demonstrated a familial clustering for heart disease."
Overall, they write, "the rate of (heart attack and cardiac arrest) among first-degree relatives of cardiac arrest patients was almost 50-percent higher than that in first-degree relatives" whose similar relations did not suffer from such attacks.
Meanwhile, researchers at Belgium's University of Antwerp say "type D" patients carried a 52-percent risk of suffering a second heart attack while those with different personalities had only a 12-percent risk.
The study indicates personality may be a factor in assessing the risk of heart attack. Other studies have shown psychological factors may affect the risk of heart attack recurrence.
In itself, worry over health is not considered a risk, researchers write, adding that emotional distress in those studied "is unrelated to disease severity but reflects individual differences in personality."
