Experts claim that thousands of premature heart attacks could be averted if families with a history of heart disease are screened.
A report published in the British Medical Journal (BMJ) claims that siblings of people with premature coronary heart disease have at least double the chance of developing the condition, while offspring are also at an increased risk.
And the report's authors called for the possibility of screening those with a close family relative with premature heart disease to be explored further.
The authors said genetic factors are in part responsible for the link, but also blamed a "shared lifestyle" within families, which can include eating similar foods, smoking and taking little or no exercise.
Ellen Mason, heart nurse at the British Heart Foundation, backed the report's recommendations.
She said: "A clear system to invite close relatives of people with premature coronary heart disease for screening could play an important part in preventing heart attacks.
"While there are doctors and nurses in hospitals who encourage visiting relatives to go to their GP surgery to have their risk assessed, often this is not considered a high priority and doesn't happen, so a more regulated procedure would be of benefit."