Researchers say people should aim for six to eight hours kip a night to minimise the danger.
And those who need to nap in the day should see a doctor if it often takes them over the guidelines.
Boffins from McMaster University, Canada, quizzed 116,632 adults in 21 countries on their sleep.
They then monitored their health for an average of eight years, during which time 4,381 died.
A further 4,365 suffered a major cardiovascular problem, such as a heart attack or stroke.
Those who slept six to eight hours a day had the lowest rates of cardiovascular disease or death.
Eight to nine hours kip was associated with a 5% higher risk and from nine to ten hours 17% higher.
Nodding off for more than ten hours saw the risk rocket by 41%.
Sleep time includes all naps and longer snoozes.
Sleeping for less than six hours a day increased the risk by 9%.
Prof Salim Yusuf said: “The general public should ensure that they get about six to eight hours of sleep a day.
“If you sleep too much regularly, say more than nine hours a day, then you may want to visit a doctor to check your overall health.
“For doctors, including questions about the duration of sleep and daytime naps in the clinical histories of your patients may be helpful in identifying people at high risk of heart and blood vessel problems or death.”
Chuangshi Wang, who also worked on the study, said: “Too little sleep could be an underlying contributor to death and cases of cardiovascular disease.
“Too much sleep may indicate underlying conditions that increase risk.
“Although daytime napping was associated with higher risks of death or cardiovascular problems in those with sufficient or longer sleep at night, this was not the case in people who slept under six hours at night. In these individuals, a daytime nap seemed to compensate for the lack of sleep at night and to mitigate the risks.”
The findings are published in the European Heart Journal.
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