Seven or more hours' sleep a night boosts the benefits to the heart of a healthy lifestyle, research suggests.
According to a large study, traditional advice on exercise, diet, drinking and smoking reduced deaths from heart disease or stroke, but even more lives were saved by also having enough sleep.
Advice on getting enough sleep could have a substantial impact on public health, say European researchers.
In theory, many heart and stroke deaths could be prevented or postponed.
A team in the Netherlands tracked heart disease and strokes in more than 14,000 men and women for more than a decade.
By the end of the study, about 600 individuals had suffered heart disease or stroke, and 129 died.
The study found that deaths were less likely in people who followed all four positive lifestyle recommendations - taking exercise, eating a healthy diet, drinking alcohol in moderation, and not smoking.
This research shows that combining a good night's sleep with other healthy lifestyle choices can reduce your risk of heart disease”
Observing all four behaviours was associated with a 57% lower risk of cardiovascular disease and a 67% lower risk of dying from stroke or heart disease, they say.
But when sufficient sleep - seven or more hours a night - was added to the other four lifestyle factors, the beneficial effect was amplified - resulting in a 65% lower risk of cardiovascular disease and an 83% lower risk of death from cardiovascular disease.
"If all participants adhered to all five healthy lifestyle factors, 36% of composite cardiovascular disease [heart disease or stroke] and 57% of fatal cardiovascular disease could theoretically be prevented or postponed," say the researchers, from the National Institute for Public Health and the Environment, Bilthoven, and Wageningen University.
"The public health impact of sufficient sleep duration, in addition to the traditional healthy lifestyle factors, could be substantial."
"From a public health point of view we should encourage people to get enough sleep and like all other healthy lifestyle factors this needs to be taught at home."
Further research was needed to fully understand the link between sleeping habits and the heart.
"If you find it difficult to drift off, avoiding caffeine and heavy meals too close to the end of the day may help.
"But if lack of sleep is becoming a problem, make sure you have a chat to your doctor."