The death rate from heart attacks in England has halved in the last decade, says an Oxford University study.
The research, published in the British Medical Journal, looked at more than 800,000 men and women who suffered heart attacks between 2002 and 2010.
They found that fewer heart attacks occurred in later years and, of those that did occur, fewer were fatal.
Researchers say improvements in NHS care and better prevention measures have contributed to the decline.
The Oxford researchers used national hospital and mortality data to analyse 840,175 men and women in England who had suffered a total of 861,134 heart attacks over eight years.
Comparing 2002 with 2010, they found death rates falling by 50% in men (78.7 per 100,000 population to 39.2) and by 53% in women (37.3 per 100,000 to 17.7).
A declining mortality rate was also seen in all age groups and for both sexes.
Focus on youngest
The research on bmj.com concluded that just over half of the decline in deaths can be attributed to a decline in the number of new heart attacks, and just under half to a decline in the death rate after a heart attack. But the greatest rates of decline occurred in men and women aged 65-74 and the lowest in those aged 30-54 and 85 and older.
The study said that rising rates of obesity and diabetes could explain the lack of improvement in the occurrence of heart attacks among the youngest age group.
The factors behind the decrease in heart attack death rate differed by age, sex and geographical area.
The research authors said that further research is needed to gain a clearer understanding of the specific elements of prevention and treatment that have led to the fall in death rates.
And Prof Peter Weissberg, medical director at the British Heart Foundation, said there was still more to do to cut unnecessary deaths.
"This impressive fall in death rates is due partly to prevention of heart attacks by better management of risk factors such as smoking, high blood pressure and cholesterol and due partly to better treatment of heart attack patients when they reach hospital.
"But far too many heart attack victims still die from a cardiac arrest before medical help arrives. Many of these deaths could be prevented by rapid cardiopulmonary resuscitation."
