They also had a 13 per cent decreased risk of dying from heart disease.
Every 10g per day increase in fibre was associated with a 15 per cent lower risk of dying over the follow-up period, the researchers found.
When the authors examined the source of fibre - be it from fruit, vegetables or cereal - they found that higher cereal fibre consumption was associated with an increased chance of long-term survival after a heart attack than other sources of fibre.
"Greater intake of dietary fibre after myocardial infarction (MI), especially cereal fibre, was inversely associated with all-cause and cardiovascular mortality," they wrote.
"In addition, participants who increased their dietary fibre intake after MI had lower long-term rates of all-cause and cardiovascular mortality.
"Possible mechanisms for the beneficial effects of a high-fibre diet on coronary heart disease risk and mortality include reductions in systemic inflammation, lower serum low-density lipoprotein cholesterol level, reduced lipid peroxidation, improved insulin sensitivity, overall better glycemic control, and a beneficial gut microbiota environment."
The NHS says that most people in the UK get about 14g of fibre a day but they should be aiming for at least 18g.
Commenting on the study, Victoria Taylor, senior dietitian at the British Heart Foundation, said: "High-fibre foods are a key part of a healthy balanced diet and this study suggests they may have a particular benefit for heart attack survivors.
"We can't say for sure what caused the fibre benefit seen here. But we do know that, on average, we're not getting enough fibre in our diets.
"Fibre comes from a range of foods including fruit and veg, beans and lentils and also from cereal products, which this study found to be particularly beneficial.
"To get more fibre, you can make simple swaps such as trading white bread for wholegrain versions or opting for higher fibre breakfast cereals like porridge or muesli."
- PAA
